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Sample records for hypertrophic rat heart

  1. Hypertrophic response of the Association of Thyroid Hormone and Exercise in the Heart of Rats

    PubMed Central

    de Souza, Fernanda Rodrigues; Resende, Elmiro Santos; Lopes, Leandro; Gonçalves, Alexandre; Chagas, Rafaella; Fidale, Thiago; Rodrigues, Poliana

    2014-01-01

    Background Cardiac hypertrophy is a component of cardiac remodeling occurring in response to an increase of the activity or functional overload of the heart. Objective Assess hypertrophic response of the association of thyroid hormone and exercise in the rat heart. Methods We used 37 Wistar rats, male, adults were randomly divided into four groups: control, hormone (TH), exercise (E), thyroid hormone and exercise (H + E); the group received daily hormone levothyroxine sodium by gavage at a dose of 20 μg thyroid hormone/100g body weight, the exercise group took swimming five times a week, with additional weight corresponding to 20% of body weight for six weeks; in group H + E were applied simultaneously TH treatment groups and E. The statistics used was analysis of variance, where appropriate, by Tukey test and Pearson correlation test. Results The T4 was greater in groups TH and H + E. The total weight of the heart was greater in patients who received thyroid hormone and left ventricular weight was greater in the TH group. The transverse diameter of cardiomyocytes increased in groups TH, E and H + E. The percentage of collagen was greater in groups E and H + E Correlation analysis between variables showed distinct responses. Conclusion The association of thyroid hormone with high-intensity exercise produced cardiac hypertrophy, and generated a standard hypertrophy not directly correlated to the degree of fibrosis. PMID:24676374

  2. Ultrastructural changes, increased oxidative stress, inflammation, and altered cardiac hypertrophic gene expressions in heart tissues of rats exposed to incense smoke.

    PubMed

    Al-Attas, Omar S; Hussain, Tajamul; Ahmed, Mukhtar; Al-Daghri, Nasser; Mohammed, Arif A; De Rosas, Edgard; Gambhir, Dikshit; Sumague, Terrance S

    2015-07-01

    Incense smoke exposure has recently been linked to cardiovascular disease risk, heart rate variability, and endothelial dysfunction. To test the possible underlying mechanisms, oxidative stress, and inflammatory markers, gene expressions of cardiac hypertrophic and xenobiotic-metabolizing enzymes and ultrastructural changes were measured, respectively, using standard, ELISA-based, real-time PCR, and transmission electron microscope procedures in heart tissues of Wistar rats after chronically exposing to Arabian incense. Malondialdehyde, tumor necrosis alpha (TNF)-α, and IL-4 levels were significantly increased, while catalase and glutathione levels were significantly declined in incense smoke-exposed rats. Incense smoke exposure also resulted in a significant increase in atrial natriuretic peptide, brain natriuretic peptide, β-myosin heavy chain, CYP1A1 and CYP1A2 messenger RNAs (mRNAs). Rats exposed to incense smoke displayed marked ultrastructural changes in heart muscle with distinct cardiac hypertrophy, which correlated with the augmented hypertrophic gene expression as well as markers of cardiac damage including creatine kinase-myocardial bound (CK-MB) and lactate dehydrogenase (LDH). Increased oxidative stress, inflammation, altered cardiac hypertrophic gene expression, tissue damage, and architectural changes in the heart may collectively contribute to increased cardiovascular disease risk in individuals exposed to incense smoke. Increased gene expressions of CYP1A1 and CYP1A2 may be instrumental in the incense smoke-induced oxidative stress and inflammation. Thus, incense smoke can be considered as a potential environmental pollutant and its long-term exposure may negatively impact human health.

  3. Direct Renin Inhibition Exerts an Anti-hypertrophic Effect Associated with Improved Mitochondrial Function in Post-infarction Heart Failure in Diabetic Rats

    PubMed Central

    Parodi-Rullan, Rebecca; Barreto-Torres, Giselle; Ruiz, Louis; Casasnovas, José; Javadov, Sabzali

    2013-01-01

    Background In addition to hypertension control, direct renin inhibition has been shown to exert direct beneficial effects on the heart in post-infarction cardiac remodeling. This study elucidates the possible contribution of mitochondria to the anti-hypertrophic effects of the direct renin inhibitor aliskiren in post-infarction heart failure complicated with diabetes in rats. Methods Diabetes was induced in male Sprague-Dawley rats by a single injection of streptozotocin (IP, 65 mg/kg body weight). After 7 days, the animals were randomly assigned to 4 groups: sham, heart failure, sham+aliskiren, and heart failure+aliskiren. Post-infarction HF was induced by coronary artery ligation for 4 weeks. Results showed that heart failure reduced ejection fraction and cardiac output by 41% (P<0.01) and 42% (P<0.05), respectively, compared to sham-operated hearts. Cardiac dysfunction was associated with suppressed state 3 respiration rates and respiratory control index in mitochondria, and increased mitochondrial permeability transition pore (PTP) opening. In addition, heart failure reduced expression of the major mitochondrial sirtuin, SIRT3 and increased acetylation of cyclophilin D, a regulatory component of the PTP. Aliskiren significantly improved cardiac function and abrogated mitochondrial perturbations. Conclusion Our results demonstrate that aliskiren attenuates post-infarction remodeling which is associated with its beneficial effects on mitochondria. PMID:22613984

  4. Propofol improves recovery of the isolated working hypertrophic heart from ischaemia-reperfusion.

    PubMed

    King, Nicola; Al Shaama, Madj; Suleiman, M-Saadeh

    2012-11-01

    The general anaesthetic propofol shows promise in protecting normal hearts against various cardiac insults, but little is known about its cardioprotective potential in hypertrophic hearts. This study tested the hypothesis that propofol at a clinically relevant dose would enhance functional recovery in hypertrophic hearts following ischaemia. Hypertrophic hearts from spontaneously hypertensive rats and hearts from their normotensive controls, Wistar Kyoto Rats, were equilibrated in the working mode prior to global normothermic ischaemia. Reperfusion commenced with 10 min in Langendorff mode, followed by 30-min working reperfusion. Functional performance was measured throughout the working mode, whilst reperfusion damage was assessed from myocardial troponin I release during Langendorff reperfusion. Where used, 4 μg/ml propofol was added 10 min before ischaemia and was washed out 10 min into working reperfusion. An additional protocol investigated recovery of hearts protected by normothermic hyperkalaemic cardioplegic arrest. Following 20-min ischaemia, reperfusion damage was significantly worse in hypertrophic hearts compared to normal hearts, whilst addition of propofol to hypertrophic hearts significantly improved the aortic flow (31 ± 5.8 vs. 11.6 ± 2.0 ml/min, n = 6-7 ± SE, p < 0.05). Propofol also conferred significant protection following 30-min ischaemia where the recovery of cardiac output and stroke volume was similar to that for cardioplegia alone. Incubation with propofol improved the NADH/NAD(+) ratio in freshly isolated cardiomyocytes from hypertrophic hearts, suggesting possible improvements in metabolic flux. These findings suggest that propofol at the clinically relevant dose of 4 μg/ml is as effective as cardioplegic arrest in protecting hypertrophic hearts against ischaemia-reperfusion.

  5. A New Animal Model for Investigation of Mechanical Unloading in Hypertrophic and Failing Hearts: Combination of Transverse Aortic Constriction and Heterotopic Heart Transplantation

    PubMed Central

    Stenzig, Justus; Biermann, Daniel; Jelinek, Marisa; Reichenspurner, Hermann; Eschenhagen, Thomas; Ehmke, Heimo; Schwoerer, Alexander P.

    2016-01-01

    Objectives Previous small animal models for simulation of mechanical unloading are solely performed in healthy or infarcted hearts, not representing the pathophysiology of hypertrophic and dilated hearts emerging in heart failure patients. In this article, we present a new and economic small animal model to investigate mechanical unloading in hypertrophic and failing hearts: the combination of transverse aortic constriction (TAC) and heterotopic heart transplantation (hHTx) in rats. Methods To induce cardiac hypertrophy and failure in rat hearts, three-week old rats underwent TAC procedure. Three and six weeks after TAC, hHTx with hypertrophic and failing hearts in Lewis rats was performed to induce mechanical unloading. After 14 days of mechanical unloading animals were euthanatized and grafts were explanted for further investigations. Results 50 TAC procedures were performed with a survival of 92% (46/50). When compared to healthy rats left ventricular surface decreased to 5.8±1.0 mm² (vs. 9.6± 2.4 mm²) (p = 0.001) after three weeks with a fractional shortening (FS) of 23.7± 4.3% vs. 28.2± 1.5% (p = 0.01). Six weeks later, systolic function decreased to 17.1± 3.2% vs. 28.2± 1.5% (p = 0.0001) and left ventricular inner surface increased to 19.9±1.1 mm² (p = 0.0001). Intraoperative graft survival during hHTx was 80% with 46 performed procedures (37/46). All transplanted organs survived two weeks of mechanical unloading. Discussion Combination of TAC and hHTx in rats offers an economic and reproducible small animal model enabling serial examination of mechanical unloading in a truly hypertrophic and failing heart, representing the typical pressure overloaded and dilated LV, occurring in patients with moderate to severe heart failure. PMID:26841021

  6. Acute effects of sildenafil and dobutamine in the hypertrophic and failing right heart in vivo.

    PubMed

    Andersen, Asger; Nielsen, Jan M; Rasalingam, Sivagowry; Sloth, Erik; Nielsen-Kudsk, Jens Erik

    2013-09-01

    Abstract The purpose of this study was to investigate whether acute intravenous administration of the phosphodiesterase type 5 (PDE-5) inhibitor sildenafil in a single clinically relevant dose improves the in vivo function of the hypertrophic and failing right ventricle (RV). Wistar rats ([Formula: see text]) were subjected to pulmonary trunk banding (PTB) causing RV hypertrophy and failure. Four weeks after surgery, they were randomized to receive an intravenous bolus dose of sildenafil (1 mg/kg; [Formula: see text]), vehicle ([Formula: see text]), or dobutamine (10 μg/kg; [Formula: see text]). Invasive RV pressures were recorded continuously, and transthoracic echocardiography was performed 1, 5, 15, 25, 35, 50, 70, and 90 minutes after injecting the bolus. Cardiac function was compared to baseline measurements to evaluate the in vivo effects of each specific treatment. The PTB procedure caused significant hypertrophy, cardiac fibrosis, and reduction in RV function evaluated by echocardiography (TAPSE) and invasive pressure measurements. Sildenafil did not improve the function of the hypertrophic failing right heart in vivo, measured by TAPSE, RV systolic pressure (RVsP), and dp/dtmax. Dobutamine improved RV function 1 minute after injection measured by TAPSE ([Formula: see text] vs. [Formula: see text] cm; [Formula: see text]), RVsP ([Formula: see text] vs. [Formula: see text] mmHg; [Formula: see text]), and dp/dtmax ([Formula: see text] vs. [Formula: see text] mmHg/s; [Formula: see text]). Acute administration of the PDE-5 inhibitor sildenafil in a single clinically relevant dose did not modulate the in vivo function of the hypertrophic failing right heart of the rat measured by echocardiography and invasive hemodynamics. In the same model, dobutamine acutely improved RV function. PMID:24618544

  7. Transthoracic echocardiography in rats. Evalution of commonly used indices of left ventricular dimensions, contractile performance, and hypertrophy in a genetic model of hypertrophic heart failure (SHHF-Mcc-facp-Rats) in comparison with Wistar rats during aging.

    PubMed

    Reffelmann, Thorsten; Kloner, Robert A

    2003-09-01

    Two-weekly echocardiographic examinations were conducted in nine SHHF-Mc-fa(cp) rats in comparison with eight age-matched Wistar rats. In the SHHF-rats, characterized by progressive LV-dilation and decreasing contractile function between 77-87 weeks of age, left ventricular (LV) hypertrophy was most sensitively demonstrated by increased LV-mass-index (p < 0.001). LV-areas and area-ejection fraction (EF) (2D-images) discriminated more sensitively in the early stages than M-mode-derived diameters and fractional shortening (FS); midwall shortening was the most sensitive parameter of reduced systolic function. Post-mortem measurements showed an excellent correlation with calculated LV-mass (r = 0.91). Post-mortem LV-volumes correlated significantly with diastolic LV-diameters, LV-areas, and calculated LV-volumes (r = 0.56-0.59). Mean within-subject standard deviations in controls were 0.5-0.6 mm (LV-diameters), 3.1-4.6 mm(2) (LV-areas), approximately 10% of the mean for FS, area-EF and midwall shortening, and approximately 20% for wall thickness and LV-mass. The data might be used to choose the most sensitive parameters, and to estimate sample size for echocardiographic investigations in rats.

  8. Decreased contractility due to energy deprivation in a transgenic rat model of hypertrophic cardiomyopathy.

    PubMed

    Luedde, Mark; Flögel, Ulrich; Knorr, Maike; Grundt, Christina; Hippe, Hans-Joerg; Brors, Benedikt; Frank, Derk; Haselmann, Uta; Antony, Claude; Voelkers, Mirko; Schrader, Juergen; Most, Patrick; Lemmer, Bjoern; Katus, Hugo A; Frey, Norbert

    2009-04-01

    Hypertrophic cardiomyopathy (HCM) is associated with cardiac hypertrophy, diastolic dysfunction, and sudden death. Recently, it has been suggested that inefficient energy utilization could be a common molecular pathway of HCM-related mutations. We have previously generated transgenic Sprague-Dawley rats overexpressing a truncated cardiac troponin T (DEL-TNT) molecule, displaying typical features of HCM such as diastolic dysfunction and an increased susceptibility to ventricular arrhythmias. We now studied these rats using 31P magnetic resonance spectroscopy (MRS). MRS demonstrated that cardiac energy metabolism was markedly impaired, as indicated by a decreased phosphocreatine to ATP ratio (-31%, p < 0.05). In addition, we assessed contractility of isolated cardiomyocytes. While DEL-TNT and control cardiomyocytes showed no difference under baseline conditions, DEL-TNT cardiomyocytes selectively exhibited a decrease in fractional shortening by 28% after 1 h in glucose-deprived medium (p < 0.05). Moreover, significant decreases in contraction velocity and relaxation velocity were observed. To identify the underlying molecular pathways, we performed transcriptional profiling using real-time PCR. DEL-TNT hearts exhibited induction of several genes critical for cardiac energy supply, including CD36, CPT-1/-2, and PGC-1alpha. Finally, DEL-TNT rats and controls were studied by radiotelemetry after being stressed by isoproterenol, revealing a significantly increased frequency of arrhythmias in transgenic animals. In summary, we demonstrate profound energetic alterations in DEL-TNT hearts, supporting the notion that inefficient cellular ATP utilization contributes to the pathogenesis of HCM. PMID:19189074

  9. Decreased contractility due to energy deprivation in a transgenic rat model of hypertrophic cardiomyopathy.

    PubMed

    Luedde, Mark; Flögel, Ulrich; Knorr, Maike; Grundt, Christina; Hippe, Hans-Joerg; Brors, Benedikt; Frank, Derk; Haselmann, Uta; Antony, Claude; Voelkers, Mirko; Schrader, Juergen; Most, Patrick; Lemmer, Bjoern; Katus, Hugo A; Frey, Norbert

    2009-04-01

    Hypertrophic cardiomyopathy (HCM) is associated with cardiac hypertrophy, diastolic dysfunction, and sudden death. Recently, it has been suggested that inefficient energy utilization could be a common molecular pathway of HCM-related mutations. We have previously generated transgenic Sprague-Dawley rats overexpressing a truncated cardiac troponin T (DEL-TNT) molecule, displaying typical features of HCM such as diastolic dysfunction and an increased susceptibility to ventricular arrhythmias. We now studied these rats using 31P magnetic resonance spectroscopy (MRS). MRS demonstrated that cardiac energy metabolism was markedly impaired, as indicated by a decreased phosphocreatine to ATP ratio (-31%, p < 0.05). In addition, we assessed contractility of isolated cardiomyocytes. While DEL-TNT and control cardiomyocytes showed no difference under baseline conditions, DEL-TNT cardiomyocytes selectively exhibited a decrease in fractional shortening by 28% after 1 h in glucose-deprived medium (p < 0.05). Moreover, significant decreases in contraction velocity and relaxation velocity were observed. To identify the underlying molecular pathways, we performed transcriptional profiling using real-time PCR. DEL-TNT hearts exhibited induction of several genes critical for cardiac energy supply, including CD36, CPT-1/-2, and PGC-1alpha. Finally, DEL-TNT rats and controls were studied by radiotelemetry after being stressed by isoproterenol, revealing a significantly increased frequency of arrhythmias in transgenic animals. In summary, we demonstrate profound energetic alterations in DEL-TNT hearts, supporting the notion that inefficient cellular ATP utilization contributes to the pathogenesis of HCM.

  10. Hypoxia-driven glycolytic and fructolytic metabolic programs: Pivotal to hypertrophic heart disease.

    PubMed

    Mirtschink, Peter; Krek, Wilhelm

    2016-07-01

    Pathologic cardiac growth is an adaptive response of the myocardium to various forms of systemic (e.g. pressure overload) or genetically-based (e. g. mutations in genes encoding sarcomeric proteins) stress. It represents a key aspect of different types of heart disease including aortic stenosis (AS) and hypertrophic cardiomyopathy (HCM). While many of the pathophysiological and hemodynamical aspects of pathologic cardiac hypertrophy have been uncovered during the last decades, its underlying metabolic determinants are only beginning to come into focus. Here, we review the epidemiological evidence and pathological features of hypertrophic heart disease in AS and HCM and consider in this context the development of microenvironmental tissue hypoxia as a key component of the heart's growth response to pathologic stress. We particularly reflect on recent evidence illustrating how activation of hypoxia-inducible factor (HIF) drives glycolytic and fructolytic metabolic programs to maintain ATP generation and support anabolic growth of the pathologically-stressed heart. Finally we discuss how this metabolic programs, when protracted, deprive the heart of energy leading ultimately to heart failure. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.

  11. Hypoxia-driven glycolytic and fructolytic metabolic programs: Pivotal to hypertrophic heart disease.

    PubMed

    Mirtschink, Peter; Krek, Wilhelm

    2016-07-01

    Pathologic cardiac growth is an adaptive response of the myocardium to various forms of systemic (e.g. pressure overload) or genetically-based (e. g. mutations in genes encoding sarcomeric proteins) stress. It represents a key aspect of different types of heart disease including aortic stenosis (AS) and hypertrophic cardiomyopathy (HCM). While many of the pathophysiological and hemodynamical aspects of pathologic cardiac hypertrophy have been uncovered during the last decades, its underlying metabolic determinants are only beginning to come into focus. Here, we review the epidemiological evidence and pathological features of hypertrophic heart disease in AS and HCM and consider in this context the development of microenvironmental tissue hypoxia as a key component of the heart's growth response to pathologic stress. We particularly reflect on recent evidence illustrating how activation of hypoxia-inducible factor (HIF) drives glycolytic and fructolytic metabolic programs to maintain ATP generation and support anabolic growth of the pathologically-stressed heart. Finally we discuss how this metabolic programs, when protracted, deprive the heart of energy leading ultimately to heart failure. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel. PMID:26896647

  12. Echocardiography Differences Between Athlete’s Heart Hearth and Hypertrophic Cardiomyopathy

    PubMed Central

    Kreso, Amir; Barakovic, Fahir; Medjedovic, Senad; Halilbasic, Amila; Klepic, Muhamed

    2015-01-01

    Introduction: Among long term athletes there is always present hypertrophy of the left ventricle walls as well as increased cardiac mass. These changes are the result of the heart muscle adaptation to load during the years of training, which should not be considered as pathology. In people suffering from hypertrophic cardiomyopathy (HCM), there is also present hypertrophy of the left ventricle walls and increased mass of the heart, but these changes are the result of pathological changes in the heart caused by a genetic predisposition for the development HCM of. Differences between myocardial hypertrophy in athletes and HCM are not clearly differentiated and there are always dilemmas between pathological and physiological hypertrophy. The goal of the study is to determine and compare the echocardiographic cardiac parameters of longtime athletes to patients with hypertrophic cardiomyopathy. Material and methods: The study included 60 subjects divided into two groups: active athletes and people with hypertrophic cardiomyopathy. Results: Mean values of IVSd recorded in GB is IVSd=17.5 mm (n=20, 95% CI, 16.00–19.00 mm), while a significantly smaller mean value is recorded in GA, IVSd=10.0 mm (n=40, 95% CI, 9.00-11.00 mm). The mean value of the left ventricle in diastole (LVDd) recorded in the GA is LVDd=51 mm (n=40; 95% CI, 48.00 to 52.00 mm), while in the group with hypertrophic cardiomyopathy (GB) mean LVDd value is 42 mm (n=20; 95% CI, 40.00 to 48.00 mm). The mean value of the rear wall of the left ventricle (LVPWd) recorded in the GA is LVDd=10 mm (n=40; 95% CI, 9.00-10.00 mm) while in the group with hypertrophic cardiomyopathy (GB) mean LVDd is 14 mm (n=20; 95% CI, 12.00 to 16.00 mm). The mean of the left ventricle during systole (LVSD) observed in GA is LVSD=34 mm (n=40; 95% CI, 32.00 to 36.00 mm), while in the group with hypertrophic cardiomyopathy (GB) mean LVSD is 28 mm (n=20; 95% CI, 24.00 to 28.83 mm). The mean ejection fraction (EF%) observed in GA is EF

  13. miR-182 Modulates Myocardial Hypertrophic Response Induced by Angiogenesis in Heart

    PubMed Central

    Li, Na; Hwangbo, Cheol; Jaba, Irina M.; Zhang, Jiasheng; Papangeli, Irinna; Han, Jinah; Mikush, Nicole; Larrivée, Bruno; Eichmann, Anne; Chun, Hyung J.; Young, Lawrence H.; Tirziu, Daniela

    2016-01-01

    Myocardial hypertrophy is an adaptive response to hemodynamic demands. Although angiogenesis is critical to support the increase in heart mass with matching blood supply, it may also promote a hypertrophic response. Previously, we showed that cardiac angiogenesis induced by placental growth factor (PlGF), promotes myocardial hypertrophy through the paracrine action of endothelium-derived NO, which triggers the degradation of regulator of G protein signaling 4 (RGS4) to activate the Akt/mTORC1 pathways in cardiomyocytes. Here, we investigated whether miRNAs contribute to the development of hypertrophic response associated with myocardial angiogenesis. We show that miR-182 is upregulated concurrently with the development of hypertrophy in PlGF mice, but not when hypertrophy was blocked by concomitant expression of PlGF and RGS4, or by PlGF expression in eNOS−/− mice. Anti-miR-182 treatment inhibits the hypertrophic response and prevents the Akt/mTORC1 activation in PlGF mice and NO-treated cardiomyocytes. miR-182 reduces the expression of Bcat2, Foxo3 and Adcy6 to regulate the hypertrophic response in PlGF mice. Particularly, depletion of Bcat2, identified as a new miR-182 target, promotes AktSer473/p70-S6KThr389 phosphorylation and cardiomyocyte hypertrophy. LV pressure overload did not upregulate miR-182. Thus, miR-182 is a novel target of endothelial-cardiomyocyte crosstalk and plays an important role in the angiogenesis induced-hypertrophic response. PMID:26888314

  14. miR-182 Modulates Myocardial Hypertrophic Response Induced by Angiogenesis in Heart.

    PubMed

    Li, Na; Hwangbo, Cheol; Jaba, Irina M; Zhang, Jiasheng; Papangeli, Irinna; Han, Jinah; Mikush, Nicole; Larrivée, Bruno; Eichmann, Anne; Chun, Hyung J; Young, Lawrence H; Tirziu, Daniela

    2016-01-01

    Myocardial hypertrophy is an adaptive response to hemodynamic demands. Although angiogenesis is critical to support the increase in heart mass with matching blood supply, it may also promote a hypertrophic response. Previously, we showed that cardiac angiogenesis induced by placental growth factor (PlGF), promotes myocardial hypertrophy through the paracrine action of endothelium-derived NO, which triggers the degradation of regulator of G protein signaling 4 (RGS4) to activate the Akt/mTORC1 pathways in cardiomyocytes. Here, we investigated whether miRNAs contribute to the development of hypertrophic response associated with myocardial angiogenesis. We show that miR-182 is upregulated concurrently with the development of hypertrophy in PlGF mice, but not when hypertrophy was blocked by concomitant expression of PlGF and RGS4, or by PlGF expression in eNOS(-/-) mice. Anti-miR-182 treatment inhibits the hypertrophic response and prevents the Akt/mTORC1 activation in PlGF mice and NO-treated cardiomyocytes. miR-182 reduces the expression of Bcat2, Foxo3 and Adcy6 to regulate the hypertrophic response in PlGF mice. Particularly, depletion of Bcat2, identified as a new miR-182 target, promotes Akt(Ser473)/p70-S6K(Thr389) phosphorylation and cardiomyocyte hypertrophy. LV pressure overload did not upregulate miR-182. Thus, miR-182 is a novel target of endothelial-cardiomyocyte crosstalk and plays an important role in the angiogenesis induced-hypertrophic response. PMID:26888314

  15. An autopsy report of acute myocardial infarction with hypertrophic obstructive cardiomyopathy-like heart.

    PubMed

    Ushikoshi, Hiroaki; Okada, Hideshi; Morishita, Kentaro; Imai, Hajime; Tomita, Hiroyuki; Nawa, Takahide; Suzuki, Kodai; Ikeshoji, Haruka; Kato, Hisaaki; Yoshida, Takahiro; Yoshida, Shozo; Shirai, Kunihiro; Toyoda, Izumi; Hara, Akira; Ogura, Shinji

    2015-01-01

    An 84-year-old woman, who was followed up as hypertrophic obstructive cardiomyopathy (HOCM) in a local hospital, was transferred to our center because of anterior chest pain and diagnosed with acute myocardial infarction (MI). Coronary angiography showed total occlusion of the mid-left anterior descending, and flow was restored after endovascular thrombectomy. An autopsy was performed after she died on hospital day 6. At autopsy, there was no significant stenosis in this vessel and the absence of plaque rupture was confirmed. Likewise, it was unclear asymmetric hypertrophy at autopsy, it could not deny that a sigmoid deformity of the basal septum occurs in elderly patients and can mimic the asymmetric septal hypertrophy of hypertrophic cardiomyopathy. MI was thought to be caused by coronary spasm or squeezing in HOCM-like heart. Therefore, it may be necessary antithrombosis therapy in HOCM-like patients with no history of paroxysmal atrial fibrillation.

  16. Cone of skin exists in rat: A "hypertrophic scarring free" animal.

    PubMed

    Zuo, Yanhai; Yu, Xiaoping; Lu, Shuliang

    2016-08-01

    Cone of skin is deemed to be related to hypertrophic scarring and absent in such traditionally "hypertrophic scarring and keloid free" animals as rat. The purpose of our study is to determine whether the cone of skin exists in rat. If it was, why it was ignored, and what was the meaning of it. The depilation of left dorsum of 32 male Sprague-Dawley rats was performed using a wax/rosin mixture. Skin samples were harvested on 0 d, 3 d, 9 d, 15 d, 21 d, 27 d, 33 d, and 39 d after depilation and stained by hematoxylin and eosin methods. Light microscopic observation of the dermis-fat interface was studied at 25× magnification. It was observed that, "dome" like fat tissue bulged up into the dermis from 3 d to 27 d and hair follicle bulged down into the "dome" like fat tissue from 15 d to 27 d and a "cone" like structure was seen. Cone of skin exists in rat in certain stages of hair follicle cycle, which is a valuable addition to the scientific literature and might be a challenge to the relation between cone of skin and hypertrophic scarring. Anat Rec, 299:1140-1144, 2016. © 2016 Wiley Periodicals, Inc. PMID:27125905

  17. Substrate uptake and metabolism are preserved in hypertrophic caveolin-3 knockout hearts

    PubMed Central

    Augustus, Ayanna S.; Buchanan, Jonathan; Addya, Sankar; Rengo, Giuseppe; Pestell, Richard G.; Fortina, Paolo; Koch, Walter J.; Bensadoun, Andre; Abel, E. Dale; Lisanti, Michael P.

    2008-01-01

    Caveolin-3 (Cav3), the primary protein component of caveolae in muscle cells, regulates numerous signaling pathways including insulin receptor signaling and facilitates free fatty acid (FA) uptake by interacting with several FA transport proteins. We previously reported that Cav3 knockout mice (Cav3KO) develop cardiac hypertrophy with diminished contractile function; however, the effects of Cav3 gene ablation on cardiac substrate utilization are unknown. The present study revealed that the uptake and oxidation of FAs and glucose were normal in hypertrophic Cav3KO hearts. Real-time PCR analysis revealed normal expression of lipid metabolism genes including FA translocase (CD36) and carnitine palmitoyl transferase-1 in Cav3KO hearts. Interestingly, myocardial cAMP content was significantly increased by 42%; however, this had no effect on PKA activity in Cav3KO hearts. Microarray expression analysis revealed a marked increase in the expression of genes involved in receptor trafficking to the plasma membrane, including Rab4a and the expression of WD repeat/FYVE domain containing proteins. We observed a fourfold increase in the expression of cellular retinol binding protein-III and a 3.5-fold increase in 17β-hydroxysteroid dehydrogenase type 11, a member of the short-chain dehydrogenase/reductase family involved in the biosynthesis and inactivation of steroid hormones. In summary, a loss of Cav3 in the heart leads to cardiac hypertrophy with normal substrate utilization. Moreover, a loss of Cav3 mRNA altered the expression of several genes not previously linked to cardiac growth and function. Thus we have identified a number of new target genes associated with the pathogenesis of cardiac hypertrophy. PMID:18552160

  18. Computational Modeling of Blood Flow and Valve Dynamics in Hearts with Hypertrophic Cardiomyopathy

    NASA Astrophysics Data System (ADS)

    Zheng, Xudong; Mittal, Rajat; Abraham, Theodore; Pinheiro, Aurelio

    2010-11-01

    Hypertrophic Cardiomyopathy (HCM) is a cardiovascular disease manifested by the thickening of the ventricular wall and often leads to a partial obstruction to the blood flow out of the left ventricle. HCM is recognized as one of the most common causes of sudden cardiac death in athletes. In a heart with HCM, the hypertrophy usually narrows the blood flow pathway to the aorta and produces a low pressure zone between the mitral valve and the hypertrophy during systole. This low pressure can suck the mitral valve leaflet back and completely block the blood flow into the aorta. In the current study, a sharp interface immersed boundary method flow solver is employed to study the hemodynamics and valve dynamics inside a heart with HCM. The three-dimensional motion and configuration of the left ventricle including mitral valve leaflets and aortic valves are reconstructed based on echo-cardio data sets. The mechanisms of aortic obstruction associated with HCM are investigated. The long term objective of this study is to develop a computational tool to aid in the assessment and surgical management of HCM.

  19. TRPC1 channels are critical for hypertrophic signaling in the heart

    PubMed Central

    Seth, Malini; Zhang, Zhu-Shan; Mao, Lan; Graham, Victoria; Burch, Jarrett; Stiber, Jonathan; Tsiokas, Leonidas; Winn, Michelle; Abramowitz, Joel; Rockman, Howard A.; Birnbaumer, Lutz; Rosenberg, Paul

    2010-01-01

    Rationale Cardiac muscle adapts to increased workload by altering cardiomyocyte size and function resulting in cardiac hypertrophy. G-protein coupled receptor (GPCR) signaling is known to govern the hypertrophic response through the regulation of ion channel activity and downstream signaling in failing cardiomyocytes. Objective Transient receptor potential canonical (TRPC) channels are GPCR operated channels previously implicated in cardiac hypertrophy. Our objective of this study is to better understand how TRPC channels influence cardiomyocyte calcium signaling. Methods and Results Here, we used whole cell patch clamp of adult cardiomyocytes to show upregulation of a non-selective cation current reminiscent of TRPC channels subjected to pressure overload. This TRPC current corresponds to the increased TRPC channel expression noted in hearts of mice subjected to pressure overload. Importantly, we show that mice lacking TRPC1 channels are missing this putative TRPC current. Moreover, Trpc1−/− mice fail to manifest evidence of maladaptive cardiac hypertrophy and maintain preserved cardiac function when subjected to hemodynamic stress and neurohormonal excess. In addition, we provide a mechanistic basis for the protection conferred to Trpc1−/− mice as mechanosensitive signaling through calcineurin/NFAT, mTOR and Akt is altered in Trpc1−/− mice. Conclusions From these studies, we suggest that TRPC1 channels are critical for the adaptation to biomechanical stress and TRPC dysregulation leads to maladaptive cardiac hypertrophy and failure. PMID:19797170

  20. Complex I deficiency due to selective loss of Ndufs4 in the mouse heart results in severe hypertrophic cardiomyopathy.

    PubMed

    Chouchani, Edward T; Methner, Carmen; Buonincontri, Guido; Hu, Chou-Hui; Logan, Angela; Sawiak, Stephen J; Murphy, Michael P; Krieg, Thomas

    2014-01-01

    Mitochondrial complex I, the primary entry point for electrons into the mitochondrial respiratory chain, is both critical for aerobic respiration and a major source of reactive oxygen species. In the heart, chronic dysfunction driving cardiomyopathy is frequently associated with decreased complex I activity, from both genetic and environmental causes. To examine the functional relationship between complex I disruption and cardiac dysfunction we used an established mouse model of mild and chronic complex I inhibition through heart-specific Ndufs4 gene ablation. Heart-specific Ndufs4-null mice had a decrease of ∼ 50% in complex I activity within the heart, and developed severe hypertrophic cardiomyopathy as assessed by magnetic resonance imaging. The decrease in complex I activity, and associated cardiac dysfunction, occurred absent an increase in mitochondrial hydrogen peroxide levels in vivo, accumulation of markers of oxidative damage, induction of apoptosis, or tissue fibrosis. Taken together, these results indicate that diminished complex I activity in the heart alone is sufficient to drive hypertrophic cardiomyopathy independently of alterations in levels of mitochondrial hydrogen peroxide or oxidative damage.

  1. Radiation induced heart disease in hypertensive rats

    SciTech Connect

    Lauk, S.; Trott, K.R.

    1988-01-01

    Spontaneously hypertensive Wistar rats were given single doses of X rays to their heart. Irradiation decreased the blood pressure before any myocardial radiation damage was apparent. Male rats, which were more hypertensive than female rats, had a shorter survival time after local heart irradiation than female rats. Antihypertensive treatment with hydralazine did not increase the survival time. It is considered that myocardial hypertrophy is the cause of the increased susceptibility of spontaneously hypertensive rats to local heart irradiation.

  2. Differentiating hypertrophic cardiomyopathy from athlete's heart: An electrocardiographic and echocardiographic approach.

    PubMed

    Grazioli, Gonzalo; Usín, Domingo; Trucco, Emilce; Sanz, Maria; Montserrat, Silvia; Vidal, Bàrbara; Gutierrez, Josep; Canal, Ramon; Brugada, Josep; Mont, Lluis; Sitges, Marta

    2016-01-01

    Differential diagnosis of hypertrophic cardiomyopathy (HCM) vs athlete's heart is challenging in individuals with mild-moderate left-ventricular hypertrophy. This study aimed to assess ECG and echocardiographic parameters proposed for the differential diagnosis of HCM. The study included 75 men in three groups: control (n=30), "gray zone" athletes with interventricular septum (IVS) measuring 13-15mm (n=25) and HCM patients with IVS of 13-18mm (n=20). The most significant differences were found in relative septal thickness (RST), calculated as the ratio of 2 x IVS to left ventricle end-diastolic diameter (LV-EDD) (0.37, 0.51, 0.71, respectively; p<0.01) and in spatial QRS-T angle as visually estimated (9.8, 33.6, 66.2, respectively; p<0.01). The capacity for differential HCM diagnosis of each of the 5 criteria was assessed using the area under the curve (AUC), as follows: LV-EDD<54 (0.60), family history (0.61), T-wave inversion (TWI) (0.67), spatial QRS-T angle>45 (0.75) and RST>0.54 (0.92). Pearson correlation between spatial QRS-T angle>45 and TWI was 0.76 (p 0.01). The combination of spatial QRS-T angle>45 and RST>0.54 for diagnosis of HCM had an AUC of 0.79. The best diagnostic criteria for HCM was RST>0.54. The spatial QRS-T angle>45 did not add sensitivity if TWI was present. No additional improvement in differential diagnosis was obtained by combining parameters.

  3. Differentiating hypertrophic cardiomyopathy from athlete's heart: An electrocardiographic and echocardiographic approach.

    PubMed

    Grazioli, Gonzalo; Usín, Domingo; Trucco, Emilce; Sanz, Maria; Montserrat, Silvia; Vidal, Bàrbara; Gutierrez, Josep; Canal, Ramon; Brugada, Josep; Mont, Lluis; Sitges, Marta

    2016-01-01

    Differential diagnosis of hypertrophic cardiomyopathy (HCM) vs athlete's heart is challenging in individuals with mild-moderate left-ventricular hypertrophy. This study aimed to assess ECG and echocardiographic parameters proposed for the differential diagnosis of HCM. The study included 75 men in three groups: control (n=30), "gray zone" athletes with interventricular septum (IVS) measuring 13-15mm (n=25) and HCM patients with IVS of 13-18mm (n=20). The most significant differences were found in relative septal thickness (RST), calculated as the ratio of 2 x IVS to left ventricle end-diastolic diameter (LV-EDD) (0.37, 0.51, 0.71, respectively; p<0.01) and in spatial QRS-T angle as visually estimated (9.8, 33.6, 66.2, respectively; p<0.01). The capacity for differential HCM diagnosis of each of the 5 criteria was assessed using the area under the curve (AUC), as follows: LV-EDD<54 (0.60), family history (0.61), T-wave inversion (TWI) (0.67), spatial QRS-T angle>45 (0.75) and RST>0.54 (0.92). Pearson correlation between spatial QRS-T angle>45 and TWI was 0.76 (p 0.01). The combination of spatial QRS-T angle>45 and RST>0.54 for diagnosis of HCM had an AUC of 0.79. The best diagnostic criteria for HCM was RST>0.54. The spatial QRS-T angle>45 did not add sensitivity if TWI was present. No additional improvement in differential diagnosis was obtained by combining parameters. PMID:27016258

  4. Heart rate turbulence and clinical prognosis in hypertrophic cardiomyopathy and myocardial infarction.

    PubMed

    Kawasaki, Tatsuya; Azuma, Akihiro; Asada, Satoshi; Hadase, Mitsuyoshi; Kamitani, Tadaaki; Kawasaki, Shingo; Kuribayashi, Toshiro; Sugihara, Hiroki

    2003-07-01

    Short-term fluctuations in sinus cycle length after a single ventricular premature complex (VPC) have attracted considerable interest and has been termed heart rate turbulence (HRT). The onset and slope of HRT have each been reported to be independent and powerful predictors of clinical prognosis in patients with myocardial infarction (MI), but there are no data available for patients with hypertrophic cardiomyopathy (HCM). Thus the present study analyzed the 2 HRT variables to determine their prognostic value in HCM patients. Holter monitoring data were obtained from 104 HCM patients, 44 MI patients and 56 normal controls, from which singular VPCs followed by >or=20 normal sinus beats were isolated and the HRT onset and slope were automatically calculated. HRT onset and slope were abnormal in MI patients, but not in HCM patients, as compared with normal control subjects (onset -1.1+/-2.9, -2.1+/-3.4, -1.4+/-5.1%; slope 10.6 +/-8.6, 18.0+/-13.9, 16.6+/-9.7 ms/beat, respectively). During the follow-up period of 27+/-10 months, 7 HCM patients and 10 MI patients either died from cardiac death or were hospitalized for congestive heart failure. In MI patients, HRT onset was higher and the HRT slope was lower in patients with cardiac events than in patients without (onset 1.1+/-2.7 vs -1.7+/-2.7%, p=0.011; slope 5.7+/-4.3 vs 12.0+/-9.0 ms/beat, p=0.028). In HCM patients, however, the HRT onset and slope were similar between patients with and without cardiac events (onset -2.0+/-2.0 vs -2.1 +/-3.5%, p=0.98; slope 18.1+/-10.9 vs 18.0+/-14.0 ms/beat, p=0.68). In conclusion, unlike MI patients, the HRT variables in selected HCM patients were not abnormal and failed to predict the clinical prognosis.

  5. Loss of the AE3 Anion Exchanger in a Hypertrophic Cardiomyopathy Model Causes Rapid Decompensation and Heart Failure

    PubMed Central

    Al Moamen, Nabeel J.; Prasad, Vikram; Bodi, Ilona; Miller, Marian L.; Neiman, Michelle L.; Lasko, Valerie M.; Alper, Seth L.; Wieczorek, David F.; Lorenz, John N.; Shull, Gary E.

    2010-01-01

    The AE3 Cl−/HCO3− exchanger is abundantly expressed in the sarcolemma of cardiomyocytes, where it mediates Cl−-uptake and HCO3−-extrusion. Inhibition of AE3-mediated Cl−/HCO3− exchange has been suggested to protect against cardiac hypertrophy; however, other studies indicate that AE3 might be necessary for optimal cardiac function. To test these hypotheses we crossed AE3-null mice, which appear phenotypically normal, with a hypertrophic cardiomyopathy mouse model carrying a Glu180Gly mutation in α–tropomyosin (TM180). Loss of AE3 had no effect on hypertrophy; however, survival of TM180/AE3 double mutants was sharply reduced compared with TM180 single mutants. Analysis of cardiac performance revealed impaired cardiac function in TM180 and TM180/AE3 mutants. TM180/AE3 double mutants were more severely affected and exhibited little response to β-adrenergic stimulation, a likely consequence of their more rapid progression to heart failure. Increased expression of calmodulin-dependent kinase II and protein phosphatase 1 and differences in methylation and localization of protein phosphatase 2A were observed, but were similar in single and double mutants. Phosphorylation of phospholamban on Ser16 was sharply increased in both single and double mutants relative to wild-type hearts under basal conditions, leading to reduced reserve capacity for β-adrenergic stimulation of phospholamban phosphorylation. Imaging analysis of isolated myocytes revealed reductions in amplitude and decay of Ca2+ transients in both mutants, with greater reductions in TM180/AE3 mutants, consistent with the greater severity of their heart failure phenotype. Thus, in the TM180 cardiomyopathy model, loss of AE3 had no apparent anti-hypertrophic effect and led to more rapid decompensation and heart failure. PMID:21056571

  6. CCN2 plays a key role in extracellular matrix gene expression in severe hypertrophic cardiomyopathy and heart failure.

    PubMed

    Tsoutsman, Tatiana; Wang, Xiaoyu; Garchow, Kendra; Riser, Bruce; Twigg, Stephen; Semsarian, Christopher

    2013-09-01

    Hypertrophic cardiomyopathy (HCM) is the most common inherited primary myocardial disorder. HCM is characterized by interstitial fibrosis and excessive accumulation of extracellular matrix (ECM) proteins. Fibrosis in HCM has been associated with impaired cardiac function and heart failure, and has been considered a key substrate for ventricular arrhythmias and sudden death. The molecular triggers underpinning ECM production are not well established. We have previously developed a double-mutant mouse model of HCM that recapitulates the phenotype seen in humans with multiple mutations, including earlier onset of the disease, progression to a dilated phenotype, severe heart failure and premature mortality. The present study investigated the expression of ECM-encoding genes in severe HCM and heart failure. Significant upregulation of structural Fn1, regulatory Mmp14, Timp1, Serpin3A, SerpinE1, SerpineE2, Tgfβ1, and Tgfβ2; and matricellular Ccn2, Postn, Spp1, Thbs1, Thbs4, and Tnc was evident from the early, pre-phenotype stage. Non-myocytes expressed ECM genes at higher levels than cardiomyocytes in normal and diseased hearts. Synchronous increase of secreted CCN2 and TIMP1 plasma levels and decrease of MMP3 levels were observed in end-stage disease. CCN2 protein expression was increased from early disease in double-mutant hearts and played an important role in ECM responses. It was a powerful modulator of ECM regulatory (Timp1 and SerpinE1) and matricellular protein-encoding (Spp1, Thbs1, Thbs4 and Tnc) gene expression in cardiomyocytes when added exogenously in vitro. Modulation of CCN2 (CTGF, connective tissue growth factor) and associated early ECM changes may represent a new therapeutic target in the treatment and prevention of heart failure in HCM. PMID:23756156

  7. Leptin as a cardiac pro-hypertrophic factor and its potential role in the development of heart failure.

    PubMed

    Karmazyn, Morris; Rajapurohitam, Venkatesh

    2014-01-01

    The identification of the adipocyte as a source of production of biologically-active peptides has materialized into an active area of research related to the role of these peptides in physiology and pathophysiology. Moreover, this research has resulted in the identification of the adipocyte as an endocrine organ producing potent bioactive compounds. An increasing number of these adipokines are being identified, the first of which was leptin, a product of the obesity gene whose primary function is to act as a satiety factor but which is now known to exert a myriad of effects. It is now recognized that virtually all adipokines produce effects on numerous organ systems including the heart and many of these, including leptin, are produced by cardiac tissue. Here we focus primarily on the diverse effects of leptin on the heart especially as it pertains to hypertrophy and discuss the potential cell signaling mechanisms underlying their actions. Current evidence suggests that leptin is a cardiac hypertrophic factor and from clinical studies there is evidence that hyperleptinemia is associated with cardiovascular risk especially as it pertains to heart failure. While more substantial research needs to be carried out, leptin may represent a potential link between obesity, which is associated with hyperleptinemia, and increased cardiovascular risk.

  8. The dietary compound curcumin inhibits p300 histone acetyltransferase activity and prevents heart failure in rats

    PubMed Central

    Morimoto, Tatsuya; Sunagawa, Yoichi; Kawamura, Teruhisa; Takaya, Tomohide; Wada, Hiromichi; Nagasawa, Atsushi; Komeda, Masashi; Fujita, Masatoshi; Shimatsu, Akira; Kita, Toru; Hasegawa, Koji

    2008-01-01

    Hemodynamic overload in the heart can trigger maladaptive hypertrophy of cardiomyocytes. A key signaling event in this process is nuclear acetylation by histone deacetylases and p300, an intrinsic histone acetyltransferase (HAT). It has been previously shown that curcumin, a polyphenol responsible for the yellow color of the spice turmeric, possesses HAT inhibitory activity with specificity for the p300/CREB-binding protein. We found that curcumin inhibited the hypertrophy-induced acetylation and DNA-binding abilities of GATA4, a hypertrophy-responsive transcription factor, in rat cardiomyocytes. Curcumin also disrupted the p300/GATA4 complex and repressed agonist- and p300-induced hypertrophic responses in these cells. Both the acetylated form of GATA4 and the relative levels of the p300/GATA4 complex markedly increased in rat hypertensive hearts in vivo. The effects of curcumin were examined in vivo in 2 different heart failure models: hypertensive heart disease in salt-sensitive Dahl rats and surgically induced myocardial infarction in rats. In both models, curcumin prevented deterioration of systolic function and heart failure–induced increases in both myocardial wall thickness and diameter. From these results, we conclude that inhibition of p300 HAT activity by the nontoxic dietary compound curcumin may provide a novel therapeutic strategy for heart failure in humans. PMID:18292809

  9. Regression of Copper-Deficient Heart Hypertrophy: Reduction in the Size of Hypertrophic Cardiomyocytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dietary copper deficiency causes cardiac hypertrophy and its transition to heart failure in a mouse model. Copper repletion results in a rapid regression of cardiac hypertrophy and prevention of heart failure. The present study was undertaken to understand dynamic changes of cardiomyocytes in the hy...

  10. Coexistence of mitochondrial DNA and β myosin heavy chain mutations in hypertrophic cardiomyopathy with late congestive heart failure

    PubMed Central

    Arbustini, E; Fasani, R; Morbini, P; Diegoli, M; Grasso, M; Dal, B; Marangoni, E; Banfi, P; Banchieri, N; Bellini, O; Comi, G; Narula, J; Campana, C; Gavazzi, A; Danesino, C; Vigano, M

    1998-01-01

    Objective—To investigate the possible coexistence of mitochondrial DNA (mtDNA) mutations in patients with β myosin heavy chain (βMHC) linked hypertrophic cardiomyopathy (HCM) who develop congestive heart failure.
Design—Molecular analysis of βMHC and mtDNA gene defects in patients with HCM.
Setting—Cardiovascular molecular diagnostic and heart transplantation reference centre in north Italy.
Patients—Four patients with HCM who underwent heart transplantation for end stage heart failure, and after pedigree analysis of 60 relatives, eight additional affected patients and 27 unaffected relatives. A total of 111 unrelated healthy adult volunteers served as controls. Disease controls included an additional 27 patients with HCM and 102 with dilated cardiomyopathy.
Intervention—Molecular analysis of DNA from myocardial and skeletal muscle tissue and from peripheral blood specimens.
Main outcome measures—Screening for mutations in βMHC (exons 3-23) and mtDNA tRNA (n = 22) genes with denaturing gradient gel electrophoresis or single strand conformational polymorphism followed by automated DNA sequencing.
Results—One proband (kindred A) (plus seven affected relatives) had arginine 249 glutamine (Arg249Gln) βMHC and heteroplasmic mtDNA tRNAIle A4300G mutations. Another unrelated patient (kindred B) with sporadic HCM had identical mutations. The remaining two patients (kindred C), a mother and son, had a novel βMHC mutation (lysine 450 glutamic acid) (Lys450Glu) and a heteroplasmic missense (T9957C, phenylalanine (Phe)->leucine (Leu)) mtDNA mutation in subunit III of the cytochrome C oxidase gene. The amount of mutant mtDNA was higher in the myocardium than in skeletal muscle or peripheral blood and in affected patients than in asymptomatic relatives. Mutations were absent in the controls. Pathological and biochemical characteristics of patients with mutations Arg249Gln plus A4300G (kindreds A and B) were identical, but different from

  11. Misconceptions and Facts About Hypertrophic Cardiomyopathy.

    PubMed

    Argulian, Edgar; Sherrid, Mark V; Messerli, Franz H

    2016-02-01

    Hypertrophic cardiomyopathy is the most common genetic heart disease. Once considered relentless, untreatable, and deadly, it has become a highly treatable disease with contemporary management. Hypertrophic cardiomyopathy is one of cardiology's "great masqueraders." Mistakes and delays in diagnosis abound. Hypertrophic cardiomyopathy commonly "masquerades" as asthma, anxiety, mitral prolapse, and coronary artery disease. However, once properly diagnosed, patients with hypertrophic cardiomyopathy can be effectively managed to improve both symptoms and survival. This review highlights some of the misconceptions about hypertrophic cardiomyopathy. Providers at all levels should have awareness of hypertrophic cardiomyopathy to promptly diagnose and properly manage these individuals. PMID:26299316

  12. Phosphodiesterase 9A Controls Nitric-oxide Independent cGMP and Hypertrophic Heart Disease

    PubMed Central

    Lee, Dong I.; Zhu, Guangshuo; Sasaki, Takashi; Cho, Gun-Sik; Hamdani, Nazha; Holewinski, Ronald; Jo, Su-Hyun; Danner, Thomas; Zhang, Manling; Rainer, Peter P.; Bedja, Djahida; Kirk, Jonathan A.; Ranek, Mark J.; Dostmann, Wolfgang R.; Kwon, Chulan; Margulies, Kenneth B.; Van Eyk, Jennifer E.; Paulus, Walter J.; Takimoto, Eiki; Kass, David A.

    2015-01-01

    Cyclic guanosine monophosphate (cGMP) is a second messenger molecule that transduces nitric oxide (NO) and natriuretic peptide (NP) coupled signaling, stimulating phosphorylation changes by protein kinase G (PKG). Enhancing cGMP synthesis or blocking its degradation by phosphodiesterase type 5A (PDE5A) protects against cardiovascular disease1,2. However, cGMP stimulation alone is limited by counter-adaptions including PDE upregulation3. Furthermore, though PDE5A regulates NO-generated cGMP4,5, NO-signaling is often depressed by heart disease6. PDEs controlling NP-coupled cGMP remain uncertain. Here we show that cGMP-selective PDE9A7,8 is expressed in mammalian heart including humans, and is upregulated by hypertrophy and cardiac failure. PDE9A regulates NP rather than NO-stimulated cGMP in heart myocytes and muscle, and its genetic or selective pharmacological inhibition protects against pathological responses to neuro-hormones, and sustained pressure-overload stress. PDE9A inhibition reverses pre-established heart disease independent of NO-synthase (NOS) activity, whereas PDE5A inhibition requires active NOS. Transcription factor activation and phospho-proteome analyses of myocytes with each PDE selectively inhibited reveals substantial differential targeting, with phosphorylation changes from PDE5A inhibition being more sensitive to NOS activation. Thus, unlike PDE5A, PDE9A can regulate cGMP signaling independent of the NO-pathway, and its role in stress-induced heart disease suggests potential as a therapeutic target. PMID:25799991

  13. Unexpected anti-hypertrophic responses to low-level stimulation of protease-activated receptors in adult rat cardiomyocytes.

    PubMed

    Fender, Anke C; Pavic, Goran; Drummond, Grant R; Dusting, Gregory J; Ritchie, Rebecca H

    2014-10-01

    Activators of protease-activated receptors PAR-1 and PAR-2 such as thrombin and synthetic hexapeptides promote hypertrophy of isolated neonatal cardiomyocytes at pathological concentrations. Since PAR-activating proteases often show dual actions at low vs. high concentrations, the potential hypertrophic effects of low-level PAR activation were examined. In H9c2 cardiomyoblasts, messenger RNA (mRNA) expression of the hypertrophic marker atrial natriuretic peptide (ANP) was significantly increased only by higher concentrations of thrombin, trypsin or the synthetic PAR-2 agonist SLIGRL. The dual PAR-1/PAR-2 agonist SFLLRN did not influence basal ANP mRNA expression in H9c2 cells. Low concentration of thrombin or trypsin (up to 0.1 U/mL) or of the synthetic ligands SFLLRN and SLIGRL (1 μM); however, all suppressed ANP mRNA expression stimulated by angiotensin II (Ang II). The PAR-1 selective ligand TFLLRN exerted a comparable effect as SFLLRN. In adult rat cardiomyocytes, protein synthesis determined by [(3)H]phenylalanine incorporation was not increased by various PAR agonists at concentrations tenfold lower than conventionally used to study PAR function in vitro (10 μM for SFLLRN or SLIGRL, 0.1 U/mL for thrombin or trypsin). The positive control endothelin-1 (ET-1, 60 nM) however significantly increased protein synthesis in adult rat cardiomyocytes. Addition of low concentrations of PAR agonists to cardiomyocytes treated with ET-1 or Ang II suppressed [(3)H]phenylalanine incorporation induced by the hypertrophic stimuli. The inhibitory effect of SFLLRN effect was partially reversed by the PAR-1 antagonist RWJ56110. These findings suggest that physiological concentrations of PAR activators may suppress hypertrophy, in contrast to the pro-hypertrophic effects evident at high concentrations. PAR-1 and PAR-2 may dynamically control cardiomyocyte growth, with the net effect critically dependent upon local agonist concentrations. The precise significance of proposed

  14. Registration of dynamic multiview 2D ultrasound and late gadolinium enhanced images of the heart: Application to hypertrophic cardiomyopathy characterization.

    PubMed

    Betancur, Julián; Simon, Antoine; Halbert, Edgar; Tavard, François; Carré, François; Hernández, Alfredo; Donal, Erwan; Schnell, Frédéric; Garreau, Mireille

    2016-02-01

    Describing and analyzing heart multiphysics requires the acquisition and fusion of multisensor cardiac images. Multisensor image fusion enables a combined analysis of these heterogeneous modalities. We propose to register intra-patient multiview 2D+t ultrasound (US) images with multiview late gadolinium-enhanced (LGE) images acquired during cardiac magnetic resonance imaging (MRI), in order to fuse mechanical and tissue state information. The proposed procedure registers both US and LGE to cine MRI. The correction of slice misalignment and the rigid registration of multiview LGE and cine MRI are studied, to select the most appropriate similarity measure. It showed that mutual information performs the best for LGE slice misalignment correction and for LGE and cine registration. Concerning US registration, dynamic endocardial contours resulting from speckle tracking echocardiography were exploited in a geometry-based dynamic registration. We propose the use of an adapted dynamic time warping procedure to synchronize cardiac dynamics in multiview US and cine MRI. The registration of US and LGE MRI was evaluated on a dataset of patients with hypertrophic cardiomyopathy. A visual assessment of 330 left ventricular regions from US images of 28 patients resulted in 92.7% of regions successfully aligned with cardiac structures in LGE. Successfully-aligned regions were then used to evaluate the abilities of strain indicators to predict the presence of fibrosis. Longitudinal peak-strain and peak-delay of aligned left ventricular regions were computed from corresponding regional strain curves from US. The Mann-Withney test proved that the expected values of these indicators change between the populations of regions with and without fibrosis (p < 0.01). ROC curves otherwise proved that the presence of fibrosis is one factor amongst others which modifies longitudinal peak-strain and peak-delay. PMID:26619189

  15. MicroRNA-1 downregulation increases connexin 43 displacement and induces ventricular tachyarrhythmias in rodent hypertrophic hearts.

    PubMed

    Curcio, Antonio; Torella, Daniele; Iaconetti, Claudio; Pasceri, Eugenia; Sabatino, Jolanda; Sorrentino, Sabato; Giampà, Salvatore; Micieli, Mariella; Polimeni, Alberto; Henning, Beverley J; Leone, Angelo; Catalucci, Daniele; Ellison, Georgina M; Condorelli, Gianluigi; Indolfi, Ciro

    2013-01-01

    Downregulation of the muscle-specific microRNA-1 (miR-1) mediates the induction of pathologic cardiac hypertrophy. Dysfunction of the gap junction protein connexin 43 (Cx43), an established miR-1 target, during cardiac hypertrophy leads to ventricular tachyarrhythmias (VT). However, it is still unknown whether miR-1 and Cx43 are interconnected in the pro-arrhythmic context of hypertrophy. Thus, in this study we investigated whether a reduction in the extent of cardiac hypertrophy could limit the pathological electrical remodeling of Cx43 and the onset of VT by modulating miR-1 levels. Wistar male rats underwent mechanical constriction of the ascending aorta to induce pathologic left ventricular hypertrophy (LVH) and afterwards were randomly assigned to receive 10mg/kg valsartan, VAL (LVH+VAL) delivered in the drinking water or placebo (LVH) for 12 weeks. Sham surgery was performed for control groups. Programmed ventricular stimulation reproducibly induced VT in LVH compared to LVH+VAL group. When compared to sham controls, rats from LVH group showed a significant decrease of miR-1 and an increase of Cx43 expression and its ERK1/2-dependent phosphorylation, which displaces Cx43 from the gap junction. Interestingly, VAL administration to rats with aortic banding significantly reduced cardiac hypertrophy and prevented miR-1 down-regulation and Cx43 up-regulation and phosphorylation. Gain- and loss-of-function experiments in neonatal cardiomyocytes (NCMs) in vitro confirmed that Cx43 is a direct target of miR-1. Accordingly, in vitro angiotensin II stimulation reduced miR-1 levels and increased Cx43 expression and phosphorylation compared to un-stimulated NCMs. Finally, in vivo miR-1 cardiac overexpression by an adenoviral vector intra-myocardial injection reduced Cx43 expression and phosphorylation in mice with isoproterenol-induced LVH. In conclusion, miR-1 regulates Cx43 expression and activity in hypertrophic cardiomyocytes in vitro and in vivo. Treatment of

  16. Hypertrophic Cardiomyopathy: A Review

    PubMed Central

    Houston, Brian A; Stevens, Gerin R

    2014-01-01

    Hypertrophic cardiomyopathy (HCM) is a global disease with cases reported in all continents, affecting people of both genders and of various racial and ethnic origins. Widely accepted as a monogenic disease caused by a mutation in 1 of 13 or more sarcomeric genes, HCM can present catastrophically with sudden cardiac death (SCD) or ventricular arrhythmias or insidiously with symptoms of heart failure. Given the velocity of progress in both the fields of heart failure and HCM, we present a review of the approach to patients with HCM, with particular attention to those with HCM and the clinical syndrome of heart failure. PMID:25657602

  17. Cardiac remodeling associated with protein increase and lipid accumulation in early-stage chronic kidney disease in rats.

    PubMed

    Kuwahara, Mieko; Bannai, Kenji; Segawa, Hiroko; Miyamoto, Ken-ichi; Yamato, Hideyuki

    2014-09-01

    Chronic kidney disease (CKD) is associated with increased risks of cardiovascular morbidity and mortality. Cardiac remodeling including myocardial fibrosis and hypertrophy is frequently observed in CKD patients. In this study, we investigate the mechanism involved in cardiac hypertrophy associated with CKD using a rat model, by morphological and chemical component changes of the hypertrophic and non-hypertrophic hearts. Sprague-Dawley rats were 4/5 nephrectomized (Nx) at 11 weeks of age and assigned to no treatment and treatment with AST-120, which was reported to affect the cardiac damage, at 18 weeks of age. At 26 weeks of age, the rats were euthanized under anesthesia, and biochemical tests as well as analysis of cardiac condition were performed by histological and spectrophotometric methods. Cardiac hypertrophy and CKD were observed in 4/5 Nx rats even though vascular calcification and myocardial fibrosis were not detected. The increasing myocardial protein was confirmed in hypertrophic hearts by infrared spectroscopy. The absorption of amide I and other protein bands in hypertrophic hearts increased at the same position as in normal cardiac absorption. Infrared spectra also showed that lipid accumulation was also detected in hypertrophic heart. Conversely, the absorptions of protein were obviously reduced in the myocardium of non-hypertrophic heart with CKD compared to that of hypertrophic heart. The lipid associated absorption was also decreased in non-hypertrophic heart. Our results suggest that cardiac remodeling associated with relatively early-stage CKD may be suppressed by reducing increased myocardial protein and ameliorating cardiac lipid load.

  18. Isoproterenol effects evaluated in heart slices of human and rat in comparison to rat heart in vivo

    SciTech Connect

    Herrmann, Julia E.; Heale, Jason; Bieraugel, Mike; Ramos, Meg; Fisher, Robyn L.; Vickers, Alison E.M.

    2014-01-15

    Human response to isoproterenol induced cardiac injury was evaluated by gene and protein pathway changes in human heart slices, and compared to rat heart slices and rat heart in vivo. Isoproterenol (10 and 100 μM) altered human and rat heart slice markers of oxidative stress (ATP and GSH) at 24 h. In this in vivo rat study (0.5 mg/kg), serum troponin concentrations increased with lesion severity, minimal to mild necrosis at 24 and 48 h. In the rat and the human heart, isoproterenol altered pathways for apoptosis/necrosis, stress/energy, inflammation, and remodeling/fibrosis. The rat and human heart slices were in an apoptotic phase, while the in vivo rat heart exhibited necrosis histologically and further progression of tissue remodeling. In human heart slices genes for several heat shock 70 kD members were altered, indicative of stress to mitigate apoptosis. The stress response included alterations in energy utilization, fatty acid processing, and the up-regulation of inducible nitric oxide synthase, a marker of increased oxidative stress in both species. Inflammation markers linked with remodeling included IL-1α, Il-1β, IL-6 and TNFα in both species. Tissue remodeling changes in both species included increases in the TIMP proteins, inhibitors of matrix degradation, the gene/protein of IL-4 linked with cardiac fibrosis, and the gene Ccl7 a chemokine that induces collagen synthesis, and Reg3b a growth factor for cardiac repair. This study demonstrates that the initial human heart slice response to isoproterenol cardiac injury results in apoptosis, stress/energy status, inflammation and tissue remodeling at concentrations similar to that in rat heart slices. - Highlights: • Human response to isoproterenol induced cardiac injury evaluated in heart slices. • Isoproterenol altered apoptosis, energy, inflammation and remodeling pathways. • Human model verified by comparison to rat heart slices and rat heart in vivo. • Human and rat respond to isoproterenol

  19. Manganese depresses rat heart muscle respiration.

    PubMed

    Miller, Kevin B; Caton, Joel S; Finley, John W

    2006-01-01

    It has previously been reported that moderately high dietary manganese (Mn) in combination with marginal magnesium (Mg) resulted in ultrastructural damage to heart mitochondria. Manganese may replace Mg in biological functions, including the role of enzyme cofactor. Manganese may accumulate and substitute for Mg during the condition of Mg-deficiency. The objective of the current study was to determine whether high Mn alters heart muscle respiration and Mg-enzyme activity as well as whole body Mn retention under marginal Mg. An additional objective was to determine whether high Mn results in increased oxidative stress. In experiment 1: forty-eight rats were fed a 2 x 3 factorial arrangement of Mn (10, 100, or 1000 mg/kg) and Mg (200 or 500 mg/kg). In experiment 2: thirty-two rats were fed one of four diets in a 2 x 2 factorial arrangement of Mn (10 or 250 mg/kg) and Mg (200 or 500 mg/kg). In experiment 3: thirty-two rats were fed one of four diets in a 2 x 2 factorial arrangement of Mn (10 or 650 mg/kg) and Mg (200 or 500 mg/kg). In experiment 2, high Mn and marginal Mg reduced (P<0.05) oxygen consumption of left ventricle muscle. Marginal Mg, but not Mn, reduced (P<0.05) activity of sarcoplasmic reticulum calcium-ATPase enzyme. Dietary Mg had no affect on (54)Mn kinetics, but high dietary Mn decreased (P<0.01) absorption, retention, and rate of excretion of (54)Mn. Neither cellular stress, measured by Comet assay, nor antioxidant activities were increased by high Mn. A strong interaction (P<0.001) between increasing Mn and adequate Mg on hematology was observed. These results confirm previous research in swine that high Mn alters myocardial integrity as well as function, but not as a result of altered calcium transport or oxidative stress.

  20. Prevention of anemia alleviates heart hypertrophy in copper deficient rats

    SciTech Connect

    Lure, M.D.; Fields, M.; Lewis, C.G. Univ. of Maryland, College Park Georgetown Univ., Washington, DC )

    1991-03-11

    The present investigation was designed to examine the role of anemia in the cardiomegaly and myocardial pathology of copper deficiency. Weanling rats were fed a copper deficient diet containing either starch (ST) or fructose (FRU) for five weeks. Six rats consuming the FRU diet were intraperitoneally injected once a week with 1.0 ml/100g bw of packed red blood cells (RBC) obtained from copper deficient rats fed ST. FRU rats injected with RBC did not develop anemia. Additionally, none of the injected rats exhibited heart hypertrophy or gross pathology and all survived. In contrast, non-injected FRU rats were anemic, exhibited severe signs of copper deficiency which include heart hypertrophy with gross pathology, and 44% died. Maintaining the hematocrit with RBC injections resulted in normal heart histology and prevented the mortality associated with the fructose x copper interaction. The finding suggest that the anemia associated with copper deficiency contributes to heart pathology.

  1. Post-immobilization eccentric training promotes greater hypertrophic and angiogenic responses than passive stretching in muscles of weanling rats.

    PubMed

    Benedini-Elias, Priscila Cação Oliveira; Morgan, Mariana Calvente; Cornachione, Anabelle Silva; Martinez, Edson Z; Mattiello-Sverzut, Ana Claudia

    2014-04-01

    This study investigated how different types of remobilization after hind limb immobilization, eccentric exercise and passive static stretching, influenced the adaptive responses of muscles with similar function and fascicle size, but differing in their contractile characteristics. Female Wistar weanling rats (21 days old) were divided into 8 groups: immobilized for 10 days, maintaining the ankle in maximum plantar flexion; immobilized and submitted to eccentric training for 10 or 21 days on a declining treadmill for 40min; immobilized and submitted to passive stretching for 10 or 21 days for 40min by maintaining the ankle in maximum dorsiflexion; control of immobilized; and control of 10 or 21 days. The soleus and plantaris muscles were analyzed using fiber distribution, lesser diameter, capillary/fiber ratio, and morphology. Results showed that the immobilization reduced the diameter of all fiber types, caused changes in fiber distribution and decreased the number of transverse capillaries in both muscles. The recovery period of the soleus muscle is longer than that of the plantaris after detraining. Moreover, eccentric training induced greater hypertrophic and angiogenic responses than passive stretching, especially after 21 days of rehabilitation. Both techniques demonstrated positive effects for muscle rehabilitation with the eccentric exercise being more effective.

  2. Decorin reduces hypertrophic scarring through inhibition of the TGF-β1/Smad signaling pathway in a rat osteomyelitis model

    PubMed Central

    Wang, Peng; Liu, Xiangyan; Xu, Peng; Lu, Jialiang; Wang, Runze; Mu, Weidong

    2016-01-01

    Chronic osteomyelitis is a bone infection that results in hypertrophic scarring of the soft tissue surrounding the infected bone. This scarring can create functional problems and its treatment is challenging. The aim of the present study was to evaluate the efficacy of decorin in treating scar formation in osteomyelitis and the underlying mechanism of its action. A rat osteomyelitis model was used, and animals were divided into three groups, as follows: Group A (control), group B (osteomyelitis model) and group C (decorin-treated). X-ray scans, hematoxylin and eosin (H&E) staining and Masson's trichrome staining were performed to observe changes in femur and muscle tissue. In order to assess the role of the transforming growth factor β1 (TGF-β1)/Smad signaling pathway in scar formation in osteomyelitis, alterations in muscle tissue morphology and in the activation of key members of the TGF-β1/Smad signaling pathway were investigated in groups A and B. According to the results of H&E staining, evident fibrosis in muscle tissue were observed at days 14 and 28 in group B. Simultaneously, the expression levels of key members of the TGF-β1/Smad signaling pathway were increased. Subsequent to treatment with decorin in group C, scarring was reduced, and significant downregulation of collagen I, TGF-β1, phosphorylated (p)Smad2 and pSmad3 protein expression levels was observed at days 14 and 28 compared with the osteomyelitis group. In conclusion, these results suggest that activation of TGF-β1 may serve an important role in the formation of scars in osteomyelitis and that decorin can reduce scar formation in an osteomyelitis rat model through inhibition of the TGF-β1/Smad signaling pathway. PMID:27698699

  3. Decorin reduces hypertrophic scarring through inhibition of the TGF-β1/Smad signaling pathway in a rat osteomyelitis model

    PubMed Central

    Wang, Peng; Liu, Xiangyan; Xu, Peng; Lu, Jialiang; Wang, Runze; Mu, Weidong

    2016-01-01

    Chronic osteomyelitis is a bone infection that results in hypertrophic scarring of the soft tissue surrounding the infected bone. This scarring can create functional problems and its treatment is challenging. The aim of the present study was to evaluate the efficacy of decorin in treating scar formation in osteomyelitis and the underlying mechanism of its action. A rat osteomyelitis model was used, and animals were divided into three groups, as follows: Group A (control), group B (osteomyelitis model) and group C (decorin-treated). X-ray scans, hematoxylin and eosin (H&E) staining and Masson's trichrome staining were performed to observe changes in femur and muscle tissue. In order to assess the role of the transforming growth factor β1 (TGF-β1)/Smad signaling pathway in scar formation in osteomyelitis, alterations in muscle tissue morphology and in the activation of key members of the TGF-β1/Smad signaling pathway were investigated in groups A and B. According to the results of H&E staining, evident fibrosis in muscle tissue were observed at days 14 and 28 in group B. Simultaneously, the expression levels of key members of the TGF-β1/Smad signaling pathway were increased. Subsequent to treatment with decorin in group C, scarring was reduced, and significant downregulation of collagen I, TGF-β1, phosphorylated (p)Smad2 and pSmad3 protein expression levels was observed at days 14 and 28 compared with the osteomyelitis group. In conclusion, these results suggest that activation of TGF-β1 may serve an important role in the formation of scars in osteomyelitis and that decorin can reduce scar formation in an osteomyelitis rat model through inhibition of the TGF-β1/Smad signaling pathway.

  4. Studies on proteolytic activities in heart muscle of diabetic rats.

    PubMed

    Dahlmann, B; Metzinger, H; Reinauer, H

    1982-06-01

    Induction of diabetes mellitus in rats following injection of streptozotocin caused reduction in rate of gain of heart weight, of protein and of DNA content in the first two weeks. During the same time interval the overall activity of acid proteinases (cathepsin D), of alkaline proteinases and of proteinase inhibitors was measured in heart muscle homogenates. No statistically significant differences were detected compared with the proteinase activities in control rats. In contrast, total aminopeptidase activity in diabetic hearts was consistently lower than in control hearts. Earlier studies on rat skeletal muscles have shown that induction of diabetes mellitus is followed by a substantial increase of alkaline proteinase as well as aminopeptidase activities. These findings are contrasted by present data obtained with heart muscle of diabetic rats, suggesting that this tissue responds differently to insulin deficiency.

  5. Myocardial Galectin-3 Expression Is Associated with Remodeling of the Pressure-Overloaded Heart and May Delay the Hypertrophic Response without Affecting Survival, Dysfunction, and Cardiac Fibrosis.

    PubMed

    Frunza, Olga; Russo, Ilaria; Saxena, Amit; Shinde, Arti V; Humeres, Claudio; Hanif, Waqas; Rai, Vikrant; Su, Ya; Frangogiannis, Nikolaos G

    2016-05-01

    The β-galactoside-binding animal lectin galectin-3 is predominantly expressed by activated macrophages and is a promising biomarker for patients with heart failure. Galectin-3 regulates inflammatory and fibrotic responses; however, its role in cardiac remodeling remains unclear. We hypothesized that galectin-3 may be up-regulated in the pressure-overloaded myocardium and regulate hypertrophy and fibrosis. In normal mouse myocardium, galectin-3 was constitutively expressed in macrophages and was localized in atrial but not ventricular cardiomyocytes. In a mouse model of transverse aortic constriction, galectin-3 expression was markedly up-regulated in the pressure-overloaded myocardium. Early up-regulation of galectin-3 was localized in subpopulations of macrophages and myofibroblasts; however, after 7 to 28 days of transverse aortic constriction, a subset of cardiomyocytes in fibrotic areas contained large amounts of galectin-3. In vitro, cytokine stimulation suppressed galectin-3 synthesis by macrophages and cardiac fibroblasts. Correlation studies revealed that cardiomyocyte- but not macrophage-specific galectin-3 localization was associated with adverse remodeling and dysfunction. Galectin-3 knockout mice exhibited accelerated cardiac hypertrophy after 7 days of pressure overload, whereas female galectin-3 knockouts had delayed dilation after 28 days of transverse aortic constriction. However, galectin-3 loss did not affect survival, systolic and diastolic dysfunction, cardiac fibrosis, and cardiomyocyte hypertrophy in the pressure-overloaded heart. Despite its potential role as a prognostic biomarker, galectin-3 is not a critical modulator of cardiac fibrosis but may delay the hypertrophic response. PMID:26948424

  6. Isoproterenol effects evaluated in heart slices of human and rat in comparison to rat heart in vivo.

    PubMed

    Herrmann, Julia E; Heale, Jason; Bieraugel, Mike; Ramos, Meg; Fisher, Robyn L; Vickers, Alison E M

    2014-01-15

    Human response to isoproterenol induced cardiac injury was evaluated by gene and protein pathway changes in human heart slices, and compared to rat heart slices and rat heart in vivo. Isoproterenol (10 and 100μM) altered human and rat heart slice markers of oxidative stress (ATP and GSH) at 24h. In this in vivo rat study (0.5mg/kg), serum troponin concentrations increased with lesion severity, minimal to mild necrosis at 24 and 48h. In the rat and the human heart, isoproterenol altered pathways for apoptosis/necrosis, stress/energy, inflammation, and remodeling/fibrosis. The rat and human heart slices were in an apoptotic phase, while the in vivo rat heart exhibited necrosis histologically and further progression of tissue remodeling. In human heart slices genes for several heat shock 70kD members were altered, indicative of stress to mitigate apoptosis. The stress response included alterations in energy utilization, fatty acid processing, and the up-regulation of inducible nitric oxide synthase, a marker of increased oxidative stress in both species. Inflammation markers linked with remodeling included IL-1α, Il-1β, IL-6 and TNFα in both species. Tissue remodeling changes in both species included increases in the TIMP proteins, inhibitors of matrix degradation, the gene/protein of IL-4 linked with cardiac fibrosis, and the gene Ccl7 a chemokine that induces collagen synthesis, and Reg3b a growth factor for cardiac repair. This study demonstrates that the initial human heart slice response to isoproterenol cardiac injury results in apoptosis, stress/energy status, inflammation and tissue remodeling at concentrations similar to that in rat heart slices.

  7. The Scaffold Protein Muscle A-Kinase Anchoring Protein β Orchestrates Cardiac Myocyte Hypertrophic Signaling Required for the Development of Heart Failure

    PubMed Central

    Kritzer, Michael D.; Li, Jinliang; Passariello, Catherine L.; Gayanilo, Marjorie; Thakur, Hrishikesh; Dayan, Joseph; Dodge-Kafka, Kimberly; Kapiloff, Michael S.

    2014-01-01

    Background Cardiac myocyte hypertrophy is regulated by an extensive intracellular signal transduction network. In vitro evidence suggests that the scaffold protein muscle A-kinase anchoring protein β (mAKAPβ) serves as a nodal organizer of hypertrophic signaling. However, the relevance of mAKAPβ signalosomes to pathological remodeling and heart failure in vivo remains unknown. Methods and Results Using conditional, cardiac myocyte–specific gene deletion, we now demonstrate that mAKAPβ expression in mice is important for the cardiac hypertrophy induced by pressure overload and catecholamine toxicity. mAKAPβ targeting prevented the development of heart failure associated with long-term transverse aortic constriction, conferring a survival benefit. In contrast to 29% of control mice (n=24), only 6% of mAKAPβ knockout mice (n=31) died in the 16 weeks of pressure overload (P=0.02). Accordingly, mAKAPβ knockout inhibited myocardial apoptosis and the development of interstitial fibrosis, left atrial hypertrophy, and pulmonary edema. This improvement in cardiac status correlated with the attenuated activation of signaling pathways coordinated by the mAKAPβ scaffold, including the decreased phosphorylation of protein kinase D1 and histone deacetylase 4 that we reveal to participate in a new mAKAP signaling module. Furthermore, mAKAPβ knockout inhibited pathological gene expression directed by myocyte-enhancer factor-2 and nuclear factor of activated T-cell transcription factors that associate with the scaffold. Conclusions mAKAPβ orchestrates signaling that regulates pathological cardiac remodeling in mice. Targeting of the underlying physical architecture of signaling networks, including mAKAPβ signalosome formation, may constitute an effective therapeutic strategy for the prevention and treatment of pathological remodeling and heart failure. PMID:24812305

  8. Hypertrophic scar.

    PubMed

    Gabriel, Vincent

    2011-05-01

    Hypertrophic scars are common complications of burn injury and other soft tissue injuries. Excessive extracellular matrix combined with inadequate remodeling of scar tissue results in an aesthetically and functionally unsatisfactory, painful, pruritic scar that can impair function. Treatment options are available to rehabilitation practitioners, but none are entirely satisfactory. An interdisciplinary clinical program is necessary for best outcomes. Challenges to be met by the rehabilitation community include research into the quantification of burn scar measurement, the effects of mechanical forces on wound healing and scar management, and the best combination of surgical, pharmacologic, and therapy interventions to maximize outcome from reconstructive procedures. PMID:21624722

  9. Impact of Cryoballoon Ablation in Hypertrophic Cardiomyopathy-related Heart Failure due to Paroxysmal Atrial Fibrillation. A Comparative Case Series

    PubMed Central

    Maagh, Petra; Plehn, Gunnar; Christoph, Arnd; Oernek, Ahmet; Meissner, Axel

    2016-01-01

    Background: Atrial fibrillation (AF) represents a turning point in hypertrophic cardiomyopathy (HCM). Pulmonary Vein Isolation (PVI) with Radiofrequency Catheter Ablation (RFCA) is accepted to be successful in restoring sinus rhythm (SR) in HCM patients. The efficacy of cryoballoon (CB) therapy in HCM patients has not been studied so far. Methods: 166 patients with AF underwent PVI with CB technology in our single center between 1/2012 and 12/2015. To evaluate the efficacy of the CB therapy in HCM patients, we compared their clinical outcome with those in “Non-HCM” AF patients in a 3 and 6 months follow-up. Results: Out of 166 AF patients (65.7% paroxysmal AF, PAF), 4 patients had HCM and PAF (young males < 50 years). During the blanking period, 26 patients (15.8%) suffered from AF recurrence (11.0% PAF), including all HCM patients. The 6 months follow up of “Non-HCM” AF patients showed acceptable results (80% stable SR), whereas the HCM patients remained AF. In Conclusion: Even if the CB provides advantages, the single device cannot be recommended in HCM patients because of early AF recurrences. Anyway, because of the specific hemodynamic changes in HCM patients with AF, ablation should be sought in an early state of its occurrence, then, however, preferably with RFCA.

  10. Impact of Cryoballoon Ablation in Hypertrophic Cardiomyopathy-related Heart Failure due to Paroxysmal Atrial Fibrillation. A Comparative Case Series

    PubMed Central

    Maagh, Petra; Plehn, Gunnar; Christoph, Arnd; Oernek, Ahmet; Meissner, Axel

    2016-01-01

    Background: Atrial fibrillation (AF) represents a turning point in hypertrophic cardiomyopathy (HCM). Pulmonary Vein Isolation (PVI) with Radiofrequency Catheter Ablation (RFCA) is accepted to be successful in restoring sinus rhythm (SR) in HCM patients. The efficacy of cryoballoon (CB) therapy in HCM patients has not been studied so far. Methods: 166 patients with AF underwent PVI with CB technology in our single center between 1/2012 and 12/2015. To evaluate the efficacy of the CB therapy in HCM patients, we compared their clinical outcome with those in “Non-HCM” AF patients in a 3 and 6 months follow-up. Results: Out of 166 AF patients (65.7% paroxysmal AF, PAF), 4 patients had HCM and PAF (young males < 50 years). During the blanking period, 26 patients (15.8%) suffered from AF recurrence (11.0% PAF), including all HCM patients. The 6 months follow up of “Non-HCM” AF patients showed acceptable results (80% stable SR), whereas the HCM patients remained AF. In Conclusion: Even if the CB provides advantages, the single device cannot be recommended in HCM patients because of early AF recurrences. Anyway, because of the specific hemodynamic changes in HCM patients with AF, ablation should be sought in an early state of its occurrence, then, however, preferably with RFCA. PMID:27647995

  11. Complete inhibition of creatine kinase in isolated perfused rat hearts

    SciTech Connect

    Fossel, E.T.; Hoefeler, H.

    1987-01-01

    Transient exposure of an isolated isovolumic perfused rat heart to low concentrations (0.5 mM) of perfusate-born iodoacetamide resulted in complete inhibition of creatine kinase and partial inhibition of glyceraldehyde-3-phosphate dehydrogenase in the heart. At low levels of developed pressure, hearts maintained mechanical function, ATP, and creatine phosphate levels at control values. However, iodoacetamide-inhibited hearts were unable to maintain control values of end diastolic pressure or peak systolic pressure as work load increased. Global ischemia resulted in loss of all ATP without loss of creatine phosphate, indicating lack of active creatine kinase. These results indicate that isovolumic perfused rat hearts are able to maintain normal function and normal levels of high-energy phosphates without active creatine kinase at low levels of developed pressure. /sup 31/P-NMR of the heart was carried out.

  12. Constant magnetic field influence on a heart beat in rats

    SciTech Connect

    Lazetic, B.; Pekaric-Nadj, N.; Kasas-Lazetic, K.

    1991-03-11

    The authors used uretan narcose to implant constant magnets of 50 mT under the skin of rats in head region. The ECG was registrated in the next 6 hours. From it they found much slower heart beat which culminated in the first 105 minutes. After 6 weeks of continual exposure the heart beat of the exposed rats was still slower then in the controls. It is concluded that a chronical exposition to the constant magnetic field affected rats organisms and no regulatory mechanism could prevent it.

  13. Nicotine and carbon monoxide: effects on the isolated rat heart.

    PubMed

    McGrath, J J

    1986-01-01

    We studied the combined effects of carbon monoxide (CO) and nicotine on the performance of the isolated rat heart. Hearts were removed from laboratory rats and perfused through the aorta with 95% O2-5% CO2 (oxygenated) Krebs-Henseleit solution (KHs). After 30 min, the perfusate was switched rapidly to one of three solutions: KHs containing 10% CO-85% O2-5% CO2 (CO), 10 micrograms/ml nicotine (Nic), or CO combined with nicotine (CO + Nic). KHs containing CO increased coronary flow by 41% without affecting heart rate or pulse pressure. Coronary flow returned to control values during recovery in oxygenated KHs. KHs containing Nic decreased heart rate by 20% and coronary flow by 28%. Pulse pressure was unaffected. Both heart rate and coronary flow returned towards control values during recovery in oxygenated KHs. KHs containing CO + Nic decreased heart rate 16% but stimulated coronary flow 13%. Heart rate returned towards control values during recovery; however, coronary flow, which declined to control values after 8 min, continued to decrease during recovery. These results indicate that the separate effects of CO and Nic on coronary flow in the isolated rat heart are opposing and reversible, but that the decrease they produce in combination is irreversible.

  14. Hypertrophic cardiomyopathy in a college athlete.

    PubMed

    Simons, S M; Moriarity, J

    1992-12-01

    The greatest catastrophy in sports is an athlete's unexpected sudden death. Identifying those athletes at risk remains a great challenge to physicians performing preseason examinations. Hypertrophic cardiomyopathy is the most common cause of nontraumatic sudden death in athletes. Most cases of this diseased heart are diagnosed easily by echocardiography. The case presented exemplifies the attention to detail required to differentiate the borderline diseased heart from the conditioned athletic heart. Once a diagnosis of hypertrophic cardiomyopathy is made, further participation in intense physical exercise is discouraged. This recommendation is necessary despite the unknown relative sudden death risk for the minimal criteria cases.

  15. The number of cardiac myocytes in the hypertrophic and hypotrophic left ventricle of the obese and calorie-restricted mouse heart

    PubMed Central

    Schipke, Julia; Banmann, Ewgenija; Nikam, Sandeep; Voswinckel, Robert; Kohlstedt, Karin; Loot, Annemarieke E; Fleming, Ingrid; Mühlfeld, Christian

    2014-01-01

    Changes in body mass due to varying amounts of calorie intake occur frequently with obesity and anorexia/cachexia being at opposite sides of the scale. Here, we tested whether a high-fat diet or calorie restriction (CR) decreases the number of cardiac myocytes and affects their volume. Ten 6–8-week-old mice were randomly assigned to a normal (control group, n = 5) or high-fat diet (obesity group, n = 5) for 28 weeks. Ten 8-week-old mice were randomly assigned to a normal (control group, n = 5) or CR diet (CR group, n = 5) for 7 days. The left ventricles of the hearts were prepared for light and electron microscopy, and analysed by design-based stereology. In CR, neither the number of cardiac myocytes, the relationship between one- and multinucleate myocytes nor their mean volume were significantly different between the groups. In contrast, in the obese mice we observed a significant increase in cell size combined with a lower number of cardiomyocytes (P < 0.05 in the one-sided U-test) and an increase in the mean number of nuclei per myocyte. The mean volume of myofibrils and mitochondria per cardiac myocyte reflected the hypertrophic and hypotrophic remodelling in obesity and CR, respectively, but were only significant in the obese mice, indicating a more profound effect of the obesity protocol than in the CR experiments. Taken together, our data indicate that long-lasting obesity is associated with a loss of cardiomyocytes of the left ventricle, but that short-term CR does not alter the number of cardiomyocytes. PMID:25322944

  16. Hypertrophic cardiomyopathy

    MedlinePlus

    ... permanent pacemaker to control the heartbeat An implanted defibrillator that recognizes life-threatening heart rhythms and sends an electrical pulse to stop them. Sometimes a defibrillator is placed, even if the patient has not ...

  17. Ventricular repolarization in a rat model of global heart failure.

    PubMed

    Krandycheva, Valeria; Kharin, Sergey; Strelkova, Marina; Shumikhin, Konstantin; Sobolev, Aleksey; Shmakov, Dmitry

    2013-07-01

    Isoproterenol in high doses induces infarction-like myocardial damage and structural and functional remodelling of the ventricular myocardium. The purpose of the present study was to investigate ventricular repolarization in a rat model of isoproterenol-induced heart failure. Isoproterenol was administered twice to female Wistar rats (170 mg/kg, s.c., 24 h apart). Four weeks after the injections, cardiac output was measured and unipolar epicardial ventricular electrograms were recorded in situ. Activation-recovery intervals were calculated to assess repolarization. Histological examination of the heart ventricles was also performed. Heart failure in rats treated with isoproterenol was indicated by myocardial histopathological damage and reduced cardiac output. In rats with heart failure, the regional differences in activation-recovery interval prolongation over the ventricular epicardium resulted in increasing heterogeneity in the activation-recovery interval distribution and increasing repolarization heterogeneity of the ventricular subepicardium. Myocardial damage and haemodynamic changes in heart failure induced by isoproterenol were accompanied by significant changes in ventricular repolarization, which were not associated with myocardial hypertrophy.

  18. Physiologic consequences of local heart irradiation in rats

    SciTech Connect

    Geist, B.J.; Lauk, S.; Bornhausen, M.; Trott, K.R. )

    1990-05-01

    Noninvasive methods have been used to study the long-term cardiovascular and pulmonary functional changes at rest and after exercise in adult rats following local heart irradiation with single x-ray doses of 15, 17.5 or 20 Gy, and in non-irradiated control animals. Rats that had undergone a chronic exercise program were compared with untrained cohorts. The earliest dysfunction detected was an increased respiratory rate (f) at 10 weeks after irradiation in the highest dose group. In contrast, both telemetric heart-rate (HR) and rhythm and indirect systolic blood pressure measurements performed at rest only revealed changes starting at 43 weeks after irradiation with 20 Gy, up to which point the rats showed no clinical signs of heart failure. However, the number of minutes required for the recovery of the HR to pre-exercise levels following the implementation of a standardized exercise challenge was elevated in untrained rats compared with their trained cohorts at 18 weeks after irradiation with 20 Gy. Increases in recovery times were required in the two lowest dose groups, starting at 26 weeks after irradiation. It was concluded that the reserve capacity of the cardiopulmonary system masks functional decrements at rest for many months following local heart irradiation, necessitating the use of techniques which reveal reductions in reserve capacities. Further, the influence of local irradiation to the heart and lungs deserves closer scrutiny due to mutual interactions.

  19. Mesenchymal Stem Cells Improve Heart Rate Variability and Baroreflex Sensitivity in Rats with Chronic Heart Failure

    PubMed Central

    de Morais, Sharon Del Bem Velloso; da Silva, Luiz Eduardo Virgilio; Lataro, Renata Maria; Silva, Carlos Alberto Aguiar; de Oliveira, Luciano Fonseca Lemos; de Carvalho, Eduardo Elias Vieira; Simões, Marcus Vinicius; da Silva Meirelles, Lindolfo; Fazan, Rubens

    2015-01-01

    Heart failure induced by myocardial infarct (MI) attenuates the heart rate variability (HRV) and baroreflex sensitivity, which are important risk factors for life-threatening cardiovascular events. Therapies with mesenchymal stem cells (MSCs) have shown promising results after MI. However, the effects of MSCs on hemodynamic (heart rate and arterial pressure) variability and baroreflex sensitivity in chronic heart failure (CHF) following MI have not been evaluated thus far. Male Wistar rats received MSCs or saline solution intravenously 1 week after ligation of the left coronary artery. Control (noninfarcted) rats were also evaluated. MI size was assessed using single-photon emission computed tomography (SPECT). The left ventricular ejection fraction (LVEF) was evaluated using radionuclide ventriculography. Four weeks after MSC injection, the animals were anesthetized and instrumented for chronic ECG recording and catheters were implanted in the femoral artery to record arterial pressure. Arterial pressure and HRVs were determined in time and frequency domain (spectral analysis) while HRV was also examined using nonlinear methods: DFA (detrended fluctuation analysis) and sample entropy. The initial MI size was the same among all infarcted rats but was reduced by MSCs. CHF rats exhibited increased myocardial interstitial collagen and sample entropy combined with the attenuation of the following cardiocirculatory parameters: DFA indices, LVEF, baroreflex sensitivity, and HRV. Nevertheless, MSCs hampered all these alterations, except the LVEF reduction. Therefore, 4 weeks after MSC therapy was applied to CHF rats, MI size and myocardial interstitial fibrosis decreased, while baroreflex sensitivity and HRV improved. PMID:26059001

  20. Responses of the working rat heart to carbon monoxide.

    PubMed

    Lin, H; McGrath, J J

    1989-07-01

    The effects of carbon monoxide (CO) were studied in the isolated working rat heart. Hearts removed from male laboratory rats were perfused via the left atrium with Krebs-Henseleit solution (KH) oxygenated with 95% O2-5% CO2 (O2). Heart rate and arterial pressures were measured by a transducer inserted in the aortic outflow line and connected to a data logger. Aortic flow was determined by collecting the effluent from the aortic bubble trap in a graduated cylinder. Coronary flow through the pulmonary cannula was collected and measured in a graduated cylinder. After 30 min, the hearts were challenged with solutions containing either CO (5% CO-90% O2-5% CO2) or N2 (5% N2-90% O2-5% CO2) for 10 min (Challenge I). After recovery in O2, the hearts were challenged with the alternate test solution (Challenge II). CO increased coronary flow (CF) and coronary flow as a percent of cardiac output (CF%) 13 and 16% respectively. N2 had no significant effect on CF or CF%. CO and N2 had no significant effect on heart rate, cardiac output, oxygen consumption or on aortic flow or pressure. These results indicate that vasodilation is the major response of the working heart to CO, and this response is not mediated by simple hypoxia. PMID:2813558

  1. The effect of Ligustrum delavayanum on isolated perfused rat heart

    PubMed Central

    Stankovičová, Tatiana; Frýdl, Miroslav; Kubicová, Mária; Baróniková, Slávka; Nagy, Milan; Grančai, Daniel; Švec, Pavel

    2001-01-01

    BACKGROUND: Extract of ligustrum leaves (Ligustrum delavayanum Hariot [Oleaceae]) is well known in traditional Chinese medicine. One of the active components, oleuropein, displays vasodilating and hypotensive effects. OBJECTIVE: To analyze the effect of 0.008% lyophilized extract of ligustrum dissolved in 0.5% ethanol on heart function. ANIMALS AND METHODS: Experiments were done on isolated rat hearts perfused by the Langendorff method in control conditions and during ischemic-reperfusion injury. RESULTS: Application of ligustrum induced positive inotropic and vasodilating effects in spontaneously beating hearts. Pretreatment of the hearts with ligustrum reduced left ventricular diastolic pressure measured during reperfusion and improved left ventricular contraction compared with hearts without any pretreatment. Ligustrum significantly suppressed the incidence and duration of cardiac reperfusion arrhythmias, expressed as G-score, from 7.40±0.58 in nontreated rats to 1.97±0.50. DISCUSSION: Application of ligustrum or ethanol alone induced changes in coordination between atria and ventricles during ischemia-reperfusion injury. The ‘g-score’, a new parameter summing the incidence and duration of atrioventricular blocks, atrioventricular dissociation and cardiac arrest, is introduced. The g-scores with ligustrum pretreatment were higher during ischemia than during reperfusion. Ethanol significantly depressed myocardial contractility and coronary flow, and nonsignificantly decreased heart rate of isolated rat hearts. Electrical changes observed during coronary reperfusion in the presence of ethanol were accompanied by deterioration of contractile function. CONCLUSIONS: Ligustrum had a significant protective effect on rat myocardium against ischemic-reperfusion injury. Ethanol partially attenuated the protective effect of ligustrum. PMID:20428448

  2. Hypertrophic cardiomyopathy in a neonate associated with nemaline myopathy.

    PubMed

    Mir, Arshid; Lemler, Matthew; Ramaciotti, Claudio; Blalock, Shannon; Ikemba, Catherine

    2012-01-01

    Nemaline myopathy is a congenital nonprogressive skeletal muscle disorder with a characteristic rod body formation in the skeletal muscle fibers. Cardiac involvement in nemaline myopathy is rare, although both dilated and hypertrophic cardiomyopathy have been reported. We describe an infant diagnosed with hypertrophic cardiomyopathy and hypotonia on the first day of life. Muscle biopsy confirmed nemaline myopathy at 3 weeks of age. The diagnosis of nemaline myopathy precluded consideration of heart transplantation, thus shifting the focus to comfort care. This is the earliest presentation of hypertrophic cardiomyopathy reported in the literature in the setting of nemaline myopathy. The approach to determining an etiology for hypertrophic cardiomyopathy in an infant is reviewed. PMID:22067214

  3. Panax ginseng reduces adriamycin-induced heart failure in rats.

    PubMed

    You, Jyh-Sheng; Huang, Hui-Feng; Chang, Ying-Ling

    2005-12-01

    The purpose of this study was to investigate the protective effects of Panax ginseng on adriamycin-induced heart failure. Wistar rats were divided into four groups: control, adriamycin, ginseng and adriamycin with ginseng. Adriamycin (cumulative dose, 15 mg/kg) was administered to rats in six equal intraperitoneal injections over a period of 2 weeks. Ginseng was administered via an oral feeding tube once a day for 30 days (cumulative dose, 150 g/kg). At the end of the 5 week post-treatment period, the hearts of the rats were used to study the synthesis rates of DNA, RNA and protein, myocardial antioxidants and lipid peroxidation. At the end of 3 weeks treatment, heart failure was characterized by ascites, congested liver and depressed cardiac function. Nucleic acid as well as protein synthesis was inhibited, lipid peroxidation was increased and myocardial glutathione peroxidase activity was decreased indicating adriamycin-induced heart failure. In contrast, the administration of ginseng, before and concurrent with adriamycin, significantly attenuated the myocardial effects, lowered the mortality as well as the amount of ascites, increased in myocardial glutathione peroxidase, macromolecular biosynthesis and superoxide dismutase activities, with a concomitant decrease in lipid peroxidation. These findings indicated that ginseng may be partially protective against adriamycin-induced heart failure.

  4. Manganese depresses rat heart muscle respiration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It has previously been reported that moderately high dietary manganese (Mn) in combination with marginal magnesium (Mg) resulted in ultrastructural damage to heart mitochondria. Manganese may replace Mg in biological functions, including the role of enzyme cofactor. Manganese may accumulate and subs...

  5. Heart Rate Changes in Electroacupuncture Treated Polycystic Ovary in Rats

    PubMed Central

    Ramadoss, Mukilan; Subbiah, Angelie Jessica; Natrajan, Chidambaranathan

    2016-01-01

    Introduction Polycystic Ovary Syndrome (PCOS) is a common metabolic disorder, it affects both humans and animals. It may induce coronary heart disease, obesity and hyperandrogenism. Previous studies show that Low frequency Electroacupuncture (EA) have an effect on PCOS, however the exact pathway is unclear. Aim To find the effect of EA on autonomic activity of the heart in Estradiol Valerate (EV) induced PCOS rats. Materials and Methods Heart rate variability (HRV) was assessed in 3 groups: 1) Control; 2) PCOS rats; and 3) PCOS rats after EA treatment (n=8 in each group). From the time domain analysis and frequency domain analysis (linear measures) HRV analysis was done. EA stimulation was given at low frequency of 2Hz for 15 min on alternate days for 4-5 weeks. Collected data were statistically analysed using One-Way Analysis of Variance with the application of multiple comparisons of Tukey test. Results EA treatment group shows significant reduction in Heart Rate (HR) and low frequency, high frequency ratio (LF/HF); and increase in RR interval, Total Power (TP) when compared to PCOS group. Conclusion The study concludes that EA treatment has a significant effect on reducing sympathetic tone and decreasing HR in PCOS. PMID:27134868

  6. Skeletal muscle electrical stimulation improves baroreflex sensitivity and heart rate variability in heart failure rats.

    PubMed

    Lazzarotto Rucatti, Ananda; Jaenisch, Rodrigo Boemo; Rossato, Douglas Dalcin; Bonetto, Jéssica Hellen Poletto; Ferreira, Janaína; Xavier, Leder Leal; Sonza, Anelise; Dal Lago, Pedro

    2015-12-01

    The goal of the current study was to evaluate the effects of electrical stimulation (ES) on the arterial baroreflex sensitivity (BRS) and cardiovascular autonomic control in rats with chronic heart failure (CHF). Male Wistar rats were designated to one of four groups: placebo sham (P-Sham, n=9), ES sham (ES-Sham, n=9), placebo CHF (P-CHF, n=9) or ES CHF (ES-CHF, n=9). The ES was adjusted at a low frequency (30 Hz), duration of 250 μs, with hold and rest time of 8s (4 weeks, 30 min/day, 5 times/week). It was applied on the gastrocnemius muscle with intensity to produce a visible muscle contraction. The rats assigned to the placebo groups performed the same procedures with the equipment turned off. The two-way ANOVA and the post hoc Student-Newman-Keuls tests (P<0.05) were used to data comparison. The BRS was higher in ES-Sham group compared to the P-Sham group and the ES-CHF group compared to the P-CHF group. ES was able to decrease heart rate sympatho-vagal modulation and peripheral sympathetic modulation in ES-CHF compared to P-CHF group. Interestingly, heart rate sympatho-vagal modulation was similar between ES-CHF and P-Sham groups. Thus, ES enhances heart rate parasympathetic modulation on heart failure (ES-CHF) compared to placebo (P-CHF), with consequent decrease of sympatho-vagal balance in the ES-CHF group compared to the P-CHF. The results show that a 4 week ES protocol in CHF rats enhances arterial BRS and cardiovascular autonomic control.

  7. Mitochondrial and Metabolic Gene Expression in the Aged Rat Heart

    PubMed Central

    Barton, Gregory P.; Sepe, Joseph J.; McKiernan, Susan H.; Aiken, Judd M.; Diffee, Gary M.

    2016-01-01

    Aging is associated with a decline in cardiac function. Exercise intervention has been suggested as a way to improve this decrement. Age-related decline in cardiac function is associated with decreases in fatty acid oxidation, mitochondrial function, and AMP-activated protein kinase (AMPK) activity. The molecular mechanisms involved with age-related changes in mitochondrial function and substrate metabolism are poorly understood. We determined gene expression differences in hearts of Young (6 mo), Old (33 mo), and old exercise trained (Old + EXE) (34 mo) FBN rats, using Qiagen PCR arrays for Glucose, Fatty acid, and Mitochondrial metabolism. Old rats demonstrated decreased (p < 0.05) expression for key genes in fatty acid oxidation, mitochondrial function, and AMPK signaling. There were no differences in the expression of genes involved in glucose metabolism with age. These gene expression changes occurred prior to altered protein translation as we found no differences in the protein content of peroxisome proliferator activated receptor gamma, coactivators 1 alpha (PGC-1α), peroxisome proliferator activated receptor alpha (PPARα), and AMPKα2 between young and old hearts. Four months of exercise training did not attenuate the decline in the gene expression in aged hearts. Despite this lack of change in gene expression, exercise-trained rats demonstrated increased exercise capacity compared to their sedentary counterparts. Taken together, our results show that differential expression of genes associated with fatty acid metabolism, AMPK signaling and mitochondrial function decrease in the aging heart which may play a role in age-related declines in fatty acid oxidation, AMPK activity, and mitochondrial function in the heart. PMID:27601998

  8. Mitochondrial and Metabolic Gene Expression in the Aged Rat Heart

    PubMed Central

    Barton, Gregory P.; Sepe, Joseph J.; McKiernan, Susan H.; Aiken, Judd M.; Diffee, Gary M.

    2016-01-01

    Aging is associated with a decline in cardiac function. Exercise intervention has been suggested as a way to improve this decrement. Age-related decline in cardiac function is associated with decreases in fatty acid oxidation, mitochondrial function, and AMP-activated protein kinase (AMPK) activity. The molecular mechanisms involved with age-related changes in mitochondrial function and substrate metabolism are poorly understood. We determined gene expression differences in hearts of Young (6 mo), Old (33 mo), and old exercise trained (Old + EXE) (34 mo) FBN rats, using Qiagen PCR arrays for Glucose, Fatty acid, and Mitochondrial metabolism. Old rats demonstrated decreased (p < 0.05) expression for key genes in fatty acid oxidation, mitochondrial function, and AMPK signaling. There were no differences in the expression of genes involved in glucose metabolism with age. These gene expression changes occurred prior to altered protein translation as we found no differences in the protein content of peroxisome proliferator activated receptor gamma, coactivators 1 alpha (PGC-1α), peroxisome proliferator activated receptor alpha (PPARα), and AMPKα2 between young and old hearts. Four months of exercise training did not attenuate the decline in the gene expression in aged hearts. Despite this lack of change in gene expression, exercise-trained rats demonstrated increased exercise capacity compared to their sedentary counterparts. Taken together, our results show that differential expression of genes associated with fatty acid metabolism, AMPK signaling and mitochondrial function decrease in the aging heart which may play a role in age-related declines in fatty acid oxidation, AMPK activity, and mitochondrial function in the heart.

  9. Mitochondrial and Metabolic Gene Expression in the Aged Rat Heart.

    PubMed

    Barton, Gregory P; Sepe, Joseph J; McKiernan, Susan H; Aiken, Judd M; Diffee, Gary M

    2016-01-01

    Aging is associated with a decline in cardiac function. Exercise intervention has been suggested as a way to improve this decrement. Age-related decline in cardiac function is associated with decreases in fatty acid oxidation, mitochondrial function, and AMP-activated protein kinase (AMPK) activity. The molecular mechanisms involved with age-related changes in mitochondrial function and substrate metabolism are poorly understood. We determined gene expression differences in hearts of Young (6 mo), Old (33 mo), and old exercise trained (Old + EXE) (34 mo) FBN rats, using Qiagen PCR arrays for Glucose, Fatty acid, and Mitochondrial metabolism. Old rats demonstrated decreased (p < 0.05) expression for key genes in fatty acid oxidation, mitochondrial function, and AMPK signaling. There were no differences in the expression of genes involved in glucose metabolism with age. These gene expression changes occurred prior to altered protein translation as we found no differences in the protein content of peroxisome proliferator activated receptor gamma, coactivators 1 alpha (PGC-1α), peroxisome proliferator activated receptor alpha (PPARα), and AMPKα2 between young and old hearts. Four months of exercise training did not attenuate the decline in the gene expression in aged hearts. Despite this lack of change in gene expression, exercise-trained rats demonstrated increased exercise capacity compared to their sedentary counterparts. Taken together, our results show that differential expression of genes associated with fatty acid metabolism, AMPK signaling and mitochondrial function decrease in the aging heart which may play a role in age-related declines in fatty acid oxidation, AMPK activity, and mitochondrial function in the heart. PMID:27601998

  10. Sodium alterations in isolated rat heart during cardioplegic arrest

    SciTech Connect

    Schepkin, V.D.; Choy, I.O.; Budinger, T.F.

    1996-12-01

    Triple-quantum-filtered (TQF) Na nuclear magnetic resonance (NMR) without chemical shift reagent is used to investigate Na derangement in isolated crystalloid perfused rat hearts during St. Thomas cardioplegic (CP) arrest. The extracellular Na contribution to the NMR TQF signal of a rat heart is found to be 73 {+-} 5%, as determined by wash-out experiments at different moments of ischemia and reperfusion. With the use of this contribution factor, the estimated intracellular Na ([Na{sup +}]{sub i}) TQF signal is 222 {+-} 13% of preischemic level after 40 min of CP arrest and 30 min of reperfusion, and the heart rate pressure product recovery is 71 {+-} 8%. These parameters are significantly better than for stop-flow ischemia: 340 {+-} 20% and 6 {+-} 3%, respectively. At 37{degrees}C, the initial delay of 15 min in [Na{sup +}]{sub i} growth occurs during CP arrest along with reduced growth later ({approximately}4.0%/min) in comparison with stop-flow ischemia ({approximately}6.7%/min). The hypothermia (21{degrees}C, 40 min) for the stop-flow ischemia and CP dramatically decreases the [Na{sup +}]{sub i} gain with the highest heart recovery for CP ({approximately}100%). These studies confirm the enhanced sensitivity of TQF NMR to [Na{sup +}]{sub i} and demonstrate the potential of NMR without chemical shift reagent to monitor [Na{sup +}]{sub i} derangements. 48 refs., 7 figs., 1 tab.

  11. Protective effects of remote ischemic preconditioning in isolated rat hearts

    PubMed Central

    Teng, Xiao; Yuan, Xin; Tang, Yue; Shi, Jingqian

    2015-01-01

    To use Langendorff model to investigate whether remote ischemic preconditioning (RIPC) attenuates post-ischemic mechanical dysfunction on isolated rat heart and to explore possible mechanisms. SD rats were randomly divided into RIPC group, RIPC + norepinephrine (NE) depletion group, RIPC + pertussis toxin (PTX) pretreatment group, ischemia/reperfusion group without treatment (ischemia group) and time control (TC) group. RIPC was achieved through interrupted occlusion of anterior mesenteric artery. Then, Langendorff model was established using routine methods. Heart function was tested; immunohistochemistry and ELISA methods were used to detect various indices related to myocardial injury. Compared with ischemia group in which the hemodynamic parameters deteriorated significantly, heart function recovered to a certain degree among the RIPC, RIPC + NE depletion, and RIPC + PTX groups (P<0.05). More apoptotic nuclei were observed in ischemia group than in the other three groups (P<0.05); more apoptotic nuclei were detected in NE depletion and PTX groups than in RIPC group (P<0.05). While, there was no significant difference between NE depletion and PTX groups. In conclusion, RIPC protection on I/R myocardium extends to the period after hearts are isolated. NE and PTX-sensitive inhibitory G protein might have a role in the protection process. PMID:26550168

  12. Primary hypertrophic osteoarthropathy (pachydermoperiostosis): a case report.

    PubMed

    Karkucak, Murat; Erturk, Engin; Capkin, Erhan; Akyazi, Hikmet; Ozden, Gonca; Tosun, Mehmet

    2007-02-01

    Hypertrophic osteoarthropathy is characterized by digital clubbing and periosteal reaction of long bones. Most cases are associated with malignancy or other conditions such as congenital heart disease, liver cirrhosis, pulmonary fibrosis, biliary atresia, and gastrointestinal polyps. We report a 19-year-old man presenting with arthritis, broadening of the fingers and clubbing of the fingers and toes for the previous 3 years. The ankles and knees were swollen. X-rays showed periosteal apposition. The search for a secondary cause remained negative. In cases of arthralgia/arthritis together with clubbed fingers, consideration must be given to hypertrophic osteoarthropathy. The primary or idiopathic form is rare and has a good prognosis.

  13. Astragaloside IV attenuates apoptosis of hypertrophic cardiomyocyte through inhibiting oxidative stress and calpain-1 activation.

    PubMed

    Mei, Meng; Tang, Futian; Lu, Meili; He, Xin; Wang, Hongxin; Hou, Xuwei; Hu, Jin; Xu, Chonghua; Han, Ronghui

    2015-11-01

    Calpain-1 activation and oxidative stress are two critical factors contributing to apoptosis of hypertrophic cardiomyocyte. Astragaloside IV (ASIV) exhibits protective effect against various heart diseases. The present study was designed to investigate whether the inhibitory effect of ASIV on isoproterenol (ISO)-induced apoptosis of hypertrophic cardiomyocyte was associated with the anti-oxidation and calpain-1 inhibition. Hypertrophy, apoptosis, mitochondrial oxidative stress and calpain-1 expression were measured in the heart tissue of Sprague-Dawley (SD) rats and H9C2 cells treated with ISO alone or combination with ASIV. The results showed that ASIV attenuated apoptotic rate, increased Bcl-2 expression, decreased Bax expression, ameliorated the integrity of mitochondrial structure and improved mitochondrial membrane potential (MMP). Moreover, ASIV combination reduced both calpain-1 protein expression and calpain activity, down-regulated mitochondrial NOX4 (mito-NOX4) expression, increased activity of mitochondrial superoxide dismutase (mito-SOD) and mitochondrial catalase (mito-CAT) compared to ISO treated alone. The results suggested that ASIV exerted anti-apoptosis effect on ISO-induced hypertrophic cardiomyocyte by attenuating oxidative stress and calpain-1 activation. PMID:26433482

  14. Role of transiently altered sarcolemmal membrane permeability and basic fibroblast growth factor release in the hypertrophic response of adult rat ventricular myocytes to increased mechanical activity in vitro.

    PubMed Central

    Kaye, D; Pimental, D; Prasad, S; Mäki, T; Berger, H J; McNeil, P L; Smith, T W; Kelly, R A

    1996-01-01

    One of the trophic factors that has been implicated in initiating or facilitating growth in response to increased mechanical stress in several tissues and cell types is basic fibroblast growth factor (bFGF; FGF-2). Although mammalian cardiac muscle cells express bFGF, it is not known whether it plays a role in mediating cardiac adaptation to increased load, nor how release of the cytosolic 18-kD isoform of bFGF would be regulated in response to increased mechanical stress. To test the hypothesis that increased mechanical activity induces transient alterations in sarcolemmal permeability that allow cytosolic bFGF to be released and subsequently to act as an autocrine and paracrine growth stimulus, we examined primary isolates of adult rat ventricular myocytes maintained in serum-free, defined medium that were continually paced at 3 Hz for up to 5 d. Paced myocytes, but not nonpaced control cells, exhibited a "hypertrophic" response, which was characterized by increases in the rate of phenylalanine incorporation, total cellular protein content, and cell size. These changes could be mimicked in control cells by exogenous recombinant bFGF and could be blocked in continually paced cells by a specific neutralizing anti-bFGF antibody. In addition, medium conditioned by continually paced myocytes contained significantly more bFGF measured by ELISA and more mitogenic activity for 3T3 cells, activity that could be reduced by a neutralizing anti-bFGF antibody. The hypothesis that transient membrane disruptions sufficient to allow release of cytosolic bFGF occur in paced myocytes was examined by monitoring the rate of uptake into myocytes from the medium of 10-kD dextran linked to fluorescein. Paced myocytes exhibited a significantly higher rate of fluoresceinlabeled dextran uptake. These data are consistent with the hypothesis that nonlethal, transient alterations in sarcolemmal membrane permeability with release of cytosolic bFGF is one mechanism by which increased

  15. Protective effect of oxymatrine on chronic rat heart failure.

    PubMed

    Hu, Shu-Ting; Tang, Ying; Shen, Ya-Feng; Ao, Hai-Hang; Bai, Jie; Wang, Yong-Liang; Yang, Yong-Ji

    2011-09-01

    Oxymatrine is one of the alkaloids extracted from the Chinese herb Sophora japonica (Sophora flavescens Ait.) with anti-inflammatory, immune reaction inhibiting, antiviral, and hepatocyte and antihepatic fibrosis protective activities. However, the effect of oxymatrine on heart failure is not yet known. In this study, the effect of oxymatrine on heart failure was investigated using a Sprague-Dawley rat model of chronic heart failure. Morphological findings showed that in the group treated with 50 and 100 mg/kg of oxymatrine; intermyofibrillar lysis disappeared, myofilaments were orderly, closely and evenly arranged; and mitochondria contained tightly packed cristae compared with the heart failure group. We investigated the cytosolic Ca(2+) transients and sarcoplasmic reticulum (SR) Ca(2+) content, and assessed the expression of ryanodine receptor (RyR2), SR-Ca(2+) ATPase (SERCA2a), and L-type Ca(2+) channel (dihydropyridine receptor, DHPR). We found that the cytosolic Ca(2+) transients were markedly increased in amplitude in the medium- (ΔF/F (0) = 26.22 ± 2.01) and high-dose groups (ΔF/F (0) = 29.49 ± 1.17) compared to the heart failure group (ΔF/F (0) = 12.12 ± 1.35, P < 0.01), with changes paralleled by a significant increase in the SR Ca(2+) content (medium-dose group: ΔF/F (0) = 32.20 ± 1.67, high-dose group: ΔF/F (0) = 32.57 ± 1.29, HF: ΔF/F (0) = 17.26 ± 1.05, P < 0.01). Moreover, we demonstrated that the expression of SERCA2a and cardiac DHPR was significantly increased in the medium- and high-dose group compared with the heart failure rats. These findings suggest that oxymatrine could improve heart failure by improving the cardiac function and that this amelioration is associated with upregulation of SERCA2a and DHPR. PMID:21691940

  16. Resveratrol Improved Flow-Mediated Outward Arterial Remodeling in Ovariectomized Rats with Hypertrophic Effect at High Dose

    PubMed Central

    Petit, Marie; Guihot, Anne-Laure; Grimaud, Linda; Vessieres, Emilie; Toutain, Bertrand; Menet, Marie-Claude; Nivet-Antoine, Valérie; Arnal, Jean-François; Loufrani, Laurent; Procaccio, Vincent; Henrion, Daniel

    2016-01-01

    Objectives Chronic increases in blood flow in resistance arteries induce outward remodeling associated with increased wall thickness and endothelium-mediated dilatation. This remodeling is essential for collateral arteries growth following occlusion of a large artery. As estrogens have a major role in this remodeling, we hypothesized that resveratrol, described as possessing phytoestrogen properties, could improve remodeling in ovariectomized rats. Methods Blood flow was increased in vivo in mesenteric arteries after ligation of adjacent arteries in 3-month old ovariectomized rats treated with resveratrol (5 or 37.5 mg/kg per day: RESV5 or RESV37.5) or vehicle. After 2 weeks arterial structure and function were measured in vitro in high flow (HF) and normal flow (NF) arteries isolated from each rat. Results Arterial diameter was greater in HF than in NF arteries in ovariectomized rats treated with RESV5 or RESV37.5, not in vehicle-treated rats. In mice lacking estrogen receptor alpha diameter was equivalent in HF and NF arteries whereas in mice treated with RESV5 diameter was greater in HF than in NF vessels. A compensatory increase in wall thickness and a greater phenylephrine-mediated contraction were observed in HF arteries. This was more pronounced in HF arteries from RESV37.5-treated rats. ERK1/2 phosphorylation, involved in hypertrophy and contraction, were higher in RESV37.5-treated rats than in RESV5- and vehicle-treated rats. Endothelium-dependent relaxation was greater in HF than in NF arteries in RESV5-treated rats only. In HF arteries from RESV37.5-treated rats relaxation was increased by superoxide reduction and markers of oxidative stress (p67phox, GP91phox) were higher than in the 2 other groups. Conclusion Resveratrol improved flow-mediated outward remodeling in ovariectomized rats thus providing a potential therapeutic tool in menopause-associated ischemic disorders. This effect seems independent of the estrogen receptor alpha. Nevertheless

  17. Heart Alterations after Domoic Acid Administration in Rats.

    PubMed

    Vieira, Andres C; Cifuentes, José Manuel; Bermúdez, Roberto; Ferreiro, Sara F; Castro, Albina Román; Botana, Luis M

    2016-03-10

    Domoic acid (DA) is one of the best known marine toxins, causative of important neurotoxic alterations. DA effects are documented both in wildlife and experimental assays, showing that this toxin causes severe injuries principally in the hippocampal area. In the present study we have addressed the long-term toxicological effects (30 days) of DA intraperitoneal administration in rats. Different histological techniques were employed in order to study DA toxicity in heart, an organ which has not been thoroughly studied after DA intoxication to date. The presence of DA was detected by immunohistochemical assays, and cellular alterations were observed both by optical and transmission electron microscopy. Although histological staining methods did not provide any observable tissue damage, transmission electron microscopy showed several injuries: a moderate lysis of myofibrils and loss of mitochondrial conformation. This is the first time the association between heart damage and the presence of the toxin has been observed.

  18. Heart Alterations after Domoic Acid Administration in Rats

    PubMed Central

    Vieira, Andres C.; Cifuentes, José Manuel; Bermúdez, Roberto; Ferreiro, Sara F.; Castro, Albina Román; Botana, Luis M.

    2016-01-01

    Domoic acid (DA) is one of the best known marine toxins, causative of important neurotoxic alterations. DA effects are documented both in wildlife and experimental assays, showing that this toxin causes severe injuries principally in the hippocampal area. In the present study we have addressed the long-term toxicological effects (30 days) of DA intraperitoneal administration in rats. Different histological techniques were employed in order to study DA toxicity in heart, an organ which has not been thoroughly studied after DA intoxication to date. The presence of DA was detected by immunohistochemical assays, and cellular alterations were observed both by optical and transmission electron microscopy. Although histological staining methods did not provide any observable tissue damage, transmission electron microscopy showed several injuries: a moderate lysis of myofibrils and loss of mitochondrial conformation. This is the first time the association between heart damage and the presence of the toxin has been observed. PMID:26978401

  19. Effect of suprachiasmatic lesions on diurnal heart rate rhythm in the rat

    NASA Technical Reports Server (NTRS)

    Saleh, M. A.; Winget, C. M.

    1977-01-01

    Heart rate and locomotor activity of rats kept under 12L/12D illumination regimen were recorded every six minutes for ten days using implantable radio transmitters. Some of the rats then received bilateral RF lesions into the suprachiasmatic nucleus (SCN). Control sham operations were performed on the rest of the animals. After recovery from surgery, recording of heart rate and locomotor activity was continued for ten days. SCN-lesioned rats showed no significant diurnal fluctuation in heart rate, while normal and sham-operated rats showed the normal diurnal rhythm in that function. The arrhythmic diurnal heart-rate pattern of SCN rats appeared to be correlated with their sporadic activity pattern. The integrity of the suprachiasmatic nucleus is therefore necessary for the generation and/or expression of diurnal rhythmicity in heart rate in the rat.

  20. A STUDY OF THE T SYSTEM IN RAT HEART

    PubMed Central

    Forssmann, W. G.; Girardier, L.

    1970-01-01

    The technique of extracellular space tracing with horseradish peroxidase is adapted for labeling the transverse tubular system (T system) in rat heart. In rat ventricular muscle the T system shows extensive branching and remarkable tortuosity. The T system can only be defined operationally, since it does not display specific morphological features throughout its entire structure. Owing to branching of the T system, a sizable proportion of the apposition between the T system and L system (or closed system) occurs at the level of longitudinal branches of the T system and is not restricted to the Z line region. The regions of apposition between the T system and L system are analyzed in rat ventricular muscle and skeletal muscle (diaphragm) and compared with the intercellular tight junctions (nexuses) of heart muscle by the use of a photometric method. The over-all thickness of the nexus is significantly smaller than that of T-L junctions in both cardiac and skeletal muscles. The thickness of the membranes of the T and L systems are not significantly different in the two muscles, but the gap between both membranes is larger in the heart. In atrial muscle the following two types of cells are found: (a) those cells with a well-developed T system in which the tubular diameter is quite uniform and the orientation predominantly longitudinal and, (b) cells with no T system, but with a well-developed L system. Atrial cells possessing a T system are richly provided with specific granules and show little micropinocytotic activity, whereas cells devoid of T system show intense micropinocytotic activity and few specific granules. The possible functional implications of these findings are discussed. PMID:4901374

  1. Inhibition of cardiac hypertrophy by probiotic-fermented purple sweet potato yogurt in spontaneously hypertensive rat hearts.

    PubMed

    Lin, Pei-Pei; Hsieh, You-Miin; Kuo, Wei-Wen; Lin, Chien-Chung; Tsai, Fuu-Jen; Tsai, Chang-Hai; Huang, Chih-Yang; Tsai, Cheng-Chih

    2012-12-01

    Cardiovascular hypertrophy is a common feature of hypertension and an important risk factor for heart damage. The regression of cardiovascular hypertrophy is currently considered an important therapeutic target in reducing the omplications of hypertension. The aim of this study was to investigate the inhibition of cardiac hypertrophy by probiotic-fermented purple sweet potato yogurt (PSPY) with high γ-aminobutyric acid (GABA) content in spontaneously hypertensive rat (SHR) hearts. Six-week-old male SHRs were separated randomly and equally into 4 experimental groups: sterile water, captopril and 2 PSPY groups with different doses (10 and 100%) for 8 weeks. The changes in myocardial architecture and key molecules of the hypertrophy-related pathway in the excised left ventricle from these rats were determined by histopathological analysis, hematoxylin and eosin staining and western blot analysis. Abnormal myocardial architecture and enlarged interstitial spaces observed in the SHRs were significantly decreased in the captopril and PSPY groups compared with the sterile water group. Moreover, the increases in atrial natriuretic peptide, B-type natriuretic peptide, phosphorilated protein kinase Cα and calmodulin-dependent protein kinase II levels in the left ventricle were accompanied by hypertension and increases in phosphorylated extracellular signal-regulated kinase 5 activities with enhanced cardiac hypertrophy. However, the protein levels of the hypertrophic-related pathways were completely reversed by the administration of PSPY. PSPY may repress the activation of ANP and BNP which subsequently inhibit the dephosphorylation of the nuclear factor of activated T-cells, cytoplasmic 3 and ultimately prevent the progression of cardiac hypertrophy.

  2. A selective androgen receptor modulator with minimal prostate hypertrophic activity restores lean body mass in aged orchidectomized male rats.

    PubMed

    Allan, George; Sbriscia, Tifanie; Linton, Olivia; Lai, Muh-Tsann; Haynes-Johnson, Donna; Bhattacharjee, Sheela; Ng, Raymond; Sui, Zhihua; Lundeen, Scott

    2008-06-01

    Androgens are required for the maintenance of normal sexual activity in adulthood and for enhancing muscle growth and lean body mass in adolescents and adults. Androgen receptor (AR) ligands with tissue selectivity (selective androgen receptor modulators, or SARMs) have potential for treating muscle wasting, hypogonadism of aging, osteoporosis, female sexual dysfunction, and other indications. JNJ-37654032 is a nonsteroidal AR ligand with mixed agonist and antagonist activity in androgen-responsive cell-based assays. It is an orally active SARM with muscle selectivity in orchidectomized rat models. It stimulated growth of the levator ani muscle with ED(50) 0.8 mg/kg, stimulating maximal growth at a dose of 3mg/kg. In contrast, it stimulated ventral prostate growth to 21% of its full size at 3mg/kg. At the same time, JNJ-37654032 reduced prostate weight in intact rats by 47% at 3mg/kg, while having no inhibitory effect on muscle. Using magnetic resonance imaging to monitor body composition, JNJ-37654032 restored about 20% of the lean body mass lost following orchidectomy in aged rats. JNJ-37654032 reduced follicle-stimulating hormone levels in orchidectomized rats and reduced testis size in intact rats. JNJ-37654032 is a potent prostate-sparing SARM with the potential for clinical benefit in muscle-wasting diseases.

  3. Antiapoptotic effect of exercise training on ovariectomized rat hearts.

    PubMed

    Huang, Chih-Yang; Lin, Yi-Yuan; Hsu, Chih-Chao; Cheng, Shiu-Min; Shyu, Woei-Cherng; Ting, Hua; Yang, Ai-Lun; Ho, Tsung-Jung; Lee, Shin-Da

    2016-08-01

    The purpose of this study was to evaluate the effects of exercise training on cardiac Fas receptor-dependent and mitochondria-dependent apoptotic pathways in ovariectomized rats. Histopathological analysis, TUNEL assay, and Western blotting were performed on the excised hearts from three groups of Sprague-Dawley rats, which were divided into a sham-operated group, a bilaterally ovariectomized group (OVX), and a bilaterally ovariectomized group that underwent treadmill running exercise for 60 min/day, 5 sessions/wk, for 10 wk (OVX-EX). The abnormal myocardial architecture, cardiac trichome-stained fibrosis and cardiac TUNEL-positive apoptotic cells in ovariectomized rats improved after exercise training. The protein levels of tumor necrosis factor-α, tumor necrosis factor receptor 1, Fas ligand, Fas receptors, Fas-associated death domain, activated caspase-8 and activated caspase-3 (Fas receptor-dependent apoptotic pathways), as well as t-Bid, Bad, Bak, Bax, cytosolic cytochrome c, activated caspase-9, and activated caspase-3 (mitochondria-dependent apoptotic pathways) were decreased in the OVX-EX group compared with the OVX group. Exercise training suppressed ovariectomy-induced cardiac Fas receptor-dependent and mitochondria-dependent apoptotic pathways in ovariectomized rat models. These findings might indicate a new therapeutic effect for exercise training to prevent cardiac apoptosis in menopausal or bilaterally oophorectomized women. PMID:27339185

  4. Nifedipine represses ion channels, transporters and Ca{sup 2+}-binding proteins in hearts of spontaneously hypertensive rats

    SciTech Connect

    Zwadlo, Carolin; Borlak, Juergen . E-mail: borlak@item.fraunhofer.de

    2006-06-15

    The Ca{sup 2+} antagonists nifedipine has been used for more than three decades to treat hypertension, but its effects on the transcriptional regulation of cardiac genes are basically unknown. We therefore studied expression of genes coding for ion channels, ion transporters and associated partners as well as Ca{sup 2+}-binding proteins in ventricular tissue of normotensive and spontaneously hypertensive (SH) rats after repeated intraperitoneally (i.p.) dosing of nifedipine. Notably, we observed significant (P < 0.05) repression in transcript levels of most of the genes investigated, including cardiac Na{sup +}, K{sup +}, Ca{sup 2+}-channels (L-type Ca{sup 2+}-channel, K{sub ir}3.4, K{sub ir}6.1, Na{sub v}1.5), ATP-driven ion exchangers (Na{sup +}-K{sup +}-ATPase, NCX-1, PMCA 2 and 4, SERCA 2a and 2b) and their associated partners (phospholamban, RyR-2) as well as cytoskeletal proteins ({alpha} and {beta}-MHC, {alpha} cardiac and {alpha} skeletal actin, troponin T and I). Repression in transcript levels was, however, only seen in ventricular tissue of hypertensive animals. This points to fundamental differences in the mode of action of nifedipine in diseased and healthy animals. Indeed, this preponderance of repressed genes will promote disturbed ion homeostasis to result in contractile dysfunction. It is of considerable importance that repressed gene expression was also seen in end-stage human heart failure [Borlak, J., Thum, T., 2003. Hallmarks of ion channel gene expression in end-stage heart failure. FASEB J. 17, 1592-1608]. We propose repression of cardiac-specific gene expression as a hallmark of nifedipine treatment in hypertrophic hearts.

  5. The Influence of a High Salt Diet on a Rat Model of Isoproterenol-Induced Heart Failure

    EPA Science Inventory

    Rat models of heart failure (HF) show varied pathology and time to disease outcome, dependent on induction method. We found that subchronic (4 weeks) isoproterenol (ISO) infusion exacerbated cardiomyopathy in Spontaneously Hypertensive Heart Failure (SHHF) rats. Others have shown...

  6. A RAT MODEL OF HEART FAILURE INDUCED BY ISOPROTERENOL AND A HIGH SALT DIET

    EPA Science Inventory

    Rat models of heart failure (HF) show varied pathology and time to disease outcome, dependent on induction method. We found that subchronic (4wk) isoproterenol (ISO) infusion in Spontaneously Hypertensive Heart Failure (SHHF) rats caused cardiac injury with minimal hypertrophy. O...

  7. Metabolic fate of rat heart endothelial lipoprotein lipase

    SciTech Connect

    Chajek-Shaul, T.; Bengtsson-Olivecrona, G.; Peterson, J.; Olivecrona, T.

    1988-09-01

    When isolated rat hearts were perfused with medium containing 125I-labeled bovine lipoprotein lipase (LPL), they bound both lipase activity and radioactivity. More than 80% of the bound lipase could be rapidly released by heparin. Low concentrations of bovine LPL displaced 50-60% of the endogeneous, endothelial-bound LPL. Higher concentrations caused additional binding. Both binding and exchange were rapid processes. The hearts continuously released endogenous LPL into the medium. An antiserum that inhibited bovine but not rat LPL was used to differentiate endogeneous and exogeneous LPL activity. When the pool of endothelial LPL was labeled with bovine 125I-labeled LPL and then chased with unlabeled bovine LPL, approximately 50% of the labeled lipase was rapidly displaced. During chase perfusion with medium only, catalytically active bovine LPL appeared in the perfusate. The rate of release was similar to that observed for endogeneous LPL activity and amounted to 10-13% of the heparin-releasable fraction in the first 5 min of perfusion. There was little or no degradation of bovine 125I-labeled LPL to fragments or acid-soluble products. These results indicate that endothelial LPL is accessible for exchange with exogeneous LPL and that detachment rather than degradation may be the pathway for catabolism of endothelial LPL.

  8. Modulation of AMP deaminase in rat hearts subjected to ischemia and reperfusion by purine riboside.

    PubMed

    Borkowski, T; Lipinski, M; Kaminski, R; Krzyminska-Stasiuk, E; Langowska, M; Raczak, G; Slominska, E M; Smolenski, R T

    2008-06-01

    Changes in AMP deaminase (AMPD) activity influence heart function and progression of heart disease, but the underlying mechanism is unknown. We evaluated the effect of purine riboside (Purr) on the activity of AMPD in perfused rat hearts and in isolated rat cardiomyocytes. Brief perfusion of the pre-ischemic heart with 200 micro M Purr resulted in activation of AMPD, more pronounced degradation of the adenine nucleotides, and reduced recovery of the adenine nucleotide pool during reperfusion. Brief incubation of rat cardiomyocytes with 200 micro M Purr also activated AMPD, while prolonged exposure resulted in enzyme inhibition. We conclude that Purr activates AMPD, whereas metabolites of this compound may inhibit the enzyme.

  9. Nickel chloride inhibits metabolic coronary vasodilatation in isolated rat hearts

    SciTech Connect

    Edoute, Y.; Rubanyi, G.M.; Vanhoutte, P.M.

    1986-03-01

    Nickel is a potent coronary vasoconstrictor and it is released from ischemic myocardium. To determine whether or not nickel ions cause coronary vasoconstriction when local vasodilator mechanisms are stimulated the authors studied the inter-relation between exogenous nickel chloride (NiCl/sub 2/) and metabolic coronary vasodilatation in isolated rat hearts perfused by a modified Langendorff technique. NiCl/sub 2/ induced dose-dependent (10/sup -7/-10/sup -5/M) increases in coronary vascular resistance in spontaneously beating hearts. Pacing of the hearts (380/min) and infusing adenosine (10/sup -6/M) evoked comparable increases in coronary flow but did not affect the coronary vasoconstriction caused by NiCl/sub 2/. At concentrations (> 10/sup -7/M) which evoked vasoconstriction, NiCl/sub 2/ significantly reduced vasodilator responses evoked by pacing, transient coronary occlusion and adenosine. Lower concentrations, which did not cause vasoconstriction, had no effect on these vasodilator responses. Thus, at relative low concentrations NiCl/sub 2/ inhibits metabolic dilatation of the coronary vessels which may contribute to the increased vascular resistance caused by the trace metal under ischemic/hypoxic conditions.

  10. Selective lymphoid irradiation and cyclosporin A in rat heart allografts

    SciTech Connect

    Kuromoto, N.; Hardy, M.A.; Fawwaz, R.; Reemtsma, K.; Nowygrod, R.

    1984-05-01

    Short-term peritransplant treatment utilizing 2-dose ALG and 1-dose Palladium-109-hematoporphyrin (PD-H) for selective lymphoid irradiation (SLI) leads to donor-specific permanent acceptance of heart allografts in the Fisher to Lewis rat model. The same treatment significantly prolongs survival of hearts transplanted to strongly histoincompatable , presensitized, and xenogeneic recipients. The purpose of this study was to evaluate synergistic effects of short-term, low-dose cyclosporin treatment and SLI in an attempt to develop a nontoxic protocol utilizing peritransplant treatment for immune preconditioning with minimal subsequent immunosuppression. Single-agent treatment alone with cyclosporin, ALG, or Pd-H resulted in a maximal mean graft survival time (MST) of 33 days. Immunosuppression with 1-dose Pd-H, 2-dose ALG, and low-dose cyclosporin (5 mg/kg) for 14 days doubled the MST to 78 days. Use of therapeutic-dose cyclosporin (20 mg/kg), given for just 3 days, was also quite effective, MST of 57 days with SLI and 43 days with ALG, but toxic; 3 of 12 recipients died of infection with functioning grafts. These results demonstrate that the use of low-dose cyclosporin over a short interval, when combined with peritransplant SLI, is a highly effective and safe method for prolonging heart allograft survival.

  11. Curcumin ameliorates streptozotocin-induced heart injury in rats.

    PubMed

    Abo-Salem, Osama M; Harisa, Gamaleldin I; Ali, Tarek M; El-Sayed, El-Sayed M; Abou-Elnour, Fatma M

    2014-06-01

    Heart failure (HF) is one of diabetic complications. This work was designed to investigate the possible modulatory effect of curcumin against streptozotocin-induced diabetes and consequently HF in rats. Rats were divided into control, vehicle-treated, curcumin-treated, diabetic-untreated, diabetic curcumin-treated, and diabetic glibenclamide-treated groups. Animal treatment was started 5 days after induction of diabetes and extended for 6 weeks. Diabetic rats showed significant increase in serum glucose, triglycerides, total cholesterol, low-density lipoprotein-cholesterol, very low density lipoprotein-cholesterol, nitric oxide, lactate dehydrogenase, cardiac malondialdehyde, plasma levels of interleukin-6, and tumor necrosis factor-alpha, and also showed marked decrease in serum high-density lipoprotein-cholesterol, cardiac reduced glutathione, and cardiac antioxidant enzymes (catalase, superoxide dismutase, and glutathione-S-transferase). However, curcumin or glibenclamide treatment significantly mitigated such changes. In conclusion, curcumin has a beneficial therapeutic effect in diabetes-induced HF, an effect that might be attributable to its antioxidant and suppressive activity on cytokines.

  12. The efficiency coefficient of the rat heart and muscular system after physical training and hypokinesia

    NASA Technical Reports Server (NTRS)

    Alyukhin, Y. S.; Davydov, A. F.

    1982-01-01

    The efficiency of an isolated heart did not change after prolonged physical training of rats for an extreme load. The increase in oxygen consumption by the entire organism in 'uphill' running as compared to the resting level in the trained rats was 14% lower than in the control animals. Prolonged hypokinesia of the rats did not elicit a change in the efficiency of the isolated heart.

  13. Hypertrophic Osteoarthropathy Presenting as Unilateral Cellulitis with Successful Treatment Using Pamidronate Disodium

    PubMed Central

    Bernardo, Sebastian G.; Burnett, Mark E.; Gordon, Marsha

    2012-01-01

    Hypertrophic pulmonary osteoarthropathy is a paraneoplastic syndrome seen in patients with lung cancer. This condition is characterized by the presence of digital clubbing, periosteal thickening, synovial thickening, and severe pain of the affected joints. Other syndromes exhibiting clubbing may or may not have underlying diseases causing their manifestation. An example is primary hypertrophic osteoarthropathy, or pachydermoperiostosis. While clubbing makes up part of the clinical picture in both hypertrophic pulmonary osteoarthropathy and hypertrophic osteoarthropathy, the latter has no underlying disease associations. Rather, primary hypertrophic osteoarthropathy is familial, idiopathic, and has a chronic course often beginning during puberty in males. Secondary hypertrophic osteoarthropathy is an acquired form of clubbing that is classically associated with lung disease. However, it has also been associated with diseases of the heart, liver, and intestines. In the setting of pulmonary malignancy, secondary hypertrophic osteoarthropathy is known as hypertrophic pulmonary osteoarthropathy. Hypertrophic pulmonary osteoarthropathy has a distinct constellation of clinical findings that includes intractable pain often refractory to treatments other than resolution of the underlying disease process. The authors herein report a case of hypertrophic pulmonary osteoarthropathy masquerading as recurrent lower extremity cellulitis with chronic hand and foot pain in the setting of pulmonary malignancy that responded dramatically to intravenous pamidronate disodium (a bisphosphonate). Given the rarity of hypertrophic osteoarthropathy associated with lung cancer and the difficulty with pain management in such circumstances, the authors present the following case in which pain was mitigated by treatment with bisphosphonate therapy. PMID:23050033

  14. Reduced expression of adherens and gap junction proteins can have a fundamental role in the development of heart failure following cardiac hypertrophy in rats.

    PubMed

    dos Santos, Daniele O; Blefari, Valdecir; Prado, Fernanda P; Silva, Carlos A; Fazan, Rubens; Salgado, Helio C; Ramos, Simone G; Prado, Cibele M

    2016-02-01

    Hypertension causes cardiac hypertrophy, cardiac dysfunction and heart failure (HF). The mechanisms implicated in the transition from compensated to decompensated cardiac hypertrophy are not fully understood. This study was aimed to investigate whether alterations in the expression of intercalated disk proteins could contribute to the transition of compensated cardiac hypertrophy to dilated heart development that culminates in HF. Male rats were submitted to abdominal aortic constriction and at 90 days post surgery (dps), three groups were observed: sham-operated animals (controls), animals with hypertrophic hearts (HH) and animals with hypertrophic + dilated hearts (HD). Blood pressure was evaluated. The hearts were collected and Western blot and immunofluorescence were performed to desmoglein-2, desmocollin-2, N-cadherin, plakoglobin, Bcatenin, and connexin-43. Cardiac systolic function was evaluated using the Vevo 2100 ultrasound system. Data were considered significant when p b 0.05. Seventy percent of the animals presented with HH and 30% were HD at 90 dps. The blood pressure increased in both groups. The amount of desmoglein-2 and desmocollin-2 expression was increased in both groups and no difference was observed in either group. The expression of N-cadherin, plakoglobin and B-catenin increased in the HHgroup and decreased in the HDgroup; and connexin-43 decreased only in theHDgroup. Therewas no difference between the ejection fraction and fractional shortening at 30 and 60 dps; however, they were decreased in the HD group at 90 dps. We found that while some proteins have increased expression accompanied by the increase in the cell volume associated with preserved systolic cardiac function in theHHgroup, these same proteins had decreased expression evenwithout significant reduction in the cell volume associated with decreased systolic cardiac function in HD group. The increased expression of desmoglein-2 and desmocollin-2 in both the HH and HD groups could

  15. Merit of Ginseng in the Treatment of Heart Failure in Type 1-Like Diabetic Rats

    PubMed Central

    Tsai, Cheng-Chia; Chan, Paul; Chen, Li-Jen; Chang, Chen Kuei; Liu, Zhongmin

    2014-01-01

    The present study investigated the merit of ginseng in the improvement of heart failure in diabetic rats and the role of peroxisome proliferator-activated receptors δ (PPARδ). We used streptozotocin-induced diabetic rat (STZ-rat) to screen the effects of ginseng on cardiac performance and PPARδ expression. Changes of body weight, water intake, and food intake were compared in three groups of age-matched rats; the normal control (Wistar rats) received vehicle, STZ-rats received vehicle and ginseng-treated STZ-rats. We also determined cardiac performances in addition to blood glucose level in these animals. The protein levels of PPARδ in hearts were identified using Western blotting analysis. In STZ-rats, cardiac performances were decreased but the food intake, water intake, and blood glucose were higher than the vehicle-treated control. After a 7-day treatment of ginseng in STZ-rats, cardiac output was markedly enhanced without changes in diabetic parameters. This treatment with ginseng also increased the PPARδ expression in hearts of STZ-rats. The related signal of cardiac contractility, troponin I phosphorylation, was also raised. Ginseng-induced increasing of cardiac output was reversed by the cotreatment with PPARδ antagonist GSK0660. Thus, we suggest that ginseng could improve heart failure through the increased PPARδ expression in STZ-rats. PMID:24745017

  16. Comparison of right ventricular contractile abnormalities in hypertrophic cardiomyopathy versus hypertensive heart disease using two dimensional strain imaging: a cross-sectional study.

    PubMed

    Afonso, Luis; Briasoulis, Alex; Mahajan, Nitin; Kondur, Ashok; Siddiqui, Fayez; Siddiqui, Sabeeh; Alesh, Issa; Cardozo, Shaun; Kottam, Anupama

    2015-12-01

    Hypertrophic cardiomyopathy (HCM) affects the right ventricle (RV) because of the anatomically hypertrophied septum and plausibly by extension of the myopathic process to the RV. We sought to investigate RV strain in patients with left ventricular hypertrophy secondary to either HCM or hypertension (H-LVH). Our cross-sectional study included 32 patients with HCM, 21 patients with H-LVH, and 11 healthy subjects, who were evaluated with transthoracic echocardiography. Using a dedicated software package, bi-dimensional acquisitions were analyzed to measure segmental longitudinal strain in apical views. Right ventricular global longitudinal strain (GLS) was calculated by averaging septal and right free wall strains. The HCM and H-LVH groups were comparable for age and demographic characteristics. Right ventricular tricuspid annular plane systolic excursion was not significantly different between HCM and H-LVH subjects. Moreover, RV GLS, septal and lateral RV myocardial strain were significantly impaired in patients with HCM (all p < 0.001). Regional and global RV strain parameters were not significantly impaired in H-LVH compared to healthy controls An RV GLS cut-off value of >14.9% differentiated HCM and H-LVH with a 90% sensitivity and a 95% specificity (p < 0.001). RV strain parameters are impaired in patients with HCM. Assessment of two-dimensional RV strain parameters could help differentiate between HCM and H-LVH.

  17. Screening for hypertrophic cardiomyopathy in cats.

    PubMed

    Häggström, Jens; Luis Fuentes, Virginia; Wess, Gerhard

    2015-12-01

    Hypertrophic cardiomyopathy (HCM) is the most common heart disease in cats, and it can lead to increased morbidity and mortality. Cats are often screened for HCM because of the presence of a heart murmur, but screening for breeding purposes has also become common. These cats are usually purebred cats of breeding age, and generally do not present with severe disease or with any clinical signs. This type of screening is particularly challenging because mild disease may be difficult to differentiate from a normal phenotype, and the margin for error is small, with potentially major consequences for the breeder. This article reviews HCM screening methods, with particular emphasis on echocardiography.

  18. Hypertrophic discoid lupus erythematosus.

    PubMed

    Farley-Loftus, Rachel; Elmariah, Sarina B; Ralston, Jonathan; Kamino, Hideko; Franks, Andrew G

    2010-11-15

    Hypertrophic discoid lupus erythematosus is a distinct form of chronic cutaneous (discoid) lupus, which is characterized by hyperkeratotic plaques that typically are observed over the face, arms, and upper trunk. We present the case of a 43-year-old man with verrucous plaques that were distributed symmetrically over the face, who initially was treated with oral antibiotics and topical glucocorticoids for acne vulgaris. A biopsy specimen confirmed the diagnosis of hypertrophic discoid lupus erythematosus. The clinical and histopathologic features of this clinical variant are reviewed.

  19. Hypertrophic cardiomyopathy in infants: clinical features and natural history

    SciTech Connect

    Maron, B.J.; Tajik, A.J.; Ruttenberg, H.D.; Graham, T.P.; Atwood, G.F.; Victorica, B.E.; Lie, J.T.; Roberts, W.C.

    1982-01-01

    The clinical and morphologic features of hypertrophic cardiomyopathy in 20 patients recognized as having cardiac disease in the first year of life are described. Fourteen of these 20 infants were initially suspected of having heart disease solely because a heart murmur was identified. However, the infants showed a variety of clinical findings, including signs of marked congestive heart failure (in the presence of nondilated ventricular cavities and normal or increased left ventricular contractility) and substantial cardiac enlargement on chest radiograph. Other findings were markedly different from those usually present in older children and adults with hypertrophic cardiomyopathy (e.g., right ventricular hypertrophy on the ECG and cyanosis). Consequently, in 14 infants, the initial clinical diagnosis was congenital cardiac malformation other than hypertrophic cardiomyopathy. The clinical course was variable in these patients, but the onset of marked congestive heart failure in the first year of life appeared to be an unfavorable prognostic sign; nine of the 11 infants with congestive heart failure died within the first year of life. In infants with hypertrophic cardiomyopathy, unlike older children and adults with this condition, sudden death was less common (two patients) than death due to progressive congestive heart failure.

  20. Effects of thyroid state on respiration of perfused rat and guinea pig hearts

    SciTech Connect

    Read, L.C.; Wallace, P.G.; Berry, M.N. )

    1987-09-01

    The effects of thyroid state on the respiration of the isolated heart were investigated using retrograde perfused rat and guinea pig hearts. In both species, hypothyroidism caused a marked depression in circulating thyroid hormone concentrations and in the respiration of the isolated, retrograde perfused heart. Hypothyroidism was caused by injecting animals with Na{sup 131}I. The effects on myocardial respiration could be attributed to changes in the contraction frequency and in the oxygen consumption per beat, with little contribution from basal respiration. Treatment of animals with thyroxine elevated plasma thyroid hormones to a similar extent in rats and guinea pigs. In the latter, thyroxine treatment was associated with substantial increases in the contraction frequency and the oxygen consumption per beat of the isolated heart. In contrast, only small changes were apparent in the retrograde perfused rat heart, observations that were confirmed in rat hearts perfused at near physiological work loads. It was concluded that rat hearts isolated from normal animals function at near maximal thyroid state, in contrast to the guinea pig heart, which requires higher circulating concentrations of thyroid hormones to attain maximal responses.

  1. [Activity of aldehyde scavenger enzymes in the heart of rats of different age during immobilized stress].

    PubMed

    Grabovetskaia, E R; Davydov, V V

    2009-01-01

    This study was made to determine the activity of aldehyde scavenger enzymes in the heart's postmitochondrial fraction of rats of different age during immobilization stress. Our study demonstrated, that immobilization of 1.5-, 2- and 12-month rats was accompanied by inhibiting activity of aldehyde dehydrogenase and aldehyde reductase. At the same time we observed an increase in glutathione transferase activity in immobilized 1.5-month-old rats and that in reductase activity in 24-month-old rats. The revealed changes can lead to a decrease in the rate of endogenous aldehyde utilization in the heart during stress at puberty.

  2. Identification and Functional Characterization of a Novel CACNA1C-Mediated Cardiac Disorder Characterized by Prolonged QT Intervals with Hypertrophic Cardiomyopathy, Congenital Heart Defects, and Sudden Cardiac Death

    PubMed Central

    Boczek, Nicole J.; Ye, Dan; Jin, Fang; Tester, David J.; Huseby, April; Bos, J. Martijn; Johnson, Aaron J.; Kanter, Ronald; Ackerman, Michael J.

    2016-01-01

    Background A portion of sudden cardiac deaths (SCD) can be attributed to structural heart diseases such as hypertrophic cardiomyopathy (HCM) or cardiac channelopathies such as long QT syndrome (LQTS); however, the underlying molecular mechanisms are quite distinct. Here, we identify a novel CACNA1C missense mutation with mixed loss-of-function/gain-of-function responsible for a complex phenotype of LQTS, HCM, SCD, and congenital heart defects (CHDs). Methods and Results Whole exome sequencing (WES) in combination with Ingenuity Variant Analysis was completed on three affected individuals and one unaffected individual from a large pedigree with concomitant LQTS, HCM, and CHDs and identified a novel CACNA1C mutation, p.Arg518Cys, as the most likely candidate mutation. Mutational analysis of exon 12 of CACNA1C was completed on 5 additional patients with a similar phenotype of LQTS plus a personal or family history of HCM-like phenotypes, and identified two additional pedigrees with mutations at the same position, p.Arg518Cys/His. Whole cell patch clamp technique was used to assess the electrophysiological effects of the identified mutations in CaV1.2, and revealed a complex phenotype, including loss of current density and inactivation in combination with increased window and late current. Conclusions Through WES and expanded cohort screening, we identified a novel genetic substrate p.Arg518Cys/His-CACNA1C, in patients with a complex phenotype including LQTS, HCM, and CHDs annotated as cardiac-only Timothy syndrome. Our electrophysiological studies, identification of mutations at the same amino acid position in multiple pedigrees, and co-segregation with disease in these pedigrees provides evidence that p.Arg518Cys/His is the pathogenic substrate for the observed phenotype. PMID:26253506

  3. Effects of increased heart work on glycolysis and adenine nucleotides in the perfused heart of normal and diabetic rats

    PubMed Central

    Opie, L. H.; Mansford, K. R. L.; Owen, Patricia

    1971-01-01

    1. In the isolated perfused rat heart, the contractile activity and the oxygen uptake were varied by altering the aortic perfusion pressure, or by the atrial perfusion technique (`working heart'). 2. The maximum increase in the contractile activity brought about an eightfold increase in the oxygen uptake. The rate of glycolytic flux rose, while tissue contents of hexose monophosphates, citrate, ATP and creatine phosphate decreased, and contents of ADP and AMP rose. 3. The changes in tissue contents of adenine nucleotides during increased heart work were time-dependent. The ATP content fell temporarily (30s and 2min) after the start of left-atrial perfusion; at 5 and 10min values were normal; and at 30 and 60min values were decreased. ADP and AMP values were increased in the first 15min, but were at control values 30 or 60min after the onset of increased heart work. 4. During increased heart work changes in the tissue contents of adenine nucleotide and of citrate appeared to play a role in altered regulation of glycolysis at the level of phosphofructokinase activity. 5. In recirculation experiments increased heart work for 30min was associated with increased entry of [14C]glucose (11.1mm) and glycogen into glycolysis and a comparable increase in formation of products of glycolysis (lactate, pyruvate and 14CO2). There was no major accumulation of intermediates. Glycogen was not a major fuel for respiration. 6. Increased glycolytic flux in Langendorff perfused and working hearts was obtained by the addition of insulin to the perfusion medium. The concomitant increases in the tissue values of hexose phosphates and of citrate contrasted with the decreased values of hexose monophosphates and of citrate during increased glycolytic flux obtained by increased heart work. 7. Decreased glycolytic flux in Langendorff perfused hearts was obtained by using acute alloxan-diabetic and chronic streptozotocin-diabetic rats; in the latter condition there were decreased tissue

  4. Manganese protects against heart mitochondrial lipid peroxidation in rats fed high levels of polyunsaturated fatty acids.

    PubMed

    Malecki, E A; Greger, J L

    1996-01-01

    We demonstrated previously that dietary manganese (Mn) deficiency depressed Mn concentrations in most tissues and consistently depressed Mn superoxide dismutase (MnSOD) levels in heart. To examine the functional consequences of these effects, we fed weanling male Sprague-Dawley rats (n = 12/diet) diets containing 20% (wt/wt) corn oil or 19% menhaden oil + 1% corn oil by weight and 0.75 or 82 mg Mn/kg diet for 2 mo (the fish oil mixture was supplemented with (+)-(mixed)-alpha-tocopherol to the level in corn oil). Heart and liver Mn concentrations in the Mn-deficient rats were 56% of those in Mn-adequate rats (P < 0.0001), confirming Mn deficiency. The Mn-deficient rats had more conjugated dienes in heart mitochondria than Mn-adequate rats (P < 0.001); rats fed fish oil had more conjugated dienes than those fed corn oil (P < 0.001). The MnSOD activity was inversely correlated with conjugated dienes (r = -0.71, P < 0.005), and Mn-deficient rats had 37% less MnSOD activity in the heart than did Mn-adequate rats (P < 0.0001). The dietary treatments did not affect heart microsomal conjugated diene formation, possibly because of compensation by copper-zinc (CuZn) SOD activity; CuZnSOD activities were 35% greater in the hearts of Mn-deficient animals (P < 0.01). Liver was less sensitive to Mn deficiency than was the heart as judged by MnSOD activity and conjugated diene formation. This work is the first to demonstrate that dietary Mn protects against in vivo oxidation of heart mitochondrial membranes. PMID:8558311

  5. A Novel Technique for Image-Guided Local Heart Irradiation in the Rat

    PubMed Central

    Sharma, Sunil; Moros, Eduardo G.; Boerma, Marjan; Sridharan, Vijayalakshmi; Han, Eun Young; Clarkson, Richard; Hauer-Jensen, Martin; Corry, Peter M.

    2014-01-01

    In radiotherapy treatment of thoracic, breast and chest wall tumors, the heart may be included (partially or fully) in the radiation field. As a result, patients may develop radiation-induced heart disease (RIHD) several years after exposure to radiation. There are few methods available to prevent or reverse RIHD and the biological mechanisms remain poorly understood. In order to further study the effects of radiation on the heart, we developed a model of local heart irradiation in rats using an image-guided small animal conformal radiation therapy device (SACRTD) developed at our institution. First, Monte Carlo based simulations were used to design an appropriate collimator. EBT-2 films were used to measure relative dosimetry, and the absolute dose rate at the isocenter was measured using the AAPM protocol TG-61. The hearts of adult male Sprague-Dawley rats were irradiated with a total dose of 21 Gy. For this purpose, rats were anesthetized with isoflurane and placed in a custom-made vertical rat holder. Each heart was irradiated with a 3-beam technique (one AP field and 2 lateral fields), with each beam delivering 7 Gy. For each field, the heart was visualized with a digital flat panel X-ray imager and placed at the isocenter of the 1.8 cm diameter beam. In biological analysis of radiation exposure, immunohistochemistry showed γH2Ax foci and nitrotyrosine throughout the irradiated hearts but not in the lungs. Long-term follow-up of animals revealed histopathological manifestations of RIHD, including myocardial degeneration and fibrosis. The results demonstrate that the rat heart irradiation technique using the SACRTD was successful and that surrounding untargeted tissues were spared, making this approach a powerful tool for in vivo radiobiological studies of RIHD. Functional and structural changes in the rat heart after local irradiation are ongoing. PMID:24000983

  6. Characterization of a fatty acid-binding protein from rat heart.

    PubMed

    Offner, G D; Troxler, R F; Brecher, P

    1986-04-25

    A fatty acid-binding protein has been isolated from rat heart and purified by gel filtration chromatography on Sephadex G-75 and anion-exchange chromatography on DE52. The circular dichroic spectrum of this protein was not affected by protein concentration, suggesting that it does not aggregate into multimers. Computer analyses of the circular dichroic spectrum predicted that rat heart fatty acid-binding protein contains approximately 22% alpha-helix, 45% beta-form and 33% unordered structure. Immunological studies showed that the fatty acid-binding proteins from rat heart and rat liver are immunochemically unrelated. The amino acid composition and partial amino acid sequence of the heart protein indicated that it is structurally related to, but distinct from, other fatty acid-binding proteins from liver, intestine, and 3T3 adipocytes. Using a binding assay which measures the transfer of fatty acids between donor liposomes and protein (Brecher, P., Saouaf, R., Sugarman, J. M., Eisenberg, D., and LaRosa, K. (1984) J. Biol. Chem. 259, 13395-13401), it was shown that both rat heart and liver fatty acid-binding proteins bind 2 mol of oleic acid or palmitic acid/mol of protein. The structural and functional relationship of rat heart fatty acid-binding protein to fatty acid-binding proteins from other tissues is discussed. PMID:3957934

  7. Neurotensin stimulates histamine release from the isolated, spontaneously beating heart of rats.

    PubMed

    Rioux, F; Kérouac, R; St-Pierre, S

    1984-07-23

    Neurotensin (NT) evoked a transient, dose-dependent histamine release (ED50 170 ng ml-1) from the rat perfused heart. Histamine release by NT occurred within seconds and lasted less than 2 min. The histamine releasing effect of NT was followed by a dose-dependent increase of the perfusion pressure and a slight tachycardia. The histamine releasing effect of NT was completely abolished in hearts derived from rats pretreated for 3 days with high doses of compound 48/80. The coronary vasoconstrictor effect of NT was increased in hearts derived from compound 48/80-pretreated rats. The mast cell inhibitor cromoglycate markedly inhibited NT-induced histamine release without affecting the coronary vasoconstrictor effect of NT. The histamine releasing effect of NT was inhibited, while its coronary vasoconstrictor effect was markedly potentiated, in hearts derived from rats pretreated with the antiallergic and antiinflammatory steroid dexamethasone. The increase of perfusion pressure evoked by NT was not modified by antihistamine drugs. Infusions of exogenous histamine (10(-6)-10(-5) g ml-1) caused a dose-dependent coronary vasodilation in the rat perfused heart. The results suggest that NT stimulates histamine release from cardiac mast cells. These results together with those obtained in previous studies suggest that mast cell mediators (particularly histamine and serotonin) are unlikely to be responsible for the coronary vasoconstrictor effect of NT in the rat perfused heart.

  8. Influence of microwaves on the beating rate of isolated rat hearts.

    PubMed

    Yee, K C; Chou, C K; Guy, A W

    1988-01-01

    Previous reports have shown that microwave exposure can decrease the beating rate of isolated rat hearts. These experiments were conducted at room temperature and with the hearts exposed to air. We observed arrhythmia frequently at room temperature, and the variation of heart beat was so large that it makes the results difficult to reproduce. Therefore, we employed a double-circulating system to provide perfusion through the coronary artery and around the outside of the heart to maintain the rat hearts at 37.7 degrees C. No arrhythmias were observed in our experiments, and the hearts were beating for at least 1 h. The effects of 16-Hz modulated 2,450-MHz pulsed microwaves (10 microseconds, 100 pps) on the beating rate of 50 isolated rat hearts were studied. Results showed no statistically significant changes of heart rate in exposed groups at SARs of 2 and 10 W/kg compared with the control group. The effect seen at 200 W/kg was shown to be similar to that resulting from heating the heart.

  9. Influence of microwaves on the beating rate of isolated rat hearts

    SciTech Connect

    Yee, K.C.; Chou, C.K.; Guy, A.W.

    1988-01-01

    Previous reports have shown that microwave exposure can decrease the beating rate of isolated rat hearts. These experiments were conducted at room temperature and with the hearts exposed to air. We observed arrhythmia frequently at room temperature, and the variation of heart beat was so large that it makes the results difficult to reproduce. Therefore, we employed a double-circulating system to provide perfusion through the coronary artery and around the outside of the heart to maintain the rat hearts at 37.7 degrees C. No arrhythmias were observed in our experiments, and the hearts were beating for at least 1 h. The effects of 16-Hz modulated 2,450-MHz pulsed microwaves (10 microseconds, 100 pps) on the beating rate of 50 isolated rat hearts were studied. Results showed no statistically significant changes of heart rate in exposed groups at SARs of 2 and 10 W/kg compared with the control group. The effect seen at 200 W/kg was shown to be similar to that resulting from heating the heart.

  10. Activity of cholinesterases of blood and heart in rats of different sex and age during muscular loads and hypokinesia

    NASA Technical Reports Server (NTRS)

    Rozanova, V. D.; Antonova, G. A.

    1979-01-01

    The activity of acetylcholinesterase (Ache) and butyrilcholinesterase (Bche) in the blood and the heart of 3 and 13 month old control male rats is considerably lower than in female rats. In 25 month old rats, no sex differences in the Ache and Bche were revealed in the heart. In 3 and 13 month old male and female rats, under conditions of muscular exercises, the Ache and Bche activity is lower, and in hypokinetic male rats -- higher than that in respective control animals. In all the rats, irrespective of sex, age, and motor conditions, Ache and Bche activity tended to decrease from the sinoatrial node to the heart apex.

  11. Regulation of atriopeptin release from the isolated rat heart

    SciTech Connect

    Currie, M.G.; Newman, W.H.

    1986-03-05

    Recent studies have demonstrated that the mammalian atria possess an endocrine function which appears to play a role in the regulation of systemic arterial pressure, fluid balance, and electrolyte homeostasis. They have begun to study the regulation of atriopeptin (atrial natriuretic factor) release into the coronary effluent of the isolated perfused rat heart. Characterization by high pressure liquid chromatography of the form of the hormone released indicates that the predominant form is the active low MW circulating hormone not the pro-hormone. The release of immunoreactive atriopeptin (iAP) was stimulated by infusion of norepinephrine (1 ..mu..M) or epinephrine (1 ..mu..M) 3.0 and 2.6-fold, respectively. The ..beta..-adrenergic agonist isoproterenol and the ..cap alpha..-2 adrenergic agonist BHT-920 lacked effects on iAP release. On the other hand, the ..cap alpha..-1 adrenergic agonist phenylephrine caused a dose-dependent increase in release of iAP. Release of iAP stimulated by phenylephrine was inhibited by the ..cap alpha.. antagonist phentolamine. Further, iAP release was stimulated 4.2-fold by phorbol ester (1 ..mu..M) but was not affected by 4-..beta.. phorbol (1 ..mu..M). From these collective data they conclude that the release of atriopeptin is stimulated by ..cap alpha..-1 receptor activation and that protein kinase C participates in the regulation of secretion. The data suggests that the sympathetic nervous system may play a physiologic role in the regulation of atriopeptin secretion.

  12. Effects of ethanol on rat heart and skeletal muscles

    SciTech Connect

    Pagala, M.; Ravindran, K.; Namba, T.; Grob, D. State Univ. of New York, Brooklyn )

    1991-03-11

    Chronic alcoholism causes myopathy of both cardiac and skeletal muscles. In order to evaluate acute effects, the authors infused ethanol intravenously in anesthetized rats, and, 10 min later, monitored the electrocardiogram, and the compound action potential and isometric tension of the anterior tibialis evoked by sciatic nerve stimulation. Ethanol at 0.1, 0.2 and 0.5 g/kg decreased the heart rate by 12%, 22% and 69%, increased the P-R interval by 5%, 25%, and 116%, and reduced the QRS amplitude by 1% , 2% and 10%, respectively. Within 5 min after infusing 0.5 g/kg ethanol, breathing was stopped. Ethanol increased the amplitude of the compound action potential and tension of the anterior tibialis by 25% at 0.1 and 0.2 g/kg, while it decreased the compound action potential by 5% and tension by 35% at 0.5 g/kg. At this dose, ethanol caused 70% decrement in amplitude of the compound action potentials and 50% fade of tetanic tensions evoked by a train of nerve stimulations at 100 Hz for 0.5 sec. When ethanol was injected intraperitoneally, about 10 times greater doses were required to produce effects equivalent to intravenous administration. These results indicate that ethanol reduces cardiac output dose-dependently, and potentiates skeletal muscle function at subintoxication doses and reduces it at higher doses.

  13. Myocardial kinetics of carbon-11-epinephrine in the isolated working rat heart

    SciTech Connect

    Nguyen, N.T.B.; DeGrado, T.R.; Chakraborty, P.

    1997-05-01

    The kinetics of EPI were studied in the isolated rat heart model to evaluate {sup 11}C-epinephrine (EPI) as a radiotracer for the assessment of sympathetic neuronal function in the heart. Isolated rat hearts were perfused in a working mode. Carbon-11-EPI was added to the perfusate during wash-in period of 20 min, followed by a washout period of 40 min. Radioactivity in the heart was externally monitored and time-activity curves were recorded as a function of time. Effluent samples were collected throughout each study to determine the fraction of {sup 11}C radioactivity as intact tracer. Time-activity curves of control hearts showed that {sup 11}C-EPI is taken up and retained by the myocardium. Desipramine inhibition (DMI) of uptake-1 resulted in a significant decrease in myocardial uptake and retention of {sup 11}C-EPI by 91% compared to controls. Addition of DMI to the perfusion medium during washout did not affect kinetics of {sup 11}C-EPI compared to control hearts. Reserpine pretreated rat hearts also showed significant decrease in tracer retention of 95% compared to controls. The metabolic data showed that, in control conditions, about 61% of {sup 11}C-EPI taken up by the rat heart is rapidly metabolized and released. Carbon-11-EPI traces sympathetic nerve terminals in the isolated rat heart. Uptake blockade by DMI and reserpine suggest that uptake and storage of {sup 11}C-EPI appear to be similar to that of norepinephrine. However, the prominent metabolic pathway warrants further consideration. These results suggest that {sup 11}C-EPI may be a suitable radiolabeled tracer for the evaluation of sympathetic vesicular function of the heart by PET. 23 refs., 3 figs., 3 tabs.

  14. Association between Functional Variables and Heart Failure after Myocardial Infarction in Rats

    PubMed Central

    Polegato, Bertha F.; Minicucci, Marcos F.; Azevedo, Paula S.; Gonçalves, Andréa F.; Lima, Aline F.; Martinez, Paula F.; Okoshi, Marina P.; Okoshi, Katashi; Paiva, Sergio A. R.; Zornoff, Leonardo A. M.

    2016-01-01

    Background Heart failure prediction after acute myocardial infarction may have important clinical implications. Objective To analyze the functional echocardiographic variables associated with heart failure in an infarction model in rats. Methods The animals were divided into two groups: control and infarction. Subsequently, the infarcted animals were divided into groups: with and without heart failure. The predictive values were assessed by logistic regression. The cutoff values predictive of heart failure were determined using ROC curves. Results Six months after surgery, 88 infarcted animals and 43 control animals were included in the study. Myocardial infarction increased left cavity diameters and the mass and wall thickness of the left ventricle. Additionally, myocardial infarction resulted in systolic and diastolic dysfunction, characterized by lower area variation fraction values, posterior wall shortening velocity, E-wave deceleration time, associated with higher values of E / A ratio and isovolumic relaxation time adjusted by heart rate. Among the infarcted animals, 54 (61%) developed heart failure. Rats with heart failure have higher left cavity mass index and diameter, associated with worsening of functional variables. The area variation fraction, the E/A ratio, E-wave deceleration time and isovolumic relaxation time adjusted by heart rate were functional variables predictors of heart failure. The cutoff values of functional variables associated with heart failure were: area variation fraction < 31.18%; E / A > 3.077; E-wave deceleration time < 42.11 and isovolumic relaxation time adjusted by heart rate < 69.08. Conclusion In rats followed for 6 months after myocardial infarction, the area variation fraction, E/A ratio, E-wave deceleration time and isovolumic relaxation time adjusted by heart rate are predictors of heart failure onset. PMID:26815462

  15. Endurance Training and Glutathione-Dependent Antioxidant Defense Mechanism in Heart of the Diabetic Rats

    PubMed Central

    Gül, Mustafa; Atalay, Mustafa; Hänninen, Osmo

    2003-01-01

    Regular physical exercise beneficially influences cardiac antioxidant defenses in normal rats. The aim of this study was to test whether endurance training can strengthen glutathione-dependent antioxidant defense mechanism and decrease lipid peroxidation in heart of the streptozotocin-induced diabetic rats. Redox status of glutathione in blood of diabetic rats in response to training and acute exercise was also examined. Eight weeks of treadmill training increased the endurance in streptozotocin-induced diabetic rats. It did not affect glutathione level in heart tissue at rest and also after exercise. On the other hand, endurance training decreased glutathione peroxidase activity in heart, while glutathione reductase and glutathione S-transferase activities were not affected either by acute exhaustive exercise or endurance training. Reduced and oxidized glutathione levels in blood were not affected by either training or acute exercise. Conjugated dienes levels in heart tissue were increased by acute exhaustive exercise and also 8 weeks treadmill training. Longer duration of exhaustion in trained group may have contributed to the increased conjugated dienes levels in heart after acute exercise. Our results suggest that endurance type exercise may make heart more susceptible to oxidative stress. Therefore it may be wise to combine aerobic exercise with insulin treatment to prevent its adverse effects on antioxidant defense in heart in patients with diabetes mellitus. PMID:24616611

  16. Caloric restriction restores the cardioprotective effect of preconditioning in the rat heart.

    PubMed

    Long, Paige; Nguyen, Quang; Thurow, Chantelle; Broderick, Tom L

    2002-07-01

    Preconditioning (PC) describes the observation that brief periods of ischemia paradoxically protect the heart and limit necrosis caused by a subsequent more prolonged period of ischemia. However, the PC response is attenuated in hearts from 9- to 12-month-old Sprague-Dawley rats, as compared to young adults. This study determined whether long-term caloric restriction (CR) could preserve the PC response, since CR increases ischemic tolerance in these hearts. Following 6 months of CR, isolated hearts underwent PC followed by ischemia and reperfusion. In contrast to control hearts in which PC response was attenuated, PC in CR hearts was clearly of benefit. In these hearts, aortic flow was increased resulting in a dramatic improvement of cardiac output. Our study suggests that CR is effective in preserving the PC response.

  17. Effect of ethanol of heart rate and blood pressure in nonstressed and stressed rats

    SciTech Connect

    Sparrow, M.G.; Roggendorf, H.; Vogel, W.H.

    1987-06-29

    The effect of ethanol on the cardiovascular system (ECG, heart rate, blood pressure) was studied in anesthetized, nonstressed or stressed rats. In anesthetized rats, ethanol showed no effect on heart rate or ECG. In nonstressed rats, ethanol sedated the animals but increased heart rate significantly. This ethanol induced tachycardia seemed the result of a direct stimulation of the sympathetic nerves to the heart. Blood pressure was not significantly affected by ethanol in these nonstressed rats. In stressed rats, marked behavioral excitation and significant increases in heart rate and blood pressure were noted. Ethanol pretreatment calmed the animals considerably during restraint. Ethanol did reduce slightly the stress-induced tachycardia but markedly reduced or antagonized stress-induced blood pressure increases. No major changes in the ECG were noted during these studies with the exception of a few individual animals which showed pathologic ECG responses to ethanol. These data show that ethanol affects cardiovascular functions differently in anesthetized, non stressed or stressed rats, and that ethanol can significantly reduce or antagonize stress-induced behavioral excitation, tachycardia and hypertension. 32 references, 4 tables.

  18. An ontogenic study of adrenomedullin gene expression in the rat lung, adrenal, kidney, and heart.

    PubMed

    Wong, P F; O, W S; Tang, F

    2012-04-01

    In this study, the gene expression of adrenomedullin (Adm) in the peripheral tissues which include lung, adrenal, kidney, and heart during development was investigated in the rat. The preproadrenomedullin (preproAdm) mRNA and mRNAs of its related receptor components, calcitonin receptor-like receptor (Crlr), and receptor activity-modifying proteins (Ramp1, 2 and 3) of the lung, adrenal, kidney, and heart were measured by real-time RT-PCR and the ADM peptide measured by radioimmunoassay in 1-, 7-, 21-day-old rats and the adult rats. From day 1 to 21, preproAdm mRNA levels increased with age in the lung, the kidney, and the heart but decreased with age in the adrenal. ADM levels, however, increased with age in the lung but decreased with age in the kidney, the adrenal, and the heart. The preproAdm levels in the lung, in the kidney, and in the adrenal all increased in the adult rat. ADM peptide levels, however, decreased in the adult rat. Crlr and Ramp2 gene expression increased with age in the lung, in the kidney, and in the heart but decreased with age in the adrenal in the prepubertal rats. The results indicate that the levels of preproAdm mRNA, ADM peptide and its receptor component mRNAs in different tissues followed different patterns of changes during development.

  19. The embryological basis of subclinical hypertrophic cardiomyopathy.

    PubMed

    Captur, Gabriella; Ho, Carolyn Y; Schlossarek, Saskia; Kerwin, Janet; Mirabel, Mariana; Wilson, Robert; Rosmini, Stefania; Obianyo, Chinwe; Reant, Patricia; Bassett, Paul; Cook, Andrew C; Lindsay, Susan; McKenna, William J; Mills, Kevin; Elliott, Perry M; Mohun, Timothy J; Carrier, Lucie; Moon, James C

    2016-06-21

    Hypertrophic cardiomyopathy (HCM) is caused by mutations in sarcomeric proteins, the commonest being MYBPC3 encoding myosin-binding protein C. It is characterised by left ventricular hypertrophy but there is an important pre-hypertrophic phenotype with features including crypts, abnormal mitral leaflets and trabeculae. We investigated these during mouse cardiac development using high-resolution episcopic microscopy. In embryonic hearts from wildtype, homozygous (HO) and heterozygous (HET) Mybpc3-targeted knock-out (KO) mice we show that crypts (one or two) are a normal part of wildtype development but they almost all resolve by birth. By contrast, HO and HET embryos had increased crypt presence, abnormal mitral valve formation and alterations in the compaction process. In scarce normal human embryos, crypts were sometimes present. This study shows that features of the human pre-hypertrophic HCM phenotype occur in the mouse. In an animal model we demonstrate that there is an embryological HCM phenotype. Crypts are a normal part of cardiac development but, along with the mitral valve and trabeculae, their developmental trajectory is altered by the presence of HCM truncating Mybpc3 gene mutation.

  20. The embryological basis of subclinical hypertrophic cardiomyopathy

    PubMed Central

    Captur, Gabriella; Ho, Carolyn Y.; Schlossarek, Saskia; Kerwin, Janet; Mirabel, Mariana; Wilson, Robert; Rosmini, Stefania; Obianyo, Chinwe; Reant, Patricia; Bassett, Paul; Cook, Andrew C.; Lindsay, Susan; McKenna, William J.; Mills, Kevin; Elliott, Perry M.; Mohun, Timothy J.; Carrier, Lucie; Moon, James C.

    2016-01-01

    Hypertrophic cardiomyopathy (HCM) is caused by mutations in sarcomeric proteins, the commonest being MYBPC3 encoding myosin-binding protein C. It is characterised by left ventricular hypertrophy but there is an important pre-hypertrophic phenotype with features including crypts, abnormal mitral leaflets and trabeculae. We investigated these during mouse cardiac development using high-resolution episcopic microscopy. In embryonic hearts from wildtype, homozygous (HO) and heterozygous (HET) Mybpc3-targeted knock-out (KO) mice we show that crypts (one or two) are a normal part of wildtype development but they almost all resolve by birth. By contrast, HO and HET embryos had increased crypt presence, abnormal mitral valve formation and alterations in the compaction process. In scarce normal human embryos, crypts were sometimes present. This study shows that features of the human pre-hypertrophic HCM phenotype occur in the mouse. In an animal model we demonstrate that there is an embryological HCM phenotype. Crypts are a normal part of cardiac development but, along with the mitral valve and trabeculae, their developmental trajectory is altered by the presence of HCM truncating Mybpc3 gene mutation. PMID:27323879

  1. The embryological basis of subclinical hypertrophic cardiomyopathy.

    PubMed

    Captur, Gabriella; Ho, Carolyn Y; Schlossarek, Saskia; Kerwin, Janet; Mirabel, Mariana; Wilson, Robert; Rosmini, Stefania; Obianyo, Chinwe; Reant, Patricia; Bassett, Paul; Cook, Andrew C; Lindsay, Susan; McKenna, William J; Mills, Kevin; Elliott, Perry M; Mohun, Timothy J; Carrier, Lucie; Moon, James C

    2016-01-01

    Hypertrophic cardiomyopathy (HCM) is caused by mutations in sarcomeric proteins, the commonest being MYBPC3 encoding myosin-binding protein C. It is characterised by left ventricular hypertrophy but there is an important pre-hypertrophic phenotype with features including crypts, abnormal mitral leaflets and trabeculae. We investigated these during mouse cardiac development using high-resolution episcopic microscopy. In embryonic hearts from wildtype, homozygous (HO) and heterozygous (HET) Mybpc3-targeted knock-out (KO) mice we show that crypts (one or two) are a normal part of wildtype development but they almost all resolve by birth. By contrast, HO and HET embryos had increased crypt presence, abnormal mitral valve formation and alterations in the compaction process. In scarce normal human embryos, crypts were sometimes present. This study shows that features of the human pre-hypertrophic HCM phenotype occur in the mouse. In an animal model we demonstrate that there is an embryological HCM phenotype. Crypts are a normal part of cardiac development but, along with the mitral valve and trabeculae, their developmental trajectory is altered by the presence of HCM truncating Mybpc3 gene mutation. PMID:27323879

  2. Long-term physiological T3 supplementation in hypertensive heart disease in rats.

    PubMed

    Weltman, Nathan Y; Pol, Christine J; Zhang, Youhua; Wang, Yibo; Koder, Adrienne; Raza, Sarah; Zucchi, Riccardo; Saba, Alessandro; Colligiani, Daria; Gerdes, A Martin

    2015-09-15

    Animal studies suggest that hypertension leads to cardiac tissue hypothyroidism, a condition that can by itself lead to heart failure. We have previously shown that short-term thyroid hormone treatment in Spontaneously Hypertensive Heart Failure (SHHF) rats near heart failure is beneficial. This study tested the hypothesis that therapeutic, long-term T3 treatment in SHHF rats can prevent or attenuate cardiac dysfunction. Female SHHF rats were treated orally with a physiological T3 dose (0.04 μg/ml) from 12 to 24 mo of age. Age-matched female SHHF and Wistar-Kyoto rats served as hypertensive and normotensive controls, respectively. SHHF rats had reduced serum free thyroid hormone levels and cardiac tissue T3 levels, LV dysfunction, and elevated LV collagen content compared with normotensive controls. Restoration of serum and cardiac tissue thyroid hormone levels in T3-treated rats was associated with no change in heart rate, but strong trends for improvement in LV systolic function and collagen levels. For instance, end-systolic diameter, fractional shortening, systolic wall stress, and LV collagen levels were no longer significantly different from controls. In conclusion, longstanding hypertension in rats led to chronic low serum and cardiac tissue thyroid hormone levels. Long-term treatment with low-dose T3 was safe. While cardiac dysfunction could not be completely prevented in the absence of antihypertensive treatment, T3 may offer additional benefits as an adjunct therapy with possible improvement in diastolic function.

  3. Long-term physiological T3 supplementation in hypertensive heart disease in rats.

    PubMed

    Weltman, Nathan Y; Pol, Christine J; Zhang, Youhua; Wang, Yibo; Koder, Adrienne; Raza, Sarah; Zucchi, Riccardo; Saba, Alessandro; Colligiani, Daria; Gerdes, A Martin

    2015-09-15

    Animal studies suggest that hypertension leads to cardiac tissue hypothyroidism, a condition that can by itself lead to heart failure. We have previously shown that short-term thyroid hormone treatment in Spontaneously Hypertensive Heart Failure (SHHF) rats near heart failure is beneficial. This study tested the hypothesis that therapeutic, long-term T3 treatment in SHHF rats can prevent or attenuate cardiac dysfunction. Female SHHF rats were treated orally with a physiological T3 dose (0.04 μg/ml) from 12 to 24 mo of age. Age-matched female SHHF and Wistar-Kyoto rats served as hypertensive and normotensive controls, respectively. SHHF rats had reduced serum free thyroid hormone levels and cardiac tissue T3 levels, LV dysfunction, and elevated LV collagen content compared with normotensive controls. Restoration of serum and cardiac tissue thyroid hormone levels in T3-treated rats was associated with no change in heart rate, but strong trends for improvement in LV systolic function and collagen levels. For instance, end-systolic diameter, fractional shortening, systolic wall stress, and LV collagen levels were no longer significantly different from controls. In conclusion, longstanding hypertension in rats led to chronic low serum and cardiac tissue thyroid hormone levels. Long-term treatment with low-dose T3 was safe. While cardiac dysfunction could not be completely prevented in the absence of antihypertensive treatment, T3 may offer additional benefits as an adjunct therapy with possible improvement in diastolic function. PMID:26254335

  4. Natriuretic Peptides as Cardiovascular Safety Biomarkers in Rats: Comparison With Blood Pressure, Heart Rate, and Heart Weight.

    PubMed

    Engle, Steven K; Watson, David E

    2016-02-01

    Cardiovascular (CV) toxicity is an important cause of failure during drug development. Blood-based biomarkers can be used to detect CV toxicity during preclinical development and prioritize compounds at lower risk of causing such toxicities. Evidence of myocardial degeneration can be detected by measuring concentrations of biomarkers such as cardiac troponin I and creatine kinase in blood; however, detection of functional changes in the CV system, such as blood pressure, generally requires studies in animals with surgically implanted pressure transducers. This is a significant limitation because sustained changes in blood pressure are often accompanied by changes in heart rate and together can lead to cardiac hypertrophy and myocardial degeneration in animals, and major adverse cardiovascular events (MACE) in humans. Increased concentrations of NPs in blood correlate with higher risk of cardiac mortality, all-cause mortality, and MACE in humans. Their utility as biomarkers of CV function and toxicity in rodents was investigated by exploring the relationships between plasma concentrations of NTproANP and NTproBNP, blood pressure, heart rate, and heart weight in Sprague Dawley rats administered compounds that caused hypotension or hypertension, including nifedipine, fluprostenol, minoxidil, L-NAME, L-thyroxine, or sunitinib for 1-2 weeks. Changes in NTproANP and/or NTproBNP concentrations were inversely correlated with changes in blood pressure. NTproANP and NTproBNP concentrations were inconsistently correlated with relative heart weights. In addition, increased heart rate was associated with increased heart weights. These studies support the use of natriuretic peptides and heart rate to detect changes in blood pressure and cardiac hypertrophy in short-duration rat studies. PMID:26609138

  5. Collagen remodeling after myocardial infarction in the rat heart.

    PubMed Central

    Cleutjens, J. P.; Verluyten, M. J.; Smiths, J. F.; Daemen, M. J.

    1995-01-01

    In this study changes in the amount and distribution of types I and III collagen mRNA and protein were investigated in the rat heart after induction of a left ventricular myocardial infarction (MI). Sham operated rats served as controls. The animals were sacrificed at different time intervals after operation. Northern blotting of cardiac RNA and hybridization with cDNA probes for types I and III procollagen revealed a 5- to 15-fold increase in the infarcted left ventricle. Type III procollagen mRNA levels were already increased at day 2 after MI, whereas type I procollagen mRNA followed this response at day 4 after MI. This increase was sustained for at least 21 days in the infarcted left ventricle for type III procollagen mRNA, whereas type 1 procollagen mRNA levels were still elevated at 90 days after MI. In the noninfarcted right ventricle a 5- to 7-fold increase was observed for both type I and type III procollagen mRNA levels, but only at day 4 after MI. In the non-infarcted septum a transient increase was observed for type I procollagen mRNA from day 7-21 (4- to 5-fold increase) and a decline to sham levels thereafter. In the septum type III procollagen mRNA levels were only elevated at 7 days after MI (4- to 5-fold increase) compared with sham operated controls. In situ hybridization with the same types I and III procollagen probes showed procollagen mRNA-producing cells in the infarcted area around necrotic cardiomyocytes, and in the interstitial cells in the non-infarcted part of the myocardium. No labeling was detected above cardiomyocytes. Combined in situ hybridization and immunohistochemistry showed that the collagen mRNA producing cells have a myofibroblast-like phenotype in the infarcted myocardium and are fibroblasts in the noninfarcted septum and right ventricle. The increase in types I and III procollagen mRNA in both infarcted and non-infarcted myocardium was followed by an increased collagen deposition, measured by computerized morphometry on

  6. Enhanced arrhythmogenicity of Freon 113 by hypoxia in the perfused rat heart

    SciTech Connect

    Kawakami, T.; Takano, T.; Araki, R. )

    1990-05-01

    The interaction of Freon 113 (1,1,2-trichloro-1,2,2-trifluoroethane) and hypoxia on the heart conduction system was studied using electrocardiogram monitoring of isolated perfused rat hearts. Freon 113 (0.2 mM) alone elicited significant atrioventricular conduction delay (p less than 0.05) and heart rate decrease (p less than 0.01), which were significantly enhanced by hypoxia (75% oxygen decrease), for instance, resulting in 2:1 AV block. The data suggest that arrhythmogenicity of Freon 113 on the heart conduction system may be enhanced synergistically by hypoxia.

  7. 31P NMR spectroscopy of hypertrophied rat heart: effect of graded global ischemia.

    PubMed

    Clarke, K; Sunn, N; Willis, R J

    1989-12-01

    To investigate the cause for the greater susceptibility of hypertrophied hearts to ischemic injury, we determined the interrelations of total work output, contractile function and energy metabolism in isolated, perfused normal and hypertrophied rat hearts subjected to graded global ischemia. Cardiac hypertrophy was induced by giving rats seven daily injections of either triiodothyronine (0.2 mg/kg) or isoproterenol (5 mg/kg). All hearts were perfused at an aortic pressure of 100 mmHg in the isovolumic mode in an NMR spectrometer (7.05 Tesla). Heart rate, developed pressure, and coronary flow were monitored simultaneously with changes in pH, creatine phosphate, ATP and inorganic phosphate. During pre-ischemic perfusion, the total work output (rate-pressure product) of hyperthyroid hearts was 28% higher than that of control hearts, whereas hearts from isoproterenol-treated animals showed no difference. However, when related to unit muscle mass, work was normal in hyperthyroid hearts and 26% lower after isoproterenol. Contractile function per unit myocardium (developed pressure/g wet weight) was lower in the hypertrophied hearts. ATP content was the same in all groups. Creatine phosphate decreased 41% after triiodothyronine and 25% after isoproterenol. Inorganic phosphate levels and intracellular pH were similar in control and isoproterenol-treated rat hearts, but were higher in the hyperthyroid rat hearts. The phosphorylation potential and the free energy change of ATP hydrolysis were lowered by hypertrophy, the levels correlating with the depressed contractile function. At each ischemic flow rate, both work and contractile function per unit myocardium were the same for all hearts, but the relations between flow and phosphorylation potential were different for each type of heart. Thus, at low flow rates, hypertrophied hearts perform the same amount of work and have the same contractile function as control hearts, but with abnormal changes in energy metabolism

  8. Combined effects of niacin and chromium treatment on heart of hyperlipidemic rats.

    PubMed

    Döger, M Mutluhan; Sokmen, Bahar B; Yanardag, Refiye

    2011-10-01

    The present study was undertaken to investigate the effects of the combination of niacin and chromium(III)-chloride on heart glutathione (GSH), lipid peroxidation (LPO) levels, serum paraoxonase (PON), gamma-glutamyl transferase (GGT) activities and protein carbonyl contents (PCC) of hyperlipidemic rats. In this study, female Swiss albino rats were used. They were divided into four groups. The animals of the first group (group I) were fed with pellet chow. The rats (group II) were fed with a lipogenic diet consisting of 2% cholesterol, 0.5% cholic acid and 20% sunflower oil added to the pellet chow, and given 3% alcoholic water for 60 days. The rats (group III) were fed with the same lipogenic diet and treated by gavage technique with CrCl(3) 6H(2)O to a dose of 250 µg/kg and 100 mg/kg niacin for 45 days, 15 days after experimental animals were done hyperlipidemic. Group IV was fed with pellet chow and treated with 250 µg/kg CrCl(3) 6H(2)O and 100 mg/kg niacin for 45 days. On the 60th day, the heart tissue and blood samples were taken from animals. As a result, heart LPO, serum GGT activity and serum PCC were increased; serum PON activity and heart GSH levels were decreased in hyperlipidemic rats. Treatment with combined niacin and chromium reversed these effects. In conclusion, the combined treatment with niacin and chromium might induce a protective effect on heart tissue.

  9. Hypothyroidism and oxidative stress: differential effect on the heart of virgin and pregnant rats.

    PubMed

    Carmona, Y V; Coria, M J; Oliveros, L B; Gimenez, M S

    2014-01-01

    The present study investigates the effects of hypothyroidism on both the redox state and the thyroid hormone receptors expression in the heart ventricle of virgin and pregnant rats.Hypothyroid state was induced by 6-n-propyl-2-thiouracil in drinking water given to Wistar rats starting 8 days before mating until day 21 of pregnancy or for 30 days in virgin rats. Serum paraoxonase-1 (PON-1) activity, serum and heart nitrites, and thiobarbituric acid-reactive substances (TBARS) were analyzed. Heart protein oxidation, as carbonyls, and copper-zinc superoxide dismutase (CuZnSOD), glutathione peroxidase (GPx), and catalase (CAT) activities, were determined. In addition, heart expressions of NADPH oxidase (NOX-2), CAT, SOD, GPx, and thyroid receptors (TRα and TRβ) mRNA were assessed by RT-PCR. Inducible and endothelial Nitric Oxide Synthase (iNOS and eNOS) were determined by Western blot. Hypothyroidism in the heart of virgin rats decreased TRα and TRβ expressions, and induced oxidative stress, leading to a decrease of nitrites and an increase of carbonyls, NOX-2 mRNA, and GPx activity. A decreased PON-1 activity suggested low protection against oxidative stress in blood circulation. Pregnancy reduced TRα and TRβ mRNA expressions and induced oxidative stress by increasing nitrite and TBARS levels, SOD and CAT activities and NOX-2, eNOS and iNOS expressions, while hypothyroidism, emphasized the decreases of TRα mRNA levels and did not alter the redox state in the heart. TR expressions and redox balance of rat hearts depend on the physiological state. Pregnancy per se seems to protect the heart against oxidative stress induced by hypothyroidism. Supporting Information for this article is available online at http://www.thieme-connect.de/ejournals/toc/hmr.

  10. The role of calcium-independent phospholipase A2 in cardiolipin remodeling in the spontaneously hypertensive heart failure rat heart.

    PubMed

    Zachman, Derek K; Chicco, Adam J; McCune, Sylvia A; Murphy, Robert C; Moore, Russell L; Sparagna, Genevieve C

    2010-03-01

    Cardiolipin (CL) is an essential phospholipid component of the inner mitochondrial membrane. In the mammalian heart, the functional form of CL is tetralinoleoyl CL [(18:2)(4)CL]. A decrease in (18:2)(4)CL content, which is believed to negatively impact mitochondrial energetics, occurs in heart failure (HF) and other mitochondrial diseases. Presumably, (18:2)(4)CL is generated by remodeling nascent CL in a series of deacylation-reacylation cycles; however, our overall understanding of CL remodeling is not yet complete. Herein, we present a novel cell culture method for investigating CL remodeling in myocytes isolated from Spontaneously Hypertensive HF rat hearts. Further, we use this method to examine the role of calcium-independent phospholipase A(2) (iPLA(2)) in CL remodeling in both HF and nonHF cardiomyocytes. Our results show that 18:2 incorporation into (18:2)(4)CL is: a) performed singly with respect to each fatty acyl moiety, b) attenuated in HF relative to nonHF, and c) partially sensitive to iPLA(2) inhibition by bromoenol lactone. These results suggest that CL remodeling occurs in a step-wise manner, that compromised 18:2 incorporation contributes to a reduction in (18:2)(4)CL in the failing rat heart, and that mitochondrial iPLA(2) plays a role in the remodeling of CL's acyl composition. PMID:19741254

  11. The role of calcium-independent phospholipase A2 in cardiolipin remodeling in the spontaneously hypertensive heart failure rat heart

    PubMed Central

    Zachman, Derek K.; Chicco, Adam J.; McCune, Sylvia A.; Murphy, Robert C.; Moore, Russell L.; Sparagna, Genevieve C.

    2010-01-01

    Cardiolipin (CL) is an essential phospholipid component of the inner mitochondrial membrane. In the mammalian heart, the functional form of CL is tetralinoleoyl CL [(18:2)4CL]. A decrease in (18:2)4CL content, which is believed to negatively impact mitochondrial energetics, occurs in heart failure (HF) and other mitochondrial diseases. Presumably, (18:2)4CL is generated by remodeling nascent CL in a series of deacylation-reacylation cycles; however, our overall understanding of CL remodeling is not yet complete. Herein, we present a novel cell culture method for investigating CL remodeling in myocytes isolated from Spontaneously Hypertensive HF rat hearts. Further, we use this method to examine the role of calcium-independent phospholipase A2 (iPLA2) in CL remodeling in both HF and nonHF cardiomyocytes. Our results show that 18:2 incorporation into (18:2)4CL is: a) performed singly with respect to each fatty acyl moiety, b) attenuated in HF relative to nonHF, and c) partially sensitive to iPLA2 inhibition by bromoenol lactone. These results suggest that CL remodeling occurs in a step-wise manner, that compromised 18:2 incorporation contributes to a reduction in (18:2)4CL in the failing rat heart, and that mitochondrial iPLA2 plays a role in the remodeling of CL's acyl composition. PMID:19741254

  12. Molecular cloning of rat cardiac troponin I and analysis of troponin I isoform expression in developing rat heart.

    PubMed

    Murphy, A M; Jones, L; Sims, H F; Strauss, A W

    1991-01-22

    We have isolated and sequenced a cDNA encoding rat cardiac troponin I. The predicted amino acid sequence was highly identical with previously reported chemically derived amino acid sequences for rabbit and bovine cardiac troponin I. Clones for slow skeletal muscle troponin I were also obtained from neonatal rat cardiac ventricle by the polymerase chain reaction. The nucleotide sequences of these clones were determined to be more than 99% identical with a previously reported rat slow skeletal troponin I cDNA [Koppe et al. (1989) J. Biol. Chem. 264, 14327-14333]. The troponin I clones hybridized to RNA from the appropriate muscle from adult animals. However, RNA from fetal and neonatal rat heart also hybridized with the slow skeletal troponin I cDNA, demonstrating its expression in fetal and neonatal rat heart. Slow skeletal troponin I steady-state mRNA levels decreased with increasing age, but cardiac troponin I mRNA levels increased through fetal and early neonatal cardiac development. Thus, during fetal and neonatal development, slow skeletal and cardiac troponin I isoforms are coexpressed in the rat heart and regulated in opposite directions. The degree of primary sequence differences in these isoforms, especially at phosphorylation sites, may result in important functional differences in the neonatal myocardium.

  13. Stabilization of mitochondrial membrane potential prevents doxorubicin-induced cardiotoxicity in isolated rat heart

    SciTech Connect

    Montaigne, David; Marechal, Xavier; Baccouch, Riadh; Modine, Thomas; Preau, Sebastien; Zannis, Konstantinos; Marchetti, Philippe; Lancel, Steve; Neviere, Remi

    2010-05-01

    The present study was undertaken to examine the effects of doxorubicin on left ventricular function and cellular energy state in intact isolated hearts, and, to test whether inhibition of mitochondrial membrane potential dissipation would prevent doxorubicin-induced mitochondrial and myocardial dysfunction. Myocardial contractile performance and mitochondrial respiration were evaluated by left ventricular tension and its first derivatives and cardiac fiber respirometry, respectively. NADH levels, mitochondrial membrane potential and glucose uptake were monitored non-invasively via epicardial imaging of the left ventricular wall of Langendorff-perfused rat hearts. Heart performance was reduced in a time-dependent manner in isolated rat hearts perfused with Krebs-Henseleit solution containing 1 muM doxorubicin. Compared with controls, doxorubicin induced acute myocardial dysfunction (dF/dt{sub max} of 105 +- 8 mN/s in control hearts vs. 49 +- 7 mN/s in doxorubicin-treated hearts; *p < 0.05). In cardiac fibers prepared from perfused hearts, doxorubicin induced depression of mitochondrial respiration (respiratory control ratio of 4.0 +- 0.2 in control hearts vs. 2.2 +- 0.2 in doxorubicin-treated hearts; *p < 0.05) and cytochrome c oxidase kinetic activity (24 +- 1 muM cytochrome c/min/mg in control hearts vs. 14 +- 3 muM cytochrome c/min/mg in doxorubicin-treated hearts; *p < 0.05). Acute cardiotoxicity induced by doxorubicin was accompanied by NADH redox state, mitochondrial membrane potential, and glucose uptake reduction. Inhibition of mitochondrial permeability transition pore opening by cyclosporine A largely prevented mitochondrial membrane potential dissipation, cardiac energy state and dysfunction. These results suggest that in intact hearts an impairment of mitochondrial metabolism is involved in the development of doxorubicin cardiotoxicity.

  14. The Regulatory Role of Nuclear Factor Kappa B in the Heart of Hereditary Hypertriglyceridemic Rat

    PubMed Central

    Vranková, Stanislava; Barta, Andrej; Klimentová, Jana; Dovinová, Ima; Líšková, Silvia; Dobešová, Zdenka; Pecháňová, Oľga; Kuneš, Jaroslav; Zicha, Josef

    2016-01-01

    Activation of nuclear factor-κB (NF-κB) by increased production of reactive oxygen species (ROS) might induce transcription and expression of different antioxidant enzymes and also of nitric oxide synthase (NOS) isoforms. Thus, we aimed at studying the effect of NF-κB inhibition, caused by JSH-23 (4-methyl-N1-(3-phenyl-propyl)-benzene-1,2-diamine) injection, on ROS and NO generation in hereditary hypertriglyceridemic (HTG) rats. 12-week-old, male Wistar and HTG rats were treated with JSH-23 (bolus, 10 μmol, i.v.). After one week, blood pressure (BP), superoxide dismutase (SOD) activity, SOD1, endothelial NOS (eNOS), and NF-κB (p65) protein expressions were higher in the heart of HTG rats compared to control rats. On the other hand, NOS activity was decreased. In HTG rats, JSH-23 treatment increased BP and heart conjugated dienes (CD) concentration (measured as the marker of tissue oxidative damage). Concomitantly, SOD activity together with SOD1 expression was decreased, while NOS activity and eNOS protein expression were increased significantly. In conclusion, NF-κB inhibition in HTG rats led to decreased ROS degradation by SOD followed by increased oxidative damage in the heart and BP elevation. In these conditions, increased NO generation may represent rather a counterregulatory mechanism activated by ROS. Nevertheless, this mechanism was not sufficient enough to compensate BP increase in HTG rats. PMID:27148433

  15. Characterization of the histamine releasing effect of neurotensin in the rat heart.

    PubMed

    Rioux, F; Kérouac, R; St-Pierre, S

    1985-01-01

    Bolus injections of neurotensin (NT) in the rat perfused heart elicited a transient, dose-dependent histamine release. The histamine releasing effect of NT appears to be independent of the heart rate and coronary perfusion pressure and it was not influenced by atropine, propanolol, prazosin, methysergide, ketanserin, indomethacin, morphine, lidocaine or by removal of the atria. However, it was potentiated by adenosine, inhibited by sub-stimulatory concentrations of NT and the mast cell membrane stabilizing drug cromoglycate but was unaltered by the calcium antagonist verapamil. The absence of calcium in the heart perfusate suppressed the histamine releasing effect of NT. These results suggest that the histamine releasing effect of NT in the rat heart results from a direct effect on ventricular mast cells and is calcium-dependent.

  16. Endoplasmic reticulum stress involved in heart and liver injury in iron-loaded rats.

    PubMed

    Lou, Li-Xia; Geng, Bin; Chen, Yu; Yu, Fang; Zhao, Jing; Tang, Chao-Shu

    2009-07-01

    1. Iron overload contributes to the pathogenesis of various diseases and directly induces tissue injury. In the present study, we investigated the relationship between heart and liver injury induced by iron overload and cellular endoplasmic reticulum (ER) stress to explore the molecular mechanism of iron overload-induced cellular injury. 2. Iron overload in rats was generated by intraperitoneal injection of iron-dextran chronically (30 mg/kg per day for 9 weeks) or acutely (300 mg/kg once). Tissue injury was assessed by determining serum lactate dehydrogenase (LDH), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity, as well as malondialdehyde (MDA) content in the heart and liver. The ER stress response was analysed by expression of glucose-response protein 78 (GRP78) and activation of caspase 12. 3. In chronic iron-loaded rats, iron levels in the heart and liver were higher, by approximately 2- and 7.8-fold, respectively (P < 0.01), compared with control. Serum LDH, ALT and AST activity, as well as MDA content, GRP78 expression and caspase 12 activity in the heart and liver, were upregulated in chronically iron-loaded rats. In acute iron-loaded rats, iron content in the heart and liver was 51% and 63% higher than in controls (both P < 0.01). Serum LDH, ALT and AST activity, MDA content in the heart and liver and levels of ER stress markers were all increased in acute iron-loaded rats. N-Acetylcysteine (150 mg/kg, s.c.) lowered the levels of these parameters in acute iron-loaded rats. 4. The results of the present study indicate that ER stress may play an important role in iron-induced tissue injury and that reactive oxygen species may mediate the ER stress response in the pathogenesis of iron-overload cellular injury. PMID:19594550

  17. Effects of middle cerebral artery occlusion on baroreceptor reflex control of heart rate in the rat.

    PubMed

    Saad, M A; Huerta, F; Trancard, J; Elghozi, J L

    1989-07-01

    Neurons in the insular cortex have recently been shown to innervate medullary autonomic nuclei such as the nucleus tractus solitarii (NTS). The present study examines the effect of lesioning the insular cortex on baroreceptor-heart rate reflex in conscious rats. We did this by occluding the stem of the left proximal middle cerebral artery which causes a lesion of the insular and adjacent lateral frontoparietal cortices. Nine and 10 days after lesioning or sham operation, reflex heart rate responses were recorded following i.v. doses of the pressor agent phenylephrine and the depressor agent sodium nitroprusside. Baroreceptor reflex parameters were determined by computerized sigmoidal curve-fitting. The overall contribution of the sympathetic and the cardiac vagus were assessed by using peripherally acting muscarinic and beta-adrenoceptor antagonists, respectively. Lesioned rats were compared to sham-operated rats. Lesioning the insular cortex did not affect mean blood pressure and heart rate. However, the lesion selectively enhanced reflex vagal bradycardia that occurred when mean blood pressure was artificially elevated. A greater vagal bradycardia with no change in the upper plateau indicated that ischemia was acting entirely on the baroreflex-dependent vagal cardiac motoneurons. There was no effect on the sympathetic heart rate range but the normalized gain of the sympathetic component was increased in those lesioned rats. These observations suggest that the unilateral cortical lesion chronically affected the baroreceptor control of heart rate through mechanisms differentially affecting the vagus and the cardiac sympathetic nerves. PMID:2778268

  18. Myocardial pharmacokinetics of ebastine, a substrate for cytochrome P450 2J, in rat isolated heart

    PubMed Central

    Kang, W; Elitzer, S; Noh, K; Bednarek, T; Weiss, M

    2011-01-01

    BACKGROUND AND PURPOSE It is well established that cytochrome P450 2J (CYP2J) enzymes are expressed preferentially in the heart, and that ebastine is a substrate for CYP2J, but it is not known whether ebastine is metabolized in myocardium. Therefore, we investigated its pharmacokinetics in the rat isolated perfused heart. EXPERIMENTAL APPROACH Rat isolated hearts were perfused in the recirculating mode with ebastine for 130 min. The concentrations of ebastine and its metabolites, hydroxyebastine and carebastine, were measured using liquid chromatography with a tandem mass spectrometry. The data were analysed by a compartmental model. The time course of negative inotropic response was linked to ebastine concentration to determine the concentration–effect relationship. KEY RESULTS Ebastine was metabolized to an intermediate compound, hydroxyebastine, which was subsequently further metabolized to carebastine. No desalkylebastine was found. The kinetics of the sequential metabolism of ebastine was well described by the compartmental model. The EC50 of the negative inotropic effect of ebastine in rat isolated heart was much higher than free plasma concentrations in humans after clinical doses. CONCLUSIONS AND IMPLICATIONS The kinetics of ebastine conversion to carebastine via hydroxyebastine resembled that observed in human liver microsomes. The results may be of interest for functional characterization of CYP2J activity in rat heart. PMID:21410688

  19. Hypertrophic cardiomyopathy: a review.

    PubMed

    Hensley, Nadia; Dietrich, Jennifer; Nyhan, Daniel; Mitter, Nanhi; Yee, May-Sann; Brady, MaryBeth

    2015-03-01

    Hypertrophic cardiomyopathy (HCM) is a relatively common disorder that anesthesiologists encounter among patients in the perioperative period. Fifty years ago, HCM was thought to be an obscure disease. Today, however, our understanding and ability to diagnose patients with HCM have improved dramatically. Patients with HCM have genotypic and phenotypic variability. Indeed, a subgroup of these patients exhibits the HCM genotype but not the phenotype (left ventricular hypertrophy). There are a number of treatment modalities for these patients, including pharmacotherapy to control symptoms, implantable cardiac defibrillators to manage malignant arrhythmias, and surgical myectomy and septal ablation to decrease the left ventricular outflow obstruction. Accurate diagnosis is vital for the perioperative management of these patients. Diagnosis is most often made using echocardiographic assessment of left ventricular hypertrophy, left ventricular outflow tract gradients, systolic and diastolic function, and mitral valve anatomy and function. Cardiac magnetic resonance imaging also has a diagnostic role by determining the extent and location of left ventricular hypertrophy and the anatomic abnormalities of the mitral valve and papillary muscles. In this review on hypertrophic cardiomyopathy for the noncardiac anesthesiologist, we discuss the clinical presentation and genetic mutations associated with HCM, the critical role of echocardiography in the diagnosis and the assessment of surgical interventions, and the perioperative management of patients with HCM undergoing noncardiac surgery and management of the parturient with HCM. PMID:25695573

  20. Heart Rate Variability in Nonlinear Rats with Different Orientation and Exploratory Activity in the Open Field.

    PubMed

    Kur'yanova, E V; Teplyi, D L; Zhukova, Yu D; Zhukovina, N V

    2015-12-01

    The basic behavioral activity of nonlinear rats was evaluated from the sum of crossed peripheral and central squares and peripheral and central rearing postures in the open fi eld test. This index was low (<20 episodes), intermediate (20-29 episodes), or high (>30 episodes). Male rats with high score of orientation and exploratory activity were characterized by higher indexes of total heart rate variability than rats with low or intermediate activity. Specimens with a greater contribution of VLF waves into the total power spectrum of heart rate variability were shown to dominate among the rats with high behavioral activity. Our results are consistent with the notions of a suprasegmental nature of VLF waves.

  1. Hydrogen-containing saline attenuates doxorubicin-induced heart failure in rats.

    PubMed

    Wu, Shujing; Zhu, Liqun; Yang, Jing; Fan, Zhixin; Dong, Yanli; Luan, Rui; Cai, Jingjing; Fu, Lu

    2014-08-01

    Interactions between doxorubicin (DOX) and iron generate reactive oxygen species and contribute to DOX-induced heart failure. Hydrogen, as a selective antioxidant, is a promising potential therapeutic option for the treatment of a variety of diseases. Therefore, we investigated the preventive effects of hydrogen treatment on DOX-induced heart failure in rats. We found that cardiac function was significantly improved and that the plasma levels of oxidative-stress markers and myocardial autophagic activity were decreased in animals treated with hydrogen-containing saline. Therefore, we conclude that hydrogen-containing saline may have beneficial effects for doxorubicin-induced heart failure.

  2. Direct cardiac effects of dobutamine, dopamine, epinephrine, and levosimendan in isolated septic rat hearts.

    PubMed

    Zausig, York A; Geilfus, Diana; Missler, Goetz; Sinner, Barbara; Graf, Bernhard M; Zink, Wolfgang

    2010-09-01

    In septic patients, myocardial depression-the so-called septic cardiomyopathy-needing inotropic support is common. The aim of this study was to compare the dose-responsive electrophysiological and mechanical properties concerning metabolic effects of clinically available inotropic agents in an isolated septic rat heart model. After 20 h of incubation, both sham-operated and septic (cecal ligation and single puncture) hearts from male Wistar rats (n = 64) were isolated and received dobutamine, dopamine, epinephrine, or levosimendan at concentrations of 10 to 10 M. Electrophysiological, mechanical, and metabolic properties were measured, and the myocardial oxygen supply-demand ratio and cardiac efficiency were calculated. With the exception of levosimendan, all of the drugs tested showed dose-dependent, significantly positive changes in chronotropy, inotropy, and lusitropy in all hearts. Maximum increases in septic hearts were dose-dependent and were ordered as follows: epinephrine > dopamine > dobutamine > levosimendan. These increases in cardiac performance were accompanied by a decrease in the myocardial oxygen supply-demand ratio. However, cardiac efficiency was significantly improved in the epinephrine-treated septic hearts. With the drug-induced increase in cardiac performance, the myocardial oxygen supply-demand ratio decreased proportionally in the epinephrine-, dobutamine-, and dopamine-treated septic hearts. However, epinephrine showed the most favorable results with regard to cardiac efficiency, and levosimendan showed no beneficial effect in septic hearts with regard to efficiency in this study.

  3. Multiscale entropy analysis of heart rate variability in heart failure, hypertensive, and sinoaortic-denervated rats: classical and refined approaches.

    PubMed

    Silva, Luiz Eduardo Virgilio; Lataro, Renata Maria; Castania, Jaci Airton; da Silva, Carlos Alberto Aguiar; Valencia, Jose Fernando; Murta, Luiz Otavio; Salgado, Helio Cesar; Fazan, Rubens; Porta, Alberto

    2016-07-01

    The analysis of heart rate variability (HRV) by nonlinear methods has been gaining increasing interest due to their ability to quantify the complexity of cardiovascular regulation. In this study, multiscale entropy (MSE) and refined MSE (RMSE) were applied to track the complexity of HRV as a function of time scale in three pathological conscious animal models: rats with heart failure (HF), spontaneously hypertensive rats (SHR), and rats with sinoaortic denervation (SAD). Results showed that HF did not change HRV complexity, although there was a tendency to decrease the entropy in HF animals. On the other hand, SHR group was characterized by reduced complexity at long time scales, whereas SAD animals exhibited a smaller short- and long-term irregularity. We propose that short time scales (1 to 4), accounting for fast oscillations, are more related to vagal and respiratory control, whereas long time scales (5 to 20), accounting for slow oscillations, are more related to sympathetic control. The increased sympathetic modulation is probably the main reason for the lower entropy observed at high scales for both SHR and SAD groups, acting as a negative factor for the cardiovascular complexity. This study highlights the contribution of the multiscale complexity analysis of HRV for understanding the physiological mechanisms involved in cardiovascular regulation.

  4. Cardiac and renal distribution of ACE and ACE-2 in rats with heart failure.

    PubMed

    Cohen-Segev, Ravit; Francis, Bahaa; Abu-Saleh, Niroz; Awad, Hoda; Lazarovich, Aviva; Kabala, Aviva; Aronson, Doron; Abassi, Zaid

    2014-10-01

    Congestive heart failure is often associated with impaired kidney function. Over-activation of the renin-angiotensin-aldosterone system (RAAS) contributes to avid salt and water retention in heart failure. While the expression of angiotensin converting enzyme (ACE), a key enzyme in the synthesis of angiotensin II (Ang II), is well established, the expression of angiotensin converting enzyme-2 (ACE-2), an enzyme responsible for angiotensin 1-7 generation, is largely unknown. This issue is of a special interest since angiotensin 1-7 counteracts many of the proliferative and hypertensive effects of angiotensin II. Therefore, the present study was designed to investigate the expression of both enzymes in the kidney and heart of rats with heart failure. Heart failure (CHF) was induced in male Sprague Dawley rats (n=9) by the creation of a surgical aorto-caval fistula. Sham-operated rats served as controls (n=8). Two weeks after surgery, the animals were sacrificed and their hearts and kidneys were harvested for assessment of cardiac remodeling and ACE and ACE-2 immunoreactivity by immunohistochemical staining. ACE immunostaining was significantly increased in the kidneys (4.34 ± 0.39% vs. 2.96 ± 0.40%, P<0.05) and hearts (4.57 ± 0.54% vs. 2.19 ± 0.37%, P<0.01) of CHF rats as compared with their sham controls. In a similar manner, ACE-2 immunoreactivity was also elevated in the kidneys (4.65 ± 1.17% vs. 1.75 ± 0.29%, P<0.05) and hearts (5.48 ± 1.11% vs. 1.13 ± 0.26%, P<0.01) of CHF rats as compared with their healthy controls. This study showed that both ACE and ACE-2 are overexpressed in the cardiac and renal tissues of animals with heart failure as compared with their sham controls. The increased expression of the beneficial ACE-2 in heart failure may serve as a compensatory response to the over-activity of the deleterious isoform, namely, angiotensin converting enzyme 1(ACE-1).

  5. Effect of zinc supplements in the attenuated cardioprotective effect of ischemic preconditioning in hyperlipidemic rat heart.

    PubMed

    Kansal, Sunil Kumar; Jyoti, Uma; Sharma, Samridhi; Kaura, Arun; Deshmukh, Rahul; Goyal, Sandeep

    2015-06-01

    Hyperlipidemia is regarded as independent risk factor in the development of ischemic heart disease, and it can increase the myocardial susceptibility to ischemia-/reperfusion (I/R)-induced injury. Hyperlipidemia attenuates the cardioprotective response of ischemic preconditioning (IPC). The present study investigated the effect of zinc supplements in the attenuated cardioprotective effect of ischemic preconditioning in hyperlipidemic rat hearts. Hyperlipidemia was induced in rat by feeding high-fat diet (HFD) for 6 weeks then the serum lipid profile was observed. In experiment, the isolated Langendorff rat heart preparation was subjected to 4 cycles of ischemic preconditioning (IPC), then 30 min of ischemia followed by 120 min of reperfusion. Myocardial infarct size was elaborated morphologically by triphenyltetrazolium chloride (TTC) staining and biochemically by lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) release from coronary effluent and left ventricular collagen content. However, the effect of zinc supplement, i.e., zinc pyrithione (10 μM) perfused during reperfusion for 120 min, significantly abrogated the attenuated cardioprotective effect of ischemic preconditioning in hyperlipidemic rat heart whereas administration of chelator of this zinc ionophore, i.e., N,N,N',N'-tetrakis(2-pyridylmethyl)ethylene diamine (TPEN; 10 μM), perfused during reperfusion 2 min before the perfusion of zinc pyrithione abrogated the cardioprotective effect of zinc supplement during experiment in hyperlipidemic rat heart. Thus, the administration of zinc supplements limits the infarct size, LDH, and CK-MB and enhanced the collagen level which suggests that the attenuated cardioprotective effect of IPC in hyperlipidemic rat is due to zinc loss during reperfusion caused by ischemia/reperfusion. PMID:25743572

  6. Enhanced sympathetic activity and cardiac sympathetic afferent reflex in rats with heart failure induced by adriamycin.

    PubMed

    Zhang, Shujuan; Zhang, Feng; Sun, Haijian; Zhou, Yebo; Han, Ying

    2012-11-01

    Our previous studies have shown that the cardiac sympathetic afferent reflex is enhanced in rats with chronic heart failure (CHF) induced by coronary artery ligation and contributes to the over-excitation of sympathetic activity. We sought to determine whether sympathetic activity and cardiac sympathetic afferent reflex were enhanced in adriamycin-induced CHF and whether angiotensin II (Ang II) in the paraventricular nucleus (PVN) was involved in enhancing sympathetic activity and cardiac sympathetic afferent reflex. Heart failure was induced by intraperitoneal injection of adriamycin for six times during 2 weeks (15 mg/kg). Six weeks after the first injection, the rats underwent anesthesia with urethane and α-chloralose. After vagotomy and baroreceptor denervation, cardiac sympathetic afferent reflex was evaluated by renal sympathetic nerve activity and mean arterial pressure (MAP) response to epicardial application of capsaicin (1.0 nmol). The response of MAP to ganglionic blockade with hexamethonium in conscious rats was performed to evaluate sympathetic activity. The renal sympathetic nerve activity and cardiac sympathetic afferent reflex were enhanced in adriamycin rats and the maximum depressor response of MAP induced by hexamethonium was significantly greater in adriamycin rats than that in control rats. Bilateral PVN microinjection of angiotensin II (Ang II) caused larger responses of the cardiac sympathetic afferent reflex, baseline renal sympathetic nerve activity and MAP in adriamycin rats than control rats. These results indicated that both sympathetic activity and cardiac sympathetic afferent reflex were enhanced and Ang II in the PVN was involved in the enhanced sympathetic activity and cardiac sympathetic afferent reflex in rats with adriamycin-induced heart failure. PMID:23554781

  7. Regulation of Cardiac Hypertrophic Signaling by Prolyl Isomerase Pin1

    PubMed Central

    Toko, Haruhiro; Konstandin, Mathias H.; Doroudgar, Shirin; Ormachea, Lucia; Joyo, Eri; Joyo, Anya Y.; Din, Shabana; Gude, Natalie A.; Collins, Brett; Völkers, Mirko; Thuerauf, Donna J.; Glembotski, Christopher C.; Chen, Chun-Hau; Lu, Kun Ping; Müller, Oliver J.; Uchida, Takafumi; Sussman, Mark A.

    2013-01-01

    Rationale Cardiac hypertrophy results from the complex interplay of differentially regulated cascades based upon the phosphorylation status of involved signaling molecules. While numerous critical regulatory kinases and phosphatases have been identified in the myocardium, the intracellular mechanism for temporal regulation of signaling duration and intensity remains obscure. In the non-myocyte context, control of folding, activity, and stability of proteins is mediated by the prolyl isomerase Pin1, but the role of Pin1 in the heart is unknown. Objective To establish the role of Pin1 in the heart. Methods and Results Here we show that either genetic deletion or cardiac over-expression of Pin1 blunts hypertrophic responses induced by transaortic constriction and consequent cardiac failure in vivo. Mechanistically, we find that Pin1 directly binds to Akt, MEK and Raf-1 in cultured cardiomyocytes following hypertrophic stimulation. Furthermore, loss of Pin1 leads to diminished hypertrophic signaling of Akt and MEK, while over-expression of Pin1 increases Raf-1 phosphorylation on the auto-inhibitory site Ser259 leading to reduced MEK activation. Conclusions Collectively, these data support a role for Pin1 as a central modulator of the intensity and duration of two major hypertrophic signaling pathways, thereby providing a novel target for regulation and control of cardiac hypertrophy. PMID:23487407

  8. Down Syndrome with Complete Atrioventricular Septal Defect, Hypertrophic Cardiomyopathy, and Pulmonary Vein Stenosis.

    PubMed

    Mahadevaiah, Guruprasad; Gupta, Manoj; Ashwath, Ravi

    2015-10-01

    The prevalence of congenital heart disease in infants with Down syndrome is 40%, compared with 0.3% in children who have normal chromosomes. Atrioventricular and ventricular septal defects are often associated with chromosomal aberrations, such as in trisomy 21, whereas hypertrophic cardiomyopathy is chiefly thought to be secondary to specific gene mutations. We found only one reported case of congenital hypertrophic cardiomyopathy and atrioventricular septal defect in an infant with Down syndrome. Here, we report atrioventricular septal defect, hypertrophic cardiomyopathy, and pulmonary vein stenosis in a neonate with Down syndrome-an apparently unique combination. In addition, we discuss the relevant medical literature.

  9. Down Syndrome with Complete Atrioventricular Septal Defect, Hypertrophic Cardiomyopathy, and Pulmonary Vein Stenosis

    PubMed Central

    Mahadevaiah, Guruprasad; Gupta, Manoj

    2015-01-01

    The prevalence of congenital heart disease in infants with Down syndrome is 40%, compared with 0.3% in children who have normal chromosomes. Atrioventricular and ventricular septal defects are often associated with chromosomal aberrations, such as in trisomy 21, whereas hypertrophic cardiomyopathy is chiefly thought to be secondary to specific gene mutations. We found only one reported case of congenital hypertrophic cardiomyopathy and atrioventricular septal defect in an infant with Down syndrome. Here, we report atrioventricular septal defect, hypertrophic cardiomyopathy, and pulmonary vein stenosis in a neonate with Down syndrome—an apparently unique combination. In addition, we discuss the relevant medical literature. PMID:26504441

  10. Differential rate responses to nicotine in rat heart: evidence for two classes of nicotinic receptors.

    PubMed

    Ji, Susan; Tosaka, Toshimasa; Whitfield, Bernard H; Katchman, Alexander N; Kandil, Abdurrahman; Knollmann, Bjoern C; Ebert, Steven N

    2002-06-01

    Nicotinic acetylcholine receptors are pentameric, typically being composed of two or more different subunits. To investigate which receptor subtypes are active in the heart, we initiated a series of experiments using an isolated perfused rat heart (Langendorff) preparation. Nicotine administration (100 microM) caused a brief decrease (-7 +/- 2%) followed by a much larger increase (17 +/- 5%) in heart rate that slowly returned to baseline within 10 to 15 min. The nicotine-induced decrease in heart rate could be abolished by an alpha7-specific antagonist, alpha-bungarotoxin (100 nM). In contrast, the nicotine-induced increase in heart rate persisted in the presence of alpha-bungarotoxin. These results suggest that the nicotinic acetylcholine receptors (nAChRs) that mediate the initial decrease in heart rate probably contain alpha7 subunits, whereas those that mediate the increase in heart rate probably do not contain alpha7 subunits. To investigate which subunits may contribute to the nicotine-induced increase in heart rate, we repeated our experiments with cytisine, an agonist at nAChRs that contain beta4 subunits. The cytisine results were similar to those obtained with nicotine, thereby suggesting that the nAChRs on sympathetic nerve terminals in the heart probably contain beta4 subunits. Thus, the results of this study show that pharmacologically distinct nAChRs are responsible for the differential effects of nicotine on heart rate. More specifically, our results suggest that alpha7 subunits participate in the initial nicotine-induced heart rate decrease, whereas beta4 subunits help to mediate the subsequent nicotine-induced rise in heart rate.

  11. Disease-associated changes in the expression of ion channels, ion receptors, ion exchangers and Ca{sup 2+}-handling proteins in heart hypertrophy

    SciTech Connect

    Zwadlo, Carolin; Borlak, Juergen . E-mail: borlak@item.fraunhofer.de

    2005-09-15

    The molecular pathology of cardiac hypertrophy is multifactorial with transcript regulation of ion channels, ion exchangers and Ca{sup 2+}-handling proteins being speculative. We therefore investigated disease-associated changes in gene expression of various ion channels and their receptors as well as ion exchangers, cytoskeletal proteins and Ca{sup 2+}-handling proteins in normotensive and spontaneously hypertensive (SHR) rats. We also compared experimental findings with results from hypertrophic human hearts, previously published (Borlak, J., and Thum, T., 2003. Hallmarks of ion channel gene expression in end-stage heart failure. FASEB J. 17, 1592-1608). We observed significant (P < 0.05) induction in transcript level of ATP-driven ion exchangers (Atp1A1, NCX-1, SERCA2a), ion channels (L-type Ca{sup 2+}-channel, K{sub ir}3.4, Na{sub v}1.5) and RyR-2 in hypertrophic hearts, while gene expression was repressed in diseased human hearts. Further, the genes coding for calreticulin and calmodulin, PMCA 1 and 4 as well as {alpha}-skeletal actin were significantly (P < 0.05) changed in hypertrophic human heart, but were unchanged in hypertrophic left ventricles of the rat heart. Notably, transcript level of {alpha}- and {beta}-MHC, calsequestrin, K{sub ir}6.1 (in the right ventricle only), phospholamban as well as troponin T were repressed in both diseased human and rat hearts. Our study enabled an identification of disease-associated candidate genes. Their regulation is likely to be the result of an imbalance between pressure load/stretch force and vascular tonus and the observed changes may provide a rational for the rhythm disturbances observed in patients with cardiac hypertrophy.

  12. The respiration and calcium content of heart mitochondria from rats with vitamin D-induced cardionecrosis.

    PubMed Central

    Zydowo, M M; Swierczyński, J; Nagel, G; Wrzołkowa, T

    1985-01-01

    Mitochondria were isolated from the heart and skeletal muscle of rats treated with three consecutive daily doses of 100 000 i.u. of calciol (cholecalciferol; 'vitamin D3'). On the fourth day after the last dose, cardiac necrosis developed. At that time mitochondria isolated from heart displayed a 10-fold higher Ca2+ content and a 6-fold lower respiratory rate with pyruvate-plus-malate as substrate as well as with other NAD-dependent substrates. No decrease in respiratory rate with succinate as substrate was observed. EDTA (5 mM) added to the medium during the isolation procedure restored both the high respiratory rate with pyruvate + malate and the low Ca2+ content of the heart mitochondria. The addition of 1 mM-CaCl2 to the medium in which a healthy (control) rat heart had been homogenized caused the same impairment of the mitochondria as did calciol treatment of the animals. No changes of mitochondria isolated from skeletal muscle were observed in rats treated with calciol. It is concluded that the heart mitochondria in vivo fail to accumulate Ca2+ from the cardiac cell overloaded with Ca2+ as the consequence of calciol treatment. Mitochondrial Ca2+ accumulation occurs during the isolation procedure unless an appropriate amount of chelating agent is added to the homogenization medium. The implication of these findings for the biochemical sequence of events in the calciol-induced cardiac necrosis is discussed. Images Fig. 1. PMID:2983684

  13. Update on hypertrophic scar treatment

    PubMed Central

    Rabello, Felipe Bettini; Souza, Cleyton Dias; Júnior, Jayme Adriano Farina

    2014-01-01

    Scar formation is a consequence of the wound healing process that occurs when body tissues are damaged by a physical injury. Hypertrophic scars and keloids are pathological scars resulting from abnormal responses to trauma and can be itchy and painful, causing serious functional and cosmetic disability. The current review will focus on the definition of hypertrophic scars, distinguishing them from keloids and on the various methods for treating hypertrophic scarring that have been described in the literature, including treatments with clearly proven efficiency and therapies with doubtful benefits. Numerous methods have been described for the treatment of abnormal scars, but to date, the optimal treatment method has not been established. This review will explore the differences between different types of nonsurgical management of hypertrophic scars, focusing on the indications, uses, mechanisms of action, associations and efficacies of the following therapies: silicone, pressure garments, onion extract, intralesional corticoid injections and bleomycin. PMID:25141117

  14. Update on hypertrophic scar treatment.

    PubMed

    Rabello, Felipe Bettini; Souza, Cleyton Dias; Farina Júnior, Jayme Adriano

    2014-08-01

    Scar formation is a consequence of the wound healing process that occurs when body tissues are damaged by a physical injury. Hypertrophic scars and keloids are pathological scars resulting from abnormal responses to trauma and can be itchy and painful, causing serious functional and cosmetic disability. The current review will focus on the definition of hypertrophic scars, distinguishing them from keloids and on the various methods for treating hypertrophic scarring that have been described in the literature, including treatments with clearly proven efficiency and therapies with doubtful benefits. Numerous methods have been described for the treatment of abnormal scars, but to date, the optimal treatment method has not been established. This review will explore the differences between different types of nonsurgical management of hypertrophic scars, focusing on the indications, uses, mechanisms of action, associations and efficacies of the following therapies: silicone, pressure garments, onion extract, intralesional corticoid injections and bleomycin. PMID:25141117

  15. Protection of isolated perfused working rat heart from oxidative stress by exogenous L-propionyl carnitine.

    PubMed

    Ronca, G; Ronca, F; Yu, G; Zucchi, R; Bertelli, A

    1992-01-01

    The effect of exogenous L-propionyl carnitine on peroxidative injury was investigated on isolated working rat hearts. The addition of 190 microM hydrogen peroxide to the perfusion buffer caused a marked decrease in aortic flow, minute work and peak aortic pressure, and a release of intracellular enzymes. In the presence of L-propionyl carnitine the haemodynamic damage was significantly lower and enzyme leakage remarkably decreased. The protection was concentration-dependent and the whole structure of the molecule was required, since carnitine alone was found less effective and propionate had no effect. In the absence of hydrogen peroxide L-propionyl carnitine increased heart performance. The effect of L-propionyl carnitine on oxidative stress could account for the beneficial effect of this substance in different models of ischaemic injury. L-propionyl carnitine increases the cardiac performance and protects the rat heart from peroxidation through metabolic and antiperoxidative mechanisms. PMID:1308473

  16. Renal and cardiac neuropeptide Y and NPY receptors in a rat model of congestive heart failure.

    PubMed

    Callanan, Ean Y; Lee, Edward W; Tilan, Jason U; Winaver, Joseph; Haramati, Aviad; Mulroney, Susan E; Zukowska, Zofia

    2007-12-01

    Neuropeptide Y (NPY) is coreleased with norepinephrine and stimulates vasoconstriction, vascular and cardiomyocyte hypertrophy via Y1 receptors (R) and angiogenesis via Y2R. Although circulating NPY is elevated in heart failure, NPY's role remains unclear. Activation of the NPY system was determined in Wistar rats with the aortocaval (A-V) fistula model of high-output heart failure. Plasma NPY levels were elevated in A-V fistula animals (115.7 +/- 15.3 vs. 63.1 +/- 17.4 pM in sham, P < 0.04). Animals either compensated [urinary Na(+) excretion returning to normal with moderate disease (COMP)] or remained decompensated with severe cardiac and renal failure (urinary Na(+) excretion <0.5 meq/day), increased heart weight, decreased mean arterial pressure and renal blood flow (RBF), and death within 5-7 days (DECOMP). Cardiac and renal tissue NPY decreased with heart failure, proportionate to the severity of renal complications. Cardiac and renal Y1R mRNA expression also decreased (1.5-fold, P < 0.005) in rats with heart failure. In contrast, Y2R expression increased up to 72-fold in the heart and 5.7-fold in the kidney (P < 0.001) proportionate to severity of heart failure and cardiac hypertrophy. Changes in receptor expression were confirmed since the Y1R agonist, [Leu31, Pro34]-NPY, had no effect on RBF, whereas the Y2R agonist (13-36)-NPY increased RBF to compensate for disease. Thus, in this model of heart failure, cardiac and renal NPY Y1 receptors decrease and Y2 receptors increase, suggesting an increased effect of NPY on the receptors involved in cardiac remodeling and angiogenesis, and highlighting an important regulatory role of NPY in congestive heart failure.

  17. Exercise training upregulates nitric oxide synthases in the kidney of rats with chronic heart failure.

    PubMed

    Ito, Daisuke; Ito, Osamu; Mori, Nobuyoshi; Cao, Pengyu; Suda, Chihiro; Muroya, Yoshikazu; Hao, Kiyotaka; Shimokawa, Hiroaki; Kohzuki, Masahiro

    2013-09-01

    There is an interaction between heart and kidney diseases, which is a condition termed cardiorenal syndrome. Exercise training has cardioprotective effects, involving upregulation of endothelial (e) nitric oxide synthase (NOS) in the cardiovascular system. However, the effects of exercise training on NOS in the kidney with heart disease are unknown. The aim of the present study was to investigate whether exercise training upregulates NOS in the kidney, left ventricle and aorta of rats with chronic heart failure (CHF). Male Sprague-Dawley rats underwent left coronary artery ligation (LCAL) to induce CHF and were randomly assigned to sedentary or treadmill exercise groups 4 weeks after LCAL. Three days after exercising for 4 weeks, urine samples were collected for 24 h and blood samples were collected following decapitation. Nitric oxide synthase activity and protein expression were examined. Significant interactions between CHF and exercise training were observed on parameters of cardiac and renal function. Exercise training improved cardiac function, decreased plasma B-type natriuretic peptide levels, decreased urinary albumin excretion and increased creatinine clearance in CHF rats. Nitric oxide synthase activity, eNOS expression and neuronal (n) NOS expression were significantly decreased in the left ventricle and kidney of CHF rats. Exercise training significantly increased NOS activity and eNOS and nNOS expression. Upregulation of NOS in the kidney and left ventricle may contribute, in part, to the renal and cardiac protective effects of exercise training in cardiorenal syndrome in CHF rats.

  18. Prenatal exposure to PFOS caused mitochondia-mediated apoptosis in heart of weaned rat.

    PubMed

    Zeng, Huai-Cai; He, Qing-Zhi; Li, Yuan-Yuan; Wu, Cheng-Qiu; Wu, Yi-Mou; Xu, Shun-Qing

    2015-09-01

    Perfluorooctanyl sulfonate (PFOS), a cardiac toxicity compound, has been widely detected in the environment and in organisms. However, the toxic mechanism is not clear. Our previous study indicated that prenatal PFOS exposure led to swollen mitochondrial with vacuolar structure and loss of cristae in offsping's heart. The purpose of this study was to investigate the effect of PFOS on the apoptosis in developing heart and mitochondria-mediated apoptosis pathway. Pregnant Sprague-Dawley (SD) rats were exposed to PFOS at doses of 0.1, 0.6, and 2.0 mg/kg-d and 0.05% Tween 80 as control by gavage from gestation day 2 (GD 2) to GD 21. Apoptosis, as well as expression of apoptosis related genes associated with mitochondrial-mediated apoptosis pathway, including p53, bcl-2, bax, cytochrome c, caspase-9, and caspase-3 were analyzed in heart tissues from weaned (postnatal day 21, PND 21) offspring. The results showed that prenatal PFOS exposure resulted in apoptosis in the offspring's heart. The mRNA and protein expression levels of p53, bax, cytochrome c, caspase-9, and caspase-3 in the offspring's heart were enhanced in various PFOS-treated groups, meanwhile, the bcl-2 expression levels were decreased. Our results indicated that prenatal PFOS exposure induced the apoptosis of weaned offspring rat heart tissue via mitochondria-mediated apoptotic pathway. PMID:24616003

  19. Prenatal exposure to PFOS caused mitochondia-mediated apoptosis in heart of weaned rat.

    PubMed

    Zeng, Huai-Cai; He, Qing-Zhi; Li, Yuan-Yuan; Wu, Cheng-Qiu; Wu, Yi-Mou; Xu, Shun-Qing

    2015-09-01

    Perfluorooctanyl sulfonate (PFOS), a cardiac toxicity compound, has been widely detected in the environment and in organisms. However, the toxic mechanism is not clear. Our previous study indicated that prenatal PFOS exposure led to swollen mitochondrial with vacuolar structure and loss of cristae in offsping's heart. The purpose of this study was to investigate the effect of PFOS on the apoptosis in developing heart and mitochondria-mediated apoptosis pathway. Pregnant Sprague-Dawley (SD) rats were exposed to PFOS at doses of 0.1, 0.6, and 2.0 mg/kg-d and 0.05% Tween 80 as control by gavage from gestation day 2 (GD 2) to GD 21. Apoptosis, as well as expression of apoptosis related genes associated with mitochondrial-mediated apoptosis pathway, including p53, bcl-2, bax, cytochrome c, caspase-9, and caspase-3 were analyzed in heart tissues from weaned (postnatal day 21, PND 21) offspring. The results showed that prenatal PFOS exposure resulted in apoptosis in the offspring's heart. The mRNA and protein expression levels of p53, bax, cytochrome c, caspase-9, and caspase-3 in the offspring's heart were enhanced in various PFOS-treated groups, meanwhile, the bcl-2 expression levels were decreased. Our results indicated that prenatal PFOS exposure induced the apoptosis of weaned offspring rat heart tissue via mitochondria-mediated apoptotic pathway.

  20. Estimation of Early Postmortem Interval Through Biochemical and Pathological Changes in Rat Heart and Kidney.

    PubMed

    Abo El-Noor, Mona Mohamed; Elhosary, Naema Mahmoud; Khedr, Naglaa Fathi; El-Desouky, Kareema Ibraheem

    2016-03-01

    Accurate estimation of time passed since death is a complicated task in forensic medicine especially in homicide or unwitnessed death investigations. Changes in oxidant/antioxidant parameters were investigated if it can be relied upon in estimating the early postmortem interval (EPI) in rat heart and kidney, and whether these changes were correlated with histopathological findings in these tissues. Heart and kidney tissues of 84 male albino rats were divided into 2 parts. One part used for estimation of levels of malondialdehyde (MDA), nitric oxide (NO), and total thiol as well as the activity of glutathione reductase (GR), glutathione S transferase, and catalase. The second part was examined histopathologically. It was found that MDA and NO were significantly increased earlier in the heart than kidney tissues. Meanwhile, total thiol, catalase, glutathione S transferase, and GR were commenced to be significantly decreased in the heart before kidney tissues. Linear regression analysis of independent variables of heart was found to be of a high predictive value of 97.2% (EPI = 8.607 - 0.240 GR + 0.002 MDA + 0.014 NO). Structural deterioration of heart started 3 to 4 hours compared with renal sections that began 5 to 6 hours after death. The relationship between oxidant and antioxidant parameters is crucial in determining the EPI. The kidney was found to be more resistible to oxidative damage. Further research on humans is needed.

  1. Exercise training improves renal excretory responses to acute volume expansion in rats with heart failure.

    PubMed

    Zheng, Hong; Li, Yi-Fan; Zucker, Irving H; Patel, Kaushik P

    2006-12-01

    Experiments were performed to test the postulate that exercise training (ExT) improves the blunted renal excretory response to acute volume expansion (VE), in part, by normalizing the neural component of the volume reflex typically observed in chronic heart failure (HF). Diuretic and natriuretic responses to acute VE were examined in sedentary and ExT groups of rats with either HF or sham-operated controls. Experiments were performed in anesthetized (Inactin) rats 6 wk after coronary ligation surgery. Histological data indicated that there was a 34.9 +/- 3.0% outer and 42.5 +/- 3.2% inner infarct of the myocardium in the HF group. Sham rats had no observable damage to the myocardium. In sedentary rats with HF, VE produced a blunted diuresis (46% of sham) and natriuresis (35% of sham) compared with sham-operated control rats. However, acute VE-induced diuresis and natriuresis in ExT rats with HF were comparable to sham rats and significantly higher than sedentary HF rats. Renal denervation abolished the salutary effects of ExT on renal excretory response to acute VE in HF. Since glomerular filtration rates were not significantly different between the groups, renal hemodynamic changes may not account for the blunted renal responses in rats with HF. Additional experiments confirmed that renal sympathetic nerve activity responses to acute VE were blunted in sedentary HF rats; however, ExT normalized the renal sympathoinhibition in HF rats. These results confirm an impairment of neurally mediated excretory responses to acute VE in rats with HF. ExT restored the blunted excretory responses as well as the renal sympathoinhibitory response to acute VE in HF rats. Thus the beneficial effects of ExT on cardiovascular regulation in HF may be partly due to improvement of the neural component of volume reflex.

  2. Somatostatin in the human heart and comparison with guinea pig and rat heart.

    PubMed Central

    Day, S M; Gu, J; Polak, J M; Bloom, S R

    1985-01-01

    Somatostatin has been shown to have negative inotropic and chronotopic effects and to restore sinus rhythm in some cases of cardiac arrhythmia. Using acid extracts, regions of human heart were examined by radioimmunoassay to determine their somatostatin content. Mean (SD) concentrations of 4.1 (0.8) pmol/g and 2.9 (0.8) pmol/g were found in atrioventricular node and right atria respectively and were significantly higher than in other heart regions. Using fresh heart tissue from guinea pigs, somatostatin was localised to cardiac nerves by immunocytochemistry. Nerves containing somatostatin were most abundant in the atria, where the concentrations measured by radioimmunoassay were 7.6 (1.0) and 2.6 (0.4) pmol/g for right and left atria respectively. Somatostatin contained in cardiac nerves may have a physiological role in the cardiac conduction system. Images PMID:2857086

  3. 5'-Adenosine monophosphate and adenosine metabolism, and adenosine responses in mouse, rat and guinea pig heart.

    PubMed

    Headrick, J P; Peart, J; Hack, B; Garnham, B; Matherne, G P

    2001-11-01

    We examined myocardial 5'-adenosine monophosphate (5'-AMP) catabolism, adenosine salvage and adenosine responses in perfused guinea pig, rat and mouse heart. MVO(2) increased from 71+/-8 microl O(2)/min per g in guinea pig to 138+/-17 and 221+/-15 microl O(2)/min per g in rat and mouse. VO(2)/beat was 0.42+/-0.03, 0.50+/-0.03 and 0.55+/-0.04 microl O(2)/g in guinea pig, rat and mouse, respectively. Resting and peak coronary flows were highest in mouse vs. rat and guinea pig, and peak ventricular pressures and Ca(2+) sensitivity declined as heart mass increased. Net myocardial 5'-AMP dephosphorylation increased significantly as mass declined (3.8+/-0.5, 9.0+/-1.4 and 11.0+/-1.6 nmol/min per g in guinea pig, rat and mouse, respectively). Despite increased 5'-AMP catabolism, coronary venous [adenosine] was similar in guinea pig, rat and mouse (45+/-8, 69+/-10 and 57+/-14 nM, respectively). Comparable venous [adenosine] was achieved by increased salvage vs. deamination: 64%, 41% and 39% of adenosine formed was rephosphorylated while 23%, 46%, and 50% was deaminated in mouse, rat and guinea pig, respectively. Moreover, only 35-45% of inosine and its catabolites derive from 5'-AMP (vs. IMP) dephosphorylation in all species. Although post-ischemic purine loss was low in mouse (due to these adaptations), functional tolerance to ischemia decreased with heart mass. Cardiovascular sensitivity to adenosine also differed between species, with A(1) receptor sensitivity being greatest in mouse while A(2) sensitivity was greatest in guinea pig. In summary: (i) cardiac 5'-AMP dephosphorylation, VO(2), contractility and Ca(2+) sensitivity all increase as heart mass falls; (ii) adaptations in adenosine salvage vs. deamination limit purine loss and yield similar adenosine levels across species; (iii) ischemic tolerance declines with heart mass; and (iv) cardiovascular sensitivity to adenosine varies, with increasing A(2) sensitivity relative to A(1) sensitivity in larger hearts.

  4. Is rate–pressure product of any use in the isolated rat heart? Assessing cardiac ‘effort’ and oxygen consumption in the Langendorff‐perfused heart

    PubMed Central

    Aksentijević, Dunja; Lewis, Hannah R.

    2016-01-01

    New Findings What is the central question of this study? Rate–pressure product (RPP) is commonly used as an index of cardiac ‘effort’. In canine and human hearts (which have a positive force–frequency relationship), RPP is linearly correlated with oxygen consumption and has therefore been widely adopted as a species‐independent index of cardiac work. However, given that isolated rodent hearts demonstrate a negative force–frequency relationship, its use in this model requires validation. What is the main finding and its importance? Despite its widespread use, RPP is not correlated with oxygen consumption (or cardiac ‘effort’) in the Langendorff‐perfused isolated rat heart. This lack of correlation was also evident when perfusions included a range of metabolic substrates, insulin or β‐adrenoceptor stimulation. Langendorff perfusion of hearts isolated from rats and mice has been used extensively for physiological, pharmacological and biochemical studies. The ability to phenotype these hearts reliably is, therefore, essential. One of the commonly used indices of function is rate–pressure product (RPP); a rather ill‐defined index of ‘work’ or, more correctly, ‘effort’. Rate–pressure product, as originally described in dog or human hearts, was shown to be correlated with myocardial oxygen consumption (MV˙O2). Despite its widespread use, the application of this index to rat or mouse hearts (which, unlike the dog or human, have a negative force–frequency relationship) has not been characterized. The aim of this study was to examine the relationship between RPP and MV˙O2 in Langendorff‐perfused rat hearts. Paced hearts (300–750 beats min−1) were perfused either with Krebs–Henseleit (KH) buffer (11 mm glucose) or with buffer supplemented with metabolic substrates and insulin. The arteriovenous oxygen consumption (MV˙O2) was recorded. Metabolic status was assessed using 31P magnetic resonance spectroscopy and lactate efflux

  5. The effect of hexane on the ventricular fibrillation threshold of the isolated perfused rat heart.

    PubMed

    Khedun, S M; Maharaj, B; Leary, W P; Lockett, C J

    1992-01-01

    This investigation was conducted to determine the influence of hexane on the ventricular fibrillation threshold of the isolated perfused rat heart and myocardial electrolyte levels. Ventricular fibrillation threshold was measured using the Langendorff perfusion apparatus. Heart rate was measured by a universal digital counter and the cardiac flow by collecting the outflow of the heating chamber below the heart into a graduated measuring cylinder. Magnesium and zinc were measured by atomic absorption spectrophotometry and potassium by flame photometry. Two groups of rats were studied; those in the experimental group were given 0.2 ml of hexane and the control group 0.2 ml olive oil subcutaneously for 90 days. Their hearts were removed under anaesthesia. Half of the experimental and control hearts were mounted on the Langendorff perfusion apparatus and the heart rate, coronary flow and ventricular fibrillation threshold were measured. The hearts of the other half were used to measure myocardial electrolyte levels. In the experimental group the ventricular fibrillation threshold decreased (4.72 (S.D. +/- 1.87) vs 9.48 (S.D. +/- 2.98); P less than 0.001). There was no change in the coronary flow and heart rate in between the groups. The mean myocardial potassium levels (2586 (S.D. +/- 162) vs 2968 (S.D. +/- 218) micrograms/g; P less than 0.001), magnesium levels (164 (S.D. +/- 28) vs 208 (S.D. +/- 18) micrograms/g; P less than 0.001) and zinc levels (19.6 (S.D. +/- 4) vs 33.8 (S.D. +/- 6.8) micrograms/g; P less than 0.001) were significantly lower in the hexane-treated group compared to controls. Hexane, a constituent of glue and benzine, is cardiotoxic; marked derangement in myocardial electrolytes and a reduced ventricular fibrillation threshold, indicating an increased myocardial vulnerability to arrhythmias, was noted in the experimental animals. PMID:1729763

  6. Cardioprotection by remote ischemic preconditioning of the rat heart is mediated by extracellular vesicles.

    PubMed

    Giricz, Zoltán; Varga, Zoltán V; Baranyai, Tamás; Sipos, Péter; Pálóczi, Krisztina; Kittel, Ágnes; Buzás, Edit I; Ferdinandy, Péter

    2014-03-01

    Remote ischemic preconditioning (RIPC) of the heart is exerted by brief ischemic insults affected on a remote organ or a remote area of the heart before a sustained cardiac ischemia. To date, little is known about the inter-organ transfer mechanisms of cardioprotection by RIPC. Exosomes and microvesicles/microparticles are vesicles of 30-100 nm and 100-1000 nm in diameter, respectively (collectively termed extracellular vesicles [EVs]). Their content of proteins, mRNAs and microRNAs, renders EV ideal conveyors of inter-organ communication. However, whether EVs are involved in RIPC, is unknown. Therefore, here we investigated whether (1) IPC induces release of EVs from the heart, and (2) EVs are necessary for cardioprotection by RIPC. Hearts of male Wistar rats were isolated and perfused in Langendorff mode. A group of donor hearts was exposed to 3 × 5-5 min global ischemia and reperfusion (IPC) or 30 min aerobic perfusion, while coronary perfusates were collected. Coronary perfusates of these hearts were given to another set of recipient isolated hearts. A group of recipient hearts received IPC effluent depleted of EVs by differential ultracentrifugation. Infarct size was determined after 30 min global ischemia and 120 min reperfusion. The presence or absence of EVs in perfusates was confirmed by dynamic light scattering, the EV marker HSP60 Western blot, and electron microscopy. IPC markedly increased EV release from the heart as assessed by HSP60. Administration of coronary perfusate from IPC donor hearts attenuated infarct size in non-preconditioned recipient hearts (12.9 ± 1.6% vs. 25.0 ± 2.7%), similarly to cardioprotection afforded by IPC (7.3 ± 2.7% vs. 22.1 ± 2.9%) on the donor hearts. Perfusates of IPC hearts depleted of EVs failed to exert cardioprotection in recipient hearts (22.0 ± 2.3%). This is the first demonstration that EVs released from the heart after IPC are necessary for cardioprotection by RIPC, evidencing the importance of vesicular

  7. Severe Calorie Restriction Reduces Cardiometabolic Risk Factors and Protects Rat Hearts from Ischemia/Reperfusion Injury

    PubMed Central

    Melo, Dirceu S.; Costa-Pereira, Liliane V.; Santos, Carina S.; Mendes, Bruno F.; Costa, Karine B.; Santos, Cynthia Fernandes F.; Rocha-Vieira, Etel; Magalhães, Flávio C.; Esteves, Elizabethe A.; Ferreira, Anderson J.; Guatimosim, Sílvia; Dias-Peixoto, Marco F.

    2016-01-01

    Background and Aims: Recent studies have proposed that if a severe caloric restriction (SCR) is initiated at the earliest period of postnatal life, it can lead to beneficial cardiac adaptations later on. We investigated the effects of SCR in Wistar rats from birth to adult age on risk factors for cardiac diseases (CD), as well as cardiac function, redox status, and HSP72 content in response to ischemia/reperfusion (I/R) injury. Methods and Results: From birth to the age of 3 months, CR50 rats were fed 50% of the food that the ad libitum group (AL) was fed. Food intake was assessed daily and body weight were assessed weekly. In the last week of the SCR protocol, systolic blood pressure and heart rate were measured and the double product index was calculated. Also, oral glucose and intraperitoneal insulin tolerance tests were performed. Thereafter, rats were decapitated, visceral fat was weighed, and blood and hearts were harvested for biochemical, functional, tissue redox status, and western blot analyzes. Compared to AL, CR50 rats had reduced the main risk factors for CD. Moreover, the FR50 rats showed increased cardiac function both at baseline conditions (45% > AL rats) and during the post-ischemic period (60% > AL rats) which may be explained by a decreased cardiac oxidative stress and increased HSP72 content. Conclusion: SCR from birth to adult age reduced risk factors for CD, increased basal cardiac function and protected hearts from the I/R, possibly by a mechanism involving ROS. PMID:27092082

  8. Caffeine-induced myocardial injury in calcium-free perfused rat hearts.

    PubMed

    Vander Heide, R S; Ganote, C E

    1985-01-01

    Hearts depleted of extracellular calcium become susceptible to injury caused by repletion of extracellular calcium (calcium paradox). It has been suggested that calcium-free perfusion causes weakening of intercalated disks and that the physical stress of contracture may cause sarcolemmal membrane rupture and creatine kinase (CK) release. To further investigate this hypothesis, the effects of caffeine on contracture, cellular morphology, and CK release were studied in control and calcium-free perfused isolated rat hearts. Control hearts perfused with 2.5 mM calcium retained normal ultrastructure for long periods of perfusion. Calcium-free hearts perfused for 12 minutes developed separations of fascia adherens portions of intercalated disks but retained intact nexus junctions. Hearts subjected to 5-minute calcium-free perfusion, followed by calcium repletion, developed a massive CK release and extensive contraction band necrosis (calcium paradox). Ten millimolar caffeine, which causes rapid calcium release from sarcoplasmic reticulum (SR), produced contracture, but not CK release, from control hearts perfused with medium containing 2.5 mM calcium. In calcium-free perfused hearts, caffeine caused sudden CK release accompanied by contracture, development of contraction bands, wide separations of cells at intercalated disks, and sarcolemmal membrane injury. Caffeine-induced injury occurred despite 3 mM amobarbital inhibition of mitochondrial respiration. Hearts perfused with caffeine in the presence of calcium relaxed when made calcium-free and did not release CK. Addition of caffeine following calcium-free perfusion at 22 C, which protects the heart from the calcium paradox, produced a rapid, transient contracture. These results are compatible with the hypothesis that myocardial cell injury in calcium-free hearts is not dependent on repletion of extracellular calcium or mitochondrial function, but can result from contracture following caffeine-induced release of

  9. Protective effect of apigenin on ischemia/reperfusion injury of the isolated rat heart.

    PubMed

    Hu, Jing; Li, Zilin; Xu, Li-ting; Sun, Ai-jun; Fu, Xiao-yan; Zhang, Li; Jing, Lin-lin; Lu, An-dong; Dong, Yi-fei; Jia, Zheng-ping

    2015-07-01

    Apigenin (Api), a mainly bioactive component of Apium graveolens L. var. dulce DC. (a traditional Chinese medicinal herb), possesses a wide range of biological activities, including antioxidant effects. It also has been shown to associate with lower prevalence of cardiovascular diseases, but its mechanisms of action remain unclear. The aim of the present study is to investigate the role of Api in isolated rat heart model of ischemia/reperfusion (I/R). Langendorff-perfused isolated rat hearts were used in our study. Api was added to the perfusate before ischemia and during reperfusion in the isolated pulsed rat heart exposed to 30-min ischemia followed by 50-min reperfusion. The treatment with Api conferred a cardioprotective effect, and the treated hearts demonstrated an improved ischemic cardiac functional recovery, a decreased myocardial infarct size, a reduced activities of creatine kinase isoenzyme and lactate dehydrogenase in the coronary flow, a reduced number of apoptotic cardiomyocytes, a reduced activity of caspase-3, up-regulation of the anti-apoptotic protein Bcl-2 and down-regulation of the pro-apoptotic protein Bax. In addition, Api inhibited the phosphorylation of p38 MAPKS during I/R. In conclusion, these observations provide preliminary evidence that Api can protect cardiomyocytes from I-/R-induced injury, at least partially, through the inhibition of p38 MAPKS signaling pathway. PMID:25377428

  10. Hydrogen sulfide post-conditioning preserves interfibrillar mitochondria of rat heart during ischemia reperfusion injury.

    PubMed

    Banu, Shakila A; Ravindran, Sriram; Kurian, Gino A

    2016-07-01

    Cardiac mitochondrial dysfunction is considered to be the main manifestation in the pathology of ischemia reperfusion injury, and by restoring its functional activity, hydrogen sulfide (H2S), a novel endogenous gaseotransmitter renders cardioprotection. Given that interfibrillar (IFM) and subsarcolemmal (SSM) mitochondria are the two main types in the heart, the present study investigates the specific H2S-mediated action on IFM and SSM during ischemic reperfusion in the Langendorff rat heart model. Rats were randomly divided into five groups, namely normal, ischemic control, reperfusion control (I/R), ischemic post-conditioning (POC), and H2S post-conditioning (POC_H2S). In reperfusion control, cardiac contractility decreased, and lactate dehydrogenase, creatine kinase, and infracted size increased compared to both normal and ischemic group. In hearts post-conditioned with H2S and the classical method improved cardiac mechanical function and decreased cardiac markers in the perfusate and infarct size significantly. Both POC and POC_H2S exerts its cardioprotective effect of preserving the IFM, as evident by significant improvement in electron transport chain enzyme activities and mitochondrial respiration. The in vitro action of H2S on IFM and SSM from normal and I/R rat heart supports H2S and mediates cardioprotection via IFM preservation. Our study indicates that IFM play an important role in POC_H2S mediated cardioprotection from reperfusion injury. PMID:26951457

  11. Cardioprotective properties of citicoline against hyperthyroidism-induced reperfusion damage in rat hearts.

    PubMed

    Hernández-Esquivel, Luz; Pavón, Natalia; Buelna-Chontal, Mabel; González-Pacheco, Héctor; Belmont, Javier; Chávez, Edmundo

    2015-06-01

    Hyperthyroidism represents an increased risk factor for cardiovascular morbidity, especially when the heart is subjected to an ischemia/reperfusion process. The aim of this study was to explore the possible protective effect of the nucleotide citicoline on the susceptibility of hyperthyroid rat hearts to undergo reperfusion-induced damage, which is associated with mitochondrial dysfunction. Hence, we analyzed the protective effect of citicoline on the electrical behavior and on the mitochondrial function in rat hearts. Hyperthyroidism was established after a daily i.p. injection of triiodothyronine (at 2 mg/kg of body weight) during 5 days. Thereafter, citicoline was administered i.p. (at 125 mg/kg of body weight) for 5 days. In hyperthyroid rat hearts, citicoline protected against reperfusion-induced ventricular arrhythmias. Moreover, citicoline maintained the accumulation of mitochondrial Ca(2+), allowing mitochondria to reach a high transmembrane electric gradient that protected against the release of cytochrome c. It also preserved the activity of the enzyme aconitase that inhibited the release of cytokines. The protection also included the inhibition of oxidative stress-induced mDNA disruption. We conclude that citicoline protects against the reperfusion damage that is found in the hyperthyroid myocardium. This effect might be due to its inhibitory action on the permeability transition in mitochondria. PMID:25589288

  12. Accumulation of amino acids in muscle of perfused rat heart. Effect of insulin

    PubMed Central

    Scharff, R.; Wool, I. G.

    1965-01-01

    1. Rat heart perfused with Krebs–Henseleit bicarbonate buffer released material containing ninhydrin-positive nitrogen, but the amount was less than that reported to be released by diaphragm; glucose, but not insulin, decreased the release of ninhydrin-positive nitrogen and increased the concentration of the same material in the intracellular water of heart. 2. When heart was perfused with a mixture of amino acids and glucose, there was actually a net uptake, and an increase in intracellular concentration, of ninhydrin-positive nitrogen. Changes in the concentration of ninhydrin-positive nitrogen did not accurately reflect changes in concentration of amino acids. 3. The effect of insulin on the actual concentration of individual amino acids in heart muscle was examined by perfusing the heart with a mixture of amino acids and other ninhydrin-positive substances in the same concentration as they are found in plasma. 4. The effect of insulin on the concentrations of amino acids in the medium and in the intracellular water of the heart was determined after perfusion for different periods of time. No clear or meaningful effect of insulin was observed, despite the fact that insulin significantly increased the accumulation, in each of the same hearts, of radioactivity from amino[14C]isobutyric acid. PMID:16749112

  13. Protective effects of drag-reducing polymers on ischemic reperfusion injury of isolated rat heart.

    PubMed

    Hu, Feng; Wang, Yali; Gong, Kaizheng; Ge, Gaoyuan; Cao, Mingqiang; Zhao, Pei; Sun, Xiaoning; Zhang, Zhengang

    2016-01-01

    Drag-reducing polymers (DRPs) are blood-soluble macromolecules that can increase blood flow and reduce vascular resistance. The purpose of the present study was to observe the effect of DRPs on ischemic reperfusion (I/R) injury of isolated rat hearts. Experiments were performed on isolated rat hearts subjected to 30 min of ischemia followed by 90 min of reperfusion in Langendorff preparations. Adult Wistar rats were divided into the following five groups: control group, I/R group, group III (I/R and 2×10(-7)  g/ml PEO reperfusion), group IV (I/R and 1×10(-6)  g/ml PEO reperfusion), and group V (I/R and 5×10(-6)  g/ml PEO reperfusion). Left ventricular end-diastolic pressure (LVEDP), left ventricular systolic pressure (LVSP), maximum rate of ventricular pressure increase and decrease ( ± dp/dtmax), heart rate (HR) and coronary flow were measured. Lactate dehydrogenase (LDH) and creatine kinase (CK) activity and coronary flow, myocardial infarction size and cardiomyocytes apoptosis were also assayed. Our results showed that PEO decreased LVEDP and increased LVSP, ± dP/dtmax in group IV and group V compared with the I/R group (all P <  0.05). The coronary flow significantly increased and the activities of LDH and CK in the coronary flow significantly decreased in group IV and group V compared with those in the I/R group (all P <  0.05). Cell apoptosis and myocardial infarction size were reduced in group IV and group V compared with the I/R group (all P <  0.05). Collectively, these results suggested that DRPs had a protective effect on cardiac I/R injury of isolated rat hearts and it may offer a new potential approach for the treatment of acute ischemic heart diseases.

  14. The Protection of Salidroside of the Heart against Acute Exhaustive Injury and Molecular Mechanism in Rat

    PubMed Central

    Wang, Yunru; Xu, Peng; Wang, Yang; Liu, Haiyan; Zhou, Yuwen; Cao, Xuebin

    2013-01-01

    Objective. To investigate the protection of salidroside of the heart against acute exhaustive injury and its mechanism of antioxidative stress and MAPKs signal transduction. Method. Adult male SD rats were divided into four groups randomly. Cardiomyocytes ultrastructure was observed by optical microscopy and transmission electron microscopy. The contents of CK, CK-MB, LDH, MDA, and SOD were determined by ELISA method, and the phosphorylation degrees of ERK and p38 MAPK were assayed by Western blotting. Cardiac function of isolated rat heart ischemia/reperfusion was detected by Langendorff technique. Results. Salidroside reduced the myocardium ultrastructure injury caused by exhaustive swimming, decreased the contents of CK, CK-MB, and LDH, improved the LVDP, ±LV dp/dtmax under the basic condition, reduced the content of MDA and the phosphorylation degree of p38 MAPK, and increased the content of SOD and the phosphorylation degree of ERK in acute exhaustive rats. Conclusion. Salidroside has the protection of the heart against acute exhaustive injury. The cardioprotection is mainly mediated by antioxidative stress and MAPKs signal transduction through reducing the content of MDA, increasing the content of SOD, and increasing p-ERK and decreasing p-p38 protein expressions in rat myocardium, which might be the mechanisms of the cardioprotective effect of salidroside. PMID:24454984

  15. Histopathological evaluation of liver, pancreas, spleen, and heart from iron-overloaded Sprague-Dawley rats.

    PubMed

    Whittaker, P; Hines, F A; Robl, M G; Dunkel, V C

    1996-01-01

    The effects of increasing dietary levels of Fe on the histopathology of liver, pancreas, spleen, and heart were examined in a rat model for iron overload. Sprague-Dawley rats were fed diets containing 35, 350, 3,500, or 20,000 micrograms Fe/g, and, after 12 wk, there was a direct correlation between increased liver nonheme Fe and lipid peroxidation measured by the lipid-conjugated diene assay. Histopathological examination of tissues revealed the following: (a) hepatocellular hemosiderosis in all groups of rats, with a dose-related accumulation of cytoplasmic Fe-positive material predominantly in hepatocytes located in the periportal region (Zone 1), (b) myocardial degeneration and necrosis (cardiomyopathy) with hemosiderin in interstitial macrophages or in myocardial fibers of animals with heart damage, (c) splenic lymphoid atrophy affecting the marginal zone of the white pulp and hemosiderin deposition in the sinusoidal macrophages, and (d) pancreatic atrophy with loss of both the endocrine and exocrine pancreatic tissue in those animals receiving 3,500 and 20,000 micrograms Fe/g of diet. The toxic effects of Fe overload in this rat model include cellular apoptosis or necrosis in heart, spleen, and pancreas and, when coupled with the findings on lipid peroxidation, suggests that oxidative stress is involved in the pathogenesis of the lesions.

  16. Role of the bradykinin B2 receptor in a rat model of local heart irradiation

    PubMed Central

    Lieblong, Benjamin J.; Sridharan, Vijayalakshmi; Srivastava, Anup K.; Moros, Eduardo G.; Sharma, Sunil K.; Boerma, Marjan

    2016-01-01

    Purpose Radiation-induced heart disease (RIHD) is a delayed effect of radiotherapy for cancers of the chest, such as breast, esophageal, and lung. Kinins are small peptides with cardioprotective properties. We previously used a rat model that lacks the precursor kininogen to demonstrate that kinins are involved in RIHD. Here, we examined the role of the kinin B2 receptor (B2R) in early radiation-induced signaling in the heart. Materials and methods Male Brown Norway rats received the B2R-selective antagonist HOE-140 (icatibant) via osmotic minipump from 5 days before until 4 weeks after 21 Gy local heart irradiation. At 4 weeks, signaling events were measured in left ventricular homogenates and nuclear extracts using western blotting and real-time polymerase chain reaction. Numbers of CD68-positive (monocytes/macrophages), CD2-positive (T-lymphocytes), and mast cells were measured using immunohistochemistry. Results Radiation-induced c-Jun phosphorylation and nuclear translocation were enhanced by HOE-140. HOE-140 did not modify endothelial nitric oxide synthase (eNOS) phosphorylation or alter numbers of CD2-positive or mast cells, but enhanced CD68-positive cell counts in irradiated hearts. Conclusions B2R signaling may regulate monocyte/macrophage infiltration and c-Jun signals in the irradiated heart. Although eNOS is a main target for kinins, the B2R may not regulate eNOS phosphorylation in response to radiation. PMID:25955317

  17. Studies on Pentoxifylline and Tocopherol Combination for Radiation-Induced Heart Disease in Rats

    SciTech Connect

    Liu Hui; Xiong Mai; Xia Yunfei; Cui Nianji; Lu Rubiao; Deng Ling; Lin Yuehao; Rong Tiehua

    2009-04-01

    Purpose: To investigate whether the application of pentoxifylline (PTX) and tocopherol l (Vit. E) could modify the development of radiation-induced heart disease and downregulate the expression of transforming growth factor (TGF)-{beta}1mRNA in rats. Methods and Materials: A total of 120 Sprague-Dawley rats were separated into four groups: control group, irradiated group, experimental group 1, and experiment group 2. Supplementation was started 3 days before irradiation; in experimental group 1, injection of PTX (15 mg/kg/d) and Vit. E (5.5 mg/kg/d) continued till the 12th week postirradiation, whereas in experimental group 2 it was continued until the 24th week postirradiation. All rats were administrated a single dose of 20 Gy irradiation to the heart except the control group. Histopathologic evaluation was performed at various time points (Days 1, 2, 4, 8, and 12 and 24th week) up to 24 weeks after irradiation. Changes of levels of TGF-{beta}1 mRNA expression were also investigated at the same time points using competitive polymerase chain reaction. Results: Compared with the irradiated group, levels of TGF-{beta}1 mRNA of the rat hearts were relatively low in the two experimental groups on the 12th week postirradiation. In experimental group 1, there was a rebound expression of TGF-{beta}1 mRNA on the 24th week postirradiation, whereas that of the experimental group 2 remained low (p < 0.05). The proportions of collagen fibers of the two experimental groups were lower than that of irradiated group (p < 0.05). A rebound could be observed in the experimental group 1. Conclusion: PTX and Vit. E downregulated the expression of TGF-{beta}1 mRNA. The irradiated rat hearts showed a marked pathologic response to the drugs. The withdrawal of drugs in the 12th week postirradiation could cause rebound effects of the development of fibrosis.

  18. Electron microscopy examination of ventricles from hypertrophied hearts of copper deficient rats

    SciTech Connect

    Medeiros, D.M.; Bagby, D.; Ovecka, G.; McCormick, R.J. )

    1989-02-15

    Male Long Evans rats were fed AIN-76 diets that were either copper adequate (8 mg/kg diet, n=6) or copper deficient (0.4 mg/Kg diet, n=6) from weaning until 8 weeks, thereafter. Copper deficiency was verified by decreased hematocrit and liver copper levels and increased heart weight in the copper deficient group. Left ventricular cardiac muscle was removed and processed from histological examination by transmission electron microscopy. In copper adequate rats the myocytes were usually separated by single rows of mitochondria with cristae in densely packed parallel arrays. In copper deficient rats, pockets of greatly proliferated mitochondria were observed between the muscle fibers. These mitochondria were enlarged vacuolized and contained fragmented cristae. Areas of poorly organized myofilaments were detected in the ventricles of copper deficient animals. Accumulation of glycogen and lipid droplets was apparent in these rats.

  19. Cardiac arrhythmias in hypertrophic cardiomyopathy.

    PubMed Central

    Bjarnason, I; Hardarson, T; Jonsson, S

    1982-01-01

    This study was designed to assess the prevalence of cardiac arrhythmias in a group of relatives of patients who had come to necropsy with hypertrophic cardiomyopathy. Another aim of the study was to assess the validity of an interventricular septal thickness of 1.3 cm or more, measured by echocardiography, as a diagnostic criterion of hypertrophic cardiomyopathy among relatives of cases proven at necropsy. Fifty close relatives of eight deceased patients were examined. By the above definition 22 relatives had hypertrophic cardiomyopathy and 28 did not. A comparison of the prevalence and types of cardiac arrhythmias, as shown by 24 hour ambulatory electrocardiographic monitoring, was made between the two groups and a third apparently healthy group of 40 people. The patients with hypertrophic cardiomyopathy showed a significant increase in supraventricular extrasystoles/24 hours, supraventricular arrhythmias, high grade ventricular arrhythmia, and the number of patients with more than 10 ventricular extrasystoles every 24 hours when compared with the other groups. There was no significant difference between normal relatives and controls. The prevalence and types of arrhythmia in these patients were similar to those found by other investigators using different diagnostic criteria. These results support the contention that these patients do indeed have hypertrophic cardiomyopathy and suggest that all close relatives of necropsy proven cases should be examined by echocardiography and subsequently by ambulatory electrocardiographic monitoring if the interventricular septal thickness is 1.3 more. PMID:7201843

  20. Furosemide modifies heart hypertrophy and glycosaminoglycan myocardium content in a rat model of neurogenic hypertension.

    PubMed

    Pourzitaki, Chryssa; Tsaousi, Georgia; Manthou, Maria Eleni; Karakiulakis, Georgios; Kouvelas, Dimitrios; Papakonstantinou, Eleni

    2016-08-01

    Hypertension is a major risk factor for atherogenesis and heart hypertrophy, both of which are associated with specific morphological and functional changes of the myocardium. Glycosaminoglycans (GAGs) are complex molecules involved both in tissue morphology and function. In the present study, we investigated the effects of neurogenic hypertension and subsequent antihypertensive treatment with furosemide, on heart hypertrophy and the content of GAGs in the myocardium. Neurogenic hypertension was achieved in male Wistar rats by bilateral aortic denervation (bAD). At days 2, 7 and 15 after surgery, animals were sacrificed and the hearts were dissected away, weighted, and homogenized. Total GAGs were assessed by measuring the uronic acid content colorimetrically and individual GAGs were isolated and characterized by enzymatic treatment, with GAG-degrading enzymes, using electrophoresis on polyacrylamide gradient gels and cellulose acetate membranes. In bAD-animals blood pressure, blood pressure lability, heart rate and heart weight were significantly increased 15 days postoperatively. These effects were prevented by treatment with furosemide. Major GAGs identified in the heart were chondroitin sulphates, heparin (H), heparan sulphate (HS) and hyaluronic acid. The content of uronic and the relative content of H and HS in the heart in bAD animals significantly decreased from day 2 to day 15 postoperatively. Furosemide prevented the bAD induced decrease in GAG content. Considering that H and HS are potent inhibitors of cardiomyocyte hypertrophy, our results indicate that heart hypertrophy induced by neurogenic hypertension may be associated with decreases in the relative content of heparin and heparan sulphate in the heart. PMID:27221775

  1. Monolayer co-culture of rat heart cells and bovine adrenal chromaffin paraneurons.

    PubMed

    Trifaró, J M; Tang, R; Novas, M L

    1990-04-01

    This paper describes a method for the preparation of co-cultures of rat heart cells and bovine adrenal chromaffin paraneurons. The most suitable condition for heart cell isolation was when a combination of trypsin-DNAse I in Locke's solution was used for digestion. The best co-culture conditions were obtained when 10(6) heart cells were plated on 7- to 8-d-old adrenal chromaffin paraneuron cultures containing 0.5 x 10(6) cells per 35-mm diameter culture dishes. Measurements of DNA (heart cells and chromaffin paraneurons), monitoring of beating frequency (heart cells), and catecholamine (chromaffin paraneurons) levels and release indicated that both cell types remain viable and functional for several weeks. Heart cells started their characteristic contractile activity 24 h earlier when plated either on viable or lysed chromaffin paraneurons, an effect apparently due to faster surface adhesion of heart cells. The beating frequency of heart cells increased after treatment of co-cultures with either noradrenaline or nicotine, with the latter agent acting indirectly through the release of chromaffin paraneuron catecholamines. Propranolol produced a dose-related inhibition of the responses to either noradrenaline or nicotine, thus suggesting that the increase in myocyte's beating activity was mediated through beta-receptors. Anti-myosin and anti-dopamine-beta-hydroxylase immunostaining was used for cell type identification and for the demonstration of body-to-body and process-to-process contacts between adrenal chromaffin paraneurons and heart cells. This co-culture system will serve as a starting point of further studies directed to understand a) the influence of a cell type on the development and on the phenotypic characteristics of a second cell type and b) the interaction of cells derived from different organs and species.

  2. The Mr 28,000 gap junction proteins from rat heart and liver are different but related.

    PubMed

    Nicholson, B J; Gros, D B; Kent, S B; Hood, L E; Revel, J P

    1985-06-10

    The sequence of the amino-terminal 32 residues of the rat heart Mr 28,000 gap junction protein presented here allows, for the first time, a sequence comparison of gap junctional proteins from different tissues (heart and liver). Comparison of the rat heart gap junction protein sequence and that available from rat liver reveals 43% sequence identity and conservative changes at an additional 25% of the positions. Both proteins exhibit a hydrophobic domain which could represent a transmembrane span of the junction. This result unequivocally demonstrates the existence of at least two forms of the gap junction protein. As yet, no homology is evident between the gap junctional proteins of either heart or liver and main intrinsic protein from rat eye lens. PMID:2987225

  3. Protein remodeling of the heart ventricles in hereditary hypertriglyceridemic rat: effect of ACE-inhibition.

    PubMed

    Simko, Fedor; Pelouch, Václav; Torok, Jozef; Luptak, Ivan; Matuskova, Jana; Pechanova, Olga; Babal, Pavel

    2005-01-01

    The aim of this study was to determine whether protein remodeling of the heart ventricles and remodeling of the aorta were present in hereditary hypertriglyceridemic (hHTG) rats and whether treatment with the angiotensin-converting enzyme inhibitor, captopril could prevent these alterations. Three groups of rats were investigated in a four week experiment control Wistar /C/rats, hHTg rats, hHTg rats given captopril (100 mg/kg/day) (hHTg + CAP). In the hHTg group, the increased systolic blood pressure (SBP) was associated with hypertrophy of the LV and RV. Protein profile analysis revealed an enhancement of metabolic protein concentration in both ventricles. The concentration of total collagenous proteins was not changed in either ventricles. However, alterations in composition of cardiac collagen were detected, characterized by higher concentration of hydroxyproline in pepsin-insoluble fraction and lower concentration of hydroxyproline in pepsin soluble faction in the LV. Hypertrophy of aorta, associated with the reduction of nitric oxide dependent relaxation, was also present in hHTG rats. Captopril normalized SBP, reduced left ventricular hypertrophy (LVH), diminished metabolic protein concentration in both ventricles, and improved NO-dependent relaxation of the aorta. Furthermore, captopril partially reversed alterations in hydroxyproline concentration in soluble and insoluble collagenous fractions of the LV. We conclude that hypertrophy of both ventricles and the aorta are present in hHTG rats, along with protein remodeling of both ventricles. Captopril partially prevented left ventricular hypertrophy development and protein remodeling of the myocardium.

  4. Functional evaluation of rat hearts transplanted after preservation in a high-pressure gaseous mixture of carbon monoxide and oxygen

    PubMed Central

    Hatayama, Naoyuki; Inubushi, Masayuki; Naito, Munekazu; Hirai, Shuichi; Jin, Yong-Nan; Tsuji, Atsushi B.; Seki, Kunihiro; Itoh, Masahiro; Saga, Tsuneo; Li, Xiao-Kang

    2016-01-01

    We recently succeeded in resuscitating an extracted rat heart following 24–48 hours of preservation in a high-pressure gaseous mixture of carbon monoxide (CO) and oxygen (O2). This study aimed to examine the function of rat hearts transplanted after being preserved in the high-pressure CO and O2 gas mixture. The hearts of donor rats were preserved in a chamber filled with CO and O2 under high pressure for 24 h (CO24h) or 48 h at 4 °C. For the positive control (PC) group, hearts immediately extracted from donor rats were used for transplantation. The preserved hearts were transplanted into recipient rats by heterotopic cervical heart transplantation. CO toxicity does not affect the grafts or the recipients. Light microscopy and [18F]-fluorodeoxyglucose positron emission tomography revealed that there were no significant differences in the size of the myocardial infarction or apoptosis of myocardial cells in post-transplant hearts between the PC and CO24h groups. Furthermore, at 100 days after the transplantation, the heart rate, weight and histological staining of the post-transplanted hearts did not differ significantly between the PC and CO24h groups. These results indicate that the function of rat hearts is well preserved after 24 hours of high-pressure preservation in a CO and O2 gas mixture. Therefore, high-pressure preservation in a gas mixture can be a useful method for organ preservation. PMID:27562456

  5. Effects of two newly synthesized analogues of lidocaine on rat arterial blood pressure and heart rate.

    PubMed

    Al Rasheed, N M; Al Sayed, M I; Al Zuhair, H H; Al Obaid, A R; Fatani, A J

    2001-04-01

    Two new analogues of lidocaine were synthesized at the College of Pharmacy, King Saud University: compound I (Methyl-2-[2-(N,N-diethylamino) acetamido]-3-cyano-4,5-dimethylbenzoate) and compound II (Methyl-2-[2-(piperidino) acetamido]-3-cyano-4,5-dimethylbenzoate). Their influence on the arterial blood pressure and the heart rate of urethane-anaesthetized rats was studied and compared with the actions of lidocaine. Compounds I, II and lidocaine induced significant dose-dependent decreases in the arterial blood pressure and heart rate, which usually returned to basal values within 3-5 min. There were significant differences in the potency of the three compounds in producing their effects on blood pressure and heart rate (P< 0.0001, ANOVA). Compound II was 14 and 6 times more potent in reducing blood pressure and 8 and 2 times more capable of reducing the heart rate than lidocaine and compound I, respectively. The results of this study also indicated the ineffectiveness of antagonists of autonomic, histaminergic and 5-HT receptor, and various vasodilators in blocking the actions of the three compounds on blood pressure and heart rate. Pretreatment with CaCl(2)significantly reduced the hypotension and bradycardia induced by the three compounds, suggesting the involvement of calcium channels, probably of the L type. Several possible mechanisms are postulated. In conclusion, the results direct attention to the capability of the two new compounds to decrease blood pressure and heart rate; affects that may have clinical potential.

  6. Acute Effects of Vagotomy on Baroreflex Equilibrium Diagram in Rats with Chronic Heart Failure.

    PubMed

    Kawada, Toru; Li, Meihua; Zheng, Can; Sugimachi, Masaru

    2016-01-01

    The arterial baroreflex system can be divided into the neural arc, from pressure input to efferent sympathetic nerve activity (SNA), and the peripheral arc, from SNA to arterial pressure (AP). Plotting the neural and peripheral arcs on a pressure-SNA plane yields a baroreflex equilibrium diagram. We examined the effects of vagotomy on the open-loop static characteristics of the carotid sinus baroreflex in normal control rats (NC, n = 10) and rats with heart failure after myocardial infarction (MI, n = 10). In the NC group, vagotomy shifted the neural arc toward higher SNA and decreased the slope of the peripheral arc. Consequently, the operating-point SNA increased without a significant change in the operating-point AP on the baroreflex equilibrium diagram. These vagotomy-induced effects were not observed in the MI group, suggesting a loss of vagal modulation of the carotid sinus baroreflex function in heart failure. PMID:27594790

  7. Acute Effects of Vagotomy on Baroreflex Equilibrium Diagram in Rats with Chronic Heart Failure

    PubMed Central

    Kawada, Toru; Li, Meihua; Zheng, Can; Sugimachi, Masaru

    2016-01-01

    The arterial baroreflex system can be divided into the neural arc, from pressure input to efferent sympathetic nerve activity (SNA), and the peripheral arc, from SNA to arterial pressure (AP). Plotting the neural and peripheral arcs on a pressure–SNA plane yields a baroreflex equilibrium diagram. We examined the effects of vagotomy on the open-loop static characteristics of the carotid sinus baroreflex in normal control rats (NC, n = 10) and rats with heart failure after myocardial infarction (MI, n = 10). In the NC group, vagotomy shifted the neural arc toward higher SNA and decreased the slope of the peripheral arc. Consequently, the operating-point SNA increased without a significant change in the operating-point AP on the baroreflex equilibrium diagram. These vagotomy-induced effects were not observed in the MI group, suggesting a loss of vagal modulation of the carotid sinus baroreflex function in heart failure.

  8. Acute Effects of Vagotomy on Baroreflex Equilibrium Diagram in Rats with Chronic Heart Failure

    PubMed Central

    Kawada, Toru; Li, Meihua; Zheng, Can; Sugimachi, Masaru

    2016-01-01

    The arterial baroreflex system can be divided into the neural arc, from pressure input to efferent sympathetic nerve activity (SNA), and the peripheral arc, from SNA to arterial pressure (AP). Plotting the neural and peripheral arcs on a pressure–SNA plane yields a baroreflex equilibrium diagram. We examined the effects of vagotomy on the open-loop static characteristics of the carotid sinus baroreflex in normal control rats (NC, n = 10) and rats with heart failure after myocardial infarction (MI, n = 10). In the NC group, vagotomy shifted the neural arc toward higher SNA and decreased the slope of the peripheral arc. Consequently, the operating-point SNA increased without a significant change in the operating-point AP on the baroreflex equilibrium diagram. These vagotomy-induced effects were not observed in the MI group, suggesting a loss of vagal modulation of the carotid sinus baroreflex function in heart failure. PMID:27594790

  9. Innervating sympathetic neurons regulate heart size and the timing of cardiomyocyte cell cycle withdrawal.

    PubMed

    Kreipke, R E; Birren, S J

    2015-12-01

    Sympathetic drive to the heart is a key modulator of cardiac function and interactions between heart tissue and innervating sympathetic fibres are established early in development. Significant innervation takes place during postnatal heart development, a period when cardiomyocytes undergo a rapid transition from proliferative to hypertrophic growth. The question of whether these innervating sympathetic fibres play a role in regulating the modes of cardiomyocyte growth was investigated using 6-hydroxydopamine (6-OHDA) to abolish early sympathetic innervation of the heart. Postnatal chemical sympathectomy resulted in rats with smaller hearts, indicating that heart growth is regulated by innervating sympathetic fibres during the postnatal period. In vitro experiments showed that sympathetic interactions resulted in delays in markers of cardiomyocyte maturation, suggesting that changes in the timing of the transition from hyperplastic to hypertrophic growth of cardiomyocytes could underlie changes in heart size in the sympathectomized animals. There was also an increase in the expression of Meis1, which has been linked to cardiomyocyte cell cycle withdrawal, suggesting that sympathetic signalling suppresses cell cycle withdrawal. This signalling involves β-adrenergic activation, which was necessary for sympathetic regulation of cardiomyocyte proliferation and hypertrophy. The effect of β-adrenergic signalling on cardiomyocyte hypertrophy underwent a developmental transition. While young postnatal cardiomyocytes responded to isoproterenol (isoprenaline) with a decrease in cell size, mature cardiomyocytes showed an increase in cell size in response to the drug. Together, these results suggest that early sympathetic effects on proliferation modulate a key transition between proliferative and hypertrophic growth of the heart and contribute to the sympathetic regulation of adult heart size.

  10. X-ray intravital microscopy for functional imaging in rat hearts using synchrotron radiation coronary microangiography

    SciTech Connect

    Umetani, K.; Fukushima, K.

    2013-03-15

    An X-ray intravital microscopy technique was developed to enable in vivo visualization of the coronary, cerebral, and pulmonary arteries in rats without exposure of organs and with spatial resolution in the micrometer range and temporal resolution in the millisecond range. We have refined the system continually in terms of the spatial resolution and exposure time. X-rays transmitted through an object are detected by an X-ray direct-conversion type detector, which incorporates an X-ray SATICON pickup tube. The spatial resolution has been improved to 6 {mu}m, yielding sharp images of small arteries. The exposure time has been shortened to around 2 ms using a new rotating-disk X-ray shutter, enabling imaging of beating rat hearts. Quantitative evaluations of the X-ray intravital microscopy technique were extracted from measurements of the smallest-detectable vessel size and detection of the vessel function. The smallest-diameter vessel viewed for measurements is determined primarily by the concentration of iodinated contrast material. The iodine concentration depends on the injection technique. We used ex vivo rat hearts under Langendorff perfusion for accurate evaluation. After the contrast agent is injected into the origin of the aorta in an isolated perfused rat heart, the contrast agent is delivered directly into the coronary arteries with minimum dilution. The vascular internal diameter response of coronary arterial circulation is analyzed to evaluate the vessel function. Small blood vessels of more than about 50 {mu}m diameters were visualized clearly at heart rates of around 300 beats/min. Vasodilation compared to the control was observed quantitatively using drug manipulation. Furthermore, the apparent increase in the number of small vessels with diameters of less than about 50 {mu}m was observed after the vasoactive agents increased the diameters of invisible small blood vessels to visible sizes. This technique is expected to offer the potential for direct

  11. X-ray intravital microscopy for functional imaging in rat hearts using synchrotron radiation coronary microangiography

    NASA Astrophysics Data System (ADS)

    Umetani, K.; Fukushima, K.

    2013-03-01

    An X-ray intravital microscopy technique was developed to enable in vivo visualization of the coronary, cerebral, and pulmonary arteries in rats without exposure of organs and with spatial resolution in the micrometer range and temporal resolution in the millisecond range. We have refined the system continually in terms of the spatial resolution and exposure time. X-rays transmitted through an object are detected by an X-ray direct-conversion type detector, which incorporates an X-ray SATICON pickup tube. The spatial resolution has been improved to 6 μm, yielding sharp images of small arteries. The exposure time has been shortened to around 2 ms using a new rotating-disk X-ray shutter, enabling imaging of beating rat hearts. Quantitative evaluations of the X-ray intravital microscopy technique were extracted from measurements of the smallest-detectable vessel size and detection of the vessel function. The smallest-diameter vessel viewed for measurements is determined primarily by the concentration of iodinated contrast material. The iodine concentration depends on the injection technique. We used ex vivo rat hearts under Langendorff perfusion for accurate evaluation. After the contrast agent is injected into the origin of the aorta in an isolated perfused rat heart, the contrast agent is delivered directly into the coronary arteries with minimum dilution. The vascular internal diameter response of coronary arterial circulation is analyzed to evaluate the vessel function. Small blood vessels of more than about 50 μm diameters were visualized clearly at heart rates of around 300 beats/min. Vasodilation compared to the control was observed quantitatively using drug manipulation. Furthermore, the apparent increase in the number of small vessels with diameters of less than about 50 μm was observed after the vasoactive agents increased the diameters of invisible small blood vessels to visible sizes. This technique is expected to offer the potential for direct

  12. Spiral hypertrophic cardiomyopathy as detected by cardiac magnetic resonance.

    PubMed

    Amin, Nessim; Williams, Ronald B; Yarmozik, June A; Biederman, Robert W W

    2014-03-01

    Hypertrophic cardiomyopathy (HCM) is a genetically determined heart muscle disease; characterized by left ventricular hypertrophy (LVH). Spiral HCM is described as having a counterclockwise rotation pattern of hypertrophy along with variable degrees of fibrosis. A 34-year-old female presented with symptoms suggestive of heart failure. Echocardiography showed concentric LVH with normal contractility. Cardiac MRI showed asymmetric septal hypertrophy with mid-cavity obliteration and a spiral pattern of variably increasing wall thickness. Late gadolinium enhancement (LGE) demonstrated several areas of abnormal postgadolinium uptake. We report a case of spiral HCM. We should consider cardiovascular magnetic resonance (CMR) as the reference standard for diagnosing HCM. PMID:24749165

  13. Topical treatments for hypertrophic scars.

    PubMed

    Zurada, Joanna M; Kriegel, David; Davis, Ira C

    2006-12-01

    Hypertrophic scars represent an abnormal, exaggerated healing response after skin injury. In addition to cosmetic concern, scars may cause pain, pruritus, contractures, and other functional impairments. Therapeutic modalities include topical medications, intralesional corticosteroids, laser therapy, and cryosurgery. Topical therapies, in particular, have become increasingly popular because of their ease of use, comfort, noninvasiveness, and relatively low cost. This review will discuss the properties and effectiveness of these agents, including pressure therapy, silicone gel sheeting and ointment, polyurethane dressing, onion extract, imiquimod 5% cream, and vitamins A and E in the prevention and treatment of hypertrophic scars. PMID:17097399

  14. Exposure of rats to ozone: evidence of damage to heart and brain

    SciTech Connect

    Rahman, I.; Massaro, G.D.; Massaro, D. )

    1992-01-01

    Ozone is a strong oxidizing agent, and in many locations it is a major atmospheric pollutant. It is phytotoxic and an important cause of lung dysfunction in humans. Recently, a significant association has been established between total atmospheric oxidants, of which ozone is one, and daily cardiovascular mortality rates. In this article, we show that exposure of rats to ozone for 5 days, in a concentration found in major urban centers, results in an increased concentration of thiobarbituric acid-reactive material (an indicator of lipid peroxidation) in heart and brain tissue as well as elevated activity of catalase and glutathione peroxidase (enzymic scavengers of peroxides) in these tissues. We examined the heart anatomically and found evidence of extracellular and intracellular edema. These findings indicate that the heart and brain are damaged by a concentration of ozone present in major urban centers; they may have important implications for chronic illness and degenerative processes in humans.

  15. Motion compensation of optical mapping signals from isolated beating rat hearts

    NASA Astrophysics Data System (ADS)

    Stender, B.; Ernst, F.; Wang, B.; Zhang, Z. X.; Schlaefer, A.

    2013-09-01

    Optical mapping is a well established technique for recording monophasic action potential traces on the epicardial surface of isolated hearts. This measuring technique offers a high spatial resolution but it is sensitive towards myocardial motion. Motion artifacts occur because the mapping between a certain tissue portion sending out fluorescent light and a pixel of the photo detector changes over time. So far this problem has been addressed by suppressing the motion or ratiometric imaging. We developed a different approach to compensate the motion artifacts based on image registration. We could demonstrate how an image deformation field temporally changing with the heart motion could be determined. Using these deformation field time series for image transformation motion signals could be generated for each image pixel which were then successfully applied to remove baseline shift and compensate motion artifacts potentially leading to errors within maps of the first arrival time. The investigation was based on five different rat hearts stained with Di-4-ANEPPS.

  16. Oxidative Stress in the Heart of Rats Infected with Trypanosoma evansi

    PubMed Central

    Baldissera, Matheus D.; Souza, Carine de F.; Bertoncheli, Cláudia M.; da Silveira, Karine L.; Grando, Thirssa H.; Porto, Bianca C. Z.; Leal, Daniela B. R.; Silva, Aleksandro S. Da; Mendes, Ricardo E.; Stefani, Lenita M.; Monteiro, Silvia G.

    2016-01-01

    This study was conducted to investigate the occurrence of oxidative stress in the heart tissue of rats infected with Trypanosoma evansi. Rats were divided into 2 groups (A and B) with 12 animals each, and further subdivided into 4 subgroups (A1 and A2, 6 animals/each; and B1 and B2, 6 animals/each). Animals in the groups B1 and B2 were subcutaneously inoculated with T. evansi. Thiobarbituric acid reactive substances (TBARS), superoxide dismutase activity (SOD), glutathione S-transferase activity (GST), reduced glutathione activity (GSH), and non-protein thiols (NPSH) in the heart tissue were evaluated. At day 5 and 15 post-infection (PI), an increase in the TBARS levels and a decrease in the SOD activity (P<0.05) were observed. GSH and GST activities were decreased in infected animals at day 15 PI (P<0.05). Considering the proper functioning of the heart, it is possible that the changes in the activity of these enzymes involved in the oxidative stress may be related, at least in part, in the pathophysiology of rats infected with T. evansi. PMID:27417077

  17. Transmission electron microscopy of heart and liver tissues from rats fed with gums arabic and tragacanth.

    PubMed

    Anderson, D M; Ashby, P; Busuttil, A; Kempson, S A; Lawson, M E

    1984-04-01

    Transmission electron microscopy has been used to examine the ultrastructure of rat hearts and livers after diet supplementation with (a) 0, 0.5, 1.5, 2.5 and 3.5% (w/w) gum tragacanth (GT) for 91 days, (b) 0 and 1% GT for 5 days (c) 0, 1, 4 and 8% (w/w) gum arabic (GA) for 28 days. The preparation and scrutiny of the electron micrographs was undertaken by two independent teams of specialists. There were no detectable abnormalities in any of the organelles in the heart and liver specimens from any of the test animals and no inclusions nor other pathological changes were observed. All micrographs showed normal, healthy tissues; particular attention was given to the mitochondria in hepatocytes as they serve as sensitive indicators of the health and state of activity of cells. In addition, the data obtained from assays of the microsomal protein and cytochrome P-450 content of the livers showed that GA and GT did not cause inductive effects. These results do not support earlier suggestions, based on in vitro assays, that GA and GT cause changes in the function of rat heart and liver mitochondria and liver microsomes; however, they confirm a report by Zbinden that the ingestion of GT does not produce abnormalities in the cardiac function of rats.

  18. Protective role of grape seed proanthocyanidin antioxidant properties on heart of streptozotocin-induced diabetic rats

    PubMed Central

    Mansouri, Esrafil; Khorsandi, Layasadat; Abdollahzade Fard, Amin

    2015-01-01

    Grape seed proanthocyanidin (GSP) bears a very powerful antioxidant effects. Studies demonstrated that proanthocyanidins protect against free radicals mediated cardiovascular and renal disorders. The present study was designed to assess the effect of GSP on the heart of diabetic rats. Forty rats were divided into four groups of 10 animals each: Group I: control, Group II: control group were given GSP, Group III: diabetic group, Group IV: diabetic group treated with GSP. Diabetes was induced by a single dose of streptozotocin, and then GSP (200 mg kg-1 body weight) was administrated for four weeks. Blood glucose, glycosylated hemoglobin (HbA1c) and also the levels of lipid peroxidation and antioxidant enzymes were examined in the heart tissues of all groups. Oral administration of GSP to diabetic rats significantly reduced (p < 0.05) heart weight, blood glucose, HbA1c and lipid peroxidation level, but increased (p < 0.05) body weight and activities antioxidant enzymes when compared to diabetic group. The results indicated that GSP could be useful for prevention or early treatment of cardiac disorder caused by diabetes. PMID:26261706

  19. Simultaneous gene expression signature of heart and peripheral blood mononuclear cells in astemizole-treated rats.

    PubMed

    Lee, Eun-Hee; Oh, Jung-Hwa; Park, Han-Jin; Kim, Do-Geun; Lee, Jong-Hwa; Kim, Choong-Yong; Kwon, Myung-Sang; Yoon, Seokjoo

    2010-08-01

    We investigated the effects of astemizole, a second-generation antihistamine, on the heart and peripheral blood mononuclear cells (PBMCs) and identified the early markers of its cardiotoxicity using gene expression profiling. Astemizole causes torsades de pointes, which is a type of ventricular tachycardia. We administered astemizole (dosage: 20, 60 mg/kg) to male Sprague-Dawley rats, using an oral gavage. Cardiac tissue and PBMCs were collected from the rats 4 h after treatment. Gene expression profiles were obtained using an Affymetrix GeneChip. The most deregulated genes were associated with energy metabolism pathways and calcium ion homeostasis in the heart of astemizole-treated rats. The most altered genes in the PBMCs were those involved in developmental processes and cardiotoxicity. Genes related to the response to oxidative stress, reactive oxygen species, heat shock proteins, hypoxia, immunity, and inflammation were also deregulated in the heart and PBMCs. These data provide further insight into the genetic pathways affected by astemizole. In addition, the simultaneously deregulated genes identified herein may be further studied. It will be interesting to find out whether single genes or certain sets of these genes could finally serve as biomarkers for cardiotoxicity of astemizole or other similar antihistamine drugs. PMID:20221588

  20. Propagation of the cardiac impulse in the diabetic rat heart: reduced conduction reserve

    PubMed Central

    Nygren, A; Olson, M L; Chen, K Y; Emmett, T; Kargacin, G; Shimoni, Y

    2007-01-01

    Diabetes mellitus is a growing epidemic with severe cardiovascular complications. Although much is known about mechanical and electrical cardiac dysfunction in diabetes, few studies have investigated propagation of the electrical signal in the diabetic heart and the associated changes in intercellular gap junctions. This study was designed to investigate these issues, using hearts from control and diabetic rats. Diabetic conditions were induced by streptozotocin (STZ), given i.v. 7–14 days before experiments. Optical mapping with the voltage-sensitive dye di-4-ANEPPS, using hearts perfused on a Langendorff apparatus, showed little change in baseline conduction velocity in diabetic hearts, reflecting the large reserve of function. However, both the gap junction uncoupler heptanol (0.5–1 mm) and elevated potassium (9 mm, to reduce cell excitability) produced a significantly greater slowing of impulse propagation in diabetic hearts than in controls. The maximal action potential upstroke velocity (an index of the sodium current) and resting potential was similar in single ventricular myocytes from control and diabetic rats, suggesting similar electrical excitability. Immunoblotting of connexin 43 (Cx43), a major gap junction component, showed no change in total expression. However, immunofluorescence labelling of Cx43 showed a significant redistribution, apparent as enhanced Cx43 lateralization. This was quantified and found to be significantly larger than in control myocytes. Labelling of two other gap junction proteins, N-cadherin and β-catenin, showed a (partial) loss of co-localization with Cx43, indicating that enhancement of lateralized Cx43 is associated with non-functional gap junctions. In conclusion, conduction reserve is smaller in the diabetic heart, priming it for impaired conduction upon further challenges. This can desynchronize contraction and contribute to arrhythmogenesis. PMID:17185336

  1. Phosphorylation and hydrolysis of 7-deazaadenine nucleotides by rat liver and beef heart mitochondria.

    PubMed

    Petrescu, I; Lascu, I; Goia, I; Markert, M; Schmidt, F H; Deaciuc, I V; Kezdi, M; Bârzu, O

    1982-03-01

    Tubercidin nucleotides [tubercidin 5'-mono-phosphate (TuMP), 5'-diphosphate (TuDP), and 5'-triphosphate (TuTP)] were tested as potential substrates for the mitochondrial phosphotransferases from rat liver and beef heart. TuDP is recognized by the mitochondrial translocase and phosphorylated by the respiratory chain enzymes in both mitochondria and submitochondrial particles from rat liver and beef heart; the low transport rate of the analogue into the matrix space of the intact organelles seems to be not a limiting step in the formation of TuTP. The phosphorylation of TuDP is significantly lower in beef heart mitochondria because of a higher specificity for ADP of the heart oxidative phosphorylation system. On the basis of the kinetic parameters of the partially purified liver mitochondrial adenylate kinase, one can conclude that the liver mitochondria are able to phosphorylate in vivo TuMP at a rate practically equal to the rate of AMP phosphorylation. The liver mitochondrial NDP kinase ensures a further fast phosphorylation of TuDP without the direct involvement of respiratory chain enzymes. In the case of heart mitochondria, two factors limit the rate of TuMP phosphorylation to TuTP: the lower acceptor activity of adenylate kinase with TuMP as compared with AMP and the different localization of heart NDP kinase situated on the inner face of the inner mitochondrial membrane. TuDP and TuTP preserve the ability of the natural nucleotides to interact with the "tight" nucleotide binding sites of isolated or membrane-bound F1. The low hydrolytic rate of TuTP with F1 may be related to the unusual flexibility of the glycosyl bond of tubercidin nucleotides in aqueous solution, with a high accessibility to syn conformation.

  2. The establishment of regular beating in populations of pacemaker heart cells. A study with tissue-cultured rat heart cells.

    PubMed

    Jongsma, H J; Tsjernina, L; de Bruijne, J

    1983-02-01

    Single isolated neonatal rat heart cells beat slowly (mean beating interval duration in the range of seconds) and irregularly (coefficient of variation greater than 40%). It is shown that slowness and irregularity of beating are intrinsic properties of the cells and are not caused by dissociation damage or lack of conditioning factors in the culture medium. When cell contacts are established either by letting the cultures grow for given amounts of time or by plating cells at increasing densities both interval duration and irregularity decrease. The beating regularity of small groups of interconnected cells (3 to 35 cells) and larger groups (200 to 15000 cells) is comparable. There is no clear cut proportionality between number of interconnected cells and beating regularity. Confluent monolayers beat fast (mean interval duration ranging between 200 and 400 ms and regular (coefficient of variation less than 5%). The hypothesis is discussed that this clock-like behavior of monolayers of heart cells is caused by the interaction of several pacemaker centers which are by themselves less regular and beat more slowly. PMID:6854658

  3. Comparison of carbon dioxide and argon euthanasia: effects on behavior, heart rate, and respiratory lesions in rats.

    PubMed

    Burkholder, Tanya H; Niel, Lee; Weed, James L; Brinster, Lauren R; Bacher, John D; Foltz, Charmaine J

    2010-07-01

    In this study we compared rat (n = 16) responses to euthanasia with either gradual-fill CO(2) or rapid induction argon gas by evaluating the animals' heart rate via radiotelemetry, behavior, and vocalizations. We also evaluated the histologic effects of the gases. Rats were placed in an open test chamber 24 h before the start of the experiment. During baseline tests, rats were exposed to oxygen to evaluate the effects of the noise and movement of gas entering the chamber; 1 wk later, rats were euthanized by gas displacement with either 10%/min CO(2) or 50%/min argon gas. Rats tended to have higher heart rats and were more active during the baseline test, but these parameters were normal before the euthanasia experiment, suggesting that the rats had acclimated to the equipment. Heart rate, behavior, and ultrasonic vocalizations were recorded for 2 min after gas introduction in both groups. All rats appeared conscious throughout the test interval. The heart rates of rats exposed to argon did not change, whereas those of rats exposed to CO(2) declined significantly. Unlike those exposed to CO(2), rats euthanized with argon gas gasped and demonstrated seizure-like activity. There were no differences in the pulmonary lesions resulting from death by either gas. Our results suggest that argon as a sole euthanasia agent is aversive to rats. CO(2) using a 10%/min displacement may be less aversive than more rapid displacements. Future research investigating methods of euthanasia should allow sufficient time for the rats to acclimate to the test apparatus.

  4. Comparison of carbon dioxide and argon euthanasia: effects on behavior, heart rate, and respiratory lesions in rats.

    PubMed

    Burkholder, Tanya H; Niel, Lee; Weed, James L; Brinster, Lauren R; Bacher, John D; Foltz, Charmaine J

    2010-07-01

    In this study we compared rat (n = 16) responses to euthanasia with either gradual-fill CO(2) or rapid induction argon gas by evaluating the animals' heart rate via radiotelemetry, behavior, and vocalizations. We also evaluated the histologic effects of the gases. Rats were placed in an open test chamber 24 h before the start of the experiment. During baseline tests, rats were exposed to oxygen to evaluate the effects of the noise and movement of gas entering the chamber; 1 wk later, rats were euthanized by gas displacement with either 10%/min CO(2) or 50%/min argon gas. Rats tended to have higher heart rats and were more active during the baseline test, but these parameters were normal before the euthanasia experiment, suggesting that the rats had acclimated to the equipment. Heart rate, behavior, and ultrasonic vocalizations were recorded for 2 min after gas introduction in both groups. All rats appeared conscious throughout the test interval. The heart rates of rats exposed to argon did not change, whereas those of rats exposed to CO(2) declined significantly. Unlike those exposed to CO(2), rats euthanized with argon gas gasped and demonstrated seizure-like activity. There were no differences in the pulmonary lesions resulting from death by either gas. Our results suggest that argon as a sole euthanasia agent is aversive to rats. CO(2) using a 10%/min displacement may be less aversive than more rapid displacements. Future research investigating methods of euthanasia should allow sufficient time for the rats to acclimate to the test apparatus. PMID:20819391

  5. Effect of acute exposure to ozone on heart rate and blood pressure of the conscious rat

    SciTech Connect

    Uchiyama, I.; Simomura, Y.; Yokoyama, E.

    1985-12-01

    Electrocardiogram and arterial blood pressure in conscious and unrestrained rats of various ages were recorded during a 3-hr exposure to filtered air or 1 ppm ozone (O/sub 3/). In general, heart rate and mean arterial blood pressure of rats significantly decreased during exposure to O/sub 3/, whereas these functional parameters remained almost stable during exposure to filtered air. Heart rate usually reached a plateau during the exposure to O/sub 3/. Additionally, PR interval and QRS complex significantly increased and premature atrial contraction and incomplete A-V block were frequently observed during the exposure to O/sub 3/. These circulatory effects of O/sub 3/ were more markedly manifested by rats 11 weeks old than either those 8 or 4 weeks old. On the other hand, no significant difference in the circulatory responses was observed between male and female rats. These circulatory effects of O/sub 3/ may be significant from the viewpoint of health effects, although its mechanisms remain unsolved.

  6. Exercise training attenuates the pressor response evoked by peripheral chemoreflex in rats with heart failure.

    PubMed

    Calegari, Leonardo; Mozzaquattro, Bruna B; Rossato, Douglas D; Quagliotto, Edson; Ferreira, Janaina B; Rasia-Filho, Alberto; Dal Lago, Pedro

    2016-09-01

    The effects of exercise training (ExT) on the pressor response elicited by potassium cyanide (KCN) in the rat model of ischemia-induced heart failure (HF) are unknown. We evaluated the effects of ExT on chemoreflex sensitivity and its interaction with baroreflex in rats with HF. Wistar rats were divided into four groups: trained HF (Tr-HF), sedentary HF (Sed-HF), trained sham (Tr-Sham), and sedentary sham (Sed-Sham). Trained animals underwent to a treadmill running protocol for 8 weeks (60 m/day, 5 days/week, 16 m/min). After ExT, arterial pressure (AP), baroreflex sensitivity (BRS), peripheral chemoreflex (KCN: 100 μg/kg body mass), and cardiac function were evaluated. The results demonstrate that ExT induces an improvement in BRS and attenuates the pressor response to KCN relative to the Sed-HF group (P < 0.05). The improvement in BRS was associated with a reduction in the pressor response following ExT in HF rats (P < 0.05). Moreover, ExT induced a reduction in left ventricular end-diastolic pressure and pulmonary congestion compared with the Sed-HF group (P < 0.05). The pressor response to KCN in the hypotensive state is decreased in sedentary HF rats. These results suggest that ExT improves cardiac function and BRS and attenuates the pressor response evoked by KCN in HF rats. PMID:27295522

  7. Effect of ethanol on function of the rat heart and skeletal muscles.

    PubMed

    Pagala, M; Ravindran, K; Amaladevi, B; Namba, T; Grob, D

    1995-06-01

    The present study was undertaken to evaluate the acute effects of ethanol on responses of the rat heart and skeletal muscles both in vivo and in vitro. In the anesthetized rat, intravenous infusion of ethanol at 0.1-0.5 g/kg body weight (33-167 mM) decreased the breathing rate by 8-83%, heart rate by 4-52%, and QRS amplitude by 5-27%, and increased the P-R interval by 1-49%. In the anterior tibialis muscle subjected to repetitive nerve stimulation at 100 Hz for 0.5 sec, ethanol at 0.1 g/kg increased the amplitude of the muscle action potential (AP) by 7%, whereas at 0.5 g/kg it decreased the muscle AP by 32%. The nerve-evoked tetanic tension was reduced by 7-34% at 0.1-0.5 g/kg ethanol. In the isolated rat heart, perfusion of ethanol at 0.1-3.0% (22-651 mM) decreased the heart rate by 8-48% and QRS amplitude by 10-39%, and increased the P-R interval by 5-61%. Left ventricular pressure was increased by 10% at 0.1% ethanol, and decreased by 80% at 3.0% ethanol. In the isolated rat phrenic nerve-diaphragm muscle preparation subjected to repetitive nerve stimulation at 100 Hz for 0.5 sec, 0.1-3.0% ethanol decreased the amplitude of the nerve AP by 5-89%, nerve-evoked muscle AP by 2-96%, and peak tetanic tension by 1-87%. On repetitive direct muscle stimulation at 100 Hz for 0.5 sec, 0.1-3.0% ethanol decreased the amplitude of the muscle-evoked muscle AP by 8-65%, and muscle-evoked tetanic tension by 2-65%. These studies indicate that ethanol causes smaller reduction in responses of the heart and skeletal muscles at clinical concentrations, but marked reduction in these responses at higher concentrations due to direct action on excitability of these tissues. At higher concentrations, ethanol causes greater reduction in excitability of the skeletal muscle than of the heart. PMID:7573793

  8. Metabolic imaging of acute and chronic infarction in the perfused rat heart using hyperpolarised [1-13C]pyruvate.

    PubMed

    Ball, Daniel R; Cruickshank, Rachel; Carr, Carolyn A; Stuckey, Daniel J; Lee, Philip; Clarke, Kieran; Tyler, Damian J

    2013-11-01

    Hyperpolarised (13)C MRI can be used to generate metabolic images of the heart in vivo. However, there have been no similar studies performed in the isolated perfused heart. Therefore, the aim of this study was to develop a method for the creation of (13)C metabolite maps of the perfused rat heart and to demonstrate the technique in a study of acute and chronic myocardial infarction. Male Wistar rat hearts were isolated, perfused and imaged before and after occlusion of the left anterior descending (LAD) coronary artery, creating an acute infarct group. In addition, a chronic infarct group was generated from hearts which had their LAD coronary artery occluded in vivo. Four weeks later, hearts were excised, perfused and imaged to generate metabolic maps of infused pyruvate and its metabolites lactate and bicarbonate. Myocardial perfusion and energetics were assessed by first-pass perfusion imaging and (31)P MRS, respectively. In both acute and chronically infarcted hearts, perfusion was reduced to the infarct region, as revealed by reduced gadolinium influx and lower signal intensity in the hyperpolarised pyruvate images. In the acute infarct region, there were significant alterations in the lactate (increased) and bicarbonate (decreased) signal ratios. In the chronically infarcted region, there was a significant reduction in both bicarbonate and lactate signals. (31)P-derived energetics revealed a significant decrease between control and chronic infarcted hearts. Significant decreases in contractile function between control and both acute and chronic infracted hearts were also seen. In conclusion, we have demonstrated that hyperpolarised pyruvate can detect reduced perfusion in the rat heart following both acute and chronic infarction. Changes in lactate and bicarbonate ratios indicate increased anaerobic metabolism in the acute infarct, which is not observed in the chronic infarct. Thus, this study has successfully demonstrated a novel imaging approach to assess

  9. Berberine treatment prevents cardiac dysfunction and remodeling through activation of 5'-adenosine monophosphate-activated protein kinase in type 2 diabetic rats and in palmitate-induced hypertrophic H9c2 cells.

    PubMed

    Chang, Wenguang; Zhang, Ming; Meng, Zhaojie; Yu, Yang; Yao, Fan; Hatch, Grant M; Chen, Li

    2015-12-15

    Diabetic cardiomyopathy is the major cause of death in type 2 diabetic patients. Berberine is an isoquinoline alkaloid extract from traditional chinese herbs and its hypoglycemic and hypolipidemic effects make it a promising drug for treatment of type 2 diabetes. We examined if berberine improved cardiac function and attenuated cardiac hypertrophy and fibrosis in high fat diet and streptozotocin induced-type 2 diabetic rats in vivo and reduced expression of hypertrophy markers in palmitate-induced hypertrophic H9c2 cells in vitro. Treatment of diabetic animals with berberine partially improved cardiac function and restored fasting blood insulin, fasting blood glucose, total cholesterol, and triglyceride levels to that of control. In addition, berberine treatment of diabetic animals increased cardiac 5'-adenosine monophosphate-activated protein kinase (AMPK) and protein kinase B (AKT) activation and reduced glycogen synthase kinase 3 beta (GSK3β) activation compared to control. Palmitate incubation of H9c2 cells resulted in cellular hypertrophy and decreased expression of alpha-myosin heavy chain (α-MHC) and increased expression of beta-myosin heavy chain (β-MHC) compared to controls. Berberine treatment of palmitate-incubated H9c2 cells reduced hypertrophy, increased α-MHC expression and decreased β-MHC expression. In addition, berberine treatment of palmitate-incubated H9c2 cells increased AMPK and AKT activation and reduced GSK3β activation. The presence of the AMPK inhibitor Compound C attenuated the effects of berberine. The results strongly indicate that berberine treatment may be protective against the development of diabetic cardiomyopathy. PMID:26522928

  10. Berberine treatment prevents cardiac dysfunction and remodeling through activation of 5'-adenosine monophosphate-activated protein kinase in type 2 diabetic rats and in palmitate-induced hypertrophic H9c2 cells.

    PubMed

    Chang, Wenguang; Zhang, Ming; Meng, Zhaojie; Yu, Yang; Yao, Fan; Hatch, Grant M; Chen, Li

    2015-12-15

    Diabetic cardiomyopathy is the major cause of death in type 2 diabetic patients. Berberine is an isoquinoline alkaloid extract from traditional chinese herbs and its hypoglycemic and hypolipidemic effects make it a promising drug for treatment of type 2 diabetes. We examined if berberine improved cardiac function and attenuated cardiac hypertrophy and fibrosis in high fat diet and streptozotocin induced-type 2 diabetic rats in vivo and reduced expression of hypertrophy markers in palmitate-induced hypertrophic H9c2 cells in vitro. Treatment of diabetic animals with berberine partially improved cardiac function and restored fasting blood insulin, fasting blood glucose, total cholesterol, and triglyceride levels to that of control. In addition, berberine treatment of diabetic animals increased cardiac 5'-adenosine monophosphate-activated protein kinase (AMPK) and protein kinase B (AKT) activation and reduced glycogen synthase kinase 3 beta (GSK3β) activation compared to control. Palmitate incubation of H9c2 cells resulted in cellular hypertrophy and decreased expression of alpha-myosin heavy chain (α-MHC) and increased expression of beta-myosin heavy chain (β-MHC) compared to controls. Berberine treatment of palmitate-incubated H9c2 cells reduced hypertrophy, increased α-MHC expression and decreased β-MHC expression. In addition, berberine treatment of palmitate-incubated H9c2 cells increased AMPK and AKT activation and reduced GSK3β activation. The presence of the AMPK inhibitor Compound C attenuated the effects of berberine. The results strongly indicate that berberine treatment may be protective against the development of diabetic cardiomyopathy.

  11. The influx of amino acids into the heart of the rat.

    PubMed Central

    Baños, G; Daniel, P M; Moorhouse, S R; Pratt, O E; Wilson, P A

    1978-01-01

    1. The influx of nineteen amino acids into the heart of the living rat was studied by a method specially devised for experiments under controlled conditions in vivo. 2. When, in separate experiments, the concentration of each amino acid in turn was artificially raised in the circulation, the influx of that amino acid into the heart increased. 3. Our data indicate that at least ten of these amino acids enter the heart in vivo by means of saturable carrier-mediated transport systems. The transport rates conform, at least approximately, to Michaelis kinetics and the transport systems are clearly, in the cases of many amino acids, active, i.e. energy-dependent. 4. The amino acids which were studied had rates of influx into the heart which differed from each other over a range of more than 10 to 1, even when allowances were made for the difference in their concentration in the circulating blood. These differences in influx were not related to such factors as the molecular size of the individual amino acids. 5. The amino acids which have a high influx into the heart are mainly those which are needed either to re-synthesize contractile protein or as oxidizable substrates. PMID:690905

  12. Ouabain triggers preconditioning through activation of the Na+,K+-ATPase signaling cascade in rat hearts

    PubMed Central

    Pierre, Sandrine V.; Yang, Changjun; Yuan, Zhaokan; Seminerio, Jennifer; Mouas, Christian; Garlid, Keith D.; Dos-Santos, Pierre; Xie, Zijian

    2007-01-01

    Objective Because ouabain activates several pathways that are critical to cardioprotective mechanisms such as ischemic preconditioning, we tested if this digitalis compound could protect the heart against ischemia-reperfusion injury through activation of the Na+,K+-ATPase/c-Src receptor complex. Methods and Results In Langendorff-perfused rat hearts, a short (4 min) administration of ouabain 10 μM followed by an 8-minute washout before 30 minutes of global ischemia and reperfusion improved cardiac function, decreased lactate dehydrogenase release and reduced infarct size by 40%. Western blot analysis revealed that ouabain activated the cardioprotective phospholipase Cγ1/protein kinase Cε (PLC-γ1/PKCε) pathway. Pre-treatment of the hearts with the Src kinase family inhibitor 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolol[3,4-d]pyrimidine (PP2) blocked not only ouabain-induced activation of PLC-γ1/PKCε pathway, but also cardiac protection. This protection was also blocked by a PKCε translocation inhibitor peptide (PKCε TIP). Conclusion Short exposure to a low concentration of ouabain protects the heart against ischemia/reperfusion injury. This effect of ouabain on the heart is most likely due to the activation of the Na+,K+-ATPase/c-Src receptor complex and subsequent stimulation of key mediators of preconditioning, namely PLC-γ1 and PKCε. PMID:17157283

  13. Long-term evaluation of myoblast seeded patches implanted on infarcted rat hearts.

    PubMed

    Giraud, Marie-Noëlle; Flueckiger, Remy; Cook, Stéphane; Ayuni, Erick; Siepe, Matthias; Carrel, Thierry; Tevaearai, Hendrik

    2010-06-01

    Cell transplantation presents great potential for treatment of patients with severe heart failure. However, its clinical application was revealed to be more challenging than initially expected in experimental studies. Further investigations need to be undertaken to define the optimal treatment conditions. We previously reported on the epicardial implantation of a bio-engineered construct of skeletal myoblast-seeded polyurethane and its preventive effect on progression toward heart failure. In the present study, we present a long-term evaluation of this functional outcome. Left anterior descending coronary ligation was performed in female Lewis rats. Two weeks later, animals were treated with either epicardial implantation of biograft, acellular scaffold, sham operation, or direct intramyocardial skeletal myoblast injection. Functional assessments were performed with serial echocardiographies every 3 months and end point left ventricle pressure was assessed. Hearts were then harvested for histological examinations. Myocardial infarction induced a slow and progressive reduction in fractional shortening after 3 months. Progression toward heart failure was significantly prevented for up to 6 months after injection of myoblasts and for up to 9 months following biograft implantation. Nevertheless, this effect vanished after 12 months, with immunohistological examinations revealing an absence of the transplanted myoblasts within the scaffold. We demonstrated that tissue therapy is superior to cell therapy for stabilization of heart function. However, beneficial effects are transient.

  14. Low-dose copper infusion into the coronary circulation induces acute heart failure in diabetic rats: New mechanism of heart disease.

    PubMed

    Cheung, Carlos Chun Ho; Soon, Choong Yee; Chuang, Chia-Lin; Phillips, Anthony R J; Zhang, Shaoping; Cooper, Garth J S

    2015-09-01

    Diabetes impairs copper (Cu) regulation, causing elevated serum Cu and urinary Cu excretion in patients with established cardiovascular disease; it also causes cardiomyopathy and chronic cardiac impairment linked to defective Cu homeostasis in rats. However, the mechanisms that link impaired Cu regulation to cardiac dysfunction in diabetes are incompletely understood. Chronic treatment with triethylenetetramine (TETA), a Cu²⁺-selective chelator, improves cardiac function in diabetic patients, and in rats with heart disease; the latter displayed ∼3-fold elevations in free Cu²⁺ in the coronary effluent when TETA was infused into their coronary arteries. To further study the nature of defective cardiac Cu regulation in diabetes, we employed an isolated-perfused, working-heart model in which we infused micromolar doses of Cu²⁺ into the coronary arteries and measured acute effects on cardiac function in diabetic and non-diabetic-control rats. Infusion of CuCl₂ solutions caused acute dose-dependent cardiac dysfunction in normal hearts. Several measures of baseline cardiac function were impaired in diabetic hearts, and these defects were exacerbated by low-micromolar Cu²⁺ infusion. The response to infused Cu²⁺ was augmented in diabetic hearts, which became defective at lower infusion levels and underwent complete pump failure (cardiac output = 0 ml/min) more often (P < 0.0001) at concentrations that only moderately impaired function of control hearts. To our knowledge, this is the first report describing the acute effects on cardiac function of pathophysiological elevations in coronary Cu²⁺. The effects of Cu²⁺ infusion occur within minutes in both control and diabetic hearts, which suggests that they are not due to remodelling. Heightened sensitivity to the acute effects of small elevations in Cu²⁺ could contribute substantively to impaired cardiac function in patients with diabetes and is thus identified as a new mechanism of heart disease.

  15. Enhanced Electrical Integration of Engineered Human Myocardium via Intramyocardial versus Epicardial Delivery in Infarcted Rat Hearts

    PubMed Central

    Gerbin, Kaytlyn A.; Yang, Xiulan; Murry, Charles E.; Coulombe, Kareen L. K.

    2015-01-01

    Cardiac tissue engineering is a promising approach to provide large-scale tissues for transplantation to regenerate the heart after ischemic injury, however, integration with the host myocardium will be required to achieve electromechanical benefits. To test the ability of engineered heart tissues to electrically integrate with the host, 10 million human embryonic stem cell (hESC)-derived cardiomyocytes were used to form either scaffold-free tissue patches implanted on the epicardium or micro-tissue particles (~1000 cells/particle) delivered by intramyocardial injection into the left ventricular wall of the ischemia/reperfusion injured athymic rat heart. Results were compared to intramyocardial injection of 10 million dispersed hESC-cardiomyocytes. Graft size was not significantly different between treatment groups and correlated inversely with infarct size. After implantation on the epicardial surface, hESC-cardiac tissue patches were electromechanically active, but they beat slowly and were not electrically coupled to the host at 4 weeks based on ex vivo fluorescent imaging of their graft-autonomous GCaMP3 calcium reporter. Histologically, scar tissue physically separated the patch graft and host myocardium. In contrast, following intramyocardial injection of micro-tissue particles and suspended cardiomyocytes, 100% of the grafts detected by fluorescent GCaMP3 imaging were electrically coupled to the host heart at spontaneous rate and could follow host pacing up to a maximum of 300–390 beats per minute (5–6.5 Hz). Gap junctions between intramyocardial graft and host tissue were identified histologically. The extensive coupling and rapid response rate of the human myocardial grafts after intramyocardial delivery suggest electrophysiological adaptation of hESC-derived cardiomyocytes to the rat heart’s pacemaking activity. These data support the use of the rat model for studying electromechanical integration of human cardiomyocytes, and they identify lack of

  16. Cardiac arrhythmia mechanisms in rats with heart failure induced by pulmonary hypertension

    PubMed Central

    Benoist, David; Stones, Rachel; Drinkhill, Mark J.; Benson, Alan P.; Yang, Zhaokang; Cassan, Cecile; Gilbert, Stephen H.; Saint, David A.; Cazorla, Olivier; Steele, Derek S.; Bernus, Olivier

    2012-01-01

    Pulmonary hypertension provokes right heart failure and arrhythmias. Better understanding of the mechanisms underlying these arrhythmias is needed to facilitate new therapeutic approaches for the hypertensive, failing right ventricle (RV). The aim of our study was to identify the mechanisms generating arrhythmias in a model of RV failure induced by pulmonary hypertension. Rats were injected with monocrotaline to induce either RV hypertrophy or failure or with saline (control). ECGs were measured in conscious, unrestrained animals by telemetry. In isolated hearts, electrical activity was measured by optical mapping and myofiber orientation by diffusion tensor-MRI. Sarcoplasmic reticular Ca2+ handling was studied in single myocytes. Compared with control animals, the T-wave of the ECG was prolonged and in three of seven heart failure animals, prominent T-wave alternans occurred. Discordant action potential (AP) alternans occurred in isolated failing hearts and Ca2+ transient alternans in failing myocytes. In failing hearts, AP duration and dispersion were increased; conduction velocity and AP restitution were steeper. The latter was intrinsic to failing single myocytes. Failing hearts had greater fiber angle disarray; this correlated with AP duration. Failing myocytes had reduced sarco(endo)plasmic reticular Ca2+-ATPase activity, increased sarcoplasmic reticular Ca2+-release fraction, and increased Ca2+ spark leak. In hypertrophied hearts and myocytes, dysfunctional adaptation had begun, but alternans did not develop. We conclude that increased electrical and structural heterogeneity and dysfunctional sarcoplasmic reticular Ca2+ handling increased the probability of alternans, a proarrhythmic predictor of sudden cardiac death. These mechanisms are potential therapeutic targets for the correction of arrhythmias in hypertensive, failing RVs. PMID:22427523

  17. CARBONYLATION OF MYOSIN HEAVY CHAINS IN RAT HEARTS DURING DIABETES

    PubMed Central

    Shao, Chun-Hong; Rozanski, George J.; Nagai, Ryoji; Stockdale, Frank E.; Patel, Kaushik P.; Wang, Mu; Singh, Jaipaul; Mayhan, William G.; Bidasee, Keshore R.

    2010-01-01

    Cardiac inotropy progressively declines during diabetes mellitus. To date, the molecular mechanisms underlying this defect remain incompletely characterized. This study tests the hypothesis that ventricular myosin heavy chains (MHC) undergo carbonylation by reactive carbonyl species (RCS) during diabetes and these modifications contribute to the inotropic decline. Male Sprague-Dawley rats were injected with streptozotocin (STZ). Fourteen days later animals were divided into two groups: one group was treated with the RCS blocker aminoguanidine for six weeks, while the other group received no treatment. After eight weeks of diabetes, cardiac ejection fraction, fractional shortening, left ventricular pressure development (+dP/dt) and myocyte shortening were decreased by 9%, 16%, 34% and 18%, respectively. Ca2+- and Mg2+-actomyosin ATPase activities and peak actomyosin syneresis were also reduced by 35%, 28%, and 72%. MHC-α to MHC-β ratio was 12:88. Mass spectrometry and Western blots revealed the presence of carbonyl adducts on MHC-α and MHC-β. Aminoguandine treatment did not alter MHC composition, but it blunted formation of carbonyl adducts and decreases in actomyosin Ca2+-sensitive ATPase activity, syneresis, myocyte shortening, cardiac ejection fraction, fractional shortening and +dP/dt induced by diabetes. From these new data it can be concluded that in addition to isozyme switching, modification of MHC by RCS also contributes to the inotropic decline seen during diabetes. PMID:20359464

  18. Carbonylation of myosin heavy chains in rat heart during diabetes.

    PubMed

    Shao, Chun-Hong; Rozanski, George J; Nagai, Ryoji; Stockdale, Frank E; Patel, Kaushik P; Wang, Mu; Singh, Jaipaul; Mayhan, William G; Bidasee, Keshore R

    2010-07-15

    Cardiac inotropy progressively declines during diabetes mellitus. To date, the molecular mechanisms underlying this defect remain incompletely characterized. This study tests the hypothesis that ventricular myosin heavy chains (MHC) undergo carbonylation by reactive carbonyl species (RCS) during diabetes and these modifications contribute to the inotropic decline. Male Sprague-Dawley rats were injected with streptozotocin (STZ). Fourteen days later the animals were divided into two groups: one group was treated with the RCS blocker aminoguanidine for 6 weeks, while the other group received no treatment. After 8 weeks of diabetes, cardiac ejection fraction, fractional shortening, left ventricular pressure development (+dP/dt) and myocyte shortening were decreased by 9%, 16%, 34% and 18%, respectively. Ca(2+)- and Mg(2+)-actomyosin ATPase activities and peak actomyosin syneresis were also reduced by 35%, 28%, and 72%. MHC-alpha to MHC-beta ratio was 12:88. Mass spectrometry and Western blots revealed the presence of carbonyl adducts on MHC-alpha and MHC-beta. Aminoguanidine treatment did not alter MHC composition, but it blunted formation of carbonyl adducts and decreases in actomyosin Ca(2+)-sensitive ATPase activity, syneresis, myocyte shortening, cardiac ejection fraction, fractional shortening and +dP/dt induced by diabetes. From these new data it can be concluded that in addition to isozyme switching, modification of MHC by RCS also contributes to the inotropic decline seen during diabetes.

  19. Persistent effects after trigeminal nerve proprioceptive stimulation by mandibular extension on rat blood pressure, heart rate and pial microcirculation.

    PubMed

    Lapi, D; Colantuoni, A; Del Seppia, C; Ghione, S; Tonlorenzi, D; Brunelli, M; Scuri, R

    2013-03-01

    The trigemino-cardiac reflex is a brainstem reflex known to lead to a decrement in heart rate and blood pressure, whereas few data have been collected about its effects on the cerebral hemodynamic. In this study we assess the in vivo effects of trigeminal nerve peripheral stimulation by mandibular extension on pial microcirculation and systemic arterial blood pressure in rats. Experiments were performed in male Wistar rats subjected to mandibular extension obtained inserting an ad hoc developed retractor between the dental arches. Mean arterial blood pressure and heart rate were recorded and the pial arterioles were visualized by fluorescence microscopy to measure the vessel diameters before (15 minutes) during (5-15 minutes) and after (80 minutes) mandibular extension. While in control rats (sham-operated rats) and in rats subjected to the dissection of the trigeminal peripheral branches mean arterial blood pressure, heart rate and pial microcirculation did not change during the whole observation period (110 minutes), in rats submitted to mandibular extension, mean arterial blood pressure, heart rate and arteriolar diameter significantly decreased during stimulation. Afterward mean arterial blood pressure remained reduced as well as heart rate, while arteriolar diameter significantly increased evidencing a vasodilatation persisting for the whole remaining observation time. Therefore, trigeminal nerve proprioceptive stimulation appears to trigger specific mechanisms regulating systemic arterial blood pressure and pial microcirculation.

  20. Sudden Heart Death More Common in Male Minority Athletes

    MedlinePlus

    ... medlineplus.gov/news/fullstory_159606.html Sudden Heart Death More Common in Male Minority Athletes Inherited condition ... found that about one-third of sudden cardiac deaths were caused by the heart condition hypertrophic cardiomyopathy. ...

  1. Exogenous oxytocin reduces signs of sickness behavior and modifies heart rate fluctuations of endotoxemic rats.

    PubMed

    Reyes-Lagos, José Javier; Hadamitzky, Martin; Peña-Castillo, Miguel Ángel; Echeverría, Juan Carlos; Bösche, Katharina; Lückemann, Laura; Schedlowski, Manfred; Pacheco-López, Gustavo

    2016-10-15

    Besides the well-known roles of oxytocin on birth, maternal bonding, and lactation, recent evidence shows that this hypothalamic hormone possesses cardioprotective, anti-inflammatory and parasympathetic neuromodulation properties. In this study, we explore the heart rate fluctuations (HRF) in an endotoxemic rodent model that was accompanied by the administration of exogenous oxytocin. The assessment of HRF has been widely used as an indirect measure of the cardiac autonomic function. In this context, adult male Dark Agouti rats were equipped with a telemetric transmitter to continuously and remotely measure the electrocardiogram, temperature, and locomotion. In a between-subjects experimental design, rats received the following peripheral treatment: saline solution as a vehicle (V); lipopolysaccharide (LPS); oxytocin (Ox); lipopolysaccharide + oxytocin (LPS+Ox). Linear and non-linear parameters of HRF were estimated starting 3h before to 24h after treatments. Our results showed that exogenous oxytocin does not modify by itself the HRF of oxytocin-treated rats in comparison to vehicle-treated rats. However, in animals undergoing endotoxemia it: a) provokes a less anticorrelated pattern in HRF, b) decreased mean heart rate, c) moderated the magnitude and duration of the LPS-induced hyperthermia, and d) increased locomotion, up to 6h after the LPS injection. The less anticorrelated pattern in the HRF and decreased mean heart rate may reflect a cardiac pacemaker coupling with cholinergic influences mediated by oxytocin during LPS-induced endotoxemia. Finally, the anti-lethargic and long-term temperature moderating effects of the administration of oxytocin during endotoxemia could be a consequence of the systemic anti-inflammatory properties of oxytocin.

  2. Effects of Various Kynurenine Metabolites on Respiratory Parameters of Rat Brain, Liver and Heart Mitochondria

    PubMed Central

    Baran, Halina; Staniek, Katrin; Bertignol-Spörr, Melanie; Attam, Martin; Kronsteiner, Carina; Kepplinger, Berthold

    2016-01-01

    Previously, we demonstrated that the endogenous glutamate receptor antagonist kynurenic acid dose-dependently and significantly affected rat heart mitochondria. Now we have investigated the effects of L-tryptophan, L-kynurenine, 3-hydroxykynurenine and kynurenic, anthranilic, 3-hydroxyanthranilic, xanthurenic and quinolinic acids on respiratory parameters (ie, state 2, state 3), respiratory control index (RC) and ADP/oxygen ratio in brain, liver and heart mitochondria of adult rats. Mitochondria were incubated with glutamate/malate (5 mM) or succinate (10 mM) and in the presence of L-tryptophan metabolites (1 mM) or in the absence, as control. Kynurenic and anthranilic acids significantly reduced RC values of heart mitochondria in the presence of glutamate/malate. Xanthurenic acid significantly reduced RC values of brain mitochondria in the presence of glutamate/malate. Furthermore, 3-hydroxykynurenine and 3-hydroxyanthranilic acid decreased RC values of brain, liver and heart mitochondria using glutamate/malate. In the presence of succinate, 3-hydroxykynurenine and 3-hydroxyanthranilic acid affected RC values of brain mitochondria, whereas in liver and heart mitochondria only 3-hydroxykynurenine lowered RC values significantly. Furthermore, lowered ADP/oxygen ratios were observed in brain mitochondria in the presence of succinate with 3-hydroxykynurenine and 3-hydroxyanthranilic acid, and to a lesser extent with glutamate/malate. In addition, 3-hydroxyanthranilic acid significantly lowered the ADP/oxygen ratio in heart mitochondria exposed to glutamate/malate, while in the liver mitochondria only a mild reduction was found. Tests of the influence of L-tryptophan and its metabolites on complex I in liver mitochondria showed that only 3-hydroxykynurenine, 3-hydroxyanthranilic acid and L-kynurenine led to a significant acceleration of NADH-driven complex I activities. The data indicate that L-tryptophan metabolites had different effects on brain, liver and heart

  3. Effects of Various Kynurenine Metabolites on Respiratory Parameters of Rat Brain, Liver and Heart Mitochondria.

    PubMed

    Baran, Halina; Staniek, Katrin; Bertignol-Spörr, Melanie; Attam, Martin; Kronsteiner, Carina; Kepplinger, Berthold

    2016-01-01

    Previously, we demonstrated that the endogenous glutamate receptor antagonist kynurenic acid dose-dependently and significantly affected rat heart mitochondria. Now we have investigated the effects of L-tryptophan, L-kynurenine, 3-hydroxykynurenine and kynurenic, anthranilic, 3-hydroxyanthranilic, xanthurenic and quinolinic acids on respiratory parameters (ie, state 2, state 3), respiratory control index (RC) and ADP/oxygen ratio in brain, liver and heart mitochondria of adult rats. Mitochondria were incubated with glutamate/malate (5 mM) or succinate (10 mM) and in the presence of L-tryptophan metabolites (1 mM) or in the absence, as control. Kynurenic and anthranilic acids significantly reduced RC values of heart mitochondria in the presence of glutamate/malate. Xanthurenic acid significantly reduced RC values of brain mitochondria in the presence of glutamate/malate. Furthermore, 3-hydroxykynurenine and 3-hydroxyanthranilic acid decreased RC values of brain, liver and heart mitochondria using glutamate/malate. In the presence of succinate, 3-hydroxykynurenine and 3-hydroxyanthranilic acid affected RC values of brain mitochondria, whereas in liver and heart mitochondria only 3-hydroxykynurenine lowered RC values significantly. Furthermore, lowered ADP/oxygen ratios were observed in brain mitochondria in the presence of succinate with 3-hydroxykynurenine and 3-hydroxyanthranilic acid, and to a lesser extent with glutamate/malate. In addition, 3-hydroxyanthranilic acid significantly lowered the ADP/oxygen ratio in heart mitochondria exposed to glutamate/malate, while in the liver mitochondria only a mild reduction was found. Tests of the influence of L-tryptophan and its metabolites on complex I in liver mitochondria showed that only 3-hydroxykynurenine, 3-hydroxyanthranilic acid and L-kynurenine led to a significant acceleration of NADH-driven complex I activities. The data indicate that L-tryptophan metabolites had different effects on brain, liver and heart

  4. Rat Heterotopic Heart Transplantation Model to Investigate Unloading-Induced Myocardial Remodeling

    PubMed Central

    Fu, Xuebin; Segiser, Adrian; Carrel, Thierry P.; Tevaearai Stahel, Hendrik T.; Most, Henriette

    2016-01-01

    Unloading of the failing left ventricle in order to achieve myocardial reverse remodeling and improvement of contractile function has been developed as a strategy with the increasing frequency of implantation of left ventricular assist devices in clinical practice. But, reverse remodeling remains an elusive target, with high variability and exact mechanisms still largely unclear. The small animal model of heterotopic heart transplantation (hHTX) in rodents has been widely implemented to study the effects of complete and partial unloading on cardiac failing and non-failing tissue to better understand the structural and molecular changes that underlie myocardial recovery. We herein review the current knowledge on the effects of volume unloading the left ventricle via different methods of hHTX in rats, differentiating between changes that contribute to functional recovery and adverse effects observed in unloaded myocardium. We focus on methodological aspects of heterotopic transplantation, which increase the correlation between the animal model and the setting of the failing unloaded human heart. Last, but not least, we describe the late use of sophisticated techniques to acquire data, such as small animal MRI and catheterization, as well as ways to assess unloaded hearts under “reloaded” conditions. While giving regard to certain limitations, heterotopic rat heart transplantation certainly represents the crucial model to mimic unloading-induced changes in the heart and as such the intricacies and challenges deserve highest consideration. Careful translational research will further improve our knowledge of the reverse remodeling process and how to potentiate its effect in order to achieve recovery of contractile function in more patients. PMID:27807535

  5. Oxidative state and oxidative metabolism of the heart from rats with adjuvant-induced arthritis.

    PubMed

    Schubert, Amanda Caroline; Wendt, Mariana Marques Nogueira; de Sá-Nakanishi, Anacharis Babeto; Amado, Ciomar Aparecida Bersani; Peralta, Rosane Marina; Comar, Jurandir Fernando; Bracht, Adelar

    2016-06-01

    The aim of the present work was to investigate, in a more extensive way, the oxidative state and parameters related to energy metabolism of the heart tissue of rats using the model of adjuvant-induced arthritis. The latter is a model for the human arthritic disease. Measurements were done in the total tissue homogenate, isolated mitochondria and cytosolic fraction. The adjuvant-induced arthritis caused several modifications in the oxidative state of the heart which, in general, indicate an increased oxidative stress (+80% reactive oxygen species), protein damage (+53% protein carbonyls) and lipid damage (+63% peroxidation) in the whole tissue. The distribution of these changes over the various cell compartments was frequently unequal. For example, protein carbonyls were increased in the whole tissue and in the cytosol, but not in the mitochondria. No changes in GSH content of the whole tissue were found, but it was increased in the mitochondria (+33%) and decreased in the cytosol (-19%). The activity of succinate dehydrogenase was 77% stimulated by arthritis; the activities of glutamate dehydrogenase, isocitrate dehydrogenase and cytochrome c oxidase were diminished by 31, 25 and 35.3%, respectively. In spite of these alterations, no changes in the mitochondrial respiratory activity and in the efficiency of energy transduction were found. It can be concluded that the adjuvant-induced arthritis in rats causes oxidative damage to the heart with an unequal intracellular distribution. Compared to the liver and brain the modifications caused by arthritis in the heart are less pronounced on variables such as GSH levels and protein integrity. Possibly this occurs because the antioxidant system of the heart is less impaired by arthritis than that reported for the former tissues. Even so, the modifications caused by arthritis represent an imbalanced situation that probably contributes to the cardiac symptoms of the arthritis disease. PMID:27032477

  6. Endurance training in early life results in long-term programming of heart mass in rats.

    PubMed

    Wadley, Glenn D; Laker, Rhianna C; McConell, Glenn K; Wlodek, Mary E

    2016-02-01

    Being born small for gestational age increases the risk of developing adult cardiovascular and metabolic diseases. This study aimed to examine if early-life exercise could increase heart mass in the adult hearts from growth restricted rats. Bilateral uterine vessel ligation to induce uteroplacental insufficiency and fetal growth restriction in the offspring (Restricted) or sham surgery (Control) was performed on day 18 of gestation in WKY rats. A separate group of sham litters had litter size reduced to five pups at birth (Reduced litter), which restricted postnatal growth. Male offspring remained sedentary or underwent treadmill running from 5 to 9 weeks (early exercise) or 20 to 24 weeks of age (later exercise). Remarkably, in Control, Restricted, and Reduced litter groups, early exercise increased (P < 0.05) absolute and relative (to body mass) heart mass in adulthood. This was despite the animals being sedentary for ~4 months after exercise. Later exercise also increased adult absolute and relative heart mass (P < 0.05). Blood pressure was not significantly altered between groups or by early or later exercise. Phosphorylation of Akt Ser(473) in adulthood was increased in the early exercise groups but not the later exercise groups. Microarray gene analysis and validation by real-time PCR did not reveal any long-term effects of early exercise on the expression of any individual genes. In summary, early exercise programs the heart for increased mass into adulthood, perhaps by an upregulation of protein synthesis based on greater phosphorylation of Akt Ser(473).

  7. Low vagally-mediated heart rate variability and increased susceptibility to ventricular arrhythmias in rats bred for high anxiety.

    PubMed

    Carnevali, Luca; Trombini, Mimosa; Graiani, Gallia; Madeddu, Denise; Quaini, Federico; Landgraf, Rainer; Neumann, Inga D; Nalivaiko, Eugene; Sgoifo, Andrea

    2014-04-10

    In humans, there is a documented association between anxiety disorders and cardiovascular disease. Putative underlying mechanisms may include an impairment of the autonomic nervous system control of cardiac function. The primary objective of the present study was to characterize cardiac autonomic modulation and susceptibility to arrhythmias in genetic lines of rats that differ largely in their anxiety level. To reach this goal, electrocardiographic recordings were performed in high-anxiety behavior (HAB, n=10) and low-anxiety behavior (LAB, n=10) rats at rest, during stressful stimuli and under autonomic pharmacological manipulations, and analyzed by means of time- and frequency-domain indexes of heart rate variability. During resting conditions, HAB rats displayed a reduced heart rate variability, mostly in terms of lower parasympathetic (vagal) modulation compared to LAB rats. In HAB rats, this relatively low cardiac vagal control was associated with smaller heart rate responsiveness to acute stressors compared to LAB counterparts. In addition, beta-adrenergic pharmacological stimulation induced a larger incidence of ventricular tachyarrhythmias in HABs compared to LABs. At sacrifice, a moderate increase in heart-body weight ratio was observed in HAB rats. We conclude that high levels of anxiety-related behavior in rats are associated with signs of i) impaired autonomic modulation of heart rate (low vagally-mediated heart rate variability), ii) poor adaptive heart rate responsiveness to stressful stimuli, iii) increased arrhythmia susceptibility, and iv) cardiac hypertrophy. These results highlight the utility of the HAB/LAB model for investigating the mechanistic basis of the comorbidity between anxiety disorders and cardiovascular disease.

  8. Neonatal rat heart cells cultured in simulated microgravity

    NASA Technical Reports Server (NTRS)

    Akins, Robert E.; Schroedl, Nancy A.; Gonda, Steve R.; Hartzell, Charles R.

    1994-01-01

    In vitro characteristics of cardiac cells cultured in simulated microgravity are reported. Tissue culture methods performed at unit gravity constrain cells to propagate, differentiate, and interact in a two dimensional (2D) plane. Neonatal rat cardiac cells in 2D culture organize predominantly as bundles of cardiomyocytes with the intervening areas filled by non-myocyte cell types. Such cardiac cell cultures respond predictably to the addition of exogenous compounds, and in many ways they represent an excellent in vitro model system. The gravity-induced 2D organization of the cells, however, does not accurately reflect the distribution of cells in the intact tissue. We have begun characterizations of a three-dimensional (3D) culturing system designed to mimic microgravity. The NASA designed High-Aspect-Ratio-Vessel (HARV) bioreactors provide a low shear environment which allows cells to be cultured in static suspension. HARV-3D cultures were prepared on microcarrier beads and compared to control-2D cultures using a combination of microscopic and biochemical techniques. Both systems were uniformly inoculated and medium exchanged at standard intervals. Cells in control cultures adhered to the polystyrene surface of the tissue culture dishes and exhibited typical 2D organization. Cells in cultured in HARV's adhered to microcarrier beads, the beads aggregated into defined clusters containing 8 to 15 beads per cluster, and the clusters exhibited distinct 3D layers: myocytes and fibroblasts appeared attached to the surfaces of beads and were overlaid by an outer cell type. In addition, cultures prepared in HARV's using alternative support matrices also displayed morphological formations not seen in control cultures. Generally, the cells prepared in HARV and control cultures were similar, however, the dramatic alterations in 3D organization recommend the HARV as an ideal vessel for the generation of tissue-like organizations of cardiac cells in simulated microgravity.

  9. Neonatal rat heart cells cultured in simulated microgravity

    NASA Technical Reports Server (NTRS)

    Akins, R. E.; Schroedl, N. A.; Gonda, S. R.; Hartzell, C. R.

    1997-01-01

    In vitro characteristics of cardiac cells cultured in simulated microgravity are reported. Tissue culture methods performed at unit gravity constrain cells to propagate, differentiate, and interact in a two-dimensional (2D) plane. Neonatal rat cardiac cells in 2D culture organize predominantly as bundles of cardiomyocytes with the intervening areas filled by nonmyocyte cell types. Such cardiac cell cultures respond predictably to the addition of exogenous compounds, and in many ways they represent an excellent in vitro model system. The gravity-induced 2D organization of the cells, however, does not accurately reflect the distribution of cells in the intact tissue. We have begun characterizations of a three-dimensional (3D) culturing system designed to mimic microgravity. The NASA-designed High-Aspect Ratio Vessel (HARV) bioreactors provide a low shear environment that allows cells to be cultured in static suspension. HARV-3D cultures were prepared on microcarrier beads and compared to control-2D cultures using a combination of microscopic and biochemical techniques. Both systems were uniformly inoculated and medium exchanged at standard intervals. Cells in control cultures adhered to the polystyrene surface of the tissue culture dishes and exhibited typical 2D organization. Cells cultured in HARVs adhered to microcarrier beads, the beads aggregated into defined clusters containing 8 to 15 beads per cluster, and the clusters exhibited distinct 3D layers: myocytes and fibroblasts appeared attached to the surfaces of beads and were overlaid by an outer cell type. In addition, cultures prepared in HARVs using alternative support matrices also displayed morphological formations not seen in control cultures. Generally, the cells prepared in HARV and control cultures were similar; however, the dramatic alterations in 3D organization recommend the HARV as an ideal vessel for the generation of tissuelike organization of cardiac cells in vitro.

  10. Protective effects of Salvia miltiorrhizae on the hearts of rats with severe acute pancreatits or obstructive jaundice*

    PubMed Central

    Zhang, Xi-ping; Feng, Guang-hua; Zhang, Jie; Cai, Yang; Tian, Hua; Zhang, Xiao-feng; Zhou, Yi-feng; Wang, Zhi-wei; Wang, Ke-yi

    2009-01-01

    Objective: To investigate the therapeutic effects and mechanisms of Salvia miltiorrhizae (Danshen) in the treatment of severe acute pancreatitis (SAP)- or obstructive jaundice (OJ)-induced heart injury. Methods: A total of 288 rats were used for SAP- (n=108) and OJ-associated (n=180) experiments. The rats were randomly divided into sham-operated, model control, and Salvia miltiorrhizae-treated groups. According to the difference of time points after operation, SAP rats in each group were subdivided into 3, 6 and 12 h subgroups (n=12), whereas OJ rats were subdivided into 7, 14, 21, and 28 d subgroups (n=15). At the corresponding time points after operation, the mortality rates of the rats, the contents of endotoxin and phospholipase A2 (PLA2) in blood, and pathological changes of the hearts were investigated. Results: The numbers of dead SAP and OJ rats in the treated groups declined as compared with those in the model control group, but not significantly (P>0.05). The contents of endotoxin (at 6 and 12 h in SAP rats and on 7, 14, 21, and 28 d in OJ rats, respectively) and PLA2 (at 6 and 12 h in SAP rats and on 28 d in OJ rats, respectively) in the treated group were significantly lower than those in the model control group (P<0.01 and P<0.001, respectively). Besides, myocardial pathological injuries were mitigated in SAP and OJ rats. Conclusion: In this study, we found that Salvia miltiorrhizae improved myocardial pathological changes, reduced the content of PLA2 in blood, and decreased the mortality rates of SAP and OJ rats, exerting protective effects on the hearts of the rats. PMID:19283874

  11. Cardioprotective Effects of Astragalin against Myocardial Ischemia/Reperfusion Injury in Isolated Rat Heart.

    PubMed

    Qu, Daoxu; Han, Jichun; Ren, Huanhuan; Yang, Wenxiao; Zhang, Xinjie; Zheng, Qiusheng; Wang, Dong

    2016-01-01

    This study aims to evaluate the cardioprotective effects of astragalin against myocardial ischemia/reperfusion (I/R) injury in isolated rat heart. The cardioprotective effects of astragalin on myocardial I/R injury were investigated on Langendorff apparatus. Adult male Sprague-Dawley rats were randomly divided into five groups. The results showed that astragalin pretreatment improved myocardial function. Compared with I/R group, lactate dehydrogenase (LDH) and creatine kinase (CK) activities in coronary flow decreased in astragalin pretreatment groups, whereas superoxide dismutase (SOD) activity and glutathione/glutathione disulfide (GSH/GSSG) ratio significantly increased. The levels of malondialdehyde (MDA), intracellular reactive oxygen species (ROS), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) decreased in astragalin-treated groups. The infarct size (IS) and apoptosis rate in hearts from astragalin-treated groups were lower than those in hearts from the I/R group. Western blot analysis also revealed that astragalin preconditioning significantly reduced Bax level, whereas Bcl-2 was increased in the myocardium. Therefore, astragalin exhibited cardioprotective effects via its antioxidative, antiapoptotic, and anti-inflammatory activities.

  12. Cardioprotective Effects of Astragalin against Myocardial Ischemia/Reperfusion Injury in Isolated Rat Heart

    PubMed Central

    Qu, Daoxu; Ren, Huanhuan; Yang, Wenxiao; Zhang, Xinjie; Zheng, Qiusheng; Wang, Dong

    2016-01-01

    This study aims to evaluate the cardioprotective effects of astragalin against myocardial ischemia/reperfusion (I/R) injury in isolated rat heart. The cardioprotective effects of astragalin on myocardial I/R injury were investigated on Langendorff apparatus. Adult male Sprague-Dawley rats were randomly divided into five groups. The results showed that astragalin pretreatment improved myocardial function. Compared with I/R group, lactate dehydrogenase (LDH) and creatine kinase (CK) activities in coronary flow decreased in astragalin pretreatment groups, whereas superoxide dismutase (SOD) activity and glutathione/glutathione disulfide (GSH/GSSG) ratio significantly increased. The levels of malondialdehyde (MDA), intracellular reactive oxygen species (ROS), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) decreased in astragalin-treated groups. The infarct size (IS) and apoptosis rate in hearts from astragalin-treated groups were lower than those in hearts from the I/R group. Western blot analysis also revealed that astragalin preconditioning significantly reduced Bax level, whereas Bcl-2 was increased in the myocardium. Therefore, astragalin exhibited cardioprotective effects via its antioxidative, antiapoptotic, and anti-inflammatory activities. PMID:26788251

  13. Changes in expression of a functional G sub i protein in cultured rat heart cells

    SciTech Connect

    Allen, I.S.; Gaa, S.T.; Rogers, T.B. )

    1988-07-01

    The muscarinic cholinergic agonist, carbachol, and pertussis toxin were used to examine the functional status of the guanine nucleotide-binding protein that inhibits adenylate cyclase (G{sub i}) in cultured neonatal rat heart myocytes. The isoproterenol stimulation of adenylate cyclase activity in myocyte membranes and adenosine 3{prime},5{prime}-cyclic monophosphate (cAMP) accumulation in intact cells (4 days in culture) were insensitive to carbachol. However, in cells cultured for 11 days, carbachol inhibited isoproterenol-stimulated cAMP accumulation by 30%. Angiotensin II (ANG II) was also found to inhibit isoproterenol-stimulated cAMP accumulation in day 11 cells in a dose-dependent manner. Pertussis toxin treatment reversed the inhibitory effects of both ANG II and carbachol, suggesting a role for G{sub i} in the process. Carbachol binding to membranes from day 4 cells was relatively insensitive to guanine nucleotides when compared with binding to membranes from day 11 or adult cells. Furthermore, pertussis toxin-mediated {sup 32}P incorporation into a 39- to 41-kDa substrate in day 11 membranes was increased 3.2-fold over that measured in day 4 membranes. These findings support the view that, although G{sub i} is expressed, it is nonfunctional in 4-day-old cultured neonatal rat heart myocytes and acquisition of functional G{sub i} is dependent on culture conditions. Furthermore, the ANG II receptor can couple to G{sub i} in heart.

  14. Cardiac actions of phencyclidine in isolated guinea pig and rat heart: possible involvement of slow channels

    SciTech Connect

    Temma, K.; Akera, T.; Ng, Y.C.

    1985-03-01

    The mechanisms responsible for the positive inotropic effect of phencyclidine were studied in isolated preparations of guinea pig and rat heart. In electrically paced left atrial muscle preparations, phencyclidine increased the force of contraction; rat heart muscle preparations were more sensitive than guinea pig heart muscle preparations. The positive inotropic effect of phencyclidine was not significantly reduced by a combination of phentolamine and nadolol; however, the effect was competitively blocked by verapamil in the presence of phentolamine and nadolol. Inhibition of the outward K+ current by tetraethylammonium chloride also produced a positive inotropic effect; however, the effect of tetraethylammonium was reduced by phentolamine and nadolol, and was almost insensitive to verapamil. The inotropic effect of phencyclidine was associated with a marked prolongation of the action potential duration and a decrease in maximal upstroke velocity of the action potential, with no change in the resting membrane potential. The specific (/sup 3/H)phencyclidine binding observed with membrane preparations from guinea pig ventricular muscle was saturable with a single class of high-affinity binding site. This binding was inhibited by verapamil, diltiazem, or nitrendipine, but not by ryanodine or tetrodotoxin. These results suggest that the positive inotropic effect of phencyclidine results from enhanced Ca/sup 2 +/ influx via slow channels, either by stimulation of the channels or secondary to inhibition of outward K/sup +/ currents.

  15. Cardiac Sympathetic Afferent Denervation Attenuates Cardiac Remodeling and Improves Cardiovascular Dysfunction in Rats with Heart Failure

    PubMed Central

    Wang, Han-Jun; Wang, Wei; Cornish, Kurtis G.; Rozanski, George J.; Zucker, Irving H.

    2014-01-01

    The enhanced cardiac sympathetic afferent reflex (CSAR) contributes to the exaggerated sympatho-excitation in chronic heart failure (CHF). Increased sympatho-excitation is positively related to mortality in CHF patients. However, the potential beneficial effects of chronic CSAR deletion on cardiac and autonomic function in CHF have not been previously explored. Here we determined the effects of chronic CSAR deletion on cardiac remodeling and autonomic dysfunction in CHF. In order to selectively delete the transient receptor potential vanilloid 1 receptor (TRPV1) -expressing CSAR afferents, epicardial application of resiniferatoxin (RTX, 50 μg/ml), an ultrapotent analogue of capsaicin, was performed during myocardium infarction (MI) surgery in rats. This procedure largely abolished the enhanced CSAR, prevented the exaggerated renal and cardiac sympathetic nerve activity and improved baroreflex sensitivity in CHF rats. Most importantly, we found that epicardial application of RTX largely prevented the elevated LVEDP, lung edema and cardiac hypertrophy, partially reduced left ventricular dimensions in the failing heart and increased cardiac contractile reserve in response to β-adrenergic receptor stimulation with isoproterenol in CHF rats. Molecular evidence showed that RTX attenuated cardiac fibrosis and apoptosis and reduced expression of fibrotic markers and TGF β-receptor I in CHF rats. Pressure - volume loop analysis showed that RTX reduced the end diastolic pressure volume relations in CHF rats indicating improved cardiac compliance. In summary, cardiac sympathetic afferent deletion exhibits protective effects against deleterious cardiac remodeling and autonomic dysfunction in CHF. These data suggest a potential new paradigm and therapeutic potential in the management of CHF. PMID:24980663

  16. SWI/SNF chromatin remodeling enzymes are associated with cardiac hypertrophy in a genetic rat model of hypertension.

    PubMed

    Mehrotra, Aanchal; Joe, Bina; de la Serna, Ivana L

    2013-12-01

    Pathological cardiac hypertrophy is characterized by a sustained increase in cardiomyocyte size and re-activation of the fetal cardiac gene program. Previous studies implicated SWI/SNF chromatin remodeling enzymes as regulators of the fetal cardiac gene program in surgical models of cardiac hypertrophy. Although hypertension is a common risk factor for developing cardiac hypertrophy, there has not yet been any investigation into the role of SWI/SNF enzymes in cardiac hypertrophy using genetic models of hypertension. In this study, we tested the hypothesis that components of the SWI/SNF complex are activated and recruited to promoters that regulate the fetal cardiac gene program in hearts that become hypertrophic as a result of salt induced hypertension. Utilizing the Dahl salt-sensitive (S) rat model, we found that the protein levels of several SWI/SNF subunits required for heart development, Brg1, Baf180, and Baf60c, are elevated in hypertrophic hearts from S rats fed a high salt diet compared with normotensive hearts from Dahl salt-resistant (R) rats fed the same diet. Furthermore, we detected significantly higher levels of SWI/SNF subunit enrichment as well as evidence of more accessible chromatin structure on two fetal cardiac gene promoters in hearts from S rats compared with R rats. Our data implicate SWI/SNF chromatin remodeling enzymes as regulators of gene expression in cardiac hypertrophy resulting from salt induced hypertension. Thus we provide novel insights into the epigenetic mechanisms by which salt induced hypertension leads to cardiac hypertrophy.

  17. Metformin Prevents the Development of Chronic Heart Failure in the SHHF Rat Model

    PubMed Central

    Cittadini, Antonio; Napoli, Raffaele; Monti, Maria Gaia; Rea, Domenica; Longobardi, Salvatore; Netti, Paolo Antonio; Walser, Marion; Samà, Mariateresa; Aimaretti, Gianluca; Isgaard, Jörgen; Saccà, Luigi

    2012-01-01

    Insulin resistance is a recently identified mechanism involved in the pathophysiology of chronic heart failure (CHF). We investigated the effects of two insulin-sensitizing drugs (metformin and rosiglitazone) in a genetic model of spontaneously hypertensive, insulin-resistant rats (SHHF). Thirty SHHF rats were randomized into three treatment groups as follows: 1) metformin (100 mg/kg per day), 2) rosiglitazone (2 mg/kg per day), and 3) no drug. Ten Sprague-Dawley rats served as normal controls. At the end of the treatment period (12 months), the cardiac phenotype was characterized by histology, echocardiography, and isolated perfused heart studies. Metformin attenuated left ventricular (LV) remodeling, as shown by reduced LV volumes, wall stress, perivascular fibrosis, and cardiac lipid accumulation. Metformin improved both systolic and diastolic indices as well as myocardial mechanical efficiency, as shown by improved ability to convert metabolic energy into mechanical work. Metformin induced a marked activation of AMP-activated protein kinase, endothelial nitric oxide synthase, and vascular endothelial growth factor and reduced tumor necrosis factor-α expression and myocyte apoptosis. Rosiglitazone did not affect LV remodeling, increased perivascular fibrosis, and promoted further cardiac lipid accumulation. In conclusion, long-term treatment with metformin, but not with rosiglitazone, prevents the development of severe CHF in the SHHF model by a wide-spectrum interaction that involves molecular, structural, functional, and metabolic-energetic mechanisms. PMID:22344560

  18. Acetyl-L-carnitine increases mitochondrial protein acetylation in the aged rat heart.

    PubMed

    Kerner, Janos; Yohannes, Elizabeth; Lee, Kwangwon; Virmani, Ashraf; Koverech, Aleardo; Cavazza, Claudio; Chance, Mark R; Hoppel, Charles

    2015-01-01

    Previously we showed that in vivo treatment of elderly Fisher 344 rats with acetylcarnitine abolished the age-associated defect in respiratory chain complex III in interfibrillar mitochondria and improved the functional recovery of the ischemic/reperfused heart. Herein, we explored mitochondrial protein acetylation as a possible mechanism for acetylcarnitine's effect. In vivo treatment of elderly rats with acetylcarnitine restored cardiac acetylcarnitine content and increased mitochondrial protein lysine acetylation and increased the number of lysine-acetylated proteins in cardiac subsarcolemmal and interfibrillar mitochondria. Enzymes of the tricarboxylic acid cycle, mitochondrial β-oxidation, and ATP synthase of the respiratory chain showed the greatest acetylation. Acetylation of isocitrate dehydrogenase, long-chain acyl-CoA dehydrogenase, complex V, and aspartate aminotransferase was accompanied by decreased catalytic activity. Several proteins were found to be acetylated only after treatment with acetylcarnitine, suggesting that exogenous acetylcarnitine served as the acetyl-donor. Two-dimensional fluorescence difference gel electrophoresis analysis revealed that acetylcarnitine treatment also induced changes in mitochondrial protein amount; a two-fold or greater increase/decrease in abundance was observed for thirty one proteins. Collectively, our data provide evidence for the first time that in the aged rat heart in vivo administration of acetylcarnitine provides acetyl groups for protein acetylation and affects the amount of mitochondrial proteins. PMID:25660059

  19. Pretreatment with Assafoetida exerts dose-dependent dual effects on rat hearts

    PubMed Central

    Esmailidehaj, Mansour; Kakoo, Mohadeseh; Rezvani, Mohammad Ebrahim; Mosaddeghmehrjardi, Mohammad Hossein

    2014-01-01

    Context: Although many studies displayed the favorable effects of Assafoetida, some of them reported that high doses of Assafoetida could lead to harmful effects. Aims: In this study, the effect of pretreatment with Assafoetida investigated on ischemic–reperfusion injury in isolated rat heart model. Materials and Methods: Thirty two male Wistar rats were divided into 4 groups of eight. Group 1 as the control (Con) group and three other groups as the treatment groups that given Assafoetida by gavage at levels of 25, 50 and 100 mg/kg, once a day for four weeks (T25, T50 and T100 groups). Then their hearts were subjected to 30 min global ischemia and 90 min reperfusion under langendorff apparatus. Results: The data shown that hemodynamic parameters including left ventricular developed pressure (LVDP) and maximum and minimum of pressure changes (±dp/dt) were increased in T25 and decreased in T50 and T100 groups during reperfusion in comparison with Con group. There was not any significant difference in the incidence of irreversible ventricular fibrillation between T25 and Con group, while it was increased in T50 and T100 groups significantly. There was not any significant difference in infarct size between all groups. Conclusion: These data indicate that pretreatment of rats with Assafoetida have cardioprotective effects in low doses and cardiotoxic effects in higher doses. Therefore, it needs more investigation in the future. PMID:24914280

  20. Reduced high-energy phosphate levels in rat hearts. II. Effects of sodium cyanate.

    PubMed

    Allison, T B; Pieper, G M; Clayton, F C; Eliot, R S

    1976-06-01

    The effects of increased blood-oxygen affinity, due to carbamylation of hemoglobin in vivo, on aerobic metabolism in the heart were studied in rats. Adult male rats were injected intraperitoneally 3 times weekly for 10 wk with sodium cyanate (60 mg/kg). Significant derangement of blood-oxygen interaction was observed. Oxygen-dissociation curves were left shifted by 13 mmHg (35.1-21.8), and the overall deoxygenation rate (k) was reduced 41% (6.142-3.624; s(-1)); P is less than 0.001 for each parameter. Heart ATP and PCr levels were reduced (ATP: 19.4-16.7; PCr: 15.0-11.0, mum/g dry wt; P is less than 0.001 for each). In addition, glycogen levels fell (161.4-112.9, mum C6/g dry wt; P is less than 0.001). Myocardial lactate levels increased 54% (2.6-4.0, mum/g dry wt; P is less than 0.01) in the cyanate-treated group. These findings strongly suggest a hypoxia-induced activation of glycolysis as a consequence of altered oxidative metabolism in rats treated with sodium cyanate. PMID:937561

  1. Morphological and functional changes in the rat heart after X irradiation: Strain differences

    SciTech Connect

    Yeung, T.K.; Lauk, S.; Simmonds, R.H.; Hopewell, J.W.; Trott, K.R. )

    1989-09-01

    The hearts of mature male rats of the Wistar and Sprague-Dawley strains were locally irradiated with single doses of 17.5 and 20.0 Gy of X rays, respectively. These two dose levels had previously been shown to result in a comparable latent period between irradiation and the death of rats of these two strains from cardiac failure. Morphological changes in the myocardium and modifications in cardiac function were assessed in the animals at 28, 70, and 100 days after irradiation. The first radiation-induced change which was observed in the myocardium was a rapid decline in capillary density and a loss of alkaline phosphatase activity by the capillary endothelial cells. The capillary density was reduced to approximately 50% of that of unirradiated control values at 28 days and to approximately 40% of the control values between 70 and 100 days after irradiation. The loss of enzyme activity was also detected at 28 days. Examination of histological sections showed an increase by 70 days in the areas with negative enzyme activity up to approximately 70% of the myocardium. The reduction in capillary density and the loss of enzyme activity occurred before any marked pathological changes were seen in the myocardium. The pathological lesions seen in the myocardium at 100 days after irradiation were qualitatively and quantitatively the same in the two strains of rat. Measurements of cardiac output in Sprague-Dawley rats showed a gradual decline in output after irradiation; however, measurements in Wistar rats showed a progressive increase in cardiac output over the same period of time. It was shown by rubidium extraction that there was an increase in the percentage of the total cardiac output distributed to the ventricular muscle of Sprague-Dawley rats, while similar measurements in Wistar rats showed no significant change.

  2. Interaction between caffeine intake and heart zinc concentrations in the rat.

    PubMed

    Rossowska, M J; Dinh, C; Gottschalk, S B; Yazdani, M; Sutton, F S; Nakamoto, T

    1990-09-01

    The purpose of the present study was to determine the levels of zinc in the hearts of growing post-weaning offspring, fetuses and their dams chronically fed caffeine. A further study was conducted to determine the distribution of Zn in subcellular heart fractions affected by acutely injecting caffeine into the veins of the adult rats. After delivery pups were raised on a 200 g protein/kg diet until day 22 of weaning. On day 22 randomly selected male offspring from each litter were divided into two groups. Group 1 was fed continuously on the same diet as a control, whereas in the experimental group offspring were fed on a 200 g protein/kg diet supplemented with caffeine (20 mg/kg). On day 49 the animals were killed and Zn, calcium and magnesium concentrations of the hearts were measured. In the second series of studies pregnant dams were randomly divided into two groups. Group 1 was fed on a 200 g protein/kg diet from day 3 of gestation, whereas in the experimental group dams were fed on the diet supplemented with caffeine. On day 22 of gestation the fetuses were surgically removed. The Zn, Ca and Mg concentrations of hearts of fetuses and dams were determined. In the third phase a caffeine solution was injected into the vein. After 45 min the hearts were removed and Zn levels in the subcellular fractions determined. The hearts of the growing offspring fed on a caffeine-supplemented diet consistently showed decreased Zn and Ca levels compared with the non-caffeine group.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. The Impact of Heart Irradiation on Dose-Volume Effects in the Rat Lung

    SciTech Connect

    Luijk, Peter van Faber, Hette; Meertens, Harm; Schippers, Jacobus M.; Langendijk, Johannes A.; Brandenburg, Sytze; Kampinga, Harm H.; Coppes, Robert P. Ph.D.

    2007-10-01

    Purpose: To test the hypothesis that heart irradiation increases the risk of a symptomatic radiation-induced loss of lung function (SRILF) and that this can be well-described as a modulation of the functional reserve of the lung. Methods and Materials: Rats were irradiated with 150-MeV protons. Dose-response curves were obtained for a significant increase in breathing frequency after irradiation of 100%, 75%, 50%, or 25% of the total lung volume, either including or excluding the heart from the irradiation field. A significant increase in the mean respiratory rate after 6-12 weeks compared with 0-4 weeks was defined as SRILF, based on biweekly measurements of the respiratory rate. The critical volume (CV) model was used to describe the risk of SRILF. Fits were done using a maximum likelihood method. Consistency between model and data was tested using a previously developed goodness-of-fit test. Results: The CV model could be fitted consistently to the data for lung irradiation only. However, this fitted model failed to predict the data that also included heart irradiation. Even refitting the model to all data resulted in a significant difference between model and data. These results imply that, although the CV model describes the risk of SRILF when the heart is spared, the model needs to be modified to account for the impact of dose to the heart on the risk of SRILF. Finally, a modified CV model is described that is consistent to all data. Conclusions: The detrimental effect of dose to the heart on the incidence of SRILF can be described by a dose dependent decrease in functional reserve of the lung.

  4. Fate of undifferentiated mouse embryonic stem cells within the rat heart: role of myocardial infarction and immune suppression

    PubMed Central

    He, Qing; Trindade, Pedro T; Stumm, Michael; Li, Jian; Zammaretti, Prisca; Bettiol, Esther; Dubois-Dauphin, Michel; Herrmann, François; Kalangos, Afksendyios; Morel, Denis; Jaconi, Marisa E

    2009-01-01

    Abstract It has recently been suggested that the infarcted rat heart microenvironment could direct pluripotent mouse embryonic stem cells to differentiate into cardiomyocytes through an in situ paracrine action. To investigate whether the heart can function as a cardiogenic niche and confer an immune privilege to embryonic stem cells, we assessed the cardiac differentiation potential of undifferentiated mouse embryonic stem cells (mESC) injected into normal, acutely or chronically infarcted rat hearts. We found that mESC survival depended on immunosuppression both in normal and infarcted hearts. However, upon Cyclosporin A treatment, both normal and infarcted rat hearts failed to induce selective cardiac differentiation of implanted mESC. Instead, teratomas developed in normal and infarcted rat hearts 1 week and 4 weeks (50% and 100%, respectively) after cell injection. Tight control of ESC commitment into a specific cardiac lineage is mandatory to avoid the risk of uncontrolled growth and tumourigenesis following transplantation of highly plastic cells into a diseased myocardium. PMID:18373734

  5. Measurement of rat heart fatty acid binding protein by ELISA. Tissue distribution, developmental changes and subcellular distribution.

    PubMed

    Crisman, T S; Claffey, K P; Saouaf, R; Hanspal, J; Brecher, P

    1987-05-01

    A class of soluble, low molecular weight proteins collectively called fatty acid binding proteins (FABP) are thought to function in the intracellular movement of fatty acids. To understand more clearly the role of FABP in cardiac metabolism, we used ELISA and immunoblotting techniques to study the distribution of heart FABP in several rat tissues, compare male and female rat heart content, quantitate developmental changes, and determine its subcellular distribution. Immunoreactive protein was found in appreciable amounts in rat heart, red skeletal muscle and kidney. Adult rat heart contained about 1.5 mg FABP/g tissue wet weight with the atrial content being approximately 50% of the ventricular concentration. No significant difference was detected between the sexes. The amount of FABP increased progressively during development from fetal to adult animals, and measureable amounts were found in 17-day-old fetal tissue. Comparisons between myoglobin and FABP showed that FABP appeared earlier than myoglobin in development, but myoglobin was more abundant than FABP at birth. Using immunoblots it was determined that rat heart FABP was localized in the cytosol with no detectable intramitochondrial material. PMID:3625779

  6. Characteristic subcellular distribution, in brain, heart and lung, of biperiden, trihexyphenidyl, and (-)-quinuclidinyl benzylate in rats.

    PubMed

    Ishizaki, J; Yokogawa, K; Nakashima, E; Ohkuma, S; Ichimura, F

    1998-01-01

    The subcellular distribution of biperiden (BP), trihexyphenidyl (TP) and (-)-quinuclidinyl benzylate (QNB) in brain, heart and lung following high dose (3.2 mg/kg) i.v. administration was investigated in rats. The subcellular distribution of BP or TP used clinically conformed with that of QNB, a typical potent central muscarinic antagonist. The concentration-time courses of the brain subcellular fractions for these drugs were of two types which decreased slowly and in parallel to the plasma concentration. The subcellular distribution in the brain and heart was dependent on the protein amount of each fraction. The percent post-nuclear fraction (P2) of the total concentration in the lung was characteristically about 3-5 times larger than that in the heart. It was elucidated that the distribution in the lung differs from that in the brain and heart, with high affinity which is not dependent on the protein amount in the P2 fraction containing lysosomes. On the other hand, at a low dose (650 ng/kg) of 3H-QNB, each fraction as a percentage of the total concentration in the brain increased in synaptic membrane and synaptic vesicles and decreased in nuclei and cytosol as compared with the high dose. These results show that although the tissue concentration-time courses of anticholinergic drugs appear to decrease simply in parallel to plasma concentration, the subcellular distribution exhibits a variety of patterns among various tissues.

  7. [Nonspecific effect of Na+/K(+)-ATPase inhibition with strophanthin or under hypothermia in rat heart].

    PubMed

    Pogorelova, V N; Panait, A I; Pogorelov, A G

    2014-01-01

    Electron probe microanalysis was applied to study the kinetics of changes in potassium and sodium concentration in muscle cells of isolated heart from Wistar rat during experimental ischemia. Hypoxic perfusion without glucose was shown to evoke the potassium deficiency and sodium accumulation in cardiac myocells. Short-term action (10 min) of strophanthin (0.1 mM/l) recovered Na/K balance in ischemic myocells. Hypothermic perfusion exhibited the opportunity to conserve the cytoplasmic elemental contents in the state corresponding to the beginning of low temperature (4 degrees C) operation. PMID:25730978

  8. The effects of interferon-alpha/beta in a model of rat heart transplantation

    NASA Technical Reports Server (NTRS)

    Slater, A. D.; Klein, J. B.; Sonnenfeld, G.; Ogden, L. L. 2nd; Gray, L. A. Jr

    1992-01-01

    Interferons have multiple immunologic effects. One such effect is the activation of expression of cell surface antigens. Interferon alpha/beta enhance expression of class I but not class II histocompatibility antigens. Contradictory information has been published regarding the effect of interferon-alpha/beta administration in patients with kidney transplantation. In a model of rat heart transplantation we demonstrated that administration of interferon-alpha/beta accelerated rejection in a dose-dependent fashion in the absence of maintenance cyclosporine. Animals treated with maintenance cyclosporine had evidence of increased rejection at 20 days that was resolved completely at 45 days with cyclosporine alone.

  9. Dietary copper supplementation reverses hypertrophic cardiomyopathy induced by chronic pressure overload in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sustained pressure overload causes cardiac hypertrophy and the transition to heart failure. We show here that dietary supplementation with physiologically relevant levels of copper (Cu) reverses pre-established hypertrophic cardiomyopathy in the presence of pressure overload induced by ascending aor...

  10. Hypertrophy of Neurons Within Cardiac Ganglia in Human, Canine, and Rat Heart Failure: The Potential Role of Nerve Growth Factor

    PubMed Central

    Singh, Sanjay; Sayers, Scott; Walter, James S.; Thomas, Donald; Dieter, Robert S.; Nee, Lisa M.; Wurster, Robert D.

    2013-01-01

    Background Autonomic imbalances including parasympathetic withdrawal and sympathetic overactivity are cardinal features of heart failure regardless of etiology; however, mechanisms underlying these imbalances remain unknown. Animal model studies of heart and visceral organ hypertrophy predict that nerve growth factor levels should be elevated in heart failure; whether this is so in human heart failure, though, remains unclear. We tested the hypotheses that neurons in cardiac ganglia are hypertrophied in human, canine, and rat heart failure and that nerve growth factor, which we hypothesize is elevated in the failing heart, contributes to this neuronal hypertrophy. Methods and Results Somal morphology of neurons from human (579.54±14.34 versus 327.45±9.17 μm2; P<0.01) and canine hearts (767.80±18.37 versus 650.23±9.84 μm2; P<0.01) failing secondary to ischemia and neurons from spontaneously hypertensive rat hearts (327.98±3.15 versus 271.29±2.79 μm2; P<0.01) failing secondary to hypertension reveal significant hypertrophy of neurons in cardiac ganglia compared with controls. Western blot analysis shows that nerve growth factor levels in the explanted, failing human heart are 250% greater than levels in healthy donor hearts. Neurons from cardiac ganglia cultured with nerve growth factor are significantly larger and have greater dendritic arborization than neurons in control cultures. Conclusions Hypertrophied neurons are significantly less excitable than smaller ones; thus, hypertrophy of vagal postganglionic neurons in cardiac ganglia would help to explain the parasympathetic withdrawal that accompanies heart failure. Furthermore, our observations suggest that nerve growth factor, which is elevated in the failing human heart, causes hypertrophy of neurons in cardiac ganglia. PMID:23959444

  11. Chronic heart failure modifies respiratory mechanics in rats: a randomized controlled trial

    PubMed Central

    Pacheco, Deise M.; Silveira, Viviane D.; Thomaz, Alex; Nunes, Ramiro B.; Elsner, Viviane R.; Dal Lago, Pedro

    2016-01-01

    ABSTRACT Objective To analyze respiratory mechanics and hemodynamic alterations in an experimental model of chronic heart failure (CHF) following myocardial infarction. Method Twenty-seven male adult Wistar rats were randomized to CHF group (n=12) or Sham group (n=15). Ten weeks after coronary ligation or sham surgery, the animals were anesthetized and submitted to respiratory mechanics and hemodynamic measurements. Pulmonary edema as well as cardiac remodeling were measured. Results The CHF rats showed pulmonary edema 26% higher than the Sham group. The respiratory system compliance (Crs) and the total lung capacity (TLC) were lower (40% and 27%, respectively) in the CHF rats when compared to the Sham group (P<0.01). There was also an increase in tissue resistance (Gti) and elastance (Hti) (28% and 45%, respectively) in the CHF group. Moreover, left ventricular end-diastolic pressure was higher (32 mmHg vs 4 mmHg, P<0.01), while the left ventricular systolic pressure was lower (118 mmHg vs 130 mmHg, P=0.02) in the CHF group when compared to the control. Pearson’s correlation coefficient showed a negative association between pulmonary edema and Crs (r=–0.70, P=0.0001) and between pulmonary edema and TLC (r=–0.67, P=0.0034). Pulmonary edema correlated positively with Gti (r=0.68, P=0.001) and Hti (r=0.68, P=0.001). Finally, there was a strong positive relationship between pulmonary edema and heart weight (r=0.80, P=0.001). Conclusion Rats with CHF present important changes in hemodynamic and respiratory mechanics, which may be associated with alterations in cardiopulmonary interactions. PMID:27556388

  12. Aberrant Glycosylation in the Left Ventricle and Plasma of Rats with Cardiac Hypertrophy and Heart Failure

    PubMed Central

    Nagai-Okatani, Chiaki; Minamino, Naoto

    2016-01-01

    Targeted proteomics focusing on post-translational modifications, including glycosylation, is a useful strategy for discovering novel biomarkers. To apply this strategy effectively to cardiac hypertrophy and resultant heart failure, we aimed to characterize glycosylation profiles in the left ventricle and plasma of rats with cardiac hypertrophy. Dahl salt-sensitive hypertensive rats, a model of hypertension-induced cardiac hypertrophy, were fed a high-salt (8% NaCl) diet starting at 6 weeks. As a result, they exhibited cardiac hypertrophy at 12 weeks and partially impaired cardiac function at 16 weeks compared with control rats fed a low-salt (0.3% NaCl) diet. Gene expression analysis revealed significant changes in the expression of genes encoding glycosyltransferases and glycosidases. Glycoproteome profiling using lectin microarrays indicated upregulation of mucin-type O-glycosylation, especially disialyl-T, and downregulation of core fucosylation on N-glycans, detected by specific interactions with Amaranthus caudatus and Aspergillus oryzae lectins, respectively. Upregulation of plasma α-l-fucosidase activity was identified as a biomarker candidate for cardiac hypertrophy, which is expected to support the existing marker, atrial natriuretic peptide and its related peptides. Proteomic analysis identified cysteine and glycine-rich protein 3, a master regulator of cardiac muscle function, as an O-glycosylated protein with altered glycosylation in the rats with cardiac hypertrophy, suggesting that alternations in O-glycosylation affect its oligomerization and function. In conclusion, our data provide evidence of significant changes in glycosylation pattern, specifically mucin-type O-glycosylation and core defucosylation, in the pathogenesis of cardiac hypertrophy and heart failure, suggesting that they are potential biomarkers for these diseases. PMID:27281159

  13. Aberrant Glycosylation in the Left Ventricle and Plasma of Rats with Cardiac Hypertrophy and Heart Failure.

    PubMed

    Nagai-Okatani, Chiaki; Minamino, Naoto

    2016-01-01

    Targeted proteomics focusing on post-translational modifications, including glycosylation, is a useful strategy for discovering novel biomarkers. To apply this strategy effectively to cardiac hypertrophy and resultant heart failure, we aimed to characterize glycosylation profiles in the left ventricle and plasma of rats with cardiac hypertrophy. Dahl salt-sensitive hypertensive rats, a model of hypertension-induced cardiac hypertrophy, were fed a high-salt (8% NaCl) diet starting at 6 weeks. As a result, they exhibited cardiac hypertrophy at 12 weeks and partially impaired cardiac function at 16 weeks compared with control rats fed a low-salt (0.3% NaCl) diet. Gene expression analysis revealed significant changes in the expression of genes encoding glycosyltransferases and glycosidases. Glycoproteome profiling using lectin microarrays indicated upregulation of mucin-type O-glycosylation, especially disialyl-T, and downregulation of core fucosylation on N-glycans, detected by specific interactions with Amaranthus caudatus and Aspergillus oryzae lectins, respectively. Upregulation of plasma α-l-fucosidase activity was identified as a biomarker candidate for cardiac hypertrophy, which is expected to support the existing marker, atrial natriuretic peptide and its related peptides. Proteomic analysis identified cysteine and glycine-rich protein 3, a master regulator of cardiac muscle function, as an O-glycosylated protein with altered glycosylation in the rats with cardiac hypertrophy, suggesting that alternations in O-glycosylation affect its oligomerization and function. In conclusion, our data provide evidence of significant changes in glycosylation pattern, specifically mucin-type O-glycosylation and core defucosylation, in the pathogenesis of cardiac hypertrophy and heart failure, suggesting that they are potential biomarkers for these diseases. PMID:27281159

  14. Inhaled vasopressin increases sociability and reduces body temperature and heart rate in rats.

    PubMed

    Ramos, Linnet; Hicks, Callum; Caminer, Alex; McGregor, Iain S

    2014-08-01

    The neuropeptides vasopressin (AVP) and oxytocin (OT) have therapeutic potential across a range of psychiatric disorders. However, there is uncertainty about the effectiveness of the intranasal route of administration that is often used to deliver these neuropeptides. Recent preclinical studies, typically involving anesthetized or restrained animals, have assessed intranasal AVP or OT effects, and have obtained somewhat inconsistent results. Here we obtained intranasal administration of AVP in rats by nebulizing the peptide (1ml of 5 or 10mg/ml solution) into a small enclosed chamber over a 2min period in which well-habituated, unanesthetized, unrestrained, rats were placed. Rats were immediately removed from the chamber and tested in the social interaction test, or assessed for changes in heart rate and body temperature using biotelemetry. Results showed that rats exposed to nebulized AVP (5 or 10mg/ml) showed increased social proximity (adjacent lying) and decreased anogenital sniffing in the social interaction test. Biotelemetry showed substantial and long lasting (>1h) hypothermic and bradycardic effects of nebulized AVP. These behavioral and physiological effects of nebulized AVP mimic those observed in recent studies with peripherally injected AVP. Plasma AVP concentrations were substantially increased 10min after nebulized AVP, producing levels above those seen with a behaviorally effective injected dose of AVP (0.005mg/kg intraperitoneal). This study thus provides a novel and effective method for neuropeptide administration to rodents. PMID:24882157

  15. Inhaled vasopressin increases sociability and reduces body temperature and heart rate in rats.

    PubMed

    Ramos, Linnet; Hicks, Callum; Caminer, Alex; McGregor, Iain S

    2014-08-01

    The neuropeptides vasopressin (AVP) and oxytocin (OT) have therapeutic potential across a range of psychiatric disorders. However, there is uncertainty about the effectiveness of the intranasal route of administration that is often used to deliver these neuropeptides. Recent preclinical studies, typically involving anesthetized or restrained animals, have assessed intranasal AVP or OT effects, and have obtained somewhat inconsistent results. Here we obtained intranasal administration of AVP in rats by nebulizing the peptide (1ml of 5 or 10mg/ml solution) into a small enclosed chamber over a 2min period in which well-habituated, unanesthetized, unrestrained, rats were placed. Rats were immediately removed from the chamber and tested in the social interaction test, or assessed for changes in heart rate and body temperature using biotelemetry. Results showed that rats exposed to nebulized AVP (5 or 10mg/ml) showed increased social proximity (adjacent lying) and decreased anogenital sniffing in the social interaction test. Biotelemetry showed substantial and long lasting (>1h) hypothermic and bradycardic effects of nebulized AVP. These behavioral and physiological effects of nebulized AVP mimic those observed in recent studies with peripherally injected AVP. Plasma AVP concentrations were substantially increased 10min after nebulized AVP, producing levels above those seen with a behaviorally effective injected dose of AVP (0.005mg/kg intraperitoneal). This study thus provides a novel and effective method for neuropeptide administration to rodents.

  16. Forskolin- and dihydroalprenolol (DHA) binding sites and adenylate cyclase activity in heart of rats fed diets containing different oils

    SciTech Connect

    Alam, S.Q.; Ren, Y.F.; Alam, B.S.

    1987-05-01

    The purpose of the present investigation was to determine if dietary lipids can induce changes in the adenylate cyclase system in rat heart. Three groups of male young Sprague-Dawley rats were fed for 6 weeks diets containing 10% corn oil (I), 8% coconut oil + 2% corn oil (II) or 10% menhaden oil (III). Adenylate cyclase activity (basal, fluoride-, isoproterenol-, and forskolin-stimulated) was higher in heart homogenates of rats in group III than in the other two groups. Concentration of the (/sup 3/H)-forskolin binding sites in the cardiac membranes were significantly higher in rats fed menhaden oil. The values (pmol/mg protein) were 4.8 +/- 0.2 (I), 4.5 +/- 0.7 (II) and 8.4 +/- 0.5 (III). There was no significant difference in the affinity of the forskolin binding sites among the 3 dietary groups. When measured at different concentrations of forskolin, the adenylate cyclase activity in cardiac membranes of rats fed menhaden oil was higher than in the other 2 groups. Concentrations of the (/sup 3/H)DHA binding sites were slightly higher but their affinity was lower in cardiac membranes of rats fed menhaden oil. The results suggest that diets containing fish oil increase the concentration of the forskolin binding sites and may also affect the characteristics of the ..beta..-adrenergic receptor in rat heart.

  17. Effects of short- and long-term exposure to ozone on heart rate and blood pressure of emphysematous rats

    SciTech Connect

    Uchiyama, I.; Yokoyama, E.

    1989-02-01

    Electrocardiogram and arterial blood pressure of elastase-treated emphysematous rats (E rats) and saline-treated control rats (S rats) were recorded continuously during exposure to either 1 ppm ozone (O/sub 3/) for 3 hr or 0.5 ppm O/sub 3/ for 6 hr. The heart rates (HRs) of both groups decreased to about 50 and 65% of the initial levels at the end of 1 ppm and 0.5 ppm O/sub 3/ exposure, respectively. Mean arterial blood pressures (MAPs) also decreased to about 76 and 82%, respectively. There was no significant difference in these responses between E and S rats, although the levels of HRs and MAPs of the E rats were always a little lower than those of the S rats. Another group of E and S rats was continuously exposed to 0.2 ppm O/sub 3/ for 4 weeks. The HRs of both E and S groups decreased to about 81 and 88% of the initial levels on the first day, respectively, although they recovered completely by the third day. No significant difference in the variation of HRs during exposure was noted between E and S rats. However, the HR responses of these rats to a challenge exposure of 0.8 ppm O/sub 3/ for 1.5 hr appeared to be different. That is, S rats were more tolerant of the challenge exposure to O/sub 3/ for 1.5 hr than the E rats.

  18. Dipeptidyl Peptidase IV Inhibition Exerts Renoprotective Effects in Rats with Established Heart Failure.

    PubMed

    Arruda-Junior, Daniel F; Martins, Flavia L; Dariolli, Rafael; Jensen, Leonardo; Antonio, Ednei L; Dos Santos, Leonardo; Tucci, Paulo J F; Girardi, Adriana C C

    2016-01-01

    Circulating dipeptidyl peptidase IV (DPPIV) activity is associated with worse cardiovascular outcomes in humans and experimental heart failure (HF) models, suggesting that DPPIV may play a role in the pathophysiology of this syndrome. Renal dysfunction is one of the key features of HF, but it remains to be determined whether DPPIV inhibitors are capable of improving cardiorenal function after the onset of HF. Therefore, the present study aimed to test the hypothesis that DPPIV inhibition by vildagliptin improves renal water and salt handling and exerts anti-proteinuric effects in rats with established HF. To this end, male Wistar rats were subjected to left ventricle (LV) radiofrequency ablation or sham operation. Six weeks after surgery, radiofrequency-ablated rats who developed HF were randomly divided into two groups and treated for 4 weeks with vildagliptin (120 mg/kg/day) or vehicle by oral gavage. Echocardiography was performed before (pretreatment) and at the end of treatment (post-treatment) to evaluate cardiac function. The fractional area change (FAC) increased (34 ± 5 vs. 45 ± 3%, p < 0.05), and the isovolumic relaxation time decreased (33 ± 2 vs. 27 ± 1 ms; p < 0.05) in HF rats treated with vildagliptin (post-treatment vs. pretreatment). On the other hand, cardiac dysfunction deteriorated further in vehicle-treated HF rats. Renal function was impaired in vehicle-treated HF rats as evidenced by fluid retention, low glomerular filtration rate (GFR) and high levels of urinary protein excretion. Vildagliptin treatment restored urinary flow, GFR, urinary sodium and urinary protein excretion to sham levels. Restoration of renal function in HF rats by DPPIV inhibition was associated with increased active glucagon-like peptide-1 (GLP-1) serum concentration, reduced DPPIV activity and increased activity of protein kinase A in the renal cortex. Furthermore, the anti-proteinuric effect of vildagliptin treatment in rats with established HF was associated with

  19. Dipeptidyl Peptidase IV Inhibition Exerts Renoprotective Effects in Rats with Established Heart Failure

    PubMed Central

    Arruda-Junior, Daniel F.; Martins, Flavia L.; Dariolli, Rafael; Jensen, Leonardo; Antonio, Ednei L.; dos Santos, Leonardo; Tucci, Paulo J. F.; Girardi, Adriana C. C.

    2016-01-01

    Circulating dipeptidyl peptidase IV (DPPIV) activity is associated with worse cardiovascular outcomes in humans and experimental heart failure (HF) models, suggesting that DPPIV may play a role in the pathophysiology of this syndrome. Renal dysfunction is one of the key features of HF, but it remains to be determined whether DPPIV inhibitors are capable of improving cardiorenal function after the onset of HF. Therefore, the present study aimed to test the hypothesis that DPPIV inhibition by vildagliptin improves renal water and salt handling and exerts anti-proteinuric effects in rats with established HF. To this end, male Wistar rats were subjected to left ventricle (LV) radiofrequency ablation or sham operation. Six weeks after surgery, radiofrequency-ablated rats who developed HF were randomly divided into two groups and treated for 4 weeks with vildagliptin (120 mg/kg/day) or vehicle by oral gavage. Echocardiography was performed before (pretreatment) and at the end of treatment (post-treatment) to evaluate cardiac function. The fractional area change (FAC) increased (34 ± 5 vs. 45 ± 3%, p < 0.05), and the isovolumic relaxation time decreased (33 ± 2 vs. 27 ± 1 ms; p < 0.05) in HF rats treated with vildagliptin (post-treatment vs. pretreatment). On the other hand, cardiac dysfunction deteriorated further in vehicle-treated HF rats. Renal function was impaired in vehicle-treated HF rats as evidenced by fluid retention, low glomerular filtration rate (GFR) and high levels of urinary protein excretion. Vildagliptin treatment restored urinary flow, GFR, urinary sodium and urinary protein excretion to sham levels. Restoration of renal function in HF rats by DPPIV inhibition was associated with increased active glucagon-like peptide-1 (GLP-1) serum concentration, reduced DPPIV activity and increased activity of protein kinase A in the renal cortex. Furthermore, the anti-proteinuric effect of vildagliptin treatment in rats with established HF was associated with

  20. Measurement of Technetium-99m Sestamibi Signals in Rats Administered a Mitochondrial Uncoupler and in a Rat Model of Heart Failure

    PubMed Central

    Kawamoto, Akira; Kato, Takao; Shioi, Tetsuo; Okuda, Junji; Kawashima, Tsuneaki; Tamaki, Yodo; Niizuma, Shinichiro; Tanada, Yohei; Takemura, Genzou; Narazaki, Michiko; Matsuda, Tetsuya; Kimura, Takeshi

    2015-01-01

    Background Many methods have been used to assess mitochondrial function. Technetium-99m sestamibi (99mTc-MIBI), a lipophilic cation, is rapidly incorporated into myocardial cells by diffusion and mainly localizes to the mitochondria. The purpose of this study was to investigate whether measurement of 99mTc-MIBI signals in animal models could be used as a tool to quantify mitochondrial membrane potential at the organ level. Methods and Results We analyzed 99mTc-MIBI signals in Sprague-Dawley (SD) rat hearts perfused with carbonyl cyanide m-chlorophenylhydrazone (CCCP), a mitochondrial uncoupler known to reduce the mitochondrial membrane potential. 99mTc-MIBI signals could be used to detect changes in the mitochondrial membrane potential with sensitivity comparable to that obtained by two-photon laser microscopy with the cationic probe tetramethylrhodamine ethyl ester (TMRE). We also measured 99mTc-MIBI signals in the hearts of SD rats administered CCCP (4 mg/kg intraperitoneally) or vehicle. 99mTc-MIBI signals decreased in rat hearts administered CCCP, and the ATP content, as measured by 31P magnetic resonance spectroscopy, decreased simultaneously. Next, we administered 99mTc-MIBI to Dahl salt-sensitive rats fed a high-salt diet, which leads to hypertension and heart failure. The 99mTc-MIBI signal per heart tissue weight was inversely correlated with heart weight, cardiac function, and the expression of atrial natriuretic factor, a marker of heart failure, and positively correlated with the accumulation of labeled fatty acid analog. The 99mTc-MIBI signal per liver tissue weight was lower than that per heart tissue weight. Conclusion Measurement of 99mTc-MIBI signals can be an effective tool for semiquantitative investigation of cardiac mitochondrial membrane potential in the SD rat model by using a chemical to decrease the mitochondrial membrane potential. The 99mTc-MIBI signal per heart tissue weight was inversely correlated with the severity of heart failure in

  1. Hypertrophic Cardiomyopathy Registry (HCMR): The rationale and design of an international, observational study of hypertrophic cardiomyopathy

    PubMed Central

    Kramer, Christopher M.; Appelbaum, Evan; Desai, Milind Y.; Desvigne-Nickens, Patrice; DiMarco, John P.; Friedrich, Matthias G.; Geller, Nancy; Heckler, Sarahfaye; Ho, Carolyn Y.; Jerosch-Herold, Michael; Ivey, Elizabeth A.; Keleti, Julianna; Kim, Dong-Yun; Kolm, Paul; Kwong, Raymond Y.; Maron, Martin S.; Schulz-Menger, Jeanette; Piechnik, Stefan; Watkins, Hugh; Weintraub, William S.; Wu, Pan; Neubauer, Stefan

    2015-01-01

    Hypertrophic cardiomyopathy (HCM) is the most common monogenic heart disease with a frequency as high as 1 in 200. In many cases, HCM is caused by mutations in genes encoding the different components of the sarcomere apparatus. HCM is characterized by unexplained left ventricular hypertrophy (LVH), myofibrillar disarray, and myocardial fibrosis. The phenotypic expression is quite variable. While the majority of patients with HCM are asymptomatic, serious consequences are experienced in a subset of affected individuals who present initially with sudden cardiac death (SCD) or progress to refractory heart failure (HF). The HCMR study is a National Heart Lung and Blood Institute (NHLBI)-sponsored 2750 patient, 41 site, international registry and natural history study designed to address limitations in extant evidence to improve prognostication in HCM (NCT01915615). In addition to collection of standard demographic, clinical, and echocardiographic variables, patients will undergo state-of-the-art cardiac magnetic resonance (CMR) for assessment of left ventricular (LV) mass and volumes as well as replacement scarring and interstitial fibrosis. In addition, genetic and biomarker analysis will be performed. HCMR has the potential to change the paradigm of risk stratification in HCM, using novel markers to identify those at higher risk. PMID:26299218

  2. The small-molecule fast skeletal troponin activator, CK-2127107, improves exercise tolerance in a rat model of heart failure.

    PubMed

    Hwee, Darren T; Kennedy, Adam R; Hartman, James J; Ryans, Julie; Durham, Nickie; Malik, Fady I; Jasper, Jeffrey R

    2015-04-01

    Heart failure-mediated skeletal myopathy, which is characterized by muscle atrophy and muscle metabolism dysfunction, often manifests as dyspnea and limb muscle fatigue. We have previously demonstrated that increasing Ca(2+) sensitivity of the sarcomere by a small-molecule fast skeletal troponin activator improves skeletal muscle force and exercise performance in healthy rats and models of neuromuscular disease. The objective of this study was to investigate the effect of a novel fast skeletal troponin activator, CK-2127107 (2-aminoalkyl-5-N-heteroarylpyrimidine), on skeletal muscle function and exercise performance in rats exhibiting heart failure-mediated skeletal myopathy. Rats underwent a left anterior descending coronary artery ligation, resulting in myocardial infarction and a progressive decline in cardiac function [left anterior descending coronary artery heart failure (LAD-HF)]. Compared with sham-operated control rats, LAD-HF rat hindlimb and diaphragm muscles exhibited significant muscle atrophy. Fatigability was increased during repeated in situ isokinetic plantar flexor muscle contractions. CK-2127107 produced a leftward shift in the force-Ca(2+) relationship of skinned, single diaphragm, and extensor digitorum longus fibers. Exercise performance, which was assessed by rotarod running, was lower in vehicle-treated LAD-HF rats than in sham controls (116 ± 22 versus 193 ± 31 seconds, respectively; mean ± S.E.M.; P = 0.04). In the LAD-HF rats, a single oral dose of CK-2127107 (10 mg/kg p.o.) increased running time compared with vehicle treatment (283 ± 47 versus 116 ± 22 seconds; P = 0.0004). In summary, CK-2127107 substantially increases exercise performance in this heart failure model, suggesting that modulation of skeletal muscle function by a fast skeletal troponin activator may be a useful therapeutic in heart failure-associated exercise intolerance. PMID:25678535

  3. The small-molecule fast skeletal troponin activator, CK-2127107, improves exercise tolerance in a rat model of heart failure.

    PubMed

    Hwee, Darren T; Kennedy, Adam R; Hartman, James J; Ryans, Julie; Durham, Nickie; Malik, Fady I; Jasper, Jeffrey R

    2015-04-01

    Heart failure-mediated skeletal myopathy, which is characterized by muscle atrophy and muscle metabolism dysfunction, often manifests as dyspnea and limb muscle fatigue. We have previously demonstrated that increasing Ca(2+) sensitivity of the sarcomere by a small-molecule fast skeletal troponin activator improves skeletal muscle force and exercise performance in healthy rats and models of neuromuscular disease. The objective of this study was to investigate the effect of a novel fast skeletal troponin activator, CK-2127107 (2-aminoalkyl-5-N-heteroarylpyrimidine), on skeletal muscle function and exercise performance in rats exhibiting heart failure-mediated skeletal myopathy. Rats underwent a left anterior descending coronary artery ligation, resulting in myocardial infarction and a progressive decline in cardiac function [left anterior descending coronary artery heart failure (LAD-HF)]. Compared with sham-operated control rats, LAD-HF rat hindlimb and diaphragm muscles exhibited significant muscle atrophy. Fatigability was increased during repeated in situ isokinetic plantar flexor muscle contractions. CK-2127107 produced a leftward shift in the force-Ca(2+) relationship of skinned, single diaphragm, and extensor digitorum longus fibers. Exercise performance, which was assessed by rotarod running, was lower in vehicle-treated LAD-HF rats than in sham controls (116 ± 22 versus 193 ± 31 seconds, respectively; mean ± S.E.M.; P = 0.04). In the LAD-HF rats, a single oral dose of CK-2127107 (10 mg/kg p.o.) increased running time compared with vehicle treatment (283 ± 47 versus 116 ± 22 seconds; P = 0.0004). In summary, CK-2127107 substantially increases exercise performance in this heart failure model, suggesting that modulation of skeletal muscle function by a fast skeletal troponin activator may be a useful therapeutic in heart failure-associated exercise intolerance.

  4. [Changes in adrenergic nerve plexuses of the heart during immobilization stress in the rat].

    PubMed

    Mar'ian, K L; Buniatian, A M

    1984-03-01

    Luminescent microscopical analysis on the state of the cardiac adrenergic neural apparatus under immobilization stress has been performed in 48 rats of August and Wistar strains. The rats of August strain demonstrate a high sensitivity to the stress: 40% of the animals died during the first 4-17 h of immobilization. Cryostate sections are treated in 2% glyoxylic acid and studied in the luminescent microscope. Quantitative analysis of density distribution of the adrenergic neural terminals is performed by means of dot nets. Decreasing luminescent brightness and decreasing density by 10-15% are noted in the right auricle, and by 30-34%--in the left ventricle, comparing to that of the control. In the animals died a sudden death these parameters are even stronger (28% and 54%, respectively). The data obtained correlate to the functional disturbances of the heart activity (fluctuations of the arterial pressure, disturbances of the rhythm, ECG changes). A suggestion is made that catecholamines content in the neural terminals of the heart is of certain importance in development of the cardiovascular disturbances under immobilization stress.

  5. Cyclic AMP-receptor proteins in heart muscle of rats flown on Cosmos 1887

    NASA Technical Reports Server (NTRS)

    Mednieks, Maija I.; Popova, Irina A.; Grindeland, Richard E.

    1991-01-01

    The cellular compartmentalization of the cyclic AMP-receptor proteins in heart ventricular tissue obtained from rats flown on the Cosmos 1887 is determined. Photoaffinity labeling of soluble and particular cell fractions with a (32P)-8-azido analog of cyclic AMP is followed by electrophoretic separation of the proteins and by autoradiographic identification of the labeled isoforms of cAPK R subunits. It is shown that RII in the particulate subcellular fraction was significantly decreased in heart cells from rats in the flight group when compared to controls. Protein banding patterns in both the cytoplasmic fraction and in a fraction enriched in chromatin-bound proteins exhibited some variability in tissues of individual animals, but showed no changes that could be directly attributed to flight conditions. No significant change was apparent in the distribution of RI or RII cyclic AMP binding in the soluble fractions. It is inferred that the cardiac cell integrity or its protein content is not compromised under flight conditions.

  6. Enzyme activities and adenine nucleotide content in aorta, heart muscle and skeletal muscle from uraemic rats.

    PubMed Central

    Krog, M.; Ejerblad, S.; Agren, A.

    1986-01-01

    A prominent feature of arterial and myocardial lesions in uraemia is necrosis of the smooth muscle cells. In this study the possibility of detecting metabolic disturbances before necroses appear was investigated. The investigation was made on rats with moderate uraemia (mean serum creatinine 165 mumol/l) of 12 weeks duration. Enzyme activities and concentrations of adenine nucleotides were measured in aorta, heart and skeletal muscles. Histological examination disclosed no changes in these organs. Hexokinase, an important glycolytic enzyme, showed decreased activity in the skeletal muscle and aorta, whereas the hexosemonophosphate shunt enzyme glucose-6-phosphate dehydrogenase remained unchanged. The aspartate aminotransferase was increased in the skeletal muscle. Fat metabolism was not disturbed as reflected by unchanged activity of hydroxyacyl-CoA-dehydrogenase. Adenylatekinase which is important for the energy supply showed markedly increased activities in all tissues examined from the uraemic rats. Decreased ATP levels were found in the heart muscle and the aorta of the uraemic animals, whereas the total pool of adenosine phosphates remained unchanged in all tissues. The animal model described offers a useful means of detecting early changes in uraemia and should be useful for studying the effects of different treatments of uraemic complications. PMID:3718844

  7. Dose-dependent immunohistochemical and ultrastructural changes after oral methylphenidate administration in rat heart tissue.

    PubMed

    Take, G; Bahcelioglu, M; Oktem, H; Tunc, E; Gözil, R; Erdogan, D; Calguner, E; Helvacioglu, F; Giray, S G; Elmas, C

    2008-08-01

    Methylphenidate, more commonly known as Ritalin, is a piperidine derivative and is the drug most often used to treat attention deficit/hyperactivity disorder, one of the most common behavioural disorders of children and young adults. Our aims were to investigate dose-dependent immunohistochemical D2 expression and ultrastructural changes of the rat heart tissue, and to demonstrate possible toxicity of the long-term and high dose use of the methylphenidate. In this study, 27 female pre-pubertal Wistar albino rats, divided into three different dose groups (5, 10 and 20 mg/kg) and their control groups, were used. They were treated orally with methylphenidate dissolved in saline solution for 5 days/week during 3 months. At the end of the third month, after perfusion fixation, left ventricle of cardiac tissue was removed. Paraffin, semi-thin and thin sections were collected and immunohistochemical, terminal deoxynucleotidyl transferase-mediated Dig-dUTP nick end labelling assay and ultrastructural studies were performed. In conclusion, we believe that Ritalin is dose-related affecting dopaminergic system to increase heart rhythm and contraction. Thus, this drug may cause degenerative ultrastructural changes in mitochondrial path.

  8. The effects of compensated cardiac hypertrophy on dihydropyridine and ryanodine receptors in rat, ferret and guinea-pig hearts.

    PubMed

    Rannou, F; Sainte-Beuve, C; Oliviero, P; Do, E; Trouvé, P; Charlemagne, D

    1995-05-01

    The number of dihydropyridine and ryanodine receptors (DHP-R and RyR) has been measured in control and hypertrophied ventricles from rats, guinea pigs and ferrets to determine whether these two channels contribute to the alterations in excitation-contraction coupling (ECC), and in Ca2+ transient during compensated cardiac hypertrophy. We found that ventricular hypertrophy did not change the density of DHP-R. Mild hypertrophy did not alter the density of RyR in the rat but decreased it in the guinea-pig and in the ferret (30% and 36%, respectively). Severe hypertrophy decreased the density of RyR by 20% in the rat and by 34% in the guinea-pig. Therefore, the decrease is greater in ferret and guinea-pig hearts than in rat heart. We conclude that the sarcoplasmic reticulum (SR) Ca2+ release channels but not the L-type Ca2+ channels could contribute to the slowing of intracellular Ca2+ movements and to the reduced velocity of shortening of the hypertrophied hearts. We suggest that, in the guinea pig and ferret hearts which express only the beta myosin heavy chain (MHC) isoform, the reduced velocity of shortening during hypertrophy is related to the decrease in RyR density, whereas in the rat, it is regulated primarily via a shift in the MHC isoform, except in severe hypertrophy in which the moderate decrease in RyR would also be involved. PMID:7473781

  9. Effects of lowering barometric pressure on guarding behavior, heart rate and blood pressure in a rat model of neuropathic pain.

    PubMed

    Sato, J; Takanari, K; Omura, S; Mizumura, K

    2001-02-16

    We investigated whether lowering barometric pressure by 20 mmHg (LP) aggravates the guarding behavior suggestive of spontaneous pain following sciatic nerve chronic constriction injury (CCI) in rats. Systemic blood pressure (BP) and heart rate (HR) of unrestrained rats were recorded telemetrically during LP both before and after the CCI surgery. CCI rats showed guarding posture in normopressure conditions, and LP increased the cumulative time of this behavior. Baseline BP but not HR was increased following CCI. LP increased BP and HR of the rats only before the CCI surgery. Animals after CCI surgery showed variable (BP, HR) and transient (HR) responses to LP. These results indicate that (1) LP aggravated spontaneous pain and increased BP and HR in the CCI rats, and (2) CCI surgery influenced BP and HR of rats.

  10. Co-administration of trientine and flaxseed oil on oxidative stress, serum lipids and heart structure in diabetic rats.

    PubMed

    Rezaei, Ali; Heidarian, Esfandiar

    2013-08-01

    The administration of flaxseed oil or flaxseed oil plus trientine in diabetic rats reduced triglyceride, very low density lipoprotein, and total cholesterol. Furthermore, the combined treatment significantly increased superoxide dismutase activity and attenuated serum Cu2+. The results suggest that the administration of flaxseed oil plus trientine is useful in controlling serum lipid abnormalities, oxidative stress, restoring heart structure, and reducing serum Cu2+ in diabetic rats.

  11. Morphological and biochemical examination of Cosmos 1887 rat heart tissue. Part 1: Ultrastructure

    NASA Technical Reports Server (NTRS)

    Philpott, D. E.; Popova, I. A.; Kato, K.; Stevenson, J.; Miquel, J.; Sapp, W.

    1990-01-01

    Morphological changes were observed in the left ventricle of rat heart tissue from animals flown on the Cosmos 1887 biosatellite for 12.5 days. These tissues were compared to the synchronous and vivarium control hearts. While many normal myofibrils were observed, others exhibited ultrastructural alterations, i.e., damaged and irregular-shaped mitochondria and generalized myofibrillar edema. Analysis of variance (ANOVA) of the volume density data revealed a statistically significant increase in glycogen and a significant decrease in mitochondria compared to the synchronous and vivarium controls. Point counting indicated an increase in lipid and myeloid bodies and a decrease in microtubules, but these changes were not statistically significant. In addition, the flight animals exhibited some patchy loss of protofibrils (actin and myosin filaments) and some abnormal supercontracted myofibrils that were not seen in the controls. This study was undertaken to gain insight into the mechanistic aspects of cardiac changes in both animals and human beings as a consequence of space travel. Cardiac hypotrophy and fluid shifts have been observed after actual or simulated weightlessness and raise concerns about the functioning of the heart and circulatory system during and after travel in space.

  12. Multiple Mass Isotopomer Tracing of Acetyl-CoA Metabolism in Langendorff-perfused Rat Hearts

    PubMed Central

    Li, Qingling; Deng, Shuang; Ibarra, Rafael A.; Anderson, Vernon E.; Brunengraber, Henri; Zhang, Guo-Fang

    2015-01-01

    We developed an isotopic technique to assess mitochondrial acetyl-CoA turnover (≈citric acid flux) in perfused rat hearts. Hearts are perfused with buffer containing tracer [13C2,2H3]acetate, which forms M5 + M4 + M3 acetyl-CoA. The buffer may also contain one or two labeled substrates, which generate M2 acetyl-CoA (e.g. [13C6]glucose or [1,2-13C2]palmitate) or/and M1 acetyl-CoA (e.g. [1-13C]octanoate). The total acetyl-CoA turnover and the contributions of fuels to acetyl-CoA are calculated from the uptake of the acetate tracer and the mass isotopomer distribution of acetyl-CoA. The method was applied to measurements of acetyl-CoA turnover under different conditions (glucose ± palmitate ± insulin ± dichloroacetate). The data revealed (i) substrate cycling between glycogen and glucose-6-P and between glucose-6-P and triose phosphates, (ii) the release of small excess acetyl groups as acetylcarnitine and ketone bodies, and (iii) the channeling of mitochondrial acetyl-CoA from pyruvate dehydrogenase to carnitine acetyltransferase. Because of this channeling, the labeling of acetylcarnitine and ketone bodies released by the heart are not proxies of the labeling of mitochondrial acetyl-CoA. PMID:25645937

  13. Diosmin pretreatment improves cardiac function and suppresses oxidative stress in rat heart after ischemia/reperfusion.

    PubMed

    Senthamizhselvan, Oomaidurai; Manivannan, Jeganathan; Silambarasan, Thangarasu; Raja, Boobalan

    2014-08-01

    Reperfusion of ischemic tissue leads to the generation of oxygen derived free radicals which plays an important role in cellular damage. Objective of the current study is to evaluate the cardio-protective and antioxidant effect of diosmin on ischemia-reperfusion related cardiac dysfunction, oxidative stress and apoptosis. Diosmin (50 and 100 mg/kg body weight (bw)) was given every day to the rats orally throughout the experimental period. Ischemia/reperfusion protocol was carried out ex vivo using langendorff perfusion method and the cardiac functional recovery was assessed in terms of percentage rate pressure product. Coronary effluents of LDH and CK-MB activities, antioxidant enzyme activities, lipid peroxidation products, activity of TCA cycle enzymes were evaluated. Moreover, in vitro superoxide anion and hydroxyl radical scavenging potential of diosmin was also quantified. Finally, quantitative real-time PCR was used for assessing Bcl-2 mRNA expression in heart. Cardiac functional recovery was impaired after reperfusion compared with continuously perfused heart. It was significantly prevented by diosmin treatment. Impaired antioxidant enzyme activities and elevated lipid peroxidation products level were also significantly suppressed. The activity of TCA cycle enzymes was protected against reperfusion stress. Down regulated Bcl-2 was also significantly increased. This study concluded that diosmin pretreatment prevents all the impaired patterns including cardiac function, oxidative stress and apoptosis associated with reperfusion in control heart by its antioxidant role.

  14. Morphological and biochemical examination of Cosmos 1887 rat heart tissue: Part I--Ultrastructure.

    PubMed

    Philpott, D E; Popova, I A; Kato, K; Stevenson, J; Miquel, J; Sapp, W

    1990-01-01

    Morphological changes were observed in the left ventricle of rat heart tissue from animals flown on the Cosmos 1887 biosatellite for 12.5 days. These tissues were compared to the synchronous and vivarium control hearts. While many normal myofibrils were observed, others exhibited ultrastructural alterations, i.e., damaged and irregular-shaped mitochondria and generalized myofibrillar edema. Analysis of variance (ANOVA) of the volume density data revealed a statistically significant increase in glycogen and a significant decrease in mitochondria compared to the synchronous and vivarium controls. Point counting indicated an increase in lipid and myeloid bodies and a decrease in microtubules, but these changes were not statistically significant. In addition, the flight animals exhibited some patchy loss of protofibrils (actin and myosin filaments) and some abnormal supercontracted myofibrils that were not seen in the controls. This study was undertaken to gain insight into the mechanistic aspects of cardiac changes in both animals and human beings as a consequence of space travel (1). Cardiac hypotrophy and fluid shifts have been observed after actual or simulated weightlessness and raise concerns about the functioning of the heart and circulatory system during and after travel in space (2-4).

  15. In situ Raman study of redox state changes of mitochondrial cytochromes in a perfused rat heart.

    PubMed

    Brazhe, Nadezda A; Treiman, Marek; Faricelli, Barbara; Vestergaard, Jakob H; Sosnovtseva, Olga

    2013-01-01

    We developed a Raman spectroscopy-based approach for simultaneous study of redox changes in c-and b-type cytochromes and for a semiquantitative estimation of the amount of oxygenated myoglobin in a perfused rat heart. Excitation at 532 nm was used to obtain Raman scattering of the myocardial surface of the isolated heart at normal and hypoxic conditions. Raman spectra of the heart under normal pO2 demonstrate unique peaks attributable to reduced c-and b-type cytochromes and oxymyoglobin (oMb). The cytochrome peaks decreased in intensity upon FCCP treatment, as predicted from uncoupling mitochondrial respiration. Conversely, transient hypoxia causes the reversible increase in the intensity of peaks assigned to cytochromes c and c1, reflecting electron stacking proximal to cytochrome oxidase due to the lack of terminal electron acceptor O2. Intensities of peaks assigned to oxy- and deoxyhemoglobin were used for the semiquantitative estimation of oMb deoxygenation that was found to be of approximately 50[Formula: see text] under hypoxia conditions.

  16. Ischemic postconditioning influences electron transport chain protein turnover in Langendorff-perfused rat hearts

    PubMed Central

    Cao, Song; Liu, Yun; Wang, Haiying; Mao, Xiaowen; Chen, Jincong; Liu, Jiming; Xia, Zhengyuan; Zhang, Lin; Liu, Xingkui

    2016-01-01

    Ischemia postconditioning (IPo) is a promising strategy in reducing myocardial ischemia reperfusion (I/R) injury (MIRI), but its specific molecular mechanism is incompletely understood. Langendorff-perfused isolated rat hearts were subjected to global I/R and received IPo in the absence or presence of the mitochondrial ATP-sensitive potassium channel (mitoKATP) blocker 5-hydroxydecanoate (5-HD). Myocardial mitochondria were extracted and mitochondrial comparative proteomics was analyzed. IPo significantly reduces post-ischemic myocardial infarction and improved cardiac function in I/R rat hearts, while 5-HD basically cancelled IPo’s myocardial protective effect. Joint application of two-dimensional polyacrylamide gel electrophoresis (2DE) and MALDI-TOF MS identified eight differentially expressed proteins between groups. Expression of cardiac succinate dehydrogenase (ubiquinone) flavoprotein subunit (SDHA) increased more than two-fold after I/R, while IPo led to overexpression of dihydrolipoyl dehydrogenase (DLD), NADH dehydrogenase (ubiquinone) flavoprotein 1 and isoform CRA_b (NDUFV1). When the mitoKATP was blocked, MICOS complex subunit Mic60 (IMMT) and Stress-70 protein (Grp75) were over expressed, while DLDH, ATPase subunit A (ATPA) and rCG44606 were decreased. Seven of the differential proteins belong to electron transport chain (ETC) or metabolism regulating proteins, and five of them were induced by closing mitoKATP in I/R hearts. We thus conclude that IPo’s myocardial protective effect relies on energy homeostasis regulation. DLD, SDHA, NDUFV1, Grp75, ATPA and rCG44606 may contribute to IPo’s cardial protective effect. PMID:26925330

  17. Influence of starvation on heart contractility and corticosterone level in rats.

    PubMed

    Lee, Sung Ryul; Ko, Tae Hee; Kim, Hyoung Kyu; Marquez, Jubert; Ko, Kyung Soo; Rhee, Byoung Doo; Han, Jin

    2015-11-01

    The physiological changes, including cardiac modification, that occur during starvation are not yet completely understood. The purpose of this study is to examine the effects of a 2-week starvation period on heart contractility, muscle mass, and irisin and corticosterone levels in rats. Rats in the starved group showed a significant reduction in the body, heart, kidney, and muscle weight (n = 23, p < 0.05). Blood glucose, total protein, and albumin showed a 44, 17.5, and 10.3 % reduction, respectively (p < 0.05). Lipid reserves, such as total lipid, triglyceride, and free fatty acid, were also comparably reduced (p < 0.05). However, the bilirubin, creatinine, blood urea nitrogen, and creatine kinase levels were higher than in the control group (p < 0.05). The blood irisin level was unchanged, but the stress-related corticosterone level was significantly higher in the starved group. The differences observed in M-mode echocardiography were further compared with the body-weight-matched control group. Starvation reduced the left ventricle mass; however, this difference was not significant compared with the body-weight-matched group (p > 0.05). In the starvation group, the impairment of cardiac output was dependent on the reduction in stroke volume and heart rate. Starvation induced a severe reduction in ejection fraction and fractional shortening when compared with the body-weight-matched control group (p < 0.05). In summary, prolonged starvation, which leads to a deficiency of available nutrition, increases the stress-related corticosterone level, impairs the cardiac output, and is associated with changes in cardiac morphogeometry.

  18. Influence of starvation on heart contractility and corticosterone level in rats.

    PubMed

    Lee, Sung Ryul; Ko, Tae Hee; Kim, Hyoung Kyu; Marquez, Jubert; Ko, Kyung Soo; Rhee, Byoung Doo; Han, Jin

    2015-11-01

    The physiological changes, including cardiac modification, that occur during starvation are not yet completely understood. The purpose of this study is to examine the effects of a 2-week starvation period on heart contractility, muscle mass, and irisin and corticosterone levels in rats. Rats in the starved group showed a significant reduction in the body, heart, kidney, and muscle weight (n = 23, p < 0.05). Blood glucose, total protein, and albumin showed a 44, 17.5, and 10.3 % reduction, respectively (p < 0.05). Lipid reserves, such as total lipid, triglyceride, and free fatty acid, were also comparably reduced (p < 0.05). However, the bilirubin, creatinine, blood urea nitrogen, and creatine kinase levels were higher than in the control group (p < 0.05). The blood irisin level was unchanged, but the stress-related corticosterone level was significantly higher in the starved group. The differences observed in M-mode echocardiography were further compared with the body-weight-matched control group. Starvation reduced the left ventricle mass; however, this difference was not significant compared with the body-weight-matched group (p > 0.05). In the starvation group, the impairment of cardiac output was dependent on the reduction in stroke volume and heart rate. Starvation induced a severe reduction in ejection fraction and fractional shortening when compared with the body-weight-matched control group (p < 0.05). In summary, prolonged starvation, which leads to a deficiency of available nutrition, increases the stress-related corticosterone level, impairs the cardiac output, and is associated with changes in cardiac morphogeometry. PMID:25784619

  19. Effect of ozone on body temperature and heart rate in the unanesthetized, unrestrained rats

    SciTech Connect

    Watkinson, W.P.; Aileru, A.A.; Dowd, S.M.; Tepper, J.T.; Gordon, C.J. )

    1990-02-26

    Previous studies from this laboratory have demonstrated the importance of changes in body core temperature (T{sub co}) as both an index and modulator of toxicity. This study examined the effects of ambient temperature (T{sub a}) on the toxicant-induced changes in T{sub co}, heart rate (HR), and other toxicological endpoints following exposure to 1 ppm ozone (O{sub 3}). Two groups of male Fischer 334 rats (n = 6/group) were implanted with radiotelemetry transmitters and allowed to recover overnight. The transmitters permitted monitoring of T{sub co} and electrocardiogram (ECG); HR was derived from the ECG signal. All animals were continually monitored according to the following protocol: control (filtered air; .25 hours); exposure (1 ppm O{sub 3}; 2 hours); recovery (filtered air; 18 hours). The first group of rats, maintained at an T{sub a} of 18-20 C, exhibited a 4-5 C drop in T{sub co} accompanied by an average 250 bpm decrease in HR. The decrease and subsequent recovery of HR appeared to precede the T{sub co} response. The second group of rats was subjected to the same experimental protocol but maintained at an T{sub a} of 30-32 C. These rats also showed decreases in T{sub co} and HR; however, these decreases only averaged {approximately}1 C and 100 bpm, respectively. These experiments demonstrate the profound impact of T{sub a} on T{sub co} and the subsequent toxic response in the conscious rat and may have important implications for the study of toxicology.

  20. Endothelial alkaline phosphatase activity loss as an early stage in the development of radiation-induced heart disease in rats

    SciTech Connect

    Lauk, S.

    1987-04-01

    Alkaline phosphatase activity of capillary endothelial cells in the heart of Wistar and Sprague-Dawley rats was studied sequentially after single doses of 10, 15, 20, or 25 Gy. Following irradiation capillary density and alkaline phosphatase activity were focally lost before myocardial degeneration or clinical symptoms of heart disease developed. Recovery from both changes took place after doses of 10 or 15 Gy. The decrease in capillary density and enzyme activity showed the same strain difference in latency times and in the extent of the lesions as previously described for pathological and clinical signs of heart disease.

  1. Blood risk factor metabolites associated with heart disease and myocardial fatty acids in copper-deficient male and female rats

    SciTech Connect

    Fields, M.; Lewis, C.; Beal, T. ); Berlin, E.; Kliman, P.G.; Peters, R.C. )

    1989-07-01

    Intact and castrated males and intact and ovariectomized female rats were fed a copper-deficient diet in order to establish whether the protection provided in females against cardiovascular pathology and mortality is due to endogenous sex hormones, and different levels of blood lipids and/or myocardial fatty acids. Seventy-three male and female rats were assigned to a copper-deficient diet (0.6 {mu}g of copper/g diet) containing 62% fructose for 8 weeks. Twelve of the male rats underwent castration and 12 of the females were ovariectomized. All animals exhibited high levels of plasma cholesterol, triglycerides, and uric acid, which were neither affected by the sex of the rat nor by the surgical treatment. The composition of fatty acids of the myocardium was similar in males and females. Except for those animals that were sacrificed by us, all other male rats died of heart pathology. In contrast, none of the female rats exhibited heart pathology and none died of the deficiency. It is suggested that heart pathology and mortality in copper deficiency are sex related and not due to high levels of plasma cholesterol, triglycerides, and uric acid or to differences in myocardial fatty acid composition.

  2. Voluntary and involuntary running in the rat show different patterns of theta rhythm, physical activity, and heart rate.

    PubMed

    Li, Jia-Yi; Kuo, Terry B J; Yen, Jiin-Cherng; Tsai, Shih-Chih; Yang, Cheryl C H

    2014-05-01

    Involuntarily exercising rats undergo more physical and mental stress than voluntarily exercising rats; however, these findings still lack electrophysiological evidence. Many studies have reported that theta rhythm appears when there is mental stress and that it is affected by emotional status. Thus we hypothesized that the differences between voluntary and involuntary movement should also exist in the hippocampal theta rhythm. Using the wheel and treadmill exercise models as voluntary and involuntary exercise models, respectively, this study wirelessly recorded the hippocampal electroencephalogram, electrocardiogram, and three-dimensional accelerations of young male rats. Treadmill and wheel exercise produced different theta patterns in the rats before and during running. Even though the waking baselines for the two exercise types were recorded in different environments, there did not exist any significant difference after distinguishing the rats' sleep/wake status. When the same movement-related parameters are considered, the treadmill running group showed more changes in their theta frequency (4-12 Hz), in their theta power between 9.5-12 Hz, and in their heart rate than the wheel running group. A positive correlation between the changes in high-frequency (9.5-12 Hz) theta power and heart rate was identified. Our results reveal various voluntary and involuntary changes in hippocampal theta rhythm as well as divergences in heart rate and high-frequency theta activity that may represent the effects of an additional emotional state or the sensory interaction during involuntary running by rats. PMID:24623507

  3. Vitamin E and Hippophea rhamnoides L. extract reduce nicotine-induced oxidative stress in rat heart.

    PubMed

    Gumustekin, Kenan; Taysi, Seyithan; Alp, Hamit Hakan; Aktas, Omer; Oztasan, Nuray; Akcay, Fatih; Suleyman, Halis; Akar, Sedat; Dane, Senol; Gul, Mustafa

    2010-06-01

    The effects of vitamin E and Hippophea rhamnoides L. extract (HRe-1) on nicotine-induced oxidative stress in rat heart were investigated. There were eight rats per group and supplementation period was 3 weeks. The groups were: nicotine [0.5 mg kg(-1)day(-1), intraperitoneal (i.p.)]; nicotine plus vitamin E [75 mg kg(-1)day(-1), intragastric (i.g.)]; nicotine plus HRe-1 (250 mg kg(-1)day(-1), i.g.); and the control group (receiving only vehicles). Nicotine increased the malondialdehyde level, which was prevented by both vitamin E and HRe-1. Glutathione peroxidase (GPx) activity in nicotine plus vitamin E supplemented group was higher than the others. Glutathione S-transferase (GST) activity in nicotine plus HRe-1 supplemented group was increased compared with the control group. Catalase activity was higher in nicotine group compared with others. GPx activity in nicotine plus vitamin E supplemented group was elevated compared with the others. Total and non-enzymatic superoxide scavenger activities in nicotine plus vitamin E supplemented group were lower than nicotine plus HRe-1 supplemented group. Superoxide dismutase (SOD) activity was higher in nicotine plus HRe-1 supplemented group compared with others. Glutathione reductase activity and nitric oxide level were not affected. Increased SOD and GST activities might have taken part in the prevention of nicotine-induced oxidative stress in HRe-1 supplemented group in rat heart. Flavonols such as quercetin, and isorahmnetin, tocopherols such as alpha-tocopherol and beta-tocopherol and carotenoids such as alpha-carotene and beta-carotene, reported to be present in H. rhamnoides L. extracts may be responsible for the antioxidant effects of this plant extract. PMID:20517898

  4. Familial hypertrophic cardiomyopathy mutations in troponin I (K183D, G203S, K206Q) enhance filament sliding.

    PubMed

    Köhler, Jan; Chen, Ying; Brenner, Bernhard; Gordon, Albert M; Kraft, Theresia; Martyn, Donald A; Regnier, Michael; Rivera, Anthony J; Wang, Chien-Kao; Chase, P Bryant

    2003-07-01

    A major cause of familial hypertrophic cardiomyopathy (FHC) is dominant mutations in cardiac sarcomeric genes. Linkage studies identified FHC-related mutations in the COOH terminus of cardiac troponin I (cTnI), a region with unknown function in Ca(2+) regulation of the heart. Using in vitro assays with recombinant rat troponin subunits, we tested the hypothesis that mutations K183Delta, G203S, and K206Q in cTnI affect Ca(2+) regulation. All three mutants enhanced Ca(2+) sensitivity and maximum speed (s(max)) of filament sliding of in vitro motility assays. Enhanced s(max) (pCa 5) was observed with rabbit skeletal and rat cardiac (alpha-MHC or beta-MHC) heavy meromyosin (HMM). We developed a passive exchange method for replacing endogenous cTn in permeabilized rat cardiac trabeculae. Ca(2+) sensitivity and maximum isometric force did not differ between preparations exchanged with cTn(cTnI,K206Q) or wild-type cTn. In both trabeculae and motility assays, there was no loss of inhibition at pCa 9. These results are consistent with COOH terminus of TnI modulating actomyosin kinetics during unloaded sliding, but not during isometric force generation, and implicate enhanced cross-bridge cycling in the cTnI-related pathway(s) to hypertrophy. PMID:12759477

  5. Low-dose copper infusion into the coronary circulation induces acute heart failure in diabetic rats: New mechanism of heart disease.

    PubMed

    Cheung, Carlos Chun Ho; Soon, Choong Yee; Chuang, Chia-Lin; Phillips, Anthony R J; Zhang, Shaoping; Cooper, Garth J S

    2015-09-01

    Diabetes impairs copper (Cu) regulation, causing elevated serum Cu and urinary Cu excretion in patients with established cardiovascular disease; it also causes cardiomyopathy and chronic cardiac impairment linked to defective Cu homeostasis in rats. However, the mechanisms that link impaired Cu regulation to cardiac dysfunction in diabetes are incompletely understood. Chronic treatment with triethylenetetramine (TETA), a Cu²⁺-selective chelator, improves cardiac function in diabetic patients, and in rats with heart disease; the latter displayed ∼3-fold elevations in free Cu²⁺ in the coronary effluent when TETA was infused into their coronary arteries. To further study the nature of defective cardiac Cu regulation in diabetes, we employed an isolated-perfused, working-heart model in which we infused micromolar doses of Cu²⁺ into the coronary arteries and measured acute effects on cardiac function in diabetic and non-diabetic-control rats. Infusion of CuCl₂ solutions caused acute dose-dependent cardiac dysfunction in normal hearts. Several measures of baseline cardiac function were impaired in diabetic hearts, and these defects were exacerbated by low-micromolar Cu²⁺ infusion. The response to infused Cu²⁺ was augmented in diabetic hearts, which became defective at lower infusion levels and underwent complete pump failure (cardiac output = 0 ml/min) more often (P < 0.0001) at concentrations that only moderately impaired function of control hearts. To our knowledge, this is the first report describing the acute effects on cardiac function of pathophysiological elevations in coronary Cu²⁺. The effects of Cu²⁺ infusion occur within minutes in both control and diabetic hearts, which suggests that they are not due to remodelling. Heightened sensitivity to the acute effects of small elevations in Cu²⁺ could contribute substantively to impaired cardiac function in patients with diabetes and is thus identified as a new mechanism of heart disease

  6. Adenosine monophosphate-activated protein kinase activation, substrate transporter translocation, and metabolism in the contracting hyperthyroid rat heart.

    PubMed

    Heather, Lisa C; Cole, Mark A; Atherton, Helen J; Coumans, Will A; Evans, Rhys D; Tyler, Damian J; Glatz, Jan F C; Luiken, Joost J F P; Clarke, Kieran

    2010-01-01

    Thyroid hormones can modify cardiac metabolism via multiple molecular mechanisms, yet their integrated effect on overall substrate metabolism is poorly understood. Here we determined the effect of hyperthyroidism on substrate metabolism in the isolated, perfused, contracting rat heart. Male Wistar rats were injected for 7 d with T(3) (0.2 mg/kg x d ip). Plasma free fatty acids increased by 97%, heart weights increased by 33%, and cardiac rate pressure product, an indicator of contractile function, increased by 33% in hyperthyroid rats. Insulin-stimulated glycolytic rates and lactate efflux rates were increased by 33% in hyperthyroid rat hearts, mediated by an increased insulin-stimulated translocation of the glucose transporter GLUT4 to the sarcolemma. This was accompanied by a 70% increase in phosphorylated AMP-activated protein kinase (AMPK) and a 100% increase in phosphorylated acetyl CoA carboxylase, confirming downstream signaling from AMPK. Fatty acid oxidation rates increased in direct proportion to the increased heart weight and rate pressure product in the hyperthyroid heart, mediated by synchronized changes in mitochondrial enzymes and respiration. Protein levels of the fatty acid transporter, fatty acid translocase (FAT/CD36), were reduced by 24% but were accompanied by a 19% increase in the sarcolemmal content of fatty acid transport protein 1 (FATP1). Thus, the relationship between fatty acid metabolism, cardiac mass, and contractile function was maintained in the hyperthyroid heart, associated with a sarcolemmal reorganization of fatty acid transporters. The combined effects of T(3)-induced AMPK activation and insulin stimulation were associated with increased sarcolemmal GLUT4 localization and glycolytic flux in the hyperthyroid heart. PMID:19940039

  7. Sex differences in the mechano-energetic effects of genistein on stunned rat and guinea pig hearts.

    PubMed

    Colareda, Germán A; Ragone, María I; Consolini, Alicia E

    2016-01-01

    Although the phytoestrogen genistein (Gen) is considered protective in cardiovascular diseases, its direct effects on stunned hearts after transient ischemia-reperfusion (I/R) are unknown. This report studied the effects of 20 μmol/L Gen on the mechano-calorimetric behaviour during I/R of rat and guinea pig hearts to evaluate the energetics of Ca(2+) homeostasis. Isolated beating hearts were perfused with control Krebs solution inside a calorimeter with or without perfusion of Gen before a transient period of I/R. Left ventricular pressure development (P) and total heat rate (Ht) were continuously measured. At 37°C, Gen did not change post-ischemic contractile recovery (PICR), but it increased the relaxation rate. However, PICR was reduced in hearts of male rats and guinea pigs at 30°C. Total muscle economy (P/Ht) showed the same behaviour as P at each temperature. Inhibition of phosphatases with orthovanadate during Gen perfusion prevented a decrease in PICR in male rat hearts, suggesting that this effect is due to tyrosine kinase inhibition. Reperfusing ischemic hearts with 10 mmol/L caffeine-36 mmol/L Na(+)-Krebs induced contracture dependent on the sarcoreticular Ca(2+) content. Contracture relaxation depends on mitochondrial Ca(2+) uptake and Gen reduced the relaxation rate. Moreover, Gen prevented the increase in Rhod-2 fluorescence (free [Ca(2+)]m) of rat cardiomyocytes. In guinea pig hearts, Gen maintained ischemic preconditioning, but was reduced by 5-hydroxydecanoate, suggesting the participation of mitochondrial adenosine triphosphate (ATP)-dependent K channels. Results suggest that Gen acts on several mechanisms that regulate myocardial calcium homeostasis and energetics during I/R, which differ in a temperature- and sex-dependent manner. PMID:26452245

  8. Sex differences in the mechano-energetic effects of genistein on stunned rat and guinea pig hearts.

    PubMed

    Colareda, Germán A; Ragone, María I; Consolini, Alicia E

    2016-01-01

    Although the phytoestrogen genistein (Gen) is considered protective in cardiovascular diseases, its direct effects on stunned hearts after transient ischemia-reperfusion (I/R) are unknown. This report studied the effects of 20 μmol/L Gen on the mechano-calorimetric behaviour during I/R of rat and guinea pig hearts to evaluate the energetics of Ca(2+) homeostasis. Isolated beating hearts were perfused with control Krebs solution inside a calorimeter with or without perfusion of Gen before a transient period of I/R. Left ventricular pressure development (P) and total heat rate (Ht) were continuously measured. At 37°C, Gen did not change post-ischemic contractile recovery (PICR), but it increased the relaxation rate. However, PICR was reduced in hearts of male rats and guinea pigs at 30°C. Total muscle economy (P/Ht) showed the same behaviour as P at each temperature. Inhibition of phosphatases with orthovanadate during Gen perfusion prevented a decrease in PICR in male rat hearts, suggesting that this effect is due to tyrosine kinase inhibition. Reperfusing ischemic hearts with 10 mmol/L caffeine-36 mmol/L Na(+)-Krebs induced contracture dependent on the sarcoreticular Ca(2+) content. Contracture relaxation depends on mitochondrial Ca(2+) uptake and Gen reduced the relaxation rate. Moreover, Gen prevented the increase in Rhod-2 fluorescence (free [Ca(2+)]m) of rat cardiomyocytes. In guinea pig hearts, Gen maintained ischemic preconditioning, but was reduced by 5-hydroxydecanoate, suggesting the participation of mitochondrial adenosine triphosphate (ATP)-dependent K channels. Results suggest that Gen acts on several mechanisms that regulate myocardial calcium homeostasis and energetics during I/R, which differ in a temperature- and sex-dependent manner.

  9. Chronic hypoxia-induced alterations in mitochondrial energy metabolism are not reversible in rat heart ventricles.

    PubMed

    Nouette-Gaulain, Karine; Biais, Matthieu; Savineau, Jean-Pierre; Marthan, Roger; Mazat, Jean-Pierre; Letellier, Thierry; Sztark, François

    2011-01-01

    Chronic hypoxia alters mitochondrial energy metabolism. In the heart, oxidative capacity of both ventricles is decreased after 3 weeks of chronic hypoxia. The aim of this study was to evaluate the reversal of these metabolic changes upon normoxia recovery. Rats were exposed to a hypobaric environment for 3 weeks and then subjected to a normoxic environment for 3 weeks (normoxia-recovery group) and compared with rats maintained in a normoxic environment (control group). Mitochondrial energy metabolism was differentially examined in both left and right ventricles. Oxidative capacity (oxygen consumption and ATP synthesis) was measured in saponin-skinned fibers. Activities of mitochondrial respiratory chain complexes and antioxidant enzymes were measured on ventricle homogenates. Morphometric analysis of mitochondria was performed on electron micrographs. In normoxia-recovery rats, oxidative capacities of right ventricles were decreased in the presence of glutamate or palmitoyl carnitine as substrates. In contrast, oxidation of palmitoyl carnitine was maintained in the left ventricle. Enzyme activities of complexes III and IV were significantly decreased in both ventricles. These functional alterations were associated with a decrease in numerical density and an increase in size of mitochondria. Finally, in the normoxia-recovery group, the antioxidant enzyme activities (catalase and glutathione peroxidase) increased. In conclusion, alterations of mitochondrial energy metabolism induced by chronic hypoxia are not totally reversible. Reactive oxygen species could be involved and should be investigated under such conditions, since they may represent a therapeutic target.

  10. Effect of antihypertensive agents - captopril and nifedipine - on the functional properties of rat heart mitochondria

    PubMed Central

    Kancirová, Ivana; Jašová, Magdaléna; Waczulíková, Iveta; Ravingerová, Táňa; Ziegelhöffer, Attila; Ferko, Miroslav

    2016-01-01

    Objective(s): Investigation of acute effect on cellular bioenergetics provides the opportunity to characterize the possible adverse effects of drugs more comprehensively. This study aimed to investigate the changes in biochemical and biophysical properties of heart mitochondria induced by captopril and nifedipine antihypertensive treatment. Materials and Methods: Male, 12-week-old Wistar rats in two experimental models (in vivo and in vitro) were used. In four groups, the effects of escalating doses of captopril, nifedipine and combination of captopril + nifedipine added to the incubation medium (in vitro) or administered per os to rat (in vivo) on mitochondrial ATP synthase activity and membrane fluidity were monitored. Results: In the in vitro model we observed a significant inhibitory effect of treatment on the ATP synthase activity (P<0.05) with nonsignificant differences in membrane fluidity. Decrease in the value of maximum reaction rate Vmax (P<0.05) without any change in the value of Michaelis-Menten constant Km, indicative of a noncompetitive inhibition, was presented. At the in vivo level, we did not demonstrate any significant changes in the ATP synthase activity and the membrane fluidity in rats receiving captopril, nifedipine, and combined therapy. Conclusion: In vitro kinetics study revealed that antihypertensive drugs (captopril and nifedipine) directly interact with mitochondrial ATP synthase. In vivo experiment did not prove any acute effect on myocardial bioenergetics and suggest that drugs do not enter cardiomyocyte and have no direct effect on mitochondria. PMID:27482342

  11. Defective stretch-induced release of atrial natriuretic peptide from aging hypertensive rat heart: possible role of phosphatidylinositol pathway.

    PubMed

    Brunner, F; Mouton, R; Lochner, A; Opie, L H

    1995-01-01

    Because the phosphatidylinositol pathway may be part of the signaling system associated with stretch-induced release of atrial natriuretic peptide (ANP), we tested the hypothesis that formation of the intermediate inositol-1,4,5-trisphosphate (IP3) is impaired when ANP release is decreased in response to atrial stretch in hearts from aging genetically hypertensive (GH) rats. Immunoreactive ANP release into the coronary effluent and IP3 levels were studied in cardiac tissues of isolated perfused hearts from normotensive control (WAG) or GH rats aged 4, 11, or 16 months. Left atria were repeatedly distended and released with a latex balloon. ANP was measured in coronary effluent, and IP3 was measured in cardiac tissues. In all age groups, stretch and relief of stretch evoked considerably less ANP release in spontaneously beating hearts from GH than from WAG rats. Hearts from GH rats aged 16 months released no ANP, but electrical pacing restored some stretch-induced ANP secretion. With repeated stretch and release of stretch of the left atrium for 2 min, IP3 levels increased in left atrial tissue in WAG but not in GH hearts of all age groups. IP3 levels in (unstretched) left ventricles were much lower than in left atria and were unaltered by atrial stretch. In aging GH rats, the capacity to release ANP on atrial stretch is largely lost, in association with complete suppression of stimulus-induced increase in IP3 levels. These data support a role for IP3 in stretch-mediated atrial ANP secretion and suggest a progressive uncoupling of this signaling pathway in aging hypertensive rats. PMID:7723347

  12. Dietary nitrate increases arginine availability and protects mitochondrial complex I and energetics in the hypoxic rat heart

    PubMed Central

    Ashmore, Tom; Fernandez, Bernadette O; Branco-Price, Cristina; West, James A; Cowburn, Andrew S; Heather, Lisa C; Griffin, Julian L; Johnson, Randall S; Feelisch, Martin; Murray, Andrew J

    2014-01-01

    Hypoxic exposure is associated with impaired cardiac energetics in humans and altered mitochondrial function, with suppressed complex I-supported respiration, in rat heart. This response might limit reactive oxygen species generation, but at the cost of impaired electron transport chain (ETC) activity. Dietary nitrate supplementation improves mitochondrial efficiency and can promote tissue oxygenation by enhancing blood flow. We therefore hypothesised that ETC dysfunction, impaired energetics and oxidative damage in the hearts of rats exposed to chronic hypoxia could be alleviated by sustained administration of a moderate dose of dietary nitrate. Male Wistar rats (n = 40) were given water supplemented with 0.7 mmol l−1 NaCl (as control) or 0.7 mmol l−1 NaNO3, elevating plasma nitrate levels by 80%, and were exposed to 13% O2 (hypoxia) or normoxia (n = 10 per group) for 14 days. Respiration rates, ETC protein levels, mitochondrial density, ATP content and protein carbonylation were measured in cardiac muscle. Complex I respiration rates and protein levels were 33% lower in hypoxic/NaCl rats compared with normoxic/NaCl controls. Protein carbonylation was 65% higher in hearts of hypoxic rats compared with controls, indicating increased oxidative stress, whilst ATP levels were 62% lower. Respiration rates, complex I protein and activity, protein carbonylation and ATP levels were all fully protected in the hearts of nitrate-supplemented hypoxic rats. Both in normoxia and hypoxia, dietary nitrate suppressed cardiac arginase expression and activity and markedly elevated cardiac l-arginine concentrations, unmasking a novel mechanism of action by which nitrate enhances tissue NO bioavailability. Dietary nitrate therefore alleviates metabolic abnormalities in the hypoxic heart, improving myocardial energetics. PMID:25172947

  13. Chronic Aerobic Exercise Decreases Lectin-Like Low Density Lipoprotein (LOX-1) Receptor Expression in Heart of Diabetic Rat

    PubMed Central

    Riahi, Simin; Mohammadi, Mohammad Taghi; Sobhani, Vahid; Ababzadeh, Shima

    2016-01-01

    Background: Overexpression of lectin-like low density lipoprotein (LOX-1) receptor plays an important role in hyperglycemia-induced vascular complications such as atherosclerosis. Based on the beneficial effects of exercise on preventing cardiovascular complications of diabetes, we aimed to examine the protective effects of aerobic exercise on expression of LOX-1 receptor and production of free radicals in the heart of diabetic rats. Methods: Four groups of rats were used: (n = 5 per group): sedentary normal, trained normal, sedentary diabetes and trained diabetes. Diabetes was induced by a single intraperitoneal injection of streptozotocin (50 mg/kg). The exercise protocol was consisted of swimming 30 min/day, 5 days/week for eight weeks. Plasma glucose was evaluated at initiation, weeks 4 and 8 of experiment. At the end of experiment, rats were sacrificed and the heart was removed for determination of nitrate, malondialdehyde, and LOX-1 gene expression. Results: In normal non-diabetic rats, the blood glucose level was <150 mg/dl; however, the induction of diabetes resulted in levels more than >400 mg/dl. Gene expression of LOX-1 was increased in the heart of diabetic rats. Exercise reduced the gene expression of this protein in diabetic states without reducing the blood glucose. Finally, swimming exercise decreased the malondialdehyde and nitrate levels in heart tissue both in control and diabetic rats. Conclusion: Swimming exercise reduces heart expression of the LOX-1 receptor in accompany with reduction of free radicals production. Since these parameters are important in generation of diabetic complications, swimming exercise is a good candidate for reducing these complications. PMID:26432573

  14. Neuroglobin protects cardiomyocytes against apoptosis and cardiac hypertrophy induced by isoproterenol in rats.

    PubMed

    Liu, Zhen-Fang; Zhang, Xiao; Qiao, Yan-Xiang; Xu, Wan-Qun; Ma, Cheng-Tai; Gu, Hua-Li; Zhou, Xiu-Mei; Shi, Lei; Cui, Chang-Xing; Xia, Di; Chen, Yu-Guo

    2015-01-01

    Neuroglobin (Ngb) is well known as a physiological role in oxygen homeostasis of neurons and perhaps a protective role against hypoxia and oxidative stress. In this study, we found that Ngb is expressed in rat heart tissues and it is related to isoproterenol induced cardiac hypertrophy. Moreover, overexpression or knock-down of Ngb influences the expression of hypertrophic markers ANP and BNP and the ratio of hypertrophic cells in rat H9c2 myoblasts when isoproterenol treatment. The Annexin V-FITC/PI Staining, Western blot and qPCR analysis showed that the involvement in p53-mediated apoptosis of cardiomyocytes of Ngb is might be the mechanism. This protein could prevent the cells against ROS and POS-induced apoptosis not only in nervous systems but also in cardiomyocytes. From the results, it is concluded that Ngb is a promising protectant in the cardiac hypertrophy, it may be a candidate target to cardiac hypertrophy for clinic treatment. PMID:26131111

  15. Diesel Exhaust-Induced Cardiac Dysfunction Is Mediated by Sympathetic Dominance in Heart Failure-Prone Rats

    EPA Science Inventory

    Short-term exposure to vehicular emissions is associated with adverse cardiac events. Diesel exhaust (DE) may provoke cardiac events through defective co-ordination of the two main autonomic nervous system (ANS) branches. We exposed heart failure-prone rats once to DE (500 g/m3 ...

  16. Influence of doxazosin on biosynthesis of S100A6 and atrial natriuretic factor peptides in the heart of spontaneously hypertensive rats.

    PubMed

    Kasacka, Irena; Piotrowska, Żaneta; Filipek, Anna; Majewski, Mariusz

    2016-02-01

    Hypertension frequently results in severe complications in cardiovascular system and histopathological changes in the heart. To better understand the cellular processes and signaling pathways responsible for the proper functioning of the heart, we decided to check whether doxazosin affects the density of structures containing S100A6 and atrial natriuretic factor in the heart of spontaneously hypertensive rats. The aim of this study is to find differences in the density of the structures containing S100A6 and atrial natriuretic factor in the heart of spontaneously hypertensive rats treated with doxazosin compared to untreated animals. Fragments of heart were collected from five spontaneously hypertensive rats and five spontaneously hypertensive rats receiving doxazosin for six weeks (dose 0.1 mg per 1 kg of body weight). On the paraffin sections S100A6 and atrial natriuretic factor peptides were localized in the heart using immunohistochemistry. Positive immunohistochemical reaction for S100A6 was observed in atrial and ventricular cardiomyocytes and in the coronary vasculature. In the heart of hypertensive rats treated with doxazosin the S100A6 immunoreactivity was significantly lower compared to untreated animals. Immunodetection of atrial natriuretic factor in the heart of rats confirmed presence of peptide in atrial myocardium. Delicate atrial natriuretic factor-immunoreactivity was observed also in few ventricular cardiomyocytes. The atrial natriuretic factor-immunosignal was significantly weaker in hearts of hypertensive rats receiving doxazosin compared to spontaneously hypertensive rats untreated. Since we found that doxazosin reduces the levels of S100A6 and atrial natriuretic factor peptides in the heart of spontaneously hypertensive rats, it can be assumed that cardiovascular disorders that occur in hypertension may be associated with disturbances of cellular processes and signaling pathways.

  17. Influence of doxazosin on biosynthesis of S100A6 and atrial natriuretic factor peptides in the heart of spontaneously hypertensive rats

    PubMed Central

    Piotrowska, Żaneta; Filipek, Anna; Majewski, Mariusz

    2016-01-01

    Hypertension frequently results in severe complications in cardiovascular system and histopathological changes in the heart. To better understand the cellular processes and signaling pathways responsible for the proper functioning of the heart, we decided to check whether doxazosin affects the density of structures containing S100A6 and atrial natriuretic factor in the heart of spontaneously hypertensive rats. The aim of this study is to find differences in the density of the structures containing S100A6 and atrial natriuretic factor in the heart of spontaneously hypertensive rats treated with doxazosin compared to untreated animals. Fragments of heart were collected from five spontaneously hypertensive rats and five spontaneously hypertensive rats receiving doxazosin for six weeks (dose 0.1 mg per 1 kg of body weight). On the paraffin sections S100A6 and atrial natriuretic factor peptides were localized in the heart using immunohistochemistry. Positive immunohistochemical reaction for S100A6 was observed in atrial and ventricular cardiomyocytes and in the coronary vasculature. In the heart of hypertensive rats treated with doxazosin the S100A6 immunoreactivity was significantly lower compared to untreated animals. Immunodetection of atrial natriuretic factor in the heart of rats confirmed presence of peptide in atrial myocardium. Delicate atrial natriuretic factor-immunoreactivity was observed also in few ventricular cardiomyocytes. The atrial natriuretic factor-immunosignal was significantly weaker in hearts of hypertensive rats receiving doxazosin compared to spontaneously hypertensive rats untreated. Since we found that doxazosin reduces the levels of S100A6 and atrial natriuretic factor peptides in the heart of spontaneously hypertensive rats, it can be assumed that cardiovascular disorders that occur in hypertension may be associated with disturbances of cellular processes and signaling pathways. PMID:26515144

  18. Early development of intracellular calcium cycling defects in intact hearts of spontaneously hypertensive rats

    PubMed Central

    Kapur, Sunil; Aistrup, Gary L.; Sharma, Rohan; Kelly, James E.; Arora, Rishi; Zheng, Jiabo; Veramasuneni, Mitra; Kadish, Alan H.; Balke, C. William

    2010-01-01

    Defects in excitation-contraction coupling have been reported in failing hearts, but little is known about the relationship between these defects and the development of heart failure (HF). We compared the early changes in intracellular Ca2+ cycling to those that underlie overt pump dysfunction and arrhythmogenesis found later in HF. Laser-scanning confocal microscopy was used to measure Ca2+ transients in myocytes of intact hearts in Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs) at different ages. Early compensatory mechanisms include a positive inotropic effect in SHRs at 7.5–9 mo compared with 6 mo. Ca2+ transient duration increased at 9 mo in SHRs, indicating changes in Ca2+ reuptake during decompensation. Cell-to-cell variability in Ca2+ transient duration increased at 7.5 mo, decreased at 9 mo, and increased again at 22 mo (overt HF), indicating extensive intercellular variability in Ca2+ transient kinetics during disease progression. Vulnerability to intercellular concordant Ca2+ alternans increased at 9–22 mo in SHRs and was mirrored by a slowing in Ca2+ transient restitution, suggesting that repolarization alternans and the resulting repolarization gradients might promote reentrant arrhythmias early in disease development. Intercellular discordant and subcellular Ca2+ alternans increased as early as 7.5 mo in SHRs and may also promote arrhythmias during the compensated phase. The incidence of spontaneous and triggered Ca2+ waves was increased in SHRs at all ages, suggesting a higher likelihood of triggered arrhythmias in SHRs compared with WKY rats well before HF develops. Thus serious and progressive defects in Ca2+ cycling develop in SHRs long before symptoms of HF occur. Defective Ca2+ cycling develops early and affects a small number of myocytes, and this number grows with age and causes the transition from asymptomatic to overt HF. These defects may also underlie the progressive susceptibility to Ca2+ alternans and Ca2+ wave

  19. Fatty Acid Chain Elongation in Palmitate-perfused Working Rat Heart

    PubMed Central

    Kerner, Janos; Minkler, Paul E.; Lesnefsky, Edward J.; Hoppel, Charles L.

    2014-01-01

    Rat hearts were perfused with [1,2,3,4-13C4]palmitic acid (M+4), and the isotopic patterns of myocardial acylcarnitines and acyl-CoAs were analyzed using ultra-HPLC-MS/MS. The 91.2% 13C enrichment in palmitoylcarnitine shows that little endogenous (M+0) palmitate contributed to its formation. The presence of M+2 myristoylcarnitine (95.7%) and M+2 acetylcarnitine (19.4%) is evidence for β-oxidation of perfused M+4 palmitic acid. Identical enrichment data were obtained in the respective acyl-CoAs. The relative 13C enrichment in M+4 (84.7%, 69.9%) and M+6 (16.2%, 17.8%) stearoyl- and arachidylcarnitine, respectively, clearly shows that the perfused palmitate is chain-elongated. The observed enrichment of 13C in acetylcarnitine (19%), M+6 stearoylcarnitine (16.2%), and M+6 arachidylcarnitine (17.8%) suggests that the majority of two-carbon units for chain elongation are derived from β-oxidation of [1,2,3,4-13C4]palmitic acid. These data are explained by conversion of the M+2 acetyl-CoA to M+2 malonyl-CoA, which serves as the acceptor for M+4 palmitoyl-CoA in chain elongation. Indeed, the 13C enrichment in mitochondrial acetyl-CoA (18.9%) and malonyl-CoA (19.9%) are identical. No 13C enrichment was found in acylcarnitine species with carbon chain lengths between 4 and 12, arguing against the simple reversal of fatty acid β-oxidation. Furthermore, isolated, intact rat heart mitochondria 1) synthesize malonyl-CoA with simultaneous inhibition of carnitine palmitoyltransferase 1b and 2) catalyze the palmitoyl-CoA-dependent incorporation of 14C from [2-14C]malonyl-CoA into lipid-soluble products. In conclusion, rat heart has the capability to chain-elongate fatty acids using mitochondria-derived two-carbon chain extenders. The data suggest that the chain elongation process is localized on the outer surface of the mitochondrial outer membrane. PMID:24558043

  20. Visualization and quantification of whole rat heart laminar structure using high-spatial resolution contrast-enhanced MRI.

    PubMed

    Gilbert, Stephen H; Benoist, David; Benson, Alan P; White, Ed; Tanner, Steven F; Holden, Arun V; Dobrzynski, Halina; Bernus, Olivier; Radjenovic, Aleksandra

    2012-01-01

    It has been shown by histology that cardiac myocytes are organized into laminae and this structure is important in function, both influencing the spread of electrical activation and enabling myocardial thickening in systole by laminar sliding. We have carried out high-spatial resolution three-dimensional MRI of the ventricular myolaminae of the entire volume of the isolated rat heart after contrast perfusion [dimeglumine gadopentate (Gd-DTPA)]. Four ex vivo rat hearts were perfused with Gd-DTPA and fixative and high-spatial resolution MRI was performed on a 9.4T MRI system. After MRI, cryosectioning followed by histology was performed. Images from MRI and histology were aligned, described, and quantitatively compared. In the three-dimensional MR images we directly show the presence of laminae and demonstrate that these are highly branching and are absent from much of the subepicardium. We visualized these MRI volumes to demonstrate laminar architecture and quantitatively demonstrated that the structural features observed are similar to those imaged in histology. We showed qualitatively and quantitatively that laminar architecture is similar in the four hearts. MRI can be used to image the laminar architecture of ex vivo hearts in three dimensions, and the images produced are qualitatively and quantitatively comparable with histology. We have demonstrated in the rat that: 1) laminar architecture is consistent between hearts; 2) myolaminae are absent from much of the subepicardium; and 3) although localized orthotropy is present throughout the myocardium, tracked myolaminae are branching structures and do not have a discrete identity.

  1. [CA²⁺ ACCUMULATION IN ISOLATED RAT HEART MITOCHONDRIA UNDER MAINTENANCE OF MITOCHONDRIAL POTENTIAL].

    PubMed

    Budko, A Yu; Strutynska, N A; Okhay, I Yu; Semenykhina, O M; Sagach, V F

    2015-01-01

    It is known that mitochondria can accumulate calcium, which regulates energy metabolism and cell death. About 90% of energy of cardiomyocytes is synthesized in mitochondria. Heart cells are also affected by the rapid changes in the Ca²⁺ concentration in the cytoplasm. Therefore, mitochondrial Ca²⁺-accumulation ability is crucial. The aim of our work was to study the accumulation of Ca²⁺ in isolated rat heart mitochondria in the presence of mitochondrial potential and different extramitochondrial Ca²⁺ concentrations. Isolated organelles were loaded with fluorescent dye Fluo-4 AM (2.5 μmol/l) at a temperature of 26°C for 30 min. It has been revealed that under these conditions high mitochondrial potential was maintained sufficiently, which is necessary for the functioning of the calcium transporting system in organelles. We established that mitochondria have a limited ability to store ionized calcium, as addition of Ca²⁺ ion in concentrations of 10, 20, 50 µmol/l ensures a certain level of accumulation in organelles with further fluorescent signal growth cessation. Addition of 100 µmol/Ca²⁺ to isolated mitochondria resulted in a significant increase in fluorescence intensity (46% in the fifth minute, compared to the fluorescence when 20 µmol/l Ca²⁺ was added) and likely to activation of cation release. It was shown that ruthenium red (10⁻⁵ mol/l), an inhibitor of Ca²⁺-uniporter, prevented accumulation of calcium ions in organelles by 89%, in the presence of 100 µmol/ Ca²⁺. It was clearly seen that heart mitochondria require Mg²⁺-ATP complex (3 mmol/l) to accumulate Ca²⁺, likely to maintain the inner membrane potential, activity of Ca²⁺ uniporter and energetic processes in organelles. Thus, the process of Ca²⁺ accumulation in rat heart mitochondria requires the maintenance of mitochondrial potential, activity of Ca²⁺-uniporter, depends on extramitochondrial Ca²⁺ concentration and presence of Mg²⁺-ATP complex.

  2. Light-emitting diode therapy (LEDT) improves functional capacity in rats with heart failure.

    PubMed

    Capalonga, Lucas; Karsten, Marlus; Hentschke, Vítor Scotta; Rossato, Douglas Dalcin; Dornelles, Maurício Pinto; Sonza, Anelise; Bagnato, Vanderlei Salvador; Ferraresi, Cleber; Parizotto, Nivaldo Antonio; Dal Lago, Pedro

    2016-07-01

    The syndrome of heart failure (HF) promotes central and peripheral dysfunctions that result in functional capacity decrease, leading to fatigue, dyspnea, and exercise intolerance. The use of light-emitting diode therapy (LEDT) has shown good results reducing fatigue and exercise intolerance, when applied on skeletal muscles before or after exercises. Thereby, the aim of this study was to compare the effects of LEDT on functional capacity, aerobic power, and hemodynamic function in HF rats. Male Wistar rats (230-260 g) were randomly allocated into three experimental groups: Sham (n = 6), Control-HF (n = 4), and LEDT-HF (n = 6). The animals were subjected to an exercise performance test (ET) with gas analysis coupled in a metabolic chamber for rats performed two times (6 and 14 weeks after myocardial infarction). On the day after the baseline aerobic capacity test, the animals were submitted during 8 weeks to the phototherapy protocol, five times/week, 60 s of irradiation, 6 J delivered per muscle group. Statistical analysis was performed by one- and two-way ANOVAs with repeated measures and Student-Newman-Keuls post hoc tests (p ≤ 0.05). Comparing the percentage difference (Δ) between baseline and the final ET, there was no significant difference for the VO2max variable considering all groups. However, Sham and LEDT-HF groups showed higher relative values than the Control-HF group, respectively, for distance covered (27.7 and 32.5 %), time of exercise test (17.7 and 20.5 %), and speed (13.6 and 12.2 %). In conclusion, LEDT was able to increase the functional capacity evaluated by distance covered, time, and speed of exercise in rats with HF. PMID:27059227

  3. 24-h Langendorff-perfused neonatal rat heart used to study the impact of adenoviral gene transfer.

    PubMed

    Wiechert, S; El-Armouche, A; Rau, T; Zimmermann, W-H; Eschenhagen, T

    2003-08-01

    The human genome project has increased the demand for simple experimental systems that allow the impact of gene manipulations to be studied under controlled ex vivo conditions. We hypothesized that, in contrast to adult hearts, neonatal hearts allow long-term perfusion and efficient gene transfer ex vivo. A Langendorff perfusion system was modified to allow perfusion for >24 h with particular emphasis on uncompromised contractile activity, sterility, online measurement of force of contraction, inotropic response to beta-adrenergic stimulation, and efficient gene transfer. The hearts were perfused with serum-free medium (DMEM + medium 199, 4 + 1) supplemented with hydrocortisone, triiodothyronine, ascorbic acid, insulin, pyruvate, l-carnitine, creatine, taurine, l-glutamine, mannitol, and antibiotics recirculating (500 ml/2 hearts) at 1 ml/min. Hearts from 2 day-old rats beat constantly at 135-155 beats/min and developed active force of 1-2 mN. During 24 h of perfusion, twitch tension increased to approximately 165% of initial values (P < 0.05), whereas the inotropic response to isoprenaline remained constant. A decrease in total protein content of 10% and histological examination indicated moderate edema, but actin and calsequestrin concentration remained unchanged and perfusion pressure remained constant at 7-11 mmHg. Perfusion with a LacZ-encoding adenovirus at 3 x 108 active virus particles yielded homogeneous transfection of approximately 80% throughout the heart and did not affect heart rate, force of contraction, or response to isoprenaline compared with uninfected controls (n = 7 each). Taken together, the 24-h Langendorff-perfused neonatal rat heart is a relatively simple, inexpensive, and robust new heart model that appears feasible as a test bed for functional genomics.

  4. Modulation of fatty acid metabolism is involved in the alleviation of isoproterenol-induced rat heart failure by fenofibrate.

    PubMed

    Li, Ping; Luo, Shike; Pan, Chunji; Cheng, Xiaoshu

    2015-12-01

    Heart failure is a disease predominantly caused by an energy metabolic disorder in cardiomyocytes. The present study investigated the inhibitory effects of fenofibrate (FF) on isoproterenol (ISO)‑induced hear failure in rats, and examined the underlying mechanisms. The rats were divided into CON, ISO (HF model), FF and FF+ISO (HF animals pretreated with FF) groups. The cardiac structure and function of the rats were assessed, and contents of free fatty acids and glucose metabolic products were determined. In addition, myocardial cells were isolated from neonatal rats and used in vitro to investigate the mechanisms by which FF relieves heart failure. Western blot analysis was performed to quantify the expression levels of peroxisome proliferator‑activated receptor (PPAR)α and uncoupling protein 2 (UCP2). FF effectively alleviated the ISO‑induced cardiac structural damage, functional decline, and fatty acid and carbohydrate metabolic abnormalities. Compared with the ISO group, the serum levels of brain natriuretic peptide (BNP), free fatty acids, lactic acid and pyruvic acid were decreased in the FF animals. In the cultured myocardial cells, lactic acid and pyruvic acid contents were lower in the supernatants obtained from the FF animals, with lower levels of mitochondrial ROS production and cell necrosis, compared with the ISO group, whereas PPARα upregulation and UCP2 downregulation occurred in the FF+ISO group. The results demonstrated that FF efficiently alleviated heart failure in the ISO‑induced rat model, possibly via promoting fatty acid oxidation. PMID:26497978

  5. Training differentially regulates elastin level and proteolysis in skeletal and heart muscles and aorta in healthy rats

    PubMed Central

    Gilbert, Anna; Wyczalkowska-Tomasik, Aleksandra; Zendzian-Piotrowska, Malgorzata; Czarkowska-Paczek, Bozena

    2016-01-01

    ABSTRACT Exercise induces changes in muscle fibers and the extracellular matrix that may depend on elastin content and the activity of proteolytic enzymes. We investigated the influence of endurance training on the gene expression and protein content and/or activity of elastin, elastase, cathepsin K, and plasmin in skeletal and heart muscles and in the aorta. Healthy rats were randomly divided into untrained (n=10) and trained (n=10; 6 weeks of endurance training with increasing load) groups. Gene expression was evaluated via qRT-PCR. Elastin content was measured via enzyme-linked immunosorbent assay and enzyme activity was measured fluorometrically. Elastin content was significantly higher in skeletal (P=0.0014) and heart muscle (P=0.000022) from trained rats versus untrained rats, but not in the aorta. Although mRNA levels in skeletal muscle did not differ between groups, the activities of elastase (P=0.0434), cathepsin K (P=0.0343) and plasmin (P=0.000046) were higher in trained rats. The levels of cathepsin K (P=0.0288) and plasminogen (P=0.0005) mRNA were higher in heart muscle from trained rats, but enzyme activity was not. Enzyme activity in the aorta did not differ between groups. Increased elastin content in muscles may result in better adaption to exercise, as may remodeling of the extracellular matrix in skeletal muscle. PMID:27069251

  6. Modulation of fatty acid metabolism is involved in the alleviation of isoproterenol-induced rat heart failure by fenofibrate

    PubMed Central

    LI, PING; LUO, SHIKE; PAN, CHUNJI; CHENG, XIAOSHU

    2015-01-01

    Heart failure is a disease predominantly caused by an energy metabolic disorder in cardiomyocytes. The present study investigated the inhibitory effects of fenofibrate (FF) on isoproterenol (ISO)-induced hear failure in rats, and examined the underlying mechanisms. The rats were divided into CON, ISO (HF model), FF and FF+ISO (HF animals pretreated with FF) groups. The cardiac structure and function of the rats were assessed, and contents of free fatty acids and glucose metabolic products were determined. In addition, myocardial cells were isolated from neonatal rats and used in vitro to investigate the mechanisms by which FF relieves heart failure. Western blot analysis was performed to quantify the expression levels of peroxisome proliferator-activated receptor (PPAR)α and uncoupling protein 2 (UCP2). FF effectively alleviated the ISO-induced cardiac structural damage, functional decline, and fatty acid and carbohydrate metabolic abnormalities. Compared with the ISO group, the serum levels of brain natriuretic peptide (BNP), free fatty acids, lactic acid and pyruvic acid were decreased in the FF animals. In the cultured myocardial cells, lactic acid and pyruvic acid contents were lower in the supernatants obtained from the FF animals, with lower levels of mitochondrial ROS production and cell necrosis, compared with the ISO group, whereas PPARα upregulation and UCP2 downregulation occurred in the FF+ISO group. The results demonstrated that FF efficiently alleviated heart failure in the ISO-induced rat model, possibly via promoting fatty acid oxidation. PMID:26497978

  7. Reactivation of peroxisome proliferator-activated receptor alpha is associated with contractile dysfunction in hypertrophied rat heart.

    PubMed

    Young, M E; Laws, F A; Goodwin, G W; Taegtmeyer, H

    2001-11-30

    In pressure overload-induced hypertrophy, the heart increases its reliance on glucose as a fuel while decreasing fatty acid oxidation. A key regulator of this substrate switching in the hypertrophied heart is peroxisome proliferator-activated receptor alpha (PPARalpha). We tested the hypothesis that down-regulation of PPARalpha is an essential component of cardiac hypertrophy at the levels of increased mass, gene expression, and metabolism by pharmacologically reactivating PPARalpha. Pressure overload (induced by constriction of the ascending aorta for 7 days in rats) resulted in cardiac hypertrophy, increased expression of fetal genes (atrial natriuretic factor and skeletal alpha-actin), decreased expression of PPARalpha and PPARalpha-regulated genes (medium chain acyl-CoA dehydrogenase and pyruvate dehydrogenase kinase 4), and caused substrate switching (measured ex vivo in the isolated working heart preparation). Treatment of rats with the specific PPARalpha agonist WY-14,643 (8 days) did not affect the trophic response or atrial natriuretic factor induction to pressure overload. However, PPARalpha activation blocked skeletal alpha-actin induction, reversed the down-regulation of measured PPARalpha-regulated genes in the hypertrophied heart, and prevented substrate switching. This PPARalpha reactivation concomitantly resulted in severe depression of cardiac power and efficiency in the hypertrophied heart (measured ex vivo). Thus, PPARalpha down-regulation is essential for the maintenance of contractile function of the hypertrophied heart. PMID:11574533

  8. Effects of High Intensity Interval Training on Pregnant Rats, and the Placenta, Heart and Liver of Their Fetuses

    PubMed Central

    Hafstad, Anne Dragøy; Basnet, Purusotam; Ytrehus, Kirsti; Acharya, Ganesh

    2015-01-01

    Objective To investigate the effects of high intensity interval training (HIIT) on the maternal heart, fetuses and placentas of pregnant rats. Methods Female Sprague-Dawley rats were randomly assigned to HIIT or sedentary control groups. The HIIT group was trained for 6 weeks with 10 bouts of high intensity uphill running on a treadmill for four minutes (at 85–90% of maximal oxygen consumption) for five days/week. After three weeks of HIIT, rats were mated. After six weeks (gestational day 20 in pregnant rats), echocardiography was performed to evaluate maternal cardiac function. Real-time PCR was performed for the quantification of gene expression, and oxidative stress and total antioxidant capacity was assessed in the tissue samples. Results Maternal heart weight and systolic function were not affected by HIIT or pregnancy. In the maternal heart, expression of 11 of 22 genes related to cardiac remodeling was influenced by pregnancy but none by HIIT. Litter size, fetal weight and placental weight were not affected by HIIT. Total antioxidant capacity, malondialdehyde content, peroxidase and superoxide dismutase activity measured in the placenta, fetal heart and liver were not influenced by HIIT. HIIT reduced the expression of eNOS (p = 0.03), hypoxia-inducible factor 1α (p = 0.04) and glutathione peroxidase 4.2 (p = 0.02) in the fetal liver and increased the expression of vascular endothelial growth factor-β (p = 0.014), superoxide dismutase 1 (p = 0.001) and tissue inhibitor of metallopeptidase 3 (p = 0.049) in the fetal heart. Conclusions Maternal cardiac function and gene expression was not affected by HIIT. Although HIIT did not affect fetal growth, level of oxidative stress and total antioxidant capacity in the fetal tissues, some genes related to oxidative stress were altered in the fetal heart and liver indicating that protective mechanisms may be activated. PMID:26566220

  9. Cardiac effects of the extract and active components of radix stephaniae tetrandrae. II. Myocardial infarct, arrhythmias, coronary arterial flow and heart rate in the isolated perfused rat heart.

    PubMed

    Yu, X C; Wu, S; Wang, G Y; Shan, J; Wong, T M; Chen, C F; Pang, K T

    2001-05-11

    The primary purpose of the present study was to compare the cardioprotective effects of the extract from radix stephaniae tetrandrae (RST) and its individual compounds, tetrandrine (Tet) and fanchinoline (Fan). Secondly, we also compared the cardiac effects of the individual compounds and the RST extract with those of verapamil, a classical Ca2+ channel blocker. The Langendorff isolated perfused rat heart preparation was used. Regional ischaemia and reperfusion was employed to induce myocardial infarct and arrhythmia. Infarct, arrhythmia, heart rate and coronary artery flow were determined in hearts treated with vehicle, RST extract, Tet, Fan, or verapamil. It was found that RST extract, of which only 9% was Tet, and Tet alone produced equally potent ameliorating effects on arrhythmia and infarct induced by ischaemia and reperfusion without further inhibiting ischaemia-reduced heart rate and coronary artery flow. Fan had no effects on arrhythmia and infarct induced by ischaemia and reperfusion; but it induced S-T segment elevation and further reduced heart rate and coronary artery flow during ischaemia. Verapamil also ameliorated the effects of ischaemia and reperfusion on arrhythmia and infarct. It should be noted that 1 microM verapamil, that produced comparable effects on infarct and arrhythmia to the RST extract and Tet, further inhibited heart rate during ischaemia. The results indicate that the RST extract produces equally potent cardioprotective and anti-arrhythmic effects as Tet alone. Both RST extract and Tet may be better choices for the treatment of arrhythmia and infarct induced by myocardial ischaemia and reperfusion than the classical Ca2+ channel blocker, verapamil as they do not further reduce heart rate during ischaemia. PMID:11432452

  10. Mass isotopomer study of anaplerosis from propionate in the perfused rat heart

    PubMed Central

    Kasumov, Takhar; Cendrowski, Andrea V.; David, France; Jobbins, Kathryn A.; Anderson, Vernon E.; Brunengraber, Henri

    2007-01-01

    Anaplerosis from propionate was investigated in rat hearts perfused with 0–2 mM [13C3]propionate and physiological concentrations of glucose, lactate and pyruvate. The data show that when the concentration of [13C3]propionate was raised from 0 to 2 mM, total anaplerosis increases from 5 to 16% of the turnover of citric acid cycle intermediates. Then, [13C3]propionate abolished anaplerosis from endogenous substrates, glucose, lactate and pyruvate. Also, while the contents of propionyl-CoA and methylmalonyl-CoA increased with [13C3]propionate concentration, the content of succinyl-CoA decreased, presumably via activation of succinyl-CoA hydrolysis by a decrease in free CoA. Under our conditions, [13C3]propionate was a purely anaplerotic substrate since there was no labeling of mitochondrial acetyl-CoA, reflected by the labeling of the acetyl moiety of citrate. PMID:17418801

  11. Protective effects of amlodipine on mitochondrial injury in ischemic reperfused rat heart.

    PubMed

    Khan, Najam Ali; Chattopadhyay, Pronobesh; Abid, Mohammad; Pawdey, Abhijeet; Kishore, Kamal; Wahi, Arun Kumar

    2012-05-01

    The most significant finding of the present study was the release of nitric oxide (NO). The effect of amlodipine on NO production associated with ischemic reperfused (IR) injury was investigated in rat heart model. Cardiac tissues from animal groups were processed for biochemical, histopathological and electron microscopic studies. There was a significant increase in myocardial catalase (CAT), superoxide dismutase (SOD) and glutathione (GSH) enzymes in amlodipine treated group (1.37, 10.27, 6.39) when compared to IR injured group (0.81, 6.87, 4.53). Histopathology studies showed amlodipine reduce cardiocyte damage in cardiac injury during the cardiac IR. Transmission electron microscopic (TEM) study confirmed the cardioprotective role of amlodipine against IR induced cardiac injury. On the basis of findings, it is hypothesized that a portion of the beneficial actions of amlodipine may involve the release or action of NO and probably by its antioxidant properties.

  12. Matrine improved the function of heart failure in rats via inhibiting apoptosis and blocking β3‑adrenoreceptor/endothelial nitric oxide synthase pathway.

    PubMed

    Yu, Jiangbo; Yang, Shusen; Wang, Xu; Gan, Runtao

    2014-12-01

    Matrine, an alkaloid isolated from the traditional Chinese medicine Sophora flavescens AIT has exhibited a number of therapeutic effects on cardiovascular and liver diseases. The purpose of the present study was to investigate whether matrine has a protective effect on heart failure in rats. Coronary artery ligation was used to induce a heart failure (CHF) model in rats. Four weeks following the procedure, the rats were treated with different doses of matrine for one month. Histopathological examination demonstrated that matrine treatment alleviated myocardial hypertrophy and cardiac fibrosis in failing hearts. Furthermore, matrine administration also inhibited the increase of plasma aspartate amino transferase, creatine phosphokinase and lactate dehydrogenase levels in CHF rats. The rats with heart failure exhibited a significant reduction in ejection fraction and fractional shortening, as well as an increase in the left ventricular end systolic dimension, and matrine attenuated this decline in heart function. Further investigation demonstrated that matrine treatment also inhibited the upregulation of Bax and increase in the Bcl‑2 expression in the failing hearts. Furthermore, the upregulation of β3-adrenoreceptor (AR) and endothelial nitric oxide synthase proteins following heart failure were also attenuated by matrine. In conclusion, matrine had a preventive role in heart failure in rats at least in part by inhibiting myocardial apoptosis and the β3-AR pathway.

  13. Beneficial effect of zinc chloride and zinc ionophore pyrithione on attenuated cardioprotective potential of preconditioning phenomenon in STZ-induced diabetic rat heart.

    PubMed

    Jamwal, Sumit; Kumar, Kushal; Reddy, B V Krishna

    2016-05-01

    Ischemic preconditioning (IPC) is well demonstrated to produce cardioprotection by phosphorylation and subsequent inactivation of glycogen synthase kinase-3β (GSk-3β) in the normal rat heart, but its effect is attenuated in the diabetic rat heart. This study was designed to investigate the effect of zinc chloride and zinc ionophore pyrithione (ZIP) on the attenuated cardioprotective potential of IPC in the diabetic rat heart. Diabetes mellitus (DM) was induced by a single intraperitoneal administration of streptozotocin (STZ) (50 mg/kg; i.p). The isolated perfused rat heart was subjected to 30 minutes of ischemia followed by 120 minutes of reperfusion. Myocardial infarct size was estimated by triphenyltetrazolium chloride (TTC) staining and cardiac injury was measured by estimating lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) in the coronary effluent. Also, GSK-3β was measured and neutrophil accumulation was measured by estimating myeloperoxidase (MPO) levels. IPC significantly decreased the myocardial infarct size, the release of LDH and CK-MB, the GSK-3β levels and the MPO levels in the normal rat heart. Pre- and post-ischemic treatment with zinc chloride and zinc ionophore pyrithione (ZIP) in the normal and diabetic rat hearts significantly decreased the myocardial infarct size, the level of CK-MB and LDH in the coronary effluent and GSK-3β and MPO levels. Our results suggest that pharmacological preconditioning with zinc chloride and ZIP significantly restored the attenuated cardioprotective potential of IPC in the diabetic rat heart. PMID:26423303

  14. Diesel Exhaust Inhalation Increases Cardiac Output, Bradyarrhythmias, and Parasympathetic Tone in Aged Heart Failure–Prone Rats

    PubMed Central

    Farraj, Aimen K.

    2013-01-01

    Acute air pollutant inhalation is linked to adverse cardiac events and death, and hospitalizations for heart failure. Diesel engine exhaust (DE) is a major air pollutant suspected to exacerbate preexisting cardiac conditions, in part, through autonomic and electrophysiologic disturbance of normal cardiac function. To explore this putative mechanism, we examined cardiophysiologic responses to DE inhalation in a model of aged heart failure–prone rats without signs or symptoms of overt heart failure. We hypothesized that acute DE exposure would alter heart rhythm, cardiac electrophysiology, and ventricular performance and dimensions consistent with autonomic imbalance while increasing biochemical markers of toxicity. Spontaneously hypertensive heart failure rats (16 months) were exposed once to whole DE (4h, target PM2.5 concentration: 500 µg/m3) or filtered air. DE increased multiple heart rate variability (HRV) parameters during exposure. In the 4h after exposure, DE increased cardiac output, left ventricular volume (end diastolic and systolic), stroke volume, HRV, and atrioventricular block arrhythmias while increasing electrocardiographic measures of ventricular repolarization (i.e., ST and T amplitudes, ST area, T-peak to T-end duration). DE did not affect heart rate relative to air. Changes in HRV positively correlated with postexposure changes in bradyarrhythmia frequency, repolarization, and echocardiographic parameters. At 24h postexposure, DE-exposed rats had increased serum C-reactive protein and pulmonary eosinophils. This study demonstrates that cardiac effects of DE inhalation are likely to occur through changes in autonomic balance associated with modulation of cardiac electrophysiology and mechanical function and may offer insights into the adverse health effects of traffic-related air pollutants. PMID:23047911

  15. Cyclic AMP-receptor proteins in heart muscle of rats flown on Cosmos 1887.

    PubMed

    Mednieks, M I; Popova, I A; Grindeland, R E

    1991-10-01

    A frequent cellular response to organismal stress is the increase in ligand binding by beta-adrenergic receptors. The extracellular signal is amplified by intracellular increases in cyclic AMP and the ensuing activation of cyclic AMP-dependent protein kinase (cAPK). The molecular mechanisms involve the binding of cyclic AMP to regulatory (R) subunits of cAPK, thus freeing the catalytic subunit for protein phosphorylation. This study was carried out to determine the cellular compartmentalization of the cyclic AMP-receptor proteins in heart ventricular tissue obtained from rats flown on the Cosmos 1887 mission. Photoaffinity labeling of soluble and particulate cell fractions with an [32P]-8-azido analog of cyclic AMP was followed by electrophoretic separation of the proteins and by autoradiographic identification of the labeled isoforms of cAPK R subunits. The results showed that RII in the particulate subcellular fraction was significantly decreased in heart cells from rats in the flight group when compared to controls. Protein banding patterns in both the cytoplasmic fraction and in a fraction enriched in chromatin-bound proteins showed some variability in tissues of individual animals, but exhibited no changes that could be directly attributed to flight conditions. No significant change was apparent in the distribution of RI or RII cyclic AMP binding in the soluble fractions. These findings indicate that the cardiac cell integrity or its protein content is not compromised under flight conditions. There is, however, what appears to be an adaptive molecular response which can be detected using microanalytical methods, indicating that a major hormone regulated mechanism may be affected during some phase of travel in space.

  16. Inhibition of KV7 Channels Protects the Rat Heart against Myocardial Ischemia and Reperfusion Injury.

    PubMed

    Hedegaard, Elise R; Johnsen, Jacob; Povlsen, Jonas A; Jespersen, Nichlas R; Shanmuganathan, Jeffrey A; Laursen, Mia R; Kristiansen, Steen B; Simonsen, Ulf; Bøtker, Hans Erik

    2016-04-01

    The voltage-gated KV7 (KCNQ) potassium channels are activated by ischemia and involved in hypoxic vasodilatation. We investigated the effect of KV7 channel modulation on cardiac ischemia and reperfusion injury and its interaction with cardioprotection by ischemic preconditioning (IPC). Reverse-transcription polymerase chain reaction revealed expression of KV7.1, KV7.4, and KV7.5 in the left anterior descending rat coronary artery and all KV7 subtypes (KV7.1-KV7.5) in the left and right ventricles of the heart. Isolated hearts were subjected to no-flow global ischemia and reperfusion with and without IPC. Infarct size was quantified by 2,3,5-triphenyltetrazolium chloride staining. Two blockers of KV7 channels, XE991 [10,10-bis(4-pyridinylmethyl)-9(10H)-anthracenone] (10 µM) and linopirdine (10 µM), reduced infarct size and exerted additive infarct reduction to IPC. An opener of KV7 channels, flupirtine (10 µM) abolished infarct size reduction by IPC. Hemodynamics were measured using a catheter inserted in the left ventricle and postischemic left ventricular recovery improved in accordance with reduction of infarct size and deteriorated with increased infarct size. XE991 (10 µM) reduced coronary flow in the reperfusion phase and inhibited vasodilatation in isolated small branches of the left anterior descending coronary artery during both simulated ischemia and reoxygenation. KV7 channels are expressed in rat coronary arteries and myocardium. Inhibition of KV7 channels exerts cardioprotection and opening of KV7 channels abrogates cardioprotection by IPC. Although safety issues should be further addressed, our findings suggest a potential role for KV7 blockers in the treatment of ischemia-reperfusion injury. PMID:26869667

  17. Non-steady-state calcium handling in failing hearts from the spontaneously hypertensive rat.

    PubMed

    Ward, Marie-Louise; Crossman, David J; Loiselle, Denis S; Cannell, Mark B

    2010-11-01

    It is generally agreed that changes in Ca(2+) cycling are often associated with heart failure, yet the impact of these changes on a beat-to-beat basis remains unclear. Measurements of isometric force and [Ca(2+)](i) were made at 37°C in left ventricular trabeculae from failing spontaneously hypertensive rat (SHR) hearts, and their normotensive Wistar-Kyoto (WKY) controls. At 1 Hz, peak stress was reduced in SHR (14.5 ± 2.4 mN mm(-2) versus 22.5 ± 6.7 mN mm⁻² for WKY), although the Ca(2+) transients were bigger (peak [Ca(2+)](i) 0.60 ± 0.08 μM versus 0.38 ± 0.03 μM for WKY) with a slower decay of fluorescence (time constant 0.105 ± 0.005 s versus 0.093 ± 0.002 s for WKY). To probe dynamic Ca(2+) cycling, two experimental protocols were used to potentiate force: (1) an interval of 30 s rest, and (2) a 30-s train of paired-pulses, and the recirculation fraction (RF) calculated for recovery to steady-state. No difference was found between rat strains for RF calculated from either peak force or Ca(2+), although the RF was dependent on potentiation protocol. Since SR uptake is slower in SHR, the lack of change in RF must be due to a parallel decrease in trans-sarcolemmal Ca(2+) extrusion. This view was supported by a slower decay of caffeine-induced Ca(2+) transients in SHR trabeculae. Confocal analysis of LV free wall showed t-tubules were distorted in SHR myocytes, with reduced intensity of NCX and SERCA2a labelling in comparison to WKY.

  18. Cyclic AMP-receptor proteins in heart muscle of rats flown on Cosmos 1887.

    PubMed

    Mednieks, M I; Popova, I A; Grindeland, R E

    1991-10-01

    A frequent cellular response to organismal stress is the increase in ligand binding by beta-adrenergic receptors. The extracellular signal is amplified by intracellular increases in cyclic AMP and the ensuing activation of cyclic AMP-dependent protein kinase (cAPK). The molecular mechanisms involve the binding of cyclic AMP to regulatory (R) subunits of cAPK, thus freeing the catalytic subunit for protein phosphorylation. This study was carried out to determine the cellular compartmentalization of the cyclic AMP-receptor proteins in heart ventricular tissue obtained from rats flown on the Cosmos 1887 mission. Photoaffinity labeling of soluble and particulate cell fractions with an [32P]-8-azido analog of cyclic AMP was followed by electrophoretic separation of the proteins and by autoradiographic identification of the labeled isoforms of cAPK R subunits. The results showed that RII in the particulate subcellular fraction was significantly decreased in heart cells from rats in the flight group when compared to controls. Protein banding patterns in both the cytoplasmic fraction and in a fraction enriched in chromatin-bound proteins showed some variability in tissues of individual animals, but exhibited no changes that could be directly attributed to flight conditions. No significant change was apparent in the distribution of RI or RII cyclic AMP binding in the soluble fractions. These findings indicate that the cardiac cell integrity or its protein content is not compromised under flight conditions. There is, however, what appears to be an adaptive molecular response which can be detected using microanalytical methods, indicating that a major hormone regulated mechanism may be affected during some phase of travel in space. PMID:1662483

  19. Hypertrophic phenotype in cardiac cell assemblies solely by structural cues and ensuing self-organization

    PubMed Central

    Chung, Chiung-yin; Bien, Harold; Sobie, Eric A.; Dasari, Vikram; McKinnon, David; Rosati, Barbara; Entcheva, Emilia

    2011-01-01

    In vitro models of cardiac hypertrophy focus exclusively on applying “external” dynamic signals (electrical, mechanical, and chemical) to achieve a hypertrophic state. In contrast, here we set out to demonstrate the role of “self-organized” cellular architecture and activity in reprogramming cardiac cell/tissue function toward a hypertrophic phenotype. We report that in neonatal rat cardiomyocyte culture, subtle out-of-plane microtopographic cues alter cell attachment, increase biomechanical stresses, and induce not only structural remodeling, but also yield essential molecular and electrophysiological signatures of hypertrophy. Increased cell size and cell binucleation, molecular up-regulation of released atrial natriuretic peptide, altered expression of classic hypertrophy markers, ion channel remodeling, and corresponding changes in electrophysiological function indicate a state of hypertrophy on par with other in vitro and in vivo models. Clinically used antihypertrophic pharmacological treatments partially reversed hypertrophic behavior in this in vitro model. Partial least-squares regression analysis, combining gene expression and functional data, yielded clear separation of phenotypes (control: cells grown on flat surfaces; hypertrophic: cells grown on quasi-3-dimensional surfaces and treated). In summary, structural surface features can guide cardiac cell attachment, and the subsequent syncytial behavior can facilitate trophic signals, unexpectedly on par with externally applied mechanical, electrical, and chemical stimulation.—Chung, C., Bien, H., Sobie, E. A., Dasari, V., McKinnon, D., Rosati, B., Entcheva, E. Hypertrophic phenotype in cardiac cell assemblies solely by structural cues and ensuing self-organization. PMID:21084696

  20. Effect of diesel emissions and coal dust inhalation on heart and pulmonary arteries of rats

    SciTech Connect

    Vallyathan, V.; Virmani, R.; Rochlani, S.; Green, F.H.; Lewis, T.

    1986-01-01

    Fischer 344 (SPF) rats were exposed by inhalation to respirable particulate levels of 2 mg/m3 diesel emissions, diesel emissions plus coal dust, coal dust, or air for 7 h/d, 5 d/wk for 24 mo. The effects of treatment on body and heart weights, right and left ventricular wall thickness, severity of cardiomyopathy, and changes in the small pulmonary arteries were evaluated after 24 mo of exposure. In all dust-exposed animals, light microscopic examination of the lungs revealed dust-laden macrophages in alveolar spaces and focal accumulations of dust-laden macrophages near the respiratory bronchioles associated with hyperplasia of type II cells. This response was more prominent in animals exposed to diesel emissions alone. Age-related myocardial fibrosis and inflammatory infiltrates were common in all four groups. No statistically significant differences were detected between the groups for heart weights, ventricular wall thickness, and pulmonary arterial wall thickness. However, animals exposed to diesel emissions did show a consistent trend toward increased pulmonary arterial wall thickness, for all size categories of artery, compared to controls.

  1. Direct effects of (-)-epicatechin and procyanidin B2 on the respiration of rat heart mitochondria.

    PubMed

    Kopustinskiene, Dalia M; Savickas, Arunas; Vetchý, David; Masteikova, Ruta; Kasauskas, Arturas; Bernatoniene, Jurga

    2015-01-01

    Flavonol (-)-epicatechin and its derived dimer procyanidin B2, present in high amounts in cocoa products, have been shown to exert beneficial effects on the heart and cardiovascular system; however, their mechanism of action has not been fully elucidated. We studied effects of (-)-epicatechin and procyanidin B2 on the oxidative phosphorylation of isolated rat heart mitochondria. (-)-Epicatechin and procyanidin B2 had stimulating effect (up to 30% compared to control) on substrate-driven (State 2) mitochondrial respiration. Their effect was dependent on the respiratory substrates used. (-)-Epicatechin at higher concentrations (from 0.27 µg/mL) significantly decreased (up to 15%) substrate- and ADP-driven (State 3) mitochondrial respiration in case of pyruvate and malate oxidation only. Procyanidin B2 (0.7-17.9 ng/mL) inhibited State 3 respiration rate up to 19%, the most profound effect being expressed with succinate as the substrate. (-)-Epicatechin at concentrations of 0.23 µg/mL and 0.46 µg/mL prevented loss of the cytochrome c from mitochondria when substrate was succinate, supporting the evidence of membrane stabilizing properties of this flavonol. Thus, both (-)-epicatechin and procyanidin B2 directly influenced mitochondrial functions and the observed effects could help to explain cardiometabolic risk reduction ascribed to the consumption of modest amounts of cocoa products.

  2. Analysis of Tyrosine Kinase Inhibitor-Mediated Decline in Contractile Force in Rat Engineered Heart Tissue

    PubMed Central

    Cuello, Friederike; Luther, Pradeep; Schulze, Thomas; Eder, Alexandra; Streichert, Thomas; Mannhardt, Ingra; Hirt, Marc N.; Schaaf, Sebastian; Stenzig, Justus; Force, Thomas

    2016-01-01

    Introduction Left ventricular dysfunction is a frequent and potentially severe side effect of many tyrosine kinase inhibitors (TKI). The mode of toxicity is not identified, but may include impairment of mitochondrial or sarcomeric function, autophagy or angiogenesis, either as an on-target or off-target mechanism. Methods and Results We studied concentration-response curves and time courses for nine TKIs in three-dimensional, force generating engineered heart tissue (EHT) from neonatal rat heart cells. We detected a concentration- and time-dependent decline in contractile force for gefitinib, lapatinib, sunitinib, imatinib, sorafenib, vandetanib and lestaurtinib and no decline in contractile force for erlotinib and dasatinib after 96 hours of incubation. The decline in contractile force was associated with an impairment of autophagy (LC3 Western blot) and appearance of autophagolysosomes (transmission electron microscopy). Conclusion This study demonstrates the feasibility to study TKI-mediated force effects in EHTs and identifies an association between a decline in contractility and inhibition of autophagic flux. PMID:26840448

  3. Differential hemodynamic effects of ethanol on rat heart: Beneficial vs. detrimental actions

    SciTech Connect

    Zou, L.Y.; Alture, B.T.; Wu, F.; Barbour, R.L.; Altura, B.M. )

    1991-03-11

    Epidemiologic studies suggest that daily ingestion of small amounts of alcohol may protect the heart, whereas higher intake may be detrimental. The authors therefore studied cardiac performance of isolated working rat hearts during perfusion with Krebs-Nenseleit medium containing three different concentrations (conc) of ethanol (ET). ET produced a biphasic hemodynamic change depending upon conc. 45 mM ET was stimulatory; higher ET were depressive. 45 mM ET increased coronary flow (CF) by 45%, cardiac output (CO) 29%, stroke volume (SV) 30%, oxygen consumption (MVO{sub 2}) 29% at 25 min, respectively. However, higher conc of ET, e.g. 90 mM, depressed most parameters. CF was reduced by 62%, CO 56%, SV 57%, peak systolic pressure (PSP) 80%, and MVO{sub 2} 77%, respectively. Lactic acid (LA) fended to increase with decline of CF. 135 mM ET decreased all cardiac parameters and MVO{sub 2} rapidly and significantly from the first 5 min. LA, LDH and CPK levels tended to be elevated, and pH tended to be reduced. These data indicate that a low conc of ET is beneficial on cardiac performance; higher concentrations of ET are detrimental. High conc of ET decrease CF leading to hypoxia, metabolic acidosis of myocardium, and cell membrane damage.

  4. Interventricular comparison of the energetics of contraction of trabeculae carneae isolated from the rat heart

    PubMed Central

    Han, June-Chiew; Taberner, Andrew J; Nielsen, Poul M F; Loiselle, Denis S

    2013-01-01

    We compare the energetics of right ventricular and left ventricular trabeculae carneae isolated from rat hearts. Using our work-loop calorimeter, we subjected trabeculae to stress-length work (W), designed to mimic the pressure–volume work of the heart. Simultaneous measurement of heat production (Q) allowed calculation of the accompanying change of enthalpy (ΔH=W+Q). From the mechanical measurements (i.e. stress and change of length), we calculated work, shortening velocity and power. In combination with heat measurements, we calculated activation heat (QA), crossbridge heat (Qxb) and two measures of cardiac efficiency: ‘mechanical efficiency’ (ɛmech=W/ΔH) and ‘crossbridge efficiency’ (ɛxb=W/(ΔH–QA)). With respect to their left ventricular counterparts, right venticular trabeculae have higher peak shortening velocity, and higher peak mechanical efficiency, but with no difference of stress development, twitch duration, work performance, shortening power or crossbridge efficiency. That is, the 35% greater maximum mechanical efficiency of right venticular than left ventricular trabeculae (13.6 vs. 10.2%) is offset by the greater metabolic cost of activation (QA) in the latter. When corrected for this difference, crossbridge efficiency does not differ between the ventricles. PMID:23184511

  5. Functional improvement and maturation of rat and human engineered heart tissue by chronic electrical stimulation.

    PubMed

    Hirt, Marc N; Boeddinghaus, Jasper; Mitchell, Alice; Schaaf, Sebastian; Börnchen, Christian; Müller, Christian; Schulz, Herbert; Hubner, Norbert; Stenzig, Justus; Stoehr, Andrea; Neuber, Christiane; Eder, Alexandra; Luther, Pradeep K; Hansen, Arne; Eschenhagen, Thomas

    2014-09-01

    Spontaneously beating engineered heart tissue (EHT) represents an advanced in vitro model for drug testing and disease modeling, but cardiomyocytes in EHTs are less mature and generate lower forces than in the adult heart. We devised a novel pacing system integrated in a setup for videooptical recording of EHT contractile function over time and investigated whether sustained electrical field stimulation improved EHT properties. EHTs were generated from neonatal rat heart cells (rEHT, n=96) or human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (hEHT, n=19). Pacing with biphasic pulses was initiated on day 4 of culture. REHT continuously paced for 16-18 days at 0.5Hz developed 2.2× higher forces than nonstimulated rEHT. This was reflected by higher cardiomyocyte density in the center of EHTs, increased connexin-43 abundance as investigated by two-photon microscopy and remarkably improved sarcomere ultrastructure including regular M-bands. Further signs of tissue maturation include a rightward shift (to more physiological values) of the Ca(2+)-response curve, increased force response to isoprenaline and decreased spontaneous beating activity. Human EHTs stimulated at 2Hz in the first week and 1.5Hz thereafter developed 1.5× higher forces than nonstimulated hEHT on day 14, an ameliorated muscular network of longitudinally oriented cardiomyocytes and a higher cytoplasm-to-nucleus ratio. Taken together, continuous pacing improved structural and functional properties of rEHTs and hEHTs to an unprecedented level. Electrical stimulation appears to be an important step toward the generation of fully mature EHT.

  6. Effects of prolonged application of isoprenaline on intracellular free magnesium concentration in isolated heart of rat.

    PubMed Central

    Nishimura, H.; Matsubara, T.; Ikoma, Y.; Nakayama, S.; Sakamoto, N.

    1993-01-01

    1. The effect of prolonged application of isoprenaline on intracellular free-Mg2+ concentration ([Mg2+]i) was examined by use of 31P-nuclear magnetic resonance (31P-n.m.r.) in rat isolated hearts. Left ventricular pressure (LVP) was simultaneously measured. 2. [Mg2+]i was estimated from the separation of the alpha- and beta-ATP peaks, using the dissociation constant of MgATP 38 microM (established previously). In normal (phosphate-free, Krebs-Henseleit) solution, [Mg2+]i was approximately 0.4 mM. 3. When isoprenaline was applied for 100 min, a transient increase in [Mg2+]i was observed during the initial 25 min, whilst concentrations of ATP ([ATP]) and phosphocreatine ([PCr]) decreased and [Pi] correspondingly increased. During the subsequent 75 min of isoprenaline application, [Mg2+]i decreased below its resting levels. Washout of isoprenaline restored [Mg2+]i and [PCr], but [ATP] remained low. These changes elicited by isoprenaline were not observed in the presence of propranolol, a typical alpha-adrenoceptor blocker. 4. Isoprenaline increased both LVP and heart rate. The increased LVP and heart rate slowly returned to lower values during prolonged application of isoprenaline, but remained higher than those before application. 5. The transient rise in [Mg2+]i elicited by isoprenaline could be attributed to the decrease in [ATP] resulting in a release of Mg2+. The subsequent decrease in [Mg2+]i during the prolonged applications suggests that beta-adrenoceptor stimulation itself facilitates Mg(2+)-extruding mechanism(s). PMID:8358545

  7. Differential effects of furnidipine and its active metabolites in rat isolated working heart.

    PubMed

    Krzemiński, Tadeusz F; Hudziak, Damian; Sielańczyk, Andrzej W; Porc, Maurycy; Kedzia, Agnieszka

    2008-01-01

    1,4,-dihydropyridines, belonging to the class of "privileged structures", are known to protect the heart from stunning, ischemia and ventricular arrhythmias and mainly used in hypertension. The aim of this study was to compare the continuous infusion of parent drug, furnidipine, with its two active metabolites (M-2; M-3) in rat isolated working heart model, where the following parameters were measured and calculated: heart rate, preload pressure, aortic systolic and diastolic pressures (AoD), as well as +/-dP/dt, aortic (AF) and coronary flow (CF), oxygen and carbon dioxide partial pressures and pH values in pulmonary effluent, myocardial oxygen consumption. At first, the optimal vasodilatatory dose of M-2 was estimated and afterwards it was compared with equivalent doses of both remaining substances. The strongest vasodilatatory effects were observed after the lowest dose of M-2 was used (10(-7) M), at the same time being without marked influence on pressure parameters. The pro-drug evoked significantly weaker influence on both flows. Furthermore, furnidipine significantly reduced AoD and AF in comparison to control as well as +dP/dt in comparison to the initial values, while M-2 did not. Both metabolites caused a significant CF increase, but M-3 additionally the AoS and AoD decrease in comparison to the control. Regarding clear differences in the measured parameters between the pro-drug and its metabolites found, the obtained results allow to claim that the metabolites vs. furnidipine possess a beneficial influence. The distinct flow shift from aorta into the coronaries was observed only after M-2 and to a lesser extent--M-3. The cardio-depressant potency of both metabolites is overcome by advantageous vasodilatatory effect. M-2, being a final product, easier to control and at the same time a precursor of the new chemical class of therapeutics, is promising as a cardio-protective agent.

  8. Hypertrophic lupus vulgaris: an unusual presentation.

    PubMed

    Jain, Vijay K; Aggarwal, Kamal; Jain, Sarika; Singh, Sunita

    2009-07-01

    Lupus vulgaris is the most common form of cutaneous tuberculosis occurring in previously sensitized individuals with a high degree of tuberculin sensitivity. Various forms including plaque, ulcerative, hypertrophic, vegetative, papular, and nodular forms have been described. A 30-year-old male patient presented with a very large hypertrophic lupus vulgaris lesion over left side of chest since 22 years. Histopathological examination showed granulomatous infiltration without caseation necrosis. The Mantoux reaction was strongly positive. Hypertrophic lupus vulgaris of such a giant size and that too at an unusual site is extremely rare and hence is being reported.

  9. The Efficiency of Barley (Hordeum vulgare) Bran in Ameliorating Blood and Treating Fatty Heart and Liver of Male Rats

    PubMed Central

    Abulnaja, Khalid O.; El Rabey, Haddad A.

    2015-01-01

    The current study focused on testing the hypolipidemic activity of two doses of barley bran on hypercholesterolemic male rats. Twenty-four male albino rats weighing 180–200 gm were divided into four groups. The first group (G1) was the negative control, the second group (G2) was the positive control group fed 2% cholesterol in the diet, and rats of the third and the fourth groups were fed 2% cholesterol and were cosupplemented with 5% and 10% barley bran, respectively, for 8 weeks. The hypercholesterolemic rats of (G2) showed an increase in lipid profile, liver enzymes, lactate dehydrogenase, creatine kinase-MB, and lipid peroxide and a decrease in antioxidant enzymes, whereas kidney function, fasting blood sugar, glycated hemoglobin total protein, and total bilirubin were not significantly affected compared with the negative control group in G1. Moreover, histology of heart, liver, and kidney of G2 rats showed histopathological changes compared with the negative control. Administration of the two doses of barley bran in G3 and G4 to the hypercholesterolemic rats ameliorated the level of lipids, liver enzymes, lactate dehydrogenase, and creatine kinase-MB. In addition, the histology of heart, liver, and kidney tissues nearly restored the normal state as in G1. PMID:25866539

  10. Autonomic control of heart rate and blood pressure in spontaneously hypertensive rats during aversive classical conditioning.

    PubMed

    Hatton, D C; Buchholz, R A; Fitzgerald, R D

    1981-12-01

    An examination was made of the heart rate (HR) and blood pressure (BP) responses of 7-9-wk-old spontaneously hypertensive rats (SHR) and genetical control Wistar/Kyoto (WKY) rats during aversive classical conditioning. Subsequent to the development of conditioned responding (CRs), assessments were made of the effects of selective autonomic blockade by methyl atropine (10 mg/kg), phentolamine (2 mg/kg), and propranolol (2 mg/kg). The CR complex in the two strains consisted of pressor BP CRs in conjunction with vagally mediated decelerative HR CRs in the SHR strain and sympathetically mediated accelerative HR CRs in the WKY strain. The decelerative SHR HR CR did not appear to be secondary to baroreceptor reflex activity, although such activity did appear to be involved in the pressor BP and decelerative HR orienting response (OR) and unconditioned response (UR) complex of the SHRs on the initial application of the CS and the US, respectively. Augmented pressor BP ORs, CRs, and URs in the SHRs relative to the WKYs and differential drug effects on BP and HR baselines of the two strains suggested the presence of enhanced sympathetic activity in the SHRs that was not reflected in the SHR decelerative HR CR. Phentolamine unmasked evidence of reflex beta 2-vasodilation deficiency in the SHRs that could have contributed to the enhancement of their BP OR and CR.

  11. Heart rate variability and electrocardiogram waveform as predictors of morbidity during hypothermia and rewarming in rats.

    PubMed

    Matthew, C B; Bastille, A M; Gonzalez, R R; Sils, I V

    2002-09-01

    This study examined electrocardiogram (ECG) waveform, heart rate (HR), mean blood pressure (BP), and HR variability as potential autonomic signatures of hypothermia and rewarming. Adult male Sprague-Dawley rats had telemetry transmitters surgically implanted, and 2 weeks were allowed for recovery prior to induction of hypothermia. Rats were lightly anesthetized (sodium pentobarbital, 35 mg/kg i.p.) and placed in a coil of copper tubing through which temperature-controlled water was circulated. Animals were cooled to a core temperature (Tc) of 20 degrees C, maintained there for 30 min, and then rewarmed. Data (Tc, BP, HR from ECG, and 10-s strips of ECG waveforms) were collected every 5 min throughout hypothermia and rewarming. Both HR and BP declined after initial increases with the drop in HR starting at a higher Tc than the drop in BP (29.6 +/- 2.4 degrees C vs. 27.1 +/- 3.3 degrees C, p < 0.05). Animals that were not successfully rewarmed exhibited a significant (p < 0.05) increase in the normalized standard deviation of interbeat intervals (IBI) throughout cooling compared with animals that were successfully rewarmed. The T wave of the ECG increased in amplitude and area with decreasing Tc. T-wave amplitude and IBI variability show potential as predictors of survival in hypothermic victims.

  12. Relaxin protects against myocardial injury caused by ischemia and reperfusion in rat heart.

    PubMed Central

    Bani, D.; Masini, E.; Bello, M. G.; Bigazzi, M.; Sacchi, T. B.

    1998-01-01

    Myocardial injury caused by ischemia and reperfusion comes from multiple pathogenic events, including endothelial damage, neutrophil extravasation into tissue, platelet and mast cell activation, and peroxidation of cell membrane lipids, which are followed by myocardial cell alterations resulting eventually in cell necrosis. The current study was designed to test the possible cardioprotective effect of the hormone relaxin, which has been found to cause coronary vessel dilation and to inhibit platelet and mast cell activation. Ischemia (for 30 minutes) was induced in rat hearts in vivo by ligature of the left anterior descending coronary artery; reperfusion (for 60 minutes or less if the rats died before this predetermined time) was induced by removal of the ligature. Relaxin (100 ng) was given intravenously 30 minutes before ischemia. The results obtained showed that relaxin strongly reduces 1) the extension of the myocardial areas affected by ischemia-reperfusion-induced damage, 2) ventricular arrhythmias, 3) mortality, 4) myocardial neutrophil number, 5) myeloperoxidase activity, a marker of neutrophil accumulation, 6) production of malonyldialdehyde, an end product of lipid peroxidation, 7) mast cell granule release, 8) calcium overload, and 9) morphological signs of myocardial cell injury. This study shows that relaxin can be regarded as an agent with a marked cardioprotective action against ischemia-reperfusion-induced myocardial injury. Images Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 PMID:9588905

  13. Altered profile of gene expression in rat hearts induced by chronic nicotine consumption.

    PubMed

    Hu, Dahai; Cao, Kun; Peterson-Wakeman, Robert; Wang, Rui

    2002-10-01

    Using a cDNA microarray technique, we analyzed the expression profile of 1081 genes in the whole heart tissue of rats. The expressions of three classes of genes encoding cellular energy metabolism enzymes, transmembrane receptors, and intracellular kinase network members were reduced by more than 2.5-fold in cardiac tissues from the rats fed with nicotine (3mg/kg/day) for 3 months. The down-regulated 11 genes included mitochondrial ATP synthase beta subunit, mitochondrial H(+) transporting ATP synthase F1 complex alpha subunit isoform 1, liver mitochondrial aldehyde dehydrogenase 2, glutathione-S-transferase mu type 2, corticotropin-releasing factor receptor 2, metabotropic glutamate receptor 2, N-methyl-D-aspartate receptor subtype 2B, muscarinic acetylcholine receptor M3, transmembrane receptor Unc5H1, glycogen synthase kinase 3alpha, and Ca(2+)/calmodulin-dependent protein kinase II beta subunit. It appears that chronic nicotine treatment affects cardiac function by modulating the expressions of genes involved in energy metabolism and signal transduction.

  14. Resveratrol improves survival, hemodynamics and energetics in a rat model of hypertension leading to heart failure.

    PubMed

    Rimbaud, Stéphanie; Ruiz, Matthieu; Piquereau, Jérôme; Mateo, Philippe; Fortin, Dominique; Veksler, Vladimir; Garnier, Anne; Ventura-Clapier, Renée

    2011-01-01

    Heart failure (HF) is characterized by contractile dysfunction associated with altered energy metabolism. This study was aimed at determining whether resveratrol, a polyphenol known to activate energy metabolism, could be beneficial as a metabolic therapy of HF. Survival, ventricular and vascular function as well as cardiac and skeletal muscle energy metabolism were assessed in a hypertensive model of HF, the Dahl salt-sensitive rat fed with a high-salt diet (HS-NT). Resveratrol (18 mg/kg/day; HS-RSV) was given for 8 weeks after hypertension and cardiac hypertrophy were established (which occurred 3 weeks after salt addition). Resveratrol treatment improved survival (64% in HS-RSV versus 15% in HS-NT, p<0.001), and prevented the 25% reduction in body weight in HS-NT (P<0.001). Moreover, RSV counteracted the development of cardiac dysfunction (fractional shortening -34% in HS-NT) as evaluated by echocardiography, which occurred without regression of hypertension or hypertrophy. Moreover, aortic endothelial dysfunction present in HS-NT was prevented in resveratrol-treated rats. Resveratrol treatment tended to preserve mitochondrial mass and biogenesis and completely protected mitochondrial fatty acid oxidation and PPARα (peroxisome proliferator-activated receptor α) expression. We conclude that resveratrol treatment exerts beneficial protective effects on survival, endothelium-dependent smooth muscle relaxation and cardiac contractile and mitochondrial function, suggesting that resveratrol or metabolic activators could be a relevant therapy in hypertension-induced HF. PMID:22028869

  15. Low Cardiac Output Leads Hepatic Fibrosis in Right Heart Failure Model Rats

    PubMed Central

    Fujimoto, Yoshitaka; Urashima, Takashi; Shimura, Daisuke; Ito, Reiji; Kawachi, Sadataka; Kajimura, Ichige; Akaike, Toru; Kusakari, Yoichiro; Fujiwara, Masako; Ogawa, Kiyoshi; Goda, Nobuhito; Ida, Hiroyuki; Minamisawa, Susumu

    2016-01-01

    Background Hepatic fibrosis progresses with right heart failure, and becomes cardiac cirrhosis in a severe case. Although its causal factor still remains unclear. Here we evaluated the progression of hepatic fibrosis using a pulmonary artery banding (PAB)-induced right heart failure model and investigated whether cardiac output (CO) is responsible for the progression of hepatic fibrosis. Methods and Results Five-week-old Sprague-Dawley rats divided into the PAB and sham-operated control groups. After 4 weeks from operation, we measured CO by echocardiography, and hepatic fibrosis ratio by pathological examination using a color analyzer. In the PAB group, CO was significantly lower by 48% than that in the control group (78.2±27.6 and 150.1±31.2 ml/min, P<0.01). Hepatic fibrosis ratio and serum hyaluronic acid, an index of hepatic fibrosis, were significantly increased in the PAB group than those in the control group (7.8±1.7 and 1.0±0.2%, P<0.01, 76.2±27.5 and 32.7±7.5 ng/ml, P<0.01). Notably, the degree of hepatic fibrosis significantly correlated a decrease in CO. Immunohistological analysis revealed that hepatic stellate cells were markedly activated in hypoxic areas, and HIF-1α positive hepatic cells were increased in the PAB group. Furthermore, by real-time PCR analyses, transcripts of profibrotic and fibrotic factors (TGF-β1, CTGF, procollargen I, procollargen III, MMP 2, MMP 9, TIMP 1, TIMP 2) were significantly increased in the PAB group. In addition, western blot analyses revealed that the protein level of HIF-1α was significantly increased in the PAB group than that in the control group (2.31±0.84 and 1.0±0.18 arbitrary units, P<0.05). Conclusions Our study demonstrated that low CO and tissue hypoxia were responsible for hepatic fibrosis in right failure heart model rats. PMID:26863419

  16. [Molecular targets and novel pharmacological options to prevent myocardial hypertrophic remodeling].

    PubMed

    Coppini, Raffaele; Ferrantini, Cecilia; Poggesi, Corrado; Mugelli, Alessandro; Olivotto, Iacopo

    2016-03-01

    Myocardial hypertrophic remodeling is a pathophysiological feature of several cardiac conditions and is the hallmark of hypertrophic cardiomyopathy (HCM), the most common monogenic inherited disease of the heart. In recent years, preclinical and clinical studies investigated the underlying molecular mechanisms and intracellular signaling pathways involved in pathologic cardiomyocyte hypertrophy and highlighted a number of possible molecular targets of therapy aimed at preventing its development. Early prevention of myocardial hypertrophic remodeling is particularly sought after in HCM, as current therapeutic strategies are unable to remove the primary cause of disease, i.e. the disease-causing gene mutation. Studies on transgenic animal models or human myocardial samples from patients with HCM identified intracellular calcium overload as a central mechanism driving pathological hypertrophy. In this review, we analyze recent preclinical and clinical studies on animal models and patients with HCM aimed at preventing or modifying hypertrophic myocardial remodeling. Mounting evidence shows that prevention of pathological hypertrophy is a feasible strategy in HCM and will enter the clinical practice in the near future. Considering the close mechanistic similarities between HCM and secondary hypertrophy, these studies are also relevant for the common forms of cardiac hypertrophy, such as hypertensive or valvular heart disease. PMID:27029877

  17. [Molecular targets and novel pharmacological options to prevent myocardial hypertrophic remodeling].

    PubMed

    Coppini, Raffaele; Ferrantini, Cecilia; Poggesi, Corrado; Mugelli, Alessandro; Olivotto, Iacopo

    2016-03-01

    Myocardial hypertrophic remodeling is a pathophysiological feature of several cardiac conditions and is the hallmark of hypertrophic cardiomyopathy (HCM), the most common monogenic inherited disease of the heart. In recent years, preclinical and clinical studies investigated the underlying molecular mechanisms and intracellular signaling pathways involved in pathologic cardiomyocyte hypertrophy and highlighted a number of possible molecular targets of therapy aimed at preventing its development. Early prevention of myocardial hypertrophic remodeling is particularly sought after in HCM, as current therapeutic strategies are unable to remove the primary cause of disease, i.e. the disease-causing gene mutation. Studies on transgenic animal models or human myocardial samples from patients with HCM identified intracellular calcium overload as a central mechanism driving pathological hypertrophy. In this review, we analyze recent preclinical and clinical studies on animal models and patients with HCM aimed at preventing or modifying hypertrophic myocardial remodeling. Mounting evidence shows that prevention of pathological hypertrophy is a feasible strategy in HCM and will enter the clinical practice in the near future. Considering the close mechanistic similarities between HCM and secondary hypertrophy, these studies are also relevant for the common forms of cardiac hypertrophy, such as hypertensive or valvular heart disease.

  18. Dietary nitrate supplementation: impact on skeletal muscle vascular control in exercising rats with chronic heart failure.

    PubMed

    Ferguson, Scott K; Holdsworth, Clark T; Colburn, Trenton D; Wright, Jennifer L; Craig, Jesse C; Fees, Alex; Jones, Andrew M; Allen, Jason D; Musch, Timothy I; Poole, David C

    2016-09-01

    Chronic heart failure (CHF) results in central and peripheral derangements that ultimately reduce skeletal muscle O2 delivery and impair exercise tolerance. Dietary nitrate (NO3 (-)) supplementation improves skeletal muscle vascular function and tolerance to exercise. We tested the hypothesis that NO3 (-) supplementation would elevate exercising skeletal muscle blood flow (BF) and vascular conductance (VC) in CHF rats. Myocardial infarction (MI) was induced (coronary artery ligation) in young adult male rats. After 21 days of recovery, rats randomly received 5 days of NO3 (-)-rich beetroot juice (CHF + BR, n = 10) or a placebo (CHF, n = 10). Mean arterial pressure (carotid artery catheter) and skeletal muscle BF (radiolabeled microspheres) were measured during treadmill exercise (20 m/min, 5% grade). CHF-induced dysfunction, as determined by myocardial infarction size (29 ± 3% and 33 ± 4% in CHF and CHF + BR, respectively) and left ventricular end-diastolic pressure (18 ± 2 and 18 ± 2 mmHg in CHF and CHF + BR, respectively), and exercising mean arterial pressure (131 ± 3 and 128 ± 4 mmHg in CHF and CHF + BR, respectively) were not different (P > 0.05) between groups. Total exercising hindlimb skeletal muscle BF (95 ± 5 and 116 ± 9 ml·min(-1)·100 g(-1) in CHF and CHF + BR, respectively) and VC (0.75 ± 0.05 and 0.90 ± 0.05 ml·min(-1)·100 g(-1)·mmHg(-1) in CHF and CHF + BR, respectively) were 22% and 20% greater in BR-supplemented rats, respectively (P < 0.05). During exercise, BF in 9 and VC in 10 hindlimb muscles and muscle portions were significantly greater in the CHF + BR group. These results provide strong evidence that dietary NO3 (-) supplementation improves skeletal muscle vascular function during exercise in rats with CHF and, thus, support the use of BR as a novel therapeutic modality for the treatment of CHF.

  19. Response of rat heart membranes and associated ion-transporting ATPases to dietary lipid.

    PubMed

    Abeywardena, M Y; McMurchie, E J; Russell, G R; Sawyer, W H; Charnock, J S

    1984-09-19

    The effects of different dietary fat intake on the lipid composition and enzyme behaviour of sarcolemmal (Na+ + K+)ATPase and sarcoplasmic reticulum Ca2+-ATPase from rat heart were investigated. Rat diets were supplemented with either sunflower seed oil (unsatd./satd. 5.6) or sheep kidney fat (unsatd./satd. 0.8). Significant changes in the phospholipid fatty acid composition were observed in both membranes after 9 weeks dietary lipid treatment. For both membranes, the total saturated/unsaturated fatty acid levels were unaffected by the dietary lipid treatment, however the proportions of the major unsaturated fatty acids were altered. Animals fed the sunflower seed oil diet exhibited an increase in n-6 fatty acids, including linoleic (18:2(n-6] and arachidonic (20:4(n-6] while the sheep kidney fat dietary rats were higher in n-3 fatty acids, principally docosahexaenoic (22:6), with the net result being a higher n-6/n-3 ratio in the sunflower seed oil group compared to sheep kidney fat dietary animals. Fluorescence polarization indicated that the fluidity of sarcoplasmic reticular membrane was greater than that of sarcolemmal membrane, with a dietary lipid-induced decrease in fluidity being observed in the sarcoplasmic reticular membrane from sheep kidney fat dietary animals. Despite these significant changes in membrane composition and physical properties, neither the specific activity nor the temperature-activity relationship (Arrhenius profile) of the associated ATPases were altered. These results suggest that with regard to the parameters measured in this study, the two ion-transporting ATPases are not modulated by changes which occur in the membrane lipid composition as a result of the diet.

  20. Heme oxygenase-1 and the ischemia-reperfusion injury in the rat heart.

    PubMed

    Masini, Emanuela; Vannacci, A; Marzocca, C; Pierpaoli, S; Giannini, L; Fantappié, O; Mazzanti, R; Mannaioni, P F

    2003-05-01

    Carbon monoxide (CO) is a signaling gas produced intracellularly by heme oxygenase (HO) enzymes using heme as a substrate. During heme breakdown, HO-1 and HO-2 release CO, biliverdin, and Fe(2+). In this study, we investigated the effects of manipulation of the HO-1 system in an in vivo model of focal ischemia-reperfusion (FIR) in the rat heart. Male Wistar albino rats, under general anesthesia and artificial ventilation, underwent thoracotomy, the pericardium was opened, and a silk suture was placed around the left descending coronary artery; ischemia was induced by tightening the suture and was monitored for 30 min. Subsequently, the ligature was released to allow reperfusion lasting for 60 min. The first group of rats was sham operated and injected intraperitoneally (i.p.) with saline. The second group underwent FIR. The third group was treated ip 18 hr before FIR with hemin (4 mg/kg). The fourth group was pretreated ip 24 hr before FIR and 6 hr before hemin with zinc protoporphyrin IX (ZnPP-IX, 50 microg/kg). Specimens of the left ventricle were taken for determination of HO expression and activity, infarct size, malonyldialdehyde (MDA) production, and tissue calcium content. FIR led to a significant increase in the generation of MDA and notably raised tissue calcium levels. Induction of HO-1 by hemin significantly decreased infarct size, incidence of reperfusion arrhythmias, MDA generation, and calcium overload induced by FIR. These effects were prevented by the HO-1 inhibitor ZnPP-IX. The present experiments show that the concerted actions of CO, iron, and biliverdin/bilirubin modulate the FIR-induced myocardial injury. PMID:12709584

  1. Influence of renovascular hypertension on the distribution of vasoactive intestinal peptide in the stomach and heart of rats

    PubMed Central

    Piotrowska, Żaneta; Janiuk, Izabela

    2015-01-01

    Arterial hypertension is associated with serious dysfunction of the cardiovascular system and digestive system. Given the relevant role of vasoactive intestinal peptide (VIP) in the regulation of digestion process, control of blood pressure and heart rate as well as cardio- and gastro-protective character of the peptide, it appeared worthwhile to undertake the research aimed at immunohistochemical identification and evaluation of VIP-positive structures in the pylorus and heart of hypertensive rats. Up to now, this issue has not been investigated. The experimental model of hypertension in rats according to Goldblatt (two-kidney one clip model of hypertension) was used in the study. The experimental material (pylorus and heart) was collected in the sixth week of the study. VIP-containing structures were evaluated using immunohistochemical and morphometric methods. The analysis of the results showed a significant increase in the number of immunoreactive VIP structures and in the intensity of immunohistochemical staining in the stomach and in the heart of hypertensive rats. Our findings indicate that VIP is an important regulator of cardiovascular and digestive system in physiological and pathological conditions. However, to better understand the exact role of VIP in hypertension further studies need to be carried out. PMID:25990439

  2. Influence of renovascular hypertension on the distribution of vasoactive intestinal peptide in the stomach and heart of rats.

    PubMed

    Kasacka, Irena; Piotrowska, Żaneta; Janiuk, Izabela

    2015-11-01

    Arterial hypertension is associated with serious dysfunction of the cardiovascular system and digestive system. Given the relevant role of vasoactive intestinal peptide (VIP) in the regulation of digestion process, control of blood pressure and heart rate as well as cardio- and gastro-protective character of the peptide, it appeared worthwhile to undertake the research aimed at immunohistochemical identification and evaluation of VIP-positive structures in the pylorus and heart of hypertensive rats. Up to now, this issue has not been investigated. The experimental model of hypertension in rats according to Goldblatt (two-kidney one clip model of hypertension) was used in the study. The experimental material (pylorus and heart) was collected in the sixth week of the study. VIP-containing structures were evaluated using immunohistochemical and morphometric methods. The analysis of the results showed a significant increase in the number of immunoreactive VIP structures and in the intensity of immunohistochemical staining in the stomach and in the heart of hypertensive rats. Our findings indicate that VIP is an important regulator of cardiovascular and digestive system in physiological and pathological conditions. However, to better understand the exact role of VIP in hypertension further studies need to be carried out.

  3. Laser application for hypertrophic rhinitis

    NASA Astrophysics Data System (ADS)

    Inouye, Tetsuzo; Tanabe, Tetsuya; Nakanoboh, Manabu; Ogura, Masami

    1995-05-01

    The CO2 and KTP/532 lasers have been used in the treatment of an allergic and hypertrophic rhinitis for the past several years. As we know, the laser enables a surgeon to perform the operation with minimum hemorrhage and minimized pain, during and after the procedure. Additionally many of these operations can be performed under local anesthesia instead of general anesthesia, on an outpatient basis. The laser is used to irradiate the mucous membranes of the inferior turbinates. Vaporization and cutting is easily done. Post operative management of the local operated area is easy. The advantages of laser surgery over regular surgical techniques are supreme for intranasal operations when performed under local anesthesia.

  4. Expression and location of HSP60 and HSP10 in the heart tissue of heat-stressed rats

    PubMed Central

    Cheng, Yanfen; Sun, Jiarui; Chen, Hongbo; Adam, Abdelnasir; Tang, Shu; Kemper, Nicole; Hartung, Jörg; Bao, Endong

    2016-01-01

    The present study aimed to analyze the expression levels and localizations of heat shock protein (HSP) 60 and HSP10 in the heart tissue of rats subjected to heat stress (42°C) for 0, 20, 80 and 100 min. Histopathological injuries and increased serum activities of serum lactate dehydrogenase and creatine kinase isoenzyme MB were detected in the heated rat myocardial cells. These results suggested that heat stress-induced acute degeneration may be sufficient to cause sudden death in animals by disrupting the function and permeability of the myocardial cell membrane. In addition, the expression levels of HSP60 were significantly increased following 20 min heat stress, whereas the expression levels of its cofactor HSP10 were not. Furthermore, the location of HSP60, but not of HSP10, was significantly altered during periods of heat stress. These results suggested that HSP60 in myocardial tissue may be more susceptive to the effects of heat stress as compared with HSP10, and that HSP10 is constitutively expressed in the heart of rats. The expression levels and localizations of HSP60 and HSP10 at the different time points of heat stress were not similar, which suggested that HSP60 and HSP10 may not form a complex in the heart tissue of heat-stressed rats.

  5. Expression and location of HSP60 and HSP10 in the heart tissue of heat-stressed rats

    PubMed Central

    Cheng, Yanfen; Sun, Jiarui; Chen, Hongbo; Adam, Abdelnasir; Tang, Shu; Kemper, Nicole; Hartung, Jörg; Bao, Endong

    2016-01-01

    The present study aimed to analyze the expression levels and localizations of heat shock protein (HSP) 60 and HSP10 in the heart tissue of rats subjected to heat stress (42°C) for 0, 20, 80 and 100 min. Histopathological injuries and increased serum activities of serum lactate dehydrogenase and creatine kinase isoenzyme MB were detected in the heated rat myocardial cells. These results suggested that heat stress-induced acute degeneration may be sufficient to cause sudden death in animals by disrupting the function and permeability of the myocardial cell membrane. In addition, the expression levels of HSP60 were significantly increased following 20 min heat stress, whereas the expression levels of its cofactor HSP10 were not. Furthermore, the location of HSP60, but not of HSP10, was significantly altered during periods of heat stress. These results suggested that HSP60 in myocardial tissue may be more susceptive to the effects of heat stress as compared with HSP10, and that HSP10 is constitutively expressed in the heart of rats. The expression levels and localizations of HSP60 and HSP10 at the different time points of heat stress were not similar, which suggested that HSP60 and HSP10 may not form a complex in the heart tissue of heat-stressed rats. PMID:27698781

  6. Cardioprotective effect of aqueous extract of Chichorium intybus on ischemia-reperfusion injury in isolated rat heart

    PubMed Central

    Sadeghi, Najmeh; Dianat, Mahin; Badavi, Mohammad; Malekzadeh, Ahad

    2015-01-01

    Objective: Several studies have shown that Chichorium intybus (C. intybus) which possesses flavonoid compounds has an effective role in treatment of cardiovascular diseases. Contractile dysfunction mostly occurs after acute myocardial infarction, cardiac bypass surgery, heart transplantation and coronary angioplasty. The aim of the present study was to investigate the effect of aqueous extract of C. intybus on ischemia- reperfusion injury in isolated rat heart. Materials and Methods: The animals were divided into four groups (Sham, Control, 1 mg/ml and 3 mg/ml of extract) of 8 rats. The aorta was cannulated, and then the heart was mounted on a Langendorff apparatus. Next, a balloon was inserted into the left ventricle (LV) and peak positive value of time derivate of LV pressure (+dp/dt), coronary flow (CF), and left ventricular systolic pressure (LVSP) in pre-ischemia and reperfusion period were calculated by a Power Lab system. All groups underwent a 30-minute global ischemia followed by a 60-minute reperfusion. Results: The results showed that heart rate (HR), coronary flow, and left ventricular developed pressure (LVDP) and rate of pressure product (RPP) significantly decreased in the control group during reperfusion, while these values in the groups receiving the extract (3mg/ml) improved significantly during reperfusion (p<0.001). Conclusion: It seems that flavonoid compounds of aqueous extract of C. intybus reduce ischemia - reperfusion injuries, suggesting its protective effect on heart function after ischemia. PMID:26693414

  7. Pentaerythritol Tetranitrate Targeting Myocardial Reactive Oxygen Species Production Improves Left Ventricular Remodeling and Function in Rats With Ischemic Heart Failure.

    PubMed

    Fraccarollo, Daniela; Galuppo, Paolo; Neuser, Jonas; Bauersachs, Johann; Widder, Julian D

    2015-11-01

    Reduced nitric oxide bioavailability contributes to progression of cardiac dysfunction and remodeling in ischemic heart failure. Clinical use of organic nitrates as nitric oxide donors is limited by development of nitrate tolerance and reactive oxygen species formation. We investigated the effects of long-term therapy with pentaerythritol tetranitrate (PETN), an organic nitrate devoid of tolerance, in rats with congestive heart failure after extensive myocardial infarction. Seven days after coronary artery ligation, rats were randomly allocated to treatment with PETN (80 mg/kg BID) or placebo for 9 weeks. Long-term PETN therapy prevented the progressive left ventricular dilatation and improved left ventricular contractile function and relaxation in rats with congestive heart failure. Mitochondrial superoxide anion production was markedly increased in the failing left ventricular myocardium and nearly normalized by PETN treatment. Gene set enrichment analysis revealed that PETN beneficially modulated the dysregulation of mitochondrial genes involved in energy metabolism, paralleled by prevention of uncoupling protein-3, thioredoxin-2, and superoxide dismutase-2 downregulation. Moreover, PETN provided a remarkable protective effect against reactive fibrosis in chronically failing hearts. Mechanistically, induction of heme oxygenase-1 by PETN prevented mitochondrial superoxide generation, NOX4 upregulation, and ensuing formation of extracellular matrix proteins in fibroblasts from failing hearts. In summary, PETN targeting reactive oxygen species generation prevented the changes of mitochondrial antioxidant enzymes and progressive fibrotic remodeling, leading to amelioration of cardiac functional performance. Therefore, PETN might be a promising therapeutic option in the treatment of ischemic heart diseases involving oxidative stress and impairment in nitric oxide bioactivity.

  8. Effect of in vivo heart irradiation on the development of antioxidant defenses and cardiac functions in the rat

    SciTech Connect

    Benderitter, M.; Assem, M.; Maupoil, V.

    1995-10-01

    During radiotherapy of thoracic tumors, the heart is often included in the primary treatment volume, and chronic impairment of myocardial function occurs. The cellular biomolecules are altered directly by radiation or damaged indirectly by free radical production. The purpose of this investigation was to evaluate the biochemical and functional response of the rat heart to a single high dose of radiation. The effect of 20 Gy local X irradiation was determined in the heart of Wistar rats under general anesthesia. Mechanical performances were measured in vitro using an isolated perfused working heart model, and cardiac antioxidant defenses were also evaluated. Hearts were studied at 1 and 4 months after irradiation. This single dose of radiation induced a marked drop in the mechanical activity of the rat heart: aortic output was significantly reduced (18% less than control values) at 1 month postirradiation and remained depressed for the rest of the experimental period (21% less than control 4 months after treatment). This suggests the development of myocardial failure after irradiation. The decline of functional parameters was associated with changes in antioxidant defenses. The decrease in cardiac levels of vitamin E (-30%) was associated with an increase in the levels of Mn-SOD and glustathione peroxidase (+45.5% and +32%, respectively, at 4 months postirradiation). However, cardiac vitamin C and catalase levels remained constant. Since these antioxidant defenses were activated relatively long after irradiation, it is suggested that this was probable due to the production of free radical species associated with the development of inflammation. 49 refs., 8 figs., 1 tab.

  9. Alternative Splicing Generates a Novel Truncated Cav1.2 Channel in Neonatal Rat Heart*

    PubMed Central

    Liao, Ping; Yu, Dejie; Hu, Zhenyu; Liang, Mui Cheng; Wang, Jue Jin; Yu, Chye Yun; Ng, Gandi; Yong, Tan Fong; Soon, Jia Lin; Chua, Yeow Leng; Soong, Tuck Wah

    2015-01-01

    L-type Cav1.2 Ca2+ channel undergoes extensive alternative splicing, generating functionally different channels. Alternatively spliced Cav1.2 Ca2+ channels have been found to be expressed in a tissue-specific manner or under pathological conditions. To provide a more comprehensive understanding of alternative splicing in Cav1.2 channel, we systematically investigated the splicing patterns in the neonatal and adult rat hearts. The neonatal heart expresses a novel 104-bp exon 33L at the IVS3-4 linker that is generated by the use of an alternative acceptor site. Inclusion of exon 33L causes frameshift and C-terminal truncation. Whole-cell electrophysiological recordings of Cav1.233L channels expressed in HEK 293 cells did not detect any current. However, when co-expressed with wild type Cav1.2 channels, Cav1.233L channels reduced the current density and altered the electrophysiological properties of the wild type Cav1.2 channels. Interestingly, the truncated 3.5-domain Cav1.233L channels also yielded a dominant negative effect on Cav1.3 channels, but not on Cav3.2 channels, suggesting that Cavβ subunits is required for Cav1.233L regulation. A biochemical study provided evidence that Cav1.233L channels enhanced protein degradation of wild type channels via the ubiquitin-proteasome system. Although the physiological significance of the Cav1.233L channels in neonatal heart is still unknown, our report demonstrates the ability of this novel truncated channel to modulate the activity of the functional Cav1.2 channels. Moreover, the human Cav1.2 channel also contains exon 33L that is developmentally regulated in heart. Unexpectedly, human exon 33L has a one-nucleotide insertion that allowed in-frame translation of a full Cav1.2 channel. An electrophysiological study showed that human Cav1.233L channel is a functional channel but conducts Ca2+ ions at a much lower level. PMID:25694430

  10. Piceatannol, a derivative of resveratrol, moderately slows INa inactivation and exerts antiarrhythmic action in ischaemia-reperfused rat hearts

    PubMed Central

    Chen, Wen-Pin; Hung, Li-Man; Hsueh, Chia-Hsiang; Lai, Ling-Ping; Su, Ming-Jai

    2009-01-01

    Background and purpose: Piceatannol is more potent than resveratrol in free radical scavenging in association with antiarrhythmic and cardioprotective activities in ischaemic-reperfused rat hearts. The present study aimed to investigate the antiarrhythmic efficacy and the underlying ionic mechanisms of piceatannol in rat hearts. Experimental approach: Action potentials and membrane currents were recorded by the whole-cell patch clamp techniques. Fluo-3 fluorimetry was used to measure cellular Ca2+ transients. Antiarrhythmic activity was examined from isolated Langendorff-perfused rat hearts. Key results: In rat ventricular cells, piceatannol (3–30 µmol·L−1) prolonged the action potential durations (APDs) and decreased the maximal rate of upstroke (Vmax) without altering Ca2+ transients. Piceatannol decreased peak INa and slowed INa inactivation, rather than induced a persistent non-inactivating current, which could be reverted by lidocaine. Resveratrol (100 µmol·L−1) decreased peak INa without slowing INa inactivation. The inhibition of peak INa or Vmax was associated with a negative shift of the voltage-dependent steady-state INa inactivation curve without altering the activation threshold. At the concentrations more than 30 µmol·L−1, piceatannol could inhibit ICa,L, Ito, IKr, Ca2+ transients and Na+-Ca2+ exchange except IK1. Piceatannol (1–10 µmol·L−1) exerted antiarrhythmic activity in isolated rat hearts subjected to ischaemia-reperfusion injury. Conclusions and implications: The additional hydroxyl group on resveratrol makes piceatannol possessing more potent in INa inhibition and uniquely slowing INa inactivation, which may contribute to its antiarrhythmic actions at low concentrations less than 10 µmol·L−1. PMID:19371352

  11. Triggering role of nitric oxide in the delayed protective effect of monophosphoryl lipid A in rat heart

    PubMed Central

    György, Katalin; Muller, Bernard; Végh, Agnes; Kleschyov, Andrei L; Stoclet, Jean-Claud

    1999-01-01

    The main objective of the present study was to further evaluate the role of nitric oxide (NO) in delayed cardiac protection against ischaemia-reperfusion injury induced by monophosphoryl lipid A (MLA).For this purpose, rats were administered with either 0.5 or 2.5 mg kg−1 MLA (i.p.). Eight or 24 h later, in vivo NO production in the heart was analysed by electron paramagnetic resonance (EPR) spin trapping technique. In parallel experiments, hearts were removed and perfused according to Langendorff. Functional ventricular parameters and incidence of ventricular fibrillation (VF) were determined after 30 min global ischaemic insult (37°C) followed by 30 min reperfusion. Vascular reactivity of aortic rings was also assessed.Hearts from rats pretreated with 2.5 mg kg−1 MLA for 24 h (but not those from rats treated with 0.5 mg kg−1 MLA for 8 and 24 h, or with 2.5 mg kg−1 MLA for 8 h) exhibited preservation of ventricular function (LVDP, ±dP/dtmax) and a reduced incidence of VF (25% vs 87.5% in vehicle control) during reperfusion. At the cardioprotective dose of 2.5 mg kg−1 (for 8 or 24 h), MLA did not produce alterations of the contractile response of aortic rings to noradrenaline.An increased formation of NO was detected in hearts removed from rats pretreated with 2.5 mg kg−1 MLA for 8 h, but not in those from rats treated for 24 h (or with 0.5 mg kg−1 MLA).Pretreatment of the animals with the inhibitors of inducible NO-synthase, aminoguanidine (2×300 mg kg−1) or L-N6-(1-Iminoethyl)-lysine (L-NIL, 10 mg kg−1) abolished both MLA (2.5 mg kg−1)-induced rise of NO production (observed 8 h after MLA) and cardioprotection (observed 24 h after MLA). However MLA-induced cardioprotection was not attenuated when the hearts were perfused with aminoguanidine (150 μM) for 30 min before the ischaemic insult.Altogether, the present data suggest that NO acts as a trigger rather then a direct

  12. Protection against hyperacute xenograft rejection of transgenic rat hearts expressing human decay accelerating factor (DAF) transplanted into primates.

    PubMed Central

    Charreau, B.; Ménoret, S.; Tesson, L.; Azimzadeh, A.; Audet, M.; Wolf, P.; Marquet, R.; Verbakel, C.; Ijzermans, J.; Cowan, P.; Pearse, M.; d'Apice, A.; Soulillou, J. P.; Anegon, I.

    1999-01-01

    BACKGROUND: Production of transgenic pigs for multiple transgenes is part of a potential strategy to prevent immunological events involved in xenograft rejection. Use of a genetically engineerable rodent as a donor in primates could allow testing in vivo of the effects of different transgenes on controlling xenograft rejection. As a first step in the development of a donor containing multiple transgenes, transgenic rats for human decay-accelerating factor (DAF) were used as heart donors to test their resistance against complement (C)-mediated rejection by non-human primates. MATERIALS AND METHODS: Transgenic rats were generated by using a construct containing the human DAF cDNA under the transcriptional control of the endothelial cell (EC)-specific human ICAM-2 promoter. DAF expression was evaluated by immunohistology and by FACS analysis of purified ECs. Resistance of transgenic hearts against C-mediated damage was evaluated by ex vivo perfusion with human serum and by transplantation into cynomolgus monkeys. RESULTS: Immunohistological analysis of DAF expression in several organs from two transgenic lines showed uniform expression on the endothelium of all blood vessels. ECs purified from transgenic hearts showed 50% DAF expression compared to human ECs and >70% reduction of C-dependent cell lysis compared to control rat ECs. Hemizygous transgenic hearts perfused with human serum showed normal function for >60 min vs. 11. 2 +/- 1.7 min in controls. Hemi- or homozygous transgenic hearts transplanted into cynomolgus monkeys showed longer survival (15.2 +/- 7 min and >4.5 hr, respectively) than controls (5.5 +/- 1.4 min). In contrast to hyperacutely rejected control hearts, rejected homozygous DAF hearts showed signs of acute vascular rejection (AVR) characterized by edema, hemorrhage, and an intense PMN infiltration. CONCLUSIONS: We demonstrate that endothelial-specific DAF expression increased heart transplant survival in a rat-to-primate model of

  13. A common factor in hypertrophic osteoarthropathy

    PubMed Central

    Carroll, K. B.; Doyle, L.

    1974-01-01

    Carroll, K. B. and Doyle, L. (1974).Thorax, 29, 262-264. A common factor in hypertrophic osteoarthropathy. Two cases of oesophageal disease with hypertrophic osteoarthropathy are presented. The unusual site of the primary lesion has prompted a review of the literature and led to the conclusion that there is a common innervation accounting for a common afferent arc which is an integral and basic part of the mechanism in this disorder. Images PMID:4831530

  14. Chronic skeletal muscle ischemia preserves coronary flow in the ischemic rat heart.

    PubMed

    Varnavas, Varnavas C; Kontaras, Konstantinos; Glava, Chryssoula; Maniotis, Christos D; Koutouzis, Michael; Baltogiannis, Giannis G; Papalois, Apostolos; Kolettis, Theofilos M; Kyriakides, Zenon S

    2011-10-01

    Chronic skeletal muscle ischemia confers cytoprotection to the ventricular myocardium during infarction, but the underlying mechanisms remain unclear. Although neovascularization in the left ventricular myocardium has been proposed as a possible mechanism, the functional capacity of such vessels has not been studied. We examined the effects of chronic limb ischemia on infarct size, coronary blood flow, and left ventricular function after ischemia-reperfusion. Hindlimb ischemia was induced in 65 Wistar rats by excision of the left femoral artery, whereas 65 rats were sham operated. After 4 wk, myocardial infarction was generated by permanent coronary artery ligation. Infarct size was measured 24 h postligation. Left ventricular function was evaluated in isolated hearts after ischemia-reperfusion, 4 wk after limb ischemia. Neovascularization was assessed by immunohistochemistry, and coronary flow was measured under maximum vasodilatation at different perfusion pressures before and after coronary ligation. Infarct size was smaller after limb ischemia compared with controls (24.4 ± 8.1% vs. 46.2 ± 9.5% of the ventricle and 47.6 ± 8.7% vs. 80.1 ± 9.3% of the ischemic area, respectively). Indexes of left ventricular function at the end of reperfusion (divided by baseline values) were improved after limb ischemia (developed pressure: 0.68 ± 0.06 vs. 0.59 ± 0.05, P = 0.008; maximum +dP/dt: 0.70 ± 0.08 vs. 0.59 ± 0.04, P = 0.004; and maximum -dP/dt: 0.86 ± 0.14 vs. 0.72 ± 0.10, P = 0.041). Coronary vessel density was markedly higher (P = 0.00021) in limb ischemic rats. In contrast to controls (F = 5.65, P = 0.00182), where coronary flow decreased, it remained unchanged (F = 1.36, P = 0.28) after ligation in limb ischemic rats. In conclusion, chronic hindlimb ischemia decreases infarct size and attenuates left ventricular dysfunction by increasing coronary collateral vessel density and blood flow.

  15. Total lymphoid irradiation in rat heart albgrafts: dose, fractionation, and combination with cyclosporin-A. [X-ray

    SciTech Connect

    Rynasiewicz, J.J.; Sutherland, D.E.R.; Kawahara, K.; Kim, T.; Najarian, J.S.

    1981-03-01

    The survival or organ allografts is prolonged in mice and rats treated with fractionated, high-dose total lymphoid irradiation (TLI). We have studied the effect of TLI, alone or in combination with donor bone marrow or pharmacologic immunosuppression (cyclosporin-A: CY-A), on the survival of heterotopic rat heart allografts. Specifically, we evaluated the generalized immunosuppressive effect of TLI as a function of accumulated dose and fractionation schedule. In addition, TLI and CY-A were used individually in schedules that by themselves gave only moderate graft prolongation and then subsequently in sequential combination.

  16. Assessment of cardiovascular apoptosis in the isolated rat heart by magnetic resonance molecular imaging.

    PubMed

    Hiller, Karl-Heinz; Waller, Christiane; Nahrendorf, Matthias; Bauer, Wolfgang R; Jakob, Peter M

    2006-01-01

    Apoptosis, an active process of cell self-destruction, is associated with myocardial ischemia. The redistribution of phosphatidylserine (PS) from the inner to the outer leaflet of the cell membrane is an early event in apoptosis. Annexin V, a protein with high specificity and tight binding to PS, was used to identify and localize apoptosis in the ischemic heart.Fluorescein-labeled annexin V has been used routinely for the assessment of apoptosis in vitro. For the detection of apoptosis in vivo, positron emission tomography and single-photon emission computed tomography have been shown to be suitable tools. In view of the relatively low spatial resolution of nuclear imaging techniques, we developed a high-resolution contrast-enhanced magnetic resonance imaging (MRI) method that allows rapid and noninvasive monitoring of apoptosis in intact organs. Instead of employing superparamagnetic iron oxide particles linked to annexin V, a new T1 contrast agent was used. To this effect, annexin V was linked to gadolinium diethylenetriamine pentaacetate (Gd-DTPA)-coated liposomes. The left coronary artery of perfused isolated rat hearts was ligated for 30 min followed by reperfusion. T(1) and T(2)* images were acquired by using an 11.7-T magnet before and after intracoronary injection of Gd-DTP-labeled annexin V to visualize apoptotic cells. A significant increase in signal intensity was visible in those regions containing cardiomyocytes in the early stage of apoptosis. Because labeling of early apoptotic cell death in intact organs by histological and immunohistochemical methods remains challenging, the use of Gd-DTPA-labeled annexin V in MRI is clearly an improvement in rapid targeting of apoptotic cells in the ischemic and reperfused myocardium.

  17. Mitochondrial and Energetic Cardiac Phenotype in Hypothyroid Rat. Relevance to Heart Failure

    PubMed Central

    Athéa, Yoni; Garnier, Anne; Fortin, Dominique; Bahi, Lahoucine; Veksler, Vladimir; Ventura-Clapier, Renée

    2007-01-01

    Changes in thyroid status are associated with profound alterations in biochemical and physiological functioning of cardiac muscle, although its impact on cardiac energy metabolism is still debated. Similarities between the changes in cardiac gene expression in pathological hypertrophy leading to heart failure, and hypothyroidism prompted scientists to suggest a role for thyroid hormone status in the development of metabolic and functional alterations in this disease. We thus investigated the effects of hypothyroidism on cardiac energy metabolism. Hypothyroid state (HYPO) was induced by thyroidectomy and propyl-thio-uracyl in male rats for three weeks. We examined the effects of hypothyroid state on oxidative capacity and mitochondrial substrate utilization by measuring oxygen consumption of saponin permeabilized cardiac fibers, mitochondrial biogenesis by RT-PCR and energy metabolism and energy transfer enzymes by spectrophotometry. The results show that maximal oxidative capacity of the myocardium was decreased from 24.9±0.9 in control (CT) to 19.3±0.7 μmole O2/min/g dw in HYPO. However, protein content and mRNA of PGC-1α and mRNA of its transcription cascade that is thought to control mitochondrial content in normal myocardium and heart failure, were unchanged in HYPO. Mitochondrial utilization of glycerol-3P (−70%), malate (−45%) and octanoate (−24%) but not pyruvate was decreased in HYPO. Moreover, the creatine kinase system and energy transfer were hardly affected in HYPO. Besides, hypothyroidism decreased the activation of other signaling pathways like p38 MAPK, AMPK and calcineurin. These results show that cellular hypothyroidism can hardly account for the specific energetic alterations of HF. PMID:17638011

  18. Coronary response to large decreases of hemoglobin-O2 affinity in isolated rat heart.

    PubMed

    Stücker, O; Vicaut, E; Villereal, M C; Ropars, C; Teisseire, B P; Duvelleroy, M A

    1985-12-01

    In this study, the consequences of large increases of P50 (O2 partial pressure at 50% oxyhemoglobin saturation) on coronary blood flow (CBF) were investigated in isolated Wistar rat heart. Rightward shifts of the O2 dissociation curve (ODC), obtained by lysing and resealing erythrocytes to encapsulate inositol hexaphosphate (IHP), led to a very large increase in P50 without side effects. Each heart was perfused alternatively with control stored human blood [P50 = 18.8 +/- 0.3 (SE) mmHg] and IHP-treated human blood (P50 = 47.1 +/- 1.7 mmHg), according to the technique of Langendorff (mean perfusion pressure 80 mmHg; hematocrit 25%). Arterial PO2 of 180 mmHg was maintained to keep arterial O2 content identical for both types of blood. When hemoglobin affinity was lowered, CBF decreased from 5.32 +/- 0.20 to 3.40 +/- 0.14 ml X min-1 X g-1, coronary sinus PO2 (PcsO2) rose from 39.9 +/- 0.9 to 69.9 +/- 4.2 mmHg, and myocardial O2 consumption (MVO2) rose slightly from 0.125 +/- 0.005 to 0.149 +/- 0.010 ml O2 X min-1 X g-1 (P less than 0.05). A significant negative correlation was found between CBF and P50 (r = -0.90; n = 32) and a significant positive correlation between PcsO2 and P50 (r = +0.84; n = 28). The coronary blood flow response to high P50 values was not abolished when maximal dilation was induced by adenosine, so this response seems independent of metabolic needs. These experiments have demonstrated that if O2 uptake by erythrocytes remains constant, in the presence of a high P50, sufficient O2 supply may be achieved with substantially less blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Sex differences in heart rate variability during sleep following prenatal nicotine exposure in rat pups.

    PubMed

    Boychuk, Carie R; Fuller, David D; Hayward, Linda F

    2011-05-16

    The influence of both prenatal nicotine exposure (PNE; 6 mg/kg/day) and sex on heart rate (HR) regulation during sleep versus wakefulness was evaluated in 13, 16 and 26 day old rat pups. Pups were chronically instrumented at least 24 h before testing. On postnatal day 13 (P13), PNE males spent significantly more time in NREM sleep and demonstrated a greater drop in HR when transitioning from quiet wake to sleep compared to age and sex matched controls (-14±5 bpm versus -1±3 bpm, respectively). Heart rate variability (HRV) analysis indicated that this state-dependent drop in HR was primarily associated with a greater reduction in sympathovagal balance (LF/HF ratio) in PNE males compared to controls. No parallel changes in indices of parasympathetic drive (HF power) were identified. In contrast, no significant effect of PNE on HR during sleep versus wakefulness was identified in P13 females. However, independent of state, a significant decrease in HF power was identified in P13 PNE females compared to controls. At P16, state-dependent differences in HR or HRV between PNE and sex-matched control pups were resolved. Additionally, at P26 no significant effect of PNE on state-dependent changes in HR or HRV was identified in either sex. Analysis of the hypothalamic peptide orexin identified that PNE induced approximately a 50% reduction in hypothalamic prepro-orexin mRNA and total mRNA was lowest in PNE males. These findings suggest that PNE induces sex dependent changes in sleep related autonomic regulation of HR during early postnatal development and these changes may be related to epigenetic alterations in the orexin system.

  20. A small-molecule inhibitor of sarcomere contractility suppresses hypertrophic cardiomyopathy in mice

    PubMed Central

    Green, Eric M.; Wakimoto, Hiroko; Anderson, Robert L.; Evanchik, Marc J.; Gorham, Joshua M.; Harrison, Brooke C.; Henze, Marcus; Kawas, Raja; Oslob, Johan D.; Rodriguez, Hector M.; Song, Yonghong; Wan, William; Leinwand, Leslie A.; Spudich, James A.; McDowell, Robert S.; Seidman, J. G.; Seidman, Christine E.

    2016-01-01

    Hypertrophic cardiomyopathy (HCM) is an inherited disease of heart muscle that can be caused by mutations in sarcomere proteins. Clinical diagnosis depends on an abnormal thickening of the heart, but the earliest signs of disease are hyperdynamic contraction and impaired relaxation. Whereas some in vitro studies of power generation by mutant and wild-type sarcomere proteins are consistent with mutant sarcomeres exhibiting enhanced contractile power, others are not. We identified a small molecule, MYK-461, that reduces contractility by decreasing the adenosine triphosphatase activity of the cardiac myosin heavy chain. Here we demonstrate that early, chronic administration of MYK-461 suppresses the development of ventricular hypertrophy, cardiomyocyte disarray, and myocardial fibrosis and attenuates hypertrophic and profibrotic gene expression in mice harboring heterozygous human mutations in the myosin heavy chain. These data indicate that hyperdynamic contraction is essential for HCM pathobiology and that inhibitors of sarcomere contraction may be a valuable therapeutic approach for HCM. PMID:26912705

  1. Hypertrophic Cardiomyopathy (HCM): How Flow Analysis May Drive Medical Management and Surgical Approach

    NASA Astrophysics Data System (ADS)

    Abraham, Theodore P.

    2011-11-01

    Hypertrophic Cardiomyopathy (HCM) is the most common inherited heart disease and occurs in 1 in 500 persons worldwide regardless of race, age and gender. It is the most common cause of sudden death in the young and also causes heart failure and cardiac arrhythmias. The primary anatomic abnormality is thickening of certain walls, or sometimes global thickening of the left or right ventricle. The patterns of thickening along with increased ventricular stiffness lead to suboptimal ventricular filling and inefficient ejection of blood from the ventricle. Treatment for HCM can be medical or surgical. The choice of therapy is driven by the presence and severity of outflow obstruction. Flow analysis could provide sophisticated information about outflow and inflow ventricular dynamics. These flow dynamics features may enable better medical choices and provide information that would allow superior surgical planning. Associate Professor of Medicine & Director, Hypertrophic Cardiomyopathy Clinic

  2. Cardiotonic and sedative effects of Cecropia pachystachya Mart. (ambay) on isolated rat hearts and conscious mice.

    PubMed

    Consolini, Alicia E; Ragone, María Inés; Migliori, Graciela N; Conforti, Paula; Volonté, María G

    2006-06-15

    Cecropia pachystachya Mart. is popularly called "ambay" and extensively used in herbal medicine of South America for cough and asthma. In Argentina it grows in neotropical rainforest (Ntr C.p.) and in a temperate region (Tp C.p.). In a previous work we showed their hypotensive properties with different potency and toxicity, and now we studied the Tp C.p. effects in isolated heart from rats and central effects of both plants on the open-field test for mice. Tp C.p. produced a positive inotropic effect on isolated rat hearts, which was not affected by 1 microM propranolol, suggesting that it is not due to a beta-adrenergic effect. In contrast, it was prevented by pretreatment with high [K](o) media, which stimulates the Na,K-ATPase pump, suggesting an inhibition of the pump by "ambay", as digital do. In the open-field test, both Ntr C.p. and Tp C.p. similarly decreased the spontaneous locomotion and exploratory behavior of mice at doses between 180 and 600 mg/kg. Ntr C.p. potentiated the effect of 3 mg/kg diazepam to one similar to 10 mg/kg diazepam, but was not antagonized by 0.5 mg/kg flumazenil. Amphetamine at 5 mg/kg prevented the sedative effect of Ntr C.p. Chromatographic analysis showed that both plants have a qualitatively similar fingerprint but quantitatively differed in at least three components. Although the purpose was not to identify them, both plants have at least 10 compounds. Two of them were in higher amount in Tp C.p. than in Ntr C.p., and then, they could be responsible for the cardiovascular toxicity of Tp C.p. In conclusion, the results suggest that ambay has cardiotonic and sedative properties. The sedative effect could be useful in cough treatment. The extract resulted additive to benzodiazepines but it did not bind to the same site on GABA-A receptor, and it was interfered by the dopamine release produced with amphetamine.

  3. miRNA-146a induces vascular smooth muscle cell apoptosis in a rat model of coronary heart disease via NF-κB pathway.

    PubMed

    Wu, Z W; Liu, Y F; Wang, S; Li, B

    2015-12-29

    The aim of this study was to investigate the role of miRNA-146a in modulating the function of vascular smooth muscle cells in a rat model of coronary heart disease. Vascular smooth muscle cells were isolated and cultured from the rat coronary heart disease model and normal rats (controls). miRNA-146a levels were measured in vascular smooth muscle cells obtained from rats with coronary heart disease and control rats. The proliferation, growth, apoptosis, and activation of the NF-κB pathway in the vascular smooth muscle cells were detected using the MTT assay and flow cytometry, respectively. The role of the NF-κB pathway in modulating the apoptosis of vascular smooth muscle cells was investigated by measuring the reactivity of the cells to an NF-κB pathway inhibitor (TPCA-1). Vascular smooth muscle cells from the disease model exhibited higher levels of miRNA-146a than that by the normal controls (P = 0.0024). The vascular smooth muscle cells obtained from rats with coronary heart disease showed decreased proliferation and growth and increased apoptosis. miRNA-146a overexpression elevated the rate of cell apoptosis. The NF-κB pathway was activated in vascular smooth muscle cells obtained from rats with coronary heart disease. Inhibition of the NF- κB pathway significantly decreased the rate of vascular smooth muscle cell apoptosis in coronary heart disease rats (P = 0.0038). In conclusion, miRNA- 146a was found to induce vascular smooth muscle cell apoptosis in rats with coronary heart disease via the activation of the NF-κB signal pathway.

  4. Pharmacological inhibition of IK1 by PA-6 in isolated rat hearts affects ventricular repolarization and refractoriness.

    PubMed

    Skarsfeldt, Mark A; Carstensen, Helena; Skibsbye, Lasse; Tang, Chuyi; Buhl, Rikke; Bentzen, Bo H; Jespersen, Thomas

    2016-04-01

    The inwardly rectifying potassium current (IK 1) conducted through Kir2.X channels contribute to repolarization of the cardiac action potential and to stabilization of the resting membrane potential in cardiomyocytes. Our aim was to investigate the effect of the recently discovered IK 1 inhibitor PA-6 on action potential repolarization and refractoriness in isolated rat hearts. Transiently transfected HEK-293 cells expressing IK 1 were voltage-clamped with ramp protocols. Langendorff-perfused heart experiments were performed on male Sprague-Dawley rats, effective refractory period, Wenckebach cycle length, and ventricular effective refractory period were determined following 200 nmol/L PA-6 perfusion. 200 nmol/L PA-6 resulted in a significant time-latency in drug effect on the IK 1 current expressed in HEK-293 cells, giving rise to a maximal effect at 20 min. In the Langendorff-perfused heart experiments, PA-6 prolonged the ventricular action potential duration at 90% repolarization (from 41.8 ± 6.5 msec to 72.6 ± 21.1 msec, 74% compared to baseline, P < 0.01, n = 6). In parallel, PA-6 significantly prolonged the ventricular effective refractory period compared to baseline (from 34.8 ± 4.6 msec to 58.1 ± 14.7 msec, 67%, P < 0.01, n = 6). PA-6 increased the short-term beat-to-beat variability and ventricular fibrillation was observed in two of six hearts. Neither atrial ERP nor duration of atrial fibrillation was altered following PA-6 application. The results show that pharmacological inhibition of cardiac IK 1 affects ventricular action potential repolarization and refractoriness and increases the risk of ventricular arrhythmia in isolated rat hearts. PMID:27117805

  5. Pharmacological inhibition of IK1 by PA-6 in isolated rat hearts affects ventricular repolarization and refractoriness.

    PubMed

    Skarsfeldt, Mark A; Carstensen, Helena; Skibsbye, Lasse; Tang, Chuyi; Buhl, Rikke; Bentzen, Bo H; Jespersen, Thomas

    2016-04-01

    The inwardly rectifying potassium current (IK 1) conducted through Kir2.X channels contribute to repolarization of the cardiac action potential and to stabilization of the resting membrane potential in cardiomyocytes. Our aim was to investigate the effect of the recently discovered IK 1 inhibitor PA-6 on action potential repolarization and refractoriness in isolated rat hearts. Transiently transfected HEK-293 cells expressing IK 1 were voltage-clamped with ramp protocols. Langendorff-perfused heart experiments were performed on male Sprague-Dawley rats, effective refractory period, Wenckebach cycle length, and ventricular effective refractory period were determined following 200 nmol/L PA-6 perfusion. 200 nmol/L PA-6 resulted in a significant time-latency in drug effect on the IK 1 current expressed in HEK-293 cells, giving rise to a maximal effect at 20 min. In the Langendorff-perfused heart experiments, PA-6 prolonged the ventricular action potential duration at 90% repolarization (from 41.8 ± 6.5 msec to 72.6 ± 21.1 msec, 74% compared to baseline, P < 0.01, n = 6). In parallel, PA-6 significantly prolonged the ventricular effective refractory period compared to baseline (from 34.8 ± 4.6 msec to 58.1 ± 14.7 msec, 67%, P < 0.01, n = 6). PA-6 increased the short-term beat-to-beat variability and ventricular fibrillation was observed in two of six hearts. Neither atrial ERP nor duration of atrial fibrillation was altered following PA-6 application. The results show that pharmacological inhibition of cardiac IK 1 affects ventricular action potential repolarization and refractoriness and increases the risk of ventricular arrhythmia in isolated rat hearts.

  6. Visualization and quantification of whole rat heart laminar structure using high-spatial resolution contrast-enhanced MRI

    PubMed Central

    Benoist, David; Benson, Alan P.; White, Ed; Tanner, Steven F.; Holden, Arun V.; Dobrzynski, Halina; Bernus, Olivier; Radjenovic, Aleksandra

    2012-01-01

    It has been shown by histology that cardiac myocytes are organized into laminae and this structure is important in function, both influencing the spread of electrical activation and enabling myocardial thickening in systole by laminar sliding. We have carried out high-spatial resolution three-dimensional MRI of the ventricular myolaminae of the entire volume of the isolated rat heart after contrast perfusion [dimeglumine gadopentate (Gd-DTPA)]. Four ex vivo rat hearts were perfused with Gd-DTPA and fixative and high-spatial resolution MRI was performed on a 9.4T MRI system. After MRI, cryosectioning followed by histology was performed. Images from MRI and histology were aligned, described, and quantitatively compared. In the three-dimensional MR images we directly show the presence of laminae and demonstrate that these are highly branching and are absent from much of the subepicardium. We visualized these MRI volumes to demonstrate laminar architecture and quantitatively demonstrated that the structural features observed are similar to those imaged in histology. We showed qualitatively and quantitatively that laminar architecture is similar in the four hearts. MRI can be used to image the laminar architecture of ex vivo hearts in three dimensions, and the images produced are qualitatively and quantitatively comparable with histology. We have demonstrated in the rat that: 1) laminar architecture is consistent between hearts; 2) myolaminae are absent from much of the subepicardium; and 3) although localized orthotropy is present throughout the myocardium, tracked myolaminae are branching structures and do not have a discrete identity. PMID:22021329

  7. Decreased long-chain fatty acid oxidation impairs postischemic recovery of the insulin-resistant rat heart.

    PubMed

    Harmancey, Romain; Vasquez, Hernan G; Guthrie, Patrick H; Taegtmeyer, Heinrich

    2013-10-01

    Diabetic patients with acute myocardial infarction are more likely to die than nondiabetic patients. In the present study we examined the effect of insulin resistance on myocardial ischemia tolerance. Hearts of rats, rendered insulin resistant by high-sucrose feeding, were subjected to ischemia/reperfusion ex vivo. Cardiac power of control hearts from chow-fed rats recovered to 93%, while insulin-resistant hearts recovered only to 80% (P<0.001 vs. control). Unexpectedly, impaired contractile recovery did not result from an impairment of glucose oxidation (576±36 vs. 593±42 nmol/min/g dry weight; not significant), but from a failure to increase and to sustain oxidation of the long-chain fatty acid oleate on reperfusion (1878±56 vs. 2070±67 nmol/min/g dry weight; P<0.05). This phenomenon was due to a reduced ability to transport oleate into mitochondria and associated with a 38-58% decrease in the mitochondrial uncoupling protein 3 (UCP3) levels. Contractile function was rescued by replacing oleate with a medium-chain fatty acid or by restoring UCP3 levels with 24 h of food withdrawal. Lastly, the knockdown of UCP3 in rat L6 myocytes also decreased oleate oxidation by 13-18% following ischemia. Together the results expose UCP3 as a critical regulator of long-chain fatty acid oxidation in the stressed heart postischemia and identify octanoate as an intervention by which myocardial metabolism can be manipulated to improve function of the insulin-resistant heart.

  8. Effect of N-acetylcysteine in hearts of rats submitted to controlled hemorrhagic shock

    PubMed Central

    de Oliveira Filho, Luiz Dantas; Saad, Karen Ruggeri; Saad, Paulo Fernandes; Koike, Marcia Kiyomi; da Silva, Sônia Maria; Montero, Edna Frasson de Souza

    2015-01-01

    Introduction Pharmacological therapy is a strategy for the prevention of complications associated with ischemia and reperfusion injury that occurs after volume replacement in the treatment of hemorrhagic shock. Objective The aim of this study was to evaluate the effect of N-acetylcysteine associated with fluid resuscitation in cardiac injury in a rat hemorrhagic shock model. Methods Mice Wister male rats were randomly and subjected to controlled hemorrhagic shock for 60 min. and then, subjected to resuscitation with Ringer lactate. In a group of six animals, 150mg/kg of N-acetylcysteine were added to fluid volume replacement. The animals were observed for 120 min and after this period, were euthanized and cardiac tissue was collected for histopathological analysis and measurement of thiobarbituric acid reactive substances and pro-and anti-inflammatory interleukin. Results Cardiac tissue of the group treated with N-acetylcysteine showed lower concentrations of thiobarbituric acid reactive substances (0.20±0.05 vs. 0.27±0.05, P=0.014) and reduced histopathological damage and edema when compared to the group whose volume replacement occurred only with Ringer lactate. There was no difference in the expression of cytokines interleukin 6 (2,138.29±316.89 vs. 1,870.16±303.68, P=0.091) and interleukin 10 (1.019,83±262,50 vs. 848.60±106.5, P=0.169) between the treated groups. Conclusion The association of N-acetylcysteine on volume replacement attenuates oxidative stress in the heart, as well myocardial damage and edema, but does not modify the expression of inflammatory cytokines. PMID:26107448

  9. S100A1 transgenic treatment of acute heart failure causes proteomic changes in rats

    PubMed Central

    Guo, Yichen; Cui, Lianqun; Jiang, Shiliang; Wang, Dongmei; Jiang, Shu; Xie, Chen; Jia, Yanping

    2016-01-01

    S100 Ca2+-binding protein A1 (S100A1) is an important regulator of myocardial contractility. The aim of the present study was to identify the underlying mechanisms of S100A1 activity via profiling the protein expression in rats administered with an S100A1 adenovirus (Ad-S100A1-EGFP) following acute myocardial infarction (AMI). LTQ OrbiTrap mass spectrometry was used to profile the protein expression in the Ad-S100A1-EGFP and control groups post-AMI. Using Protein Analysis Through Evolutionary Relationships (PANTHER) analysis, 134 energy metabolism-associated proteins, which comprised 20 carbohydrate metabolism-associated and 27 lipid metabolism associated proteins, were identified as differentially expressed in the Ad-S100A1-EGFP hearts compared with controls. The majority of the differentially expressed proteins identified were important enzymes involved in energy metabolism. The present study identified 12 Ca2+-binding proteins and 22 cytoskeletal proteins. The majority of the proteins expressed in the Ad-S100A1-EGFP group were upregulated compared with the control group. These results were further validated using western blot analysis. Following AMI, Ca2+ is crucial for the recovery of myocardial function in S100A1 transgenic rats as indicated by the upregulation of proteins associated with energy metabolism and Ca2+-binding. Thus, the current study ascertained that energy production and contractile ability were enhanced after AMI in the ventricular myocardium of the Ad-S100A1-EGFP group. PMID:27357314

  10. Glycyrrhetinic acid as inhibitor or amplifier of permeability transition in rat heart mitochondria.

    PubMed

    Battaglia, Valentina; Brunati, Anna Maria; Fiore, Cristina; Rossi, Carlo Alberto; Salvi, Mauro; Tibaldi, Elena; Palermo, Mario; Armanini, Decio; Toninello, Antonio

    2008-01-01

    Glycyrrhetinic acid (GE), a hydrolysis product of glycyrrhizic acid, one of the main constituents of licorice root, is able, depending on its concentration, to prevent or to induce the mitochondrial permeability transition (MPT) (a phenomenon related to oxidative stress) in rat heart mitochondria (RHM). In RHM, below a threshold concentration of 7.5 microM, GE prevents oxidative stress and MPT induced by supraphysiological Ca2+ concentrations. Above this concentration, GE induces oxidative stress by interacting with a Fe-S centre of Complex I, thus producing ROS, and amplifies the opening of the transition pore, once again induced by Ca2+. GE also inhibits Ca2+ transport in RHM, thereby preventing the oxidative stress induced by the cation. However, the reduced amount of Ca2+ transported in the matrix is sufficient to predispose adenine nucleotide translocase for pore opening. Comparisons between observed results and the effects of GE in rat liver mitochondria (RLM), in which the drug induces only MPT without exhibiting any protective effect, confirm that it interacts in a different way with RHM, suggesting tissue specificity for its action. The concentration dependence of the opposite effects of GE, in RHM but not RLM, is most probably due to the existence of a different, more complex, pathway by means of which GE reaches its target. It follows that high GE concentrations are necessary to stimulate the oxidative stress capable of inducing MPT, because of the above effect, which prevents the interaction of low concentrations of GE with the Fe-S centre. The reported results also explain the mechanism of apoptosis induction by GE in cardiomyocytes. PMID:17980701

  11. Activation of Central Angiotensin Type 2 Receptors by Compound 21 Improves Arterial Baroreflex Sensitivity in Rats With Heart Failure

    PubMed Central

    Gao, Juan; Zucker, Irving H.

    2014-01-01

    BACKGROUND In a previous study we demonstrated that central administration of compound 21 (C21), a nonpeptide AT2R agonist, inhibited sympathetic tone in normal rats. In this study, we hypothesized that C21 exerts a similar effect in rats with coronary ligation–induced heart failure (HF). METHODS C21 was intracerebroventricularly infused for 7 days by osmotic mini pump. Blood pressure (BP) and heart rate (HR) were recorded by radiotelemetry in the conscious state to measure spontaneous arterial baroreflex sensitivity. Urine was collected for measurement of norepinephrine excretion. On the last day of C21 treatment, renal sympathetic nerve activity, BP, and HR were directly recorded under anesthesia, and the induced arterial baroreflex sensitivity was evaluated. Protein expressions of neuronal nitric oxide synthase (nNOS) and angiotensin II type 1 receptor (AT1R) in the subfornical organ, paraventricular nucleus, rostral ventrolateral medulla, and nucleus tractus solitarius were determined by Western blot analysis. RESULTS C21-treated HF rats displayed significantly less norepinephrine excretion (2,385.6±121.1 vs. 3,677.3±147.6ng/24 hours; P < 0.05) and lower renal sympathetic nerve activity (50.2±1.9% of max vs. 70.9±8.2% of max; P < 0.05) than vehicle-treated HF rats. C21-treated rats also exhibited improved spontaneous arterial baroreflex sensitivity and induced arterial baroreflex sensitivity. Bolus intracerebroventricular injection of angiotensin II–evoked pressor and sympatho-excitatory responses were attenuated in the C21-treated HF rats, which displayed upregulated nNOS and downregulated AT1R expression in the subfornical organ, paraventricular nucleus, and rostral ventrolateral medulla. CONCLUSIONS Activation of central angiotensin II type 2 receptor AT2R by C21 suppresses sympathetic outflow in rats with HF by improving baroreflex sensitivity and may provide important benefit in the HF syndrome. PMID:24687998

  12. Reversible transition from a hypertrophic to a dilated cardiomyopathy

    PubMed Central

    Spillmann, Frank; Kühl, Uwe; Van Linthout, Sophie; Dominguez, Fernando; Escher, Felicitas; Schultheiss, Heinz‐Peter; Pieske, Burkert

    2015-01-01

    Abstract We report the case of a 17‐year‐old female patient with known hypertrophic cardiomyopathy and a Wolff‐Parkinson‐White syndrome. She came to our department for further evaluation of a new diagnosed dilated cardiomyopathy characterized by an enlargement of the left ventricle and a fall in ejection fraction. Clinically, she complained about atypical chest pain, arrhythmic episodes with presyncopal events, and dyspnea (NYHA III) during the last 6 months. Non‐invasive and invasive examinations including magnetic resonance imaging, electrophysiological examinations, and angiography did not lead to a conclusive diagnosis. Therefore, endomyocardial biopsies (EMBs) were taken to investigate whether a specific myocardial disease caused the impairment of the left ventricular function. EMB analysis resulted in the diagnosis of a virus‐negative, active myocarditis. Based on this diagnosis, an immunosuppressive treatment with prednisolone and azathioprine was started, which led to an improvement of cardiac function and symptoms within 3 months after initiating therapy. In conclusion, we show that external stress triggered by myocarditis can induce a reversible transition from a hypertrophic cardiomyopathy to a dilated cardiomyopathy phenotype. This case strongly underlines the need for a thorough and invasive examination of heart failure of unknown causes, including EMB investigations as recommend by the actual ESC position statement.

  13. Volume of myocardium perfused by coronary artery branches as estimated from 3D micro-CT images of rat hearts

    NASA Astrophysics Data System (ADS)

    Lund, Patricia E.; Naessens, Lauren C.; Seaman, Catherine A.; Reyes, Denise A.; Ritman, Erik L.

    2000-04-01

    Average myocardial perfusion is remarkably consistent throughout the heart wall under resting conditions and the velocity of blood flow is fairly reproducible from artery to artery. Based on these observations, and the fact that flow through an artery is the product of arterial cross-sectional area and blood flow velocity, we would expect the volume of myocardium perfused to be proportional to the cross-sectional area of the coronary artery perfusing that volume of myocardium. This relationship has been confirmed by others in pigs, dogs and humans. To test the body size-dependence of this relationship we used the hearts from rats, 3 through 25 weeks of age. The coronary arteries were infused with radiopaque microfil polymer and the hearts scanned in a micro- CT scanner. Using these 3D images we measured the volume of myocardium and the arterial cross-sectional area of the artery that perfused that volume of myocardium. The average constant of proportionality was found to be 0.15 +/- 0.08 cm3/mm2. Our data showed no statistically different estimates of the constant of proportionality in the rat hearts of different ages nor between the left and right coronary arteries. This constant is smaller than that observed in large animals and humans, but this difference is consistent with the body mass-dependence on metabolic rate.

  14. Restoring redox balance enhances contractility in heart trabeculae from type 2 diabetic rats exposed to high glucose

    PubMed Central

    Bhatt, Niraj M.; Aon, Miguel A.; Tocchetti, Carlo G.; Shen, Xiaoxu; Dey, Swati; Ramirez-Correa, Genaro; O′Rourke, Brian; Gao, Wei Dong

    2014-01-01

    Hearts from type 2 diabetic (T2DM) subjects are chronically subjected to hyperglycemia and hyperlipidemia, both thought to contribute to oxidizing conditions and contractile dysfunction. How redox alterations and contractility interrelate, ultimately diminishing T2DM heart function, remains poorly understood. Herein we tested whether the fatty acid palmitate (Palm), in addition to its energetic contribution, rescues function by improving redox [glutathione (GSH), NAD(P)H, less oxidative stress] in T2DM rat heart trabeculae subjected to high glucose. Using cardiac trabeculae from Zucker Diabetic Fatty (ZDF) rats, we assessed the impact of low glucose (EG) and high glucose (HG), in absence or presence of Palm or insulin, on force development, energetics, and redox responses. We found that in EG ZDF and lean trabeculae displayed similar contractile work, yield of contractile work (Ycw), representing the ratio of force time integral over rate of O2 consumption. Conversely, HG had a negative impact on Ycw, whereas Palm, but not insulin, completely prevented contractile loss. This effect was associated with higher GSH, less oxidative stress, and augmented matrix GSH/thioredoxin (Trx) in ZDF mitochondria. Restoration of myocardial redox with GSH ethyl ester also rescued ZDF contractile function in HG, independently from Palm. These results support the idea that maintained redox balance, via increased GSH and Trx antioxidant activities to resist oxidative stress, is an essential protective response of the diabetic heart to keep contractile function. PMID:25485897

  15. The Dynamic Nature of Hypertrophic and Fibrotic Remodeling of the Fish Ventricle

    PubMed Central

    Keen, Adam N.; Fenna, Andrew J.; McConnell, James C.; Sherratt, Michael J.; Gardner, Peter; Shiels, Holly A.

    2016-01-01

    Chronic pressure or volume overload can cause the vertebrate heart to remodel. The hearts of fish remodel in response to seasonal temperature change. Here we focus on the passive properties of the fish heart. Building upon our previous work on thermal-remodeling of the rainbow trout ventricle, we hypothesized that chronic cooling would initiate fibrotic cardiac remodeling, with increased myocardial stiffness, similar to that seen with pathological hypertrophy in mammals. We hypothesized that, in contrast to pathological hypertrophy in mammals, the remodeling response in fish would be plastic and the opposite response would occur following chronic warming. Rainbow trout held at 10°C (control group) were chronically (>8 weeks) exposed to cooling (5°C) or warming (18°C). Chronic cold induced hypertrophy in the highly trabeculated inner layer of the fish heart, with a 41% increase in myocyte bundle cross-sectional area, and an up-regulation of hypertrophic marker genes. Cold acclimation also increased collagen deposition by 1.7-fold and caused an up-regulation of collagen promoting genes. In contrast, chronic warming reduced myocyte bundle cross-sectional area, expression of hypertrophic markers and collagen deposition. Functionally, the cold-induced fibrosis and hypertrophy were associated with increased passive stiffness of the whole ventricle and with increased micromechanical stiffness of tissue sections. The opposite occurred with chronic warming. These findings suggest chronic cooling in the trout heart invokes a hypertrophic phenotype with increased cardiac stiffness and fibrosis that are associated with pathological hypertrophy in the mammalian heart. The loss of collagen and increased compliance following warming is particularly interesting as it suggests fibrosis may oscillate seasonally in the fish heart, revealing a more dynamic nature than the fibrosis associated with dysfunction in mammals. PMID:26834645

  16. The effect of acute stress exposure on ischemia and reperfusion injury in rat heart: role of oxytocin.

    PubMed

    Moghimian, Maryam; Faghihi, Mahdieh; Karimian, Seyed Morteza; Imani, Alireza

    2012-07-01

    Previous studies showed the protective effects of oxytocin (OT) on myocardial injury in ischemic and reperfused rat heart. Moreover, exposure to various stressors not only evokes sudden cardiovascular effects but also triggers the release of OT in the rat. The present study was aimed to evaluate the possible cardioprotective effects of endogenous OT released in response to stress (St), and effects of administration of exogenous OT on the ischemic-reperfused isolated heart of rats previously exposed to St. Wistar rats were divided into six groups: ischemia/reperfusion (IR); St: rats exposed to swim St for 10 min before anesthesia; St+atosiban (ATO): an OT receptor antagonist, was administered (1.5 mg/kg i.p.) prior to St; St+OT: OT was administered (0.03 mg/kg i.p.) prior to St; OT: OT was administrated prior to anesthesia; ATO was given prior to anesthesia. Isolated hearts were perfused with Krebs buffer solution by the Langendorff method and subjected to 30 min of regional ischemia followed by 60 min of reperfusion. The infarct size (IS) and creatine kinase MB isoenzyme (CK-MB) and lactate dehydrogenase (LDH) in coronary effluent were measured. Hemodynamic parameters were recorded throughout the experiment. The plasma concentrations of OT and corticosterone were significantly increased by St. Unexpectedly St decreased IR injury compared with the IR alone group. OT administration significantly inhibited myocardial injury, and administration of ATO with St abolished recovery of the rate pressure product, and increased IS and levels of CK-MB and LDH. These findings indicate that activation of cardiac OT receptors by OT released in response to St may participate in cardioprotection and inhibition of myocardial IR injury.

  17. Functional and Electrical Integration of Induced Pluripotent Stem Cell-Derived Cardiomyocytes in a Myocardial Infarction Rat Heart.

    PubMed

    Higuchi, Takahiro; Miyagawa, Shigeru; Pearson, James T; Fukushima, Satsuki; Saito, Atsuhiro; Tsuchimochi, Hirotsugu; Sonobe, Takashi; Fujii, Yutaka; Yagi, Naoto; Astolfo, Alberto; Shirai, Mikiyasu; Sawa, Yoshiki

    2015-01-01

    In vitro expanded beating cardiac myocytes derived from induced pluripotent stem cells (iPSC-CMs) are a promising source of therapy for cardiac regeneration. Meanwhile, the cell sheet method has been shown to potentially maximize survival, functionality, and integration of the transplanted cells into the heart. It is thus hypothesized that transplanted iPSC-CMs in a cell sheet manner may contribute to functional recovery via direct mechanical effects on the myocardial infarction (MI) heart. F344/NJcl-rnu/rnu rats were left coronary artery ligated (n = 30), followed by transplantation of Dsred-labeled iPSC-CM cell sheets of murine origin over the infarct heart surface. Effects of the treatment were assessed, including in vivo molecular/cellular evaluations using a synchrotron radiation scattering technique. Ejection fraction and activation recovery interval were significantly greater from day 3 onward after iPSC-CM transplantation compared to those after sham operation. A number of transplanted iPSC-CMs were present on the heart surface expressing cardiac myosin or connexin 43 over 2 weeks, assessed by immunoconfocal microscopy, while mitochondria in the transplanted iPSC-CMs gradually showed mature structure as assessed by electron microscopy. Of note, X-ray diffraction identified 1,0 and 1,1 equatorial reflections attributable to myosin and actin-myosin lattice planes typical of organized cardiac muscle fibers within the transplanted cell sheets at 4 weeks, suggesting cyclic systolic myosin mass transfer to actin filaments in the transplanted iPSC-CMs. Transplantation of iPSC-CM cell sheets into the heart yielded functional and electrical recovery with cyclic contraction of transplanted cells in the rat MI heart, indicating that this strategy may be a promising cardiac muscle replacement therapy.

  18. Protection against cellular damage in the rat heart by hyperosmotic solutions.

    PubMed

    Harding, R J; Duncan, C J

    1999-10-01

    In this comparative study, rat hearts were perfused at 37 degrees C with three clearly defined protocols: the Ca2+ paradox, the O(2) paradox, and with 20 mM caffeine. Each protocol involved an initial priming (Ca(2+)(0) depletion or anoxia; stage 1) and subsequent full activation (Ca(2+)(0) repletion, caffeine or reoxygenation; stage 2) of the damage system of the sarcolemma. Creatine kinase release in stage 2 was completely inhibited (P < 0.001) in all three protocols when 420 mOsm was added to the perfusion medium throughout the experiments, or only during stage 1, or only during stage 2. Increasing the perfusion pressure in the Ca2+ paradox significantly (P < 0.001) exacerbated creatine kinase release, although this was still completely inhibited at 28 degrees C. Amiloride (1 mM) inhibited creatine kinase release completely at 40 cm of water pressure but only some 50% at 80 cm of water pressure. It is suggested that the transmembrane damage system needs to be uncoupled or deactivated by modifying its relationship with the cytosol or with the underlying cytoskeleton by hyperosmotic cell shrinkage for only one of the stages in all three protocols to block the damage pathway. Increased perfusion pressure has the opposite effect and exacerbates damage. PMID:10527760

  19. Evaluation of activity inotropic of a new steroid derivative using an isolated rat heart model

    PubMed Central

    Lauro, Figueroa-Valverde; Francisco, Díaz-Cedillo; Elodia, García-Cervera; Eduardo, Pool-Gómez; Maria, López-Ramos; Marcela, Rosas-Nexticapa; Lenin, Hau-Heredia; Bety, Sarabia-Alcocer; Landy, Campos-Ramos

    2014-01-01

    There are studies which indicate that some steroid derivatives have inotropic activity; nevertheless, the cellular site and mechanism of action at cardiovascular level is very confusing. In order, to clarify these phenomena in this study, a new estradiol derivative was synthesized with the objective of to evaluate its biological activity on left ventricular pressure and characterize their molecular mechanism. The Langendorff technique was used to measure changes on perfusion pressure and coronary resistance in an isolated rat heart model in absence or presence of the estradiol derivative. Additionally, to characterize the molecular mechanism involved in the inotropic activity induced by the OTBDS-estradiol-hexanoic acid derivative was evaluated by measuring left ventricular pressure in absence or presence of following compounds; tamoxifen, prazosin, metoprolol, indomethacin and nifedipine. The results showed that the OTBDS-estradiol-hexanoic acid derivative significantly increased the perfusion pressure and coronary resistance in comparison with the control conditions. Additionally, other data indicate that OTBDS-estradiol-hexanoic acid derivative increase left ventricular pressure in a dose-dependent manner (0.001 to 100 nM); nevertheless, this phenomenon was significantly inhibited only by nifedipine at a dose of 1 nM. These data suggest that positive inotropic activity induced by the OTBDS-estradiol-hexanoic acid derivative is via activation of L-type calcium channel. This phenomenon is a particularly interesting because the positive inotropic activity induced by this steroid derivative involves a molecular mechanism different in comparison with other positive inotropic drugs. PMID:24995077

  20. The protective role of neocuproine against cardiac damage in isolated perfused rat hearts.

    PubMed

    Applebaum, Y J; Kuvin, J; Borman, J B; Uretzky, G; Chevion, M

    1990-01-01

    The effect of neocuproine on cardiac injury was studied using retrogradely perfused isolated rat hearts in two experimental systems. In the first system, where hydrogen peroxide-induced damage was studied, neocuproine at the range of 40-175 microM provided protection at the level of 70-85%, as demonstrated by the reduced loss in the peak systolic pressure (P), in +dP/dt and in -dP/dt. In the second system, where ischemia/reperfusion-induced arrhythmias were studied, neocuproine (42 microM) provided a marked protection against cardiac injury as demonstrated by the lowering of the incidence in irreversible ventricular fibrillation, by decreasing the duration of ventricular fibrillation and by the concomitant increase of the duration of normal sinus rhythm, and by improving the post-ischemic recovery of P, +dP/dt and -dP/dt. Free radicals have already been implicated as causative agents in cardiac injury resulting from either hydrogen peroxide or ischemia followed by reperfusion. Additionally, iron and copper have already been shown to drastically exacerbate the injurious effects of free radicals. Thus, the results reported here with neocuproine, a highly effective chelator for both iron and copper, as well as with adventitious copper and with the combination of neocuproine and copper, are in accord with the mediatory role of transition metals in enhancing the deleterious effects induced by free radicals.

  1. Evaluation of activity inotropic of a new steroid derivative using an isolated rat heart model.

    PubMed

    Lauro, Figueroa-Valverde; Francisco, Díaz-Cedillo; Elodia, García-Cervera; Eduardo, Pool-Gómez; Maria, López-Ramos; Marcela, Rosas-Nexticapa; Lenin, Hau-Heredia; Bety, Sarabia-Alcocer; Landy, Campos-Ramos

    2014-01-01

    There are studies which indicate that some steroid derivatives have inotropic activity; nevertheless, the cellular site and mechanism of action at cardiovascular level is very confusing. In order, to clarify these phenomena in this study, a new estradiol derivative was synthesized with the objective of to evaluate its biological activity on left ventricular pressure and characterize their molecular mechanism. The Langendorff technique was used to measure changes on perfusion pressure and coronary resistance in an isolated rat heart model in absence or presence of the estradiol derivative. Additionally, to characterize the molecular mechanism involved in the inotropic activity induced by the OTBDS-estradiol-hexanoic acid derivative was evaluated by measuring left ventricular pressure in absence or presence of following compounds; tamoxifen, prazosin, metoprolol, indomethacin and nifedipine. The results showed that the OTBDS-estradiol-hexanoic acid derivative significantly increased the perfusion pressure and coronary resistance in comparison with the control conditions. Additionally, other data indicate that OTBDS-estradiol-hexanoic acid derivative increase left ventricular pressure in a dose-dependent manner (0.001 to 100 nM); nevertheless, this phenomenon was significantly inhibited only by nifedipine at a dose of 1 nM. These data suggest that positive inotropic activity induced by the OTBDS-estradiol-hexanoic acid derivative is via activation of L-type calcium channel. This phenomenon is a particularly interesting because the positive inotropic activity induced by this steroid derivative involves a molecular mechanism different in comparison with other positive inotropic drugs.

  2. Positive inotropic activity induced by a dehydroisoandrosterone derivative in isolated rat heart model.

    PubMed

    Figueroa-Valverde, L; Díaz-Cedillo, F; García-Cervera, E; Pool Gómez, E; López-Ramos, M; Rosas-Nexticapa, M; Martinez-Camacho, R

    2013-10-01

    Experimental studies indicate that some steroid derivatives have inotropic activity; nevertheless, there is scarce information about the effects of the dehydroisoandrosterone and its derivatives at cardiovascular level. In addition, to date the cellular site and mechanism of action of dehydroisoandrosterone at cardiovascular level is very confusing. In order, to clarify those phenomena in this study, a dehydroisoandrosterone derivative was synthesized with the objective of to evaluate its activity on perfusion pressure and coronary resistance and compare this phenomenon with the effect exerted by dehydroisoandrosterone. The Langendorff technique was used to measure changes on perfusion pressure and coronary resistance in an isolated rat heart model in absence or presence of dehydroisoandrosterone and its derivative. Additionally, to characterize the molecular mechanism involved in the inotropic activity induced by dehydroisoandrosterone derivative was evaluated by measuring left ventricular pressure in absence or presence of following compounds; flutamide, prazosin, metoprolol and nifedipine. The results showed that dehydroisoandrosterone derivative significantly increased the perfusion pressure and coronary resistance in comparison with the control conditions and dehydroisoandrosterone. Additionally, other data indicate that dehydroisoandrosterone derivative increase left ventricular pressure in a dose-dependent manner [1 × 10(-9)-1 × 10(-4) mmol]; nevertheless, this phenomenon was significantly inhibited by nifedipine at a dose of 1 × 10(-6) mmol. In conclusion, these data suggest that dehydroisoandrosterone derivative induces positive inotropic activity through of activation the L-type calcium channel.

  3. Reversibility of electrophysiological changes induced by chronic high-altitude hypoxia in adult rat heart.

    PubMed

    Chouabe, C; Amsellem, J; Espinosa, L; Ribaux, P; Blaineau, S; Mégas, P; Bonvallet, R

    2002-04-01

    Recent studies indicate that regression of left ventricular hypertrophy normalizes membrane ionic current abnormalities. This work was designed to determine whether regression of right ventricular hypertrophy induced by permanent high-altitude exposure (4,500 m, 20 days) in adult rats also normalizes changes of ventricular myocyte electrophysiology. According to the current data, prolonged action potential, decreased transient outward current density, and increased inward sodium/calcium exchange current density normalized 20 days after the end of altitude exposure, whereas right ventricular hypertrophy evidenced by both the right ventricular weight-to-heart weight ratio and the right ventricular free wall thickness measurement normalized 40 days after the end of altitude exposure. This morphological normalization occurred at both the level of muscular tissue, as shown by the decrease toward control values of some myocyte parameters (perimeter, capacitance, and width), and the level of the interstitial collagenous connective tissue. In the chronic high-altitude hypoxia model, the regression of right ventricular hypertrophy would not be a prerequisite for normalization of ventricular electrophysiological abnormalities. PMID:11893582

  4. Endogenous adenosine release is involved in the control of heart rate in rats.

    PubMed

    Jammes, Yves; Joulia, Fabrice; Steinberg, Jean Guillaume; Ravailhe, Sylvie; Delpierre, Stéphane; Condo, Jocelyne; Guieu, Regis; Delliaux, Stéphane

    2015-08-01

    Intravenous (i.v.) injections of adenosine exert marked effects on heart rate (HR) and arterial blood pressure (BP), but the role of an endogenous adenosine release by vagal stimulation has not been evaluated. In anaesthetized rats, we examined HR and BP changes induced by 1 min electrical vagal stimulation in the control condition, and then after i.v. injections of (i) atropine, (ii) propranolol, (iii) caffeine, (iv) 8 cyclopentyl-1,3-dipropylxanthine (DPCPX), or (v) dipyridamole to increase the plasma concentration of adenosine (APC). APC was measured by chromatography in the arterial blood before and at the end of vagal stimulation. The decrease in HR in the controls during vagal stimulation was markedly attenuated, but persisted after i.v. injections of atropine and propranolol. When first administered, DPCPX modestly but significantly reduced the HR response to vagal stimulation, but this disappeared after i.v. caffeine administration. Both the HR and BP responses were significantly accentuated after i.v. injection of dipyridamole. Vagal stimulation induced a significant increase in APC, proportional to the magnitude of HR decrease. Our data suggest that the inhibitory effects of electrical vagal stimulations on HR and BP were partly mediated through the activation of A1 and A2 receptors by an endogenous adenosine release. Our experimental data could help to understand the effects of ischemic preconditioning, which are partially mediated by adenosine. PMID:26222197

  5. Effects of moderate heart failure and functional overload on rat plantaris muscle

    NASA Technical Reports Server (NTRS)

    Spangenburg, Espen E.; Lees, Simon J.; Otis, Jeff S.; Musch, Timothy I.; Talmadge, Robert J.; Williams, Jay H.

    2002-01-01

    It is thought that changes in sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) of skeletal muscle contribute to alterations in skeletal muscle function during congestive heart failure (CHF). It is well established that exercise training can improve muscle function. However, it is unclear whether similar adaptations will result from exercise training in a CHF patient. Therefore, the purpose of this study was to determine whether skeletal muscle during moderate CHF adapts to increased activity, utilizing the functional overload (FO) model. Significant increases in plantaris mass of the CHF-FO and sham-FO groups compared with the CHF and control (sham) groups were observed. Ca(2+) uptake rates were significantly elevated in the CHF group compared with all other groups. No differences were detected in Ca(2+) uptake rates between the CHF-FO, sham, and sham-FO groups. Increases in Ca(2+) uptake rates in moderate-CHF rats were not due to changes in SERCA isoform proportions; however, FO may have attenuated the CHF-induced increases through alterations in SERCA isoform expression. Therefore, changes in skeletal muscle Ca(2+) handling during moderate CHF may be due to alterations in regulatory mechanisms, which exercise may override, by possibly altering SERCA isoform expression.

  6. Iron transport by proteoliposomes containing mitochondrial F(1)F(0) ATP synthase isolated from rat heart.

    PubMed

    Kim, Misun; Song, Eunsook

    2010-04-01

    In this work, we present evidence of Fe(2+) transport by rat heart mitochondrial F(1)F(0) ATP synthase. Iron uptake by the vesicles containing the enzyme was concentration- and temperature-dependent, with an optimum temperature of 37 degrees C. Both ATP and ADP stimulated iron uptake in a concentration-dependent manner, whereas AMP, AMPPCP, and mADP did not. Inhibitors of the enzyme, oligomycin, and resveratrol similarly blocked iron transport. The iron uptake was confirmed by inhibition using specific antibodies against the alpha, beta, and c subunits of the enzyme. Interestingly, slight transport of common divalent and trivalent metal ions such as Mg(+2), Ca(+2), Mn(+2), Zn(+2), Cu(+2), Fe(+3), and Al(+3) was observed. Moreover, Cu(+2), even in the nM range, inhibited iron uptake and attained maximum inhibition of approximately 56%. Inorganic phosphate (Pi) in the medium exerted an opposite effect depending on the type of adenosine nucleotide, which was suppressed with ATP, but enhanced with ADP. A similarly stimulating effect of ATP and ADP with an inverse effect of Pi suggests that the activity of ATPase and ATP synthase may be associated with iron uptake in a different manner, probably via antiport of H(+). PMID:20100539

  7. Purinergic component in the coronary vasodilatation to acetylcholine after ischemia-reperfusion in perfused rat hearts.

    PubMed

    García-Villalón, Ángel Luis; Granado, Miriam; Monge, Luis; Fernández, Nuria; Carreño-Tarragona, Gonzalo; Amor, Sara

    2014-01-01

    To determine the involvement of purinergic receptors in coronary endothelium-dependent relaxation, the response to acetylcholine (1 × 10(-8) to 3 × 10(-7)M) was recorded in isolated rat hearts perfused according to the Langendorff procedure before and after 30 min of ischemia and 15 min of reperfusion and after the inhibition of nitric oxide synthesis with L-NAME (10(-4)M), in the absence and presence of the antagonist of purinergic P2X receptors, PPADS (3 × 10(-6)M), and of the antagonist of purinergic P2Y receptors, Reactive Blue 2 (3 × 10(-7)M). In control conditions, the relaxation to acetylcholine was not altered by PPADS or Reactive Blue 2. The relaxation to acetylcholine was reduced after ischemia-reperfusion, and, in this condition, it was further reduced by treatment with PPADS or Reactive Blue 2. Likewise, the relaxation to acetylcholine was reduced by L-NAME, and reduced further by Reactive Blue 2 but not by PPADS. These results suggest that the relaxation to acetylcholine may be partly mediated by purinergic receptors after ischemia-reperfusion, due to the reduction of nitric oxide release in this condition.

  8. Hemidesmus indicus and Hibiscus rosa-sinensis Affect Ischemia Reperfusion Injury in Isolated Rat Hearts

    PubMed Central

    Khandelwal, Vinoth Kumar Megraj; Balaraman, R.; Pancza, Dezider; Ravingerová, Táňa

    2011-01-01

    Hemidesmus indicus (L.) R. Br. (HI) and Hibiscus rosa-sinensis L. (HRS) are widely used traditional medicine. We investigated cardioprotective effects of these plants applied for 15 min at concentrations of 90, 180, and 360 μg/mL in Langendorff-perfused rat hearts prior to 25-min global ischemia/120-min reperfusion (I/R). Functional recovery (left ventricular developed pressure—LVDP, and rate of development of pressure), reperfusion arrhythmias, and infarct size (TTC staining) served as the endpoints. A transient increase in LVDP (32%–75%) occurred at all concentrations of HI, while coronary flow (CF) was significantly increased after HI 180 and 360. Only a moderate increase in LVDP (21% and 55%) and a tendency to increase CF was observed at HRS 180 and 360. HI and HRS at 180 and 360 significantly improved postischemic recovery of LVDP. Both the drugs dose-dependently reduced the numbers of ectopic beats and duration of ventricular tachycardia. The size of infarction was significantly decreased by HI 360, while HRS significantly reduced the infarct size at all concentrations in a dose-dependent manner. Thus, it can be concluded that HI might cause vasodilation, positive inotropic effect, and cardioprotection, while HRS might cause these effects at higher concentrations. However, further study is needed to elucidate the exact mechanism of their actions. PMID:20953394

  9. Differential microRNA Expression and Regulation in the Rat Model of Post-Infarction Heart Failure

    PubMed Central

    Liu, Xueyan; Meng, Heyu; Jiang, Chao; Yang, Sibao; Cui, Fengwen; Yang, Ping

    2016-01-01

    Background Heart failure is a complex end stage of various cardiovascular diseases with a poor prognosis, and the mechanisms for development and progression of heart failure have always been a hot point. However, the molecular mechanisms underlying the post transcriptional regulation of heart failure have not been fully elucidated. Current data suggest that microRNAs (miRNAs) are involved in the pathogenesis of heart failure and could serve as a new biomarker, but the precise regulatory mechanisms are still unclear. Methods The differential miRNA profile in a rat model of post-infarction heart failure was determined using high throughout sequencing and analyzed through bioinformatics approaches. The results were validated using qRT-PCR for 8 selected miRNAs. Then the expression patterns of 4 miRNAs were analyzed in different periods after myocardial infarction. Finally, gain- and loss-of-function experiments of rno-miR-122-5p and rno-miR-184 were analyzed in H2O2 treated H9c2 cells. Results In the heart failure sample, 78 miRNAs were significantly upregulated and 28 were downregulated compared to the controls. GO and KEGG pathway analysis further indicated the likely roles of these miRNAs in heart failure. Time-course analysis revealed different expression patterns of 4 miRNAs: rno-miR-122-5p, rno-miR-199a-5p, rno-miR-184 and rno-miR-208a-3p. Additionally, rno-miR-122-5p and rno-miR-184 were proved to promote apoptosis in vitro. Conclusions Differential profile and expression patterns of miRNAs in the rats model of post-infarction heart failure were found, and the pro-apoptotic roles of rno-miR-122-5p and rno-miR-184 were revealed. These findings may provide a novel way that may assist in heart failure diagnosis and treatment. PMID:27504893

  10. Effects of an acidic phospholipase A2 purified from Ophiophagus hannah (king cobra) venom on rat heart.

    PubMed

    Huang, M Z; Wang, Q C; Liu, G F

    1993-05-01

    An acidic phospholipase A2 (OHV A-PLA2) purified from Ophiophagus hannah venom had a cardiotoxic action on rat heart. In rats OHV A-PLA2 (2-4 mg/kg) caused ECG abnormalities including decreased heart rate, prolonged P-R interval, widened QRS complex and complete A-V block. When tested on isolated rat right atria, OHV A-PLA2 (10-20 micrograms/ml) produced a positive chronotropic effect. When tested on isolated rat left atria or papillary muscle preparations, OHV A-PLA2 (2.5-20 micrograms/ml) caused positive inotropic effect, followed by contracture. The positive inotropic effects could be abolished by high Ca2+ and enhanced by low Ca2+; both treatments accelerated contracture. The contracture could be inhibited in Mn2+ (5 mM)-containing medium and abolished by Ca(2+)-free bath solution containing 1 mM EDTA. The cardiotoxic action of OHV A-PLA2 was not influenced by verapamil, tetrodotoxin, propranolol, phentolamine, atropine or indomethacin. It is suggested that the cardiotoxic effects of OHV A-PLA2 may result from increasing intracellular levels of Ca2+.

  11. Effect of curcumin on permeability of coronary artery and expression of related proteins in rat coronary atherosclerosis heart disease model

    PubMed Central

    Li, Xiaolong; Lu, Yan; Sun, Yi; Zhang, Qi

    2015-01-01

    Objective: Our objective is to explore the effect of curcumin on permeability of coronary artery and expression of related proteins in rat coronary atherosclerosis heart disease model. Methods: 45 healthy male Wistar rats of clean grade were selected and divided into treatment group, model control group and blank control group. The rats in the treatment group and model control group received high-fat diet for 12 weeks and intraperitoneal injection of VD3 to establish rat coronary atherosclerosis heart disease model. After modeling, the rats in the treatment group received gavage of 100 mg/(kg·d) curcimin, and the rats in the model control group and blank control group received gavage of 5 ml/(kg·d) distilled water, the intervention time was 4 weeks. After intervention, the rats were killed, and the hearts were dissected to obtain the samples of coronary artery. After embedding and frozen section, immunofluorescence method was used to detect the change of endarterium permeability in 3 groups, Western blot was used to detect matrix metalloproteinase-9 (MMP-9) and CD40L in coronary artery tissue, and enzyme linked immunosorbent assay (ELISA) was used to detect serum tumor necrosis factor-α (TNF-α) and C reaction protein (CRP). Results: After modeling, compared with the blank control group, total cholesterol (TC), triglyceride (TG) and low density lipoprotein cholesterin (LDL-c) in the treatment group and model control group were significantly higher (P<0.05), however, high density lipoprotein cholesterin (HDL-c) was significantly lower. The pathological sections showed that there was lipidosis in rat coronary artery in treatment group and model control group, indicating that the modeling was successful. Immunofluorescence showed that there was only a little fluorochrome permeability in artery in blank control group, there was some fluorochrome permeability in artery in the treatment group and there was a lot of fluorochrome permeability in artery in the model

  12. Intramyocardial implantation of differentiated rat bone marrow mesenchymal stem cells enhanced by TGF-β1 improves cardiac function in heart failure rats

    PubMed Central

    Lv, Y.; Liu, B.; Wang, H.P.; Zhang, L.

    2016-01-01

    The present study tested the hypotheses that i) transforming growth factor beta 1 (TGF-β1) enhances differentiation of rat bone marrow mesenchymal stem cells (MSCs) towards the cardiomyogenic phenotype and ii) intramyocardial implantation of the TGF-β1-treated MSCs improves cardiac function in heart failure rats. MSCs were treated with different concentrations of TGF-β1 for 72 h, and then morphological characteristics, surface antigens and mRNA expression of several transcription factors were assessed. Intramyocardial implantation of these TGF-β1-treated MSCs to infarcted heart was also investigated. MSCs were initially spindle-shaped with irregular processes. On day 28 after TGF-β1 treatment, MSCs showed fusiform shape, orientating parallel with one another, and were connected with adjoining cells forming myotube-like structures. Immunofluorescence revealed the expression of cardiomyocyte-specific proteins, α-sarcomeric actin and troponin T, in these cells. The mRNA expression of GATA4 and Nkx2.5 genes was slightly increased on day 7, enhanced on day 14 and decreased on day 28 while α-MHC gene was not expressed on day 7, but expressed slightly on day 14 and enhanced on day 28. Transmission electron microscopy showed that the induced cells had myofilaments, z line-like substances, desmosomes, and gap junctions, in contrast with control cells. Furthermore, intramyocardial implantation of TGF-β1-treated MSCs to infarcted heart reduced scar area and increased the number of muscle cells. This structure regeneration was concomitant with the improvement of cardiac function, evidenced by decreased left ventricular end-diastolic pressure, increased left ventricular systolic pressure and increased maximal positive pressure development rate. Taken together, these results indicate that intramyocardial implantation of differentiated MSCs enhanced by TGF-β1 improved cardiac function in heart failure rats. PMID:27254663

  13. Comparative proteomics reveals abnormal binding of ATGL and dysferlin on lipid droplets from pressure overload-induced dysfunctional rat hearts.

    PubMed

    Li, Linghai; Zhang, Huina; Wang, Weiyi; Hong, Yun; Wang, Jifeng; Zhang, Shuyan; Xu, Shimeng; Shu, Qingbo; Li, Juanfen; Yang, Fuquan; Zheng, Min; Qian, Zongjie; Liu, Pingsheng

    2016-01-01

    Excessive retention of neutral lipids in cardiac lipid droplets (LDs) is a common observation in cardiomyopathy. Thus, the systematic investigation of the cardiac LD proteome will help to dissect the underlying mechanisms linking cardiac steatosis and myocardial dysfunction. Here, after isolation of LDs from normal and dysfunctional Sprague-Dawley rat hearts, we identified 752 heart-associated LD proteins using iTRAQ quantitative proteomic method, including 451 proteins previously unreported on LDs. The most noteworthy finding was the identification of the membrane resealing protein, dysferlin. An analysis of dysferlin truncation mutants indicated that its C2 domain was responsible for its LD localization. Quantitative proteomic results further determined that 27 proteins were increased and 16 proteins were decreased in LDs from post pressure overload-induced dysfunctional hearts, compared with normal hearts. Notably, adipose triacylglycerol lipase (ATGL) was dramatically decreased and dysferlin was substantially increased on dysfunctional cardiac LDs. This study for the first time reveals the dataset of the heart LD proteome in healthy tissue and the variation of it under cardiac dysfunction. These findings highlight an association between the altered LD protein localization of dysferlin and ATGL and myocardial dysfunction. PMID:26795240

  14. Comparative proteomics reveals abnormal binding of ATGL and dysferlin on lipid droplets from pressure overload-induced dysfunctional rat hearts

    PubMed Central

    Li, Linghai; Zhang, Huina; Wang, Weiyi; Hong, Yun; Wang, Jifeng; Zhang, Shuyan; Xu, Shimeng; Shu, Qingbo; Li, Juanfen; Yang, Fuquan; Zheng, Min; Qian, Zongjie; Liu, Pingsheng

    2016-01-01

    Excessive retention of neutral lipids in cardiac lipid droplets (LDs) is a common observation in cardiomyopathy. Thus, the systematic investigation of the cardiac LD proteome will help to dissect the underlying mechanisms linking cardiac steatosis and myocardial dysfunction. Here, after isolation of LDs from normal and dysfunctional Sprague-Dawley rat hearts, we identified 752 heart-associated LD proteins using iTRAQ quantitative proteomic method, including 451 proteins previously unreported on LDs. The most noteworthy finding was the identification of the membrane resealing protein, dysferlin. An analysis of dysferlin truncation mutants indicated that its C2 domain was responsible for its LD localization. Quantitative proteomic results further determined that 27 proteins were increased and 16 proteins were decreased in LDs from post pressure overload-induced dysfunctional hearts, compared with normal hearts. Notably, adipose triacylglycerol lipase (ATGL) was dramatically decreased and dysferlin was substantially increased on dysfunctional cardiac LDs. This study for the first time reveals the dataset of the heart LD proteome in healthy tissue and the variation of it under cardiac dysfunction. These findings highlight an association between the altered LD protein localization of dysferlin and ATGL and myocardial dysfunction. PMID:26795240

  15. The effect on rat embryonic heart rate of Na+, K+, and Ca2+ channel blockers, and the human teratogen phenytoin, changes with gestational age.

    PubMed

    Nilsson, Mats F; Ritchie, Helen; Webster, William S

    2013-10-01

    In this study, we compared the effects of four ion channel blockers on rat embryonic heart function during the organogenic period from gestational day (GD) 10 to 15, to determine the changes in dependence on ion channels during rat cardiac development. Rat embryos in culture were exposed to either the human ether-á-go-go-related gene potassium channel blocker, dofetilide (400 nM); the sodium channel blocker, lidocaine (250 μM); the L-type calcium channel blocker, nifedipine (1.8 μM); or the multichannel blocker, phenytoin (200 μM). Lidocaine slowed the heart rate (HR) with the effect becoming more severe with increasing GD. Dofetilide slowed the embryonic HR and caused arrhythmias with the most severe effect on GD 11 to 13. Nifedipine primarily caused a negative inotropic effect except on GD 10 when it stopped the heart in most embryos. Phenytoin stopped the heart of most GD 10 to 12 embryos while on GD 13 to 15 phenytoin slowed the heart. The results demonstrate that as the rat heart develops during the organogenic period its functional dependence on ion channels changes markedly. These changes are important for understanding drug effects on the embryo during pregnancy and the methodology used provides a simple procedure for assessing drug effects on the developing heart.

  16. An integrated study of heart pain and behavior in freely moving rats (using fos as a marker for neuronal activation).

    PubMed

    Albutaihi, Ibrahim A M; DeJongste, Mike J L; Ter Horst, Gert J

    2004-01-01

    The awareness in specific brain centers of angina pectoris most often results from ischemic episodes in the heart. These ischemic episodes induce the release of a collage of chemicals that activate chemosensitive and mechanoreceptive receptors in the heart, which in turn excite receptors of the sympathetic afferent pathways. Ascending pain signals from these fibers result in the activation of the brain centers which are involved in the perception and integration of cardiac pain. Cytochemical studies of the nervous system provide the opportunity to identify these areas at the cellular level. In the present investigation, cardiac nociception was studied in the brains and the spinal cords of rats, using Fos protein as a marker of neuronal activation, following the application of pain-inducing chemicals to the heart. Induction of myocardial pain in conscious rats was achieved by infusion of bradykinin (0.5 microg) or capsaicin (5 microg) into the pericardial sac. During pain stimulation, the rats demonstrated pain behavior, in conjunction with alterations in heart rate and blood pressure. The cerebral Fos expression pattern was studied 2 h after pain stimulation. In contrast to the control group, increased Fos expression was found following the use of both capsaicin and bradykinin in a variety of areas of the brain. Bradykinin, but not capsaicin, induced Fos expression in the upper thoracic and upper cervical spinal cord; these segments are the sites where cardiac sympathetic fibers terminate. This finding suggests that these two chemicals use two different pathways, and provides extra evidence for the role of the vagus nerve in the transmission of cardiac nociception. Different cerebral areas showed an increase in the c-fos activity following pericardial application of pain-inducing chemicals. The role of these cerebral areas in the integration of cardiac pain is discussed in relation to the identified pathways which transmit cardiac pain. PMID:15305089

  17. Novel Insights into the Cardio-Protective Effects of FGF21 in Lean and Obese Rat Hearts

    PubMed Central

    Chen, Jing; Ramanjaneya, Manjunath; Bari, Muhammad F.; Bhudia, Sunil K.; Hillhouse, Edward W.; Tan, Bee K.; Randeva, Harpal S.

    2014-01-01

    Aims Fibroblast growth factor 21 (FGF21) is a hepatic metabolic regulator with pleotropic actions. Its plasma concentrations are increased in obesity and diabetes; states associated with an increased incidence of cardiovascular disease. We therefore investigated the direct effect of FGF21 on cardio-protection in obese and lean hearts in response to ischemia. Methods and Results FGF21, FGF21-receptor 1 (FGFR1) and beta-Klotho (βKlotho) were expressed in rodent, human hearts and primary rat cardiomyocytes. Cardiac FGF21 was expressed and secreted (real time RT-PCR/western blot and ELISA) in an autocrine-paracrine manner, in response to obesity and hypoxia, involving FGFR1-βKlotho components. Cardiac-FGF21 expression and secretion were increased in response to global ischemia. In contrast βKlotho was reduced in obese hearts. In isolated adult rat cardiomyocytes, FGF21 activated PI3K/Akt (phosphatidylinositol 3-kinase/Akt), ERK1/2(extracellular signal-regulated kinase) and AMPK (AMP-activated protein kinase) pathways. In Langendorff perfused rat [adult male wild-type wistar] hearts, FGF21 administration induced significant cardio-protection and restoration of function following global ischemia. Inhibition of PI3K/Akt, AMPK, ERK1/2 and ROR-α (retinoic-acid receptor alpha) pathway led to significant decrease of FGF21 induced cardio-protection and restoration of cardiac function in response to global ischemia. More importantly, this cardio-protective response induced by FGF21 was reduced in obesity, although the cardiac expression profiles and circulating FGF21 levels were increased. Conclusion In an ex vivo Langendorff system, we show that FGF21 induced cardiac protection and restoration of cardiac function involving autocrine-paracrine pathways, with reduced effect in obesity. Collectively, our findings provide novel insights into FGF21-induced cardiac effects in obesity and ischemia. PMID:24498293

  18. Glutamate protects against Ca(2+) paradox-induced injury and inhibits calpain activity in isolated rat hearts.

    PubMed

    Zhang, Jian-Ying; Kong, Ling-Heng; Lai, Dong; Jin, Zhen-Xiao; Gu, Xiao-Ming; Zhou, Jing-Jun

    2016-10-01

    This study determined the effects of glutamate on the Ca(2+) paradoxical heart, which is a model for Ca(2+) overload-induced injury during myocardial ischaemia and reperfusion, and evaluated its effect on a known mediator of injury, calpain. An isolated rat heart was retrogradely perfused in a Langendorff apparatus. Ca(2+) paradox was elicited via perfusion with a Ca(2+) -free Krebs-Henseleit (KH) solution for 3 minutes followed by Ca(2+) -containing normal KH solution for 30 minutes. The Ca(2+) paradoxical heart exhibited almost no viable tissue on triphenyltetrazolium chloride staining and markedly increased LDH release, caspase-3 activity, cytosolic cytochrome c content, and apoptotic index. These hearts also displayed significantly increased LVEDP and a disappearance of LVDP. Glutamate (5 and 20 mmol/L) significantly alleviated Ca(2+) paradox-induced injury. In contrast, 20 mmol/L mannitol had no effect on Ca(2+) paradox. Ca(2+) paradox significantly increased the extent of the translocation of μ-calpain to the sarcolemmal membrane and the proteolysis of α-fodrin, which suggests calpain activation. Glutamate also blocked these effects. A non-selective inhibitor of glutamate transporters, dl-TBOA (10 μmol/L), had no effect on control hearts, but it reversed glutamate-induced cardioprotection and reduction in calpain activity. Glutamate treatment significantly increased intracellular glutamate content in the Ca(2+) paradoxical heart, which was also blocked by dl-TBOA. We conclude that glutamate protects the heart against Ca(2+) overload-induced injury via glutamate transporters, and the inhibition of calpain activity is involved in this process.

  19. Protective Effect of Antenatal Antioxidant on Nicotine-Induced Heart Ischemia-Sensitive Phenotype in Rat Offspring.

    PubMed

    Xiao, DaLiao; Wang, Lei; Huang, Xiaohui; Li, Yong; Dasgupta, Chiranjib; Zhang, Lubo

    2016-01-01

    Fetal nicotine exposure increased risk of developing cardiovascular disease later in life. The present study tested the hypothesis that perinatal nicotine-induced programming of heart ischemia-sensitive phenotype is mediated by enhanced reactive oxygen species (ROS) in offspring. Nicotine was administered to pregnant rats via subcutaneous osmotic minipumps from day 4 of gestation to day 10 after birth, in the absence or presence of a ROS inhibitor, N-acetyl-cysteine (NAC) in drinking water. Experiments were conducted in 8 month old age male offspring. Isolated hearts were perfused in a Langendorff preparation. Perinatal nicotine treatment significantly increased ischemia and reperfusion-induced left ventricular injury, and decreased post-ischemic recovery of left ventricular function and coronary flow rate. In addition, nicotine enhanced cardiac ROS production and significantly attenuated protein kinase Cε (PKCε) protein abundance in the heart. Although nicotine had no effect on total cardiac glycogen synthase kinase-3β (GSK3β) protein expression, it significantly increased the phosphorylation of GSK3β at serine 9 residue in the heart. NAC inhibited nicotine-mediated increase in ROS production, recovered PKCε gene expression and abrogated increased phosphorylation of GSK3β. Of importance, NAC blocked perinatal nicotine-induced increase in ischemia and reperfusion injury in the heart. These findings provide novel evidence that increased oxidative stress plays a causal role in perinatal nicotine-induced developmental programming of ischemic sensitive phenotype in the heart, and suggest potential therapeutic targets of anti-oxidative stress in the treatment of ischemic heart disease.

  20. Use of fluorescent antimyosin and DNA labeling for the estimation of the myoblast and myocyte population of primary rat heart cell cultures

    SciTech Connect

    Masse, M.J.O.; Harary, I.

    1981-01-01

    Cell division in heart muscle cells progressively ceases during the development of the rat heart, leading to an adult stage with muscle cells incapable of cell division. We have quantitatively determined the number of dividing and nondividing heart muscle cells in cultures derived from different stages of the developing rat heart with the use of /sup 3/HTdR continuous labeling and fluorescent antimyosin staining. The cultures were derived from 14 and 17 day postcoital (dPC) rat embryos and from 1 and 4 day postnatal (dPN) rats. The percent nondividing cells increased with development and the age of the postnatal rat. The percent nondividing cells in 14 dPC equalled 21%, 17 dPC equalled 25%, 1 dPN equalled 44%, and 4 dPN equalled 60%. This method for the quantitative determination of dividing and nondividing cells in the developing rat heart provides a model that is useful for the study of the mechanism of the loss of cell division capacity.

  1. Hypertrophic pachymeningitis accompanying neuromyelitis optica spectrum disorder: A case report.

    PubMed

    Kon, Tomoya; Nishijima, Haruo; Haga, Rie; Funamizu, Yukihisa; Ueno, Tatsuya; Arai, Akira; Suzuki, Chieko; Nunomura, Jin-ichi; Baba, Masayuki; Takahashi, Toshiyuki; Tomiyama, Masahiko

    2015-10-15

    We report a case of idiopathic cerebral hypertrophic pachymeningitis accompanying neuromyelitis optica spectrum disorder. No other identifiable cause of pachymeningitis was detected. Corticosteroid therapy was effective for both diseases. Hypertrophic pachymeningitis is closely related to autoimmune inflammatory disease of the central nervous system. This case supports the hypothesis that hypertrophic pachymeningitis can be a rare comorbidity of neuromyelitis optica spectrum disorder.

  2. Diadenosine tetra- and pentaphosphates affect contractility and bioelectrical activity in the rat heart via P2 purinergic receptors.

    PubMed

    Pustovit, Ksenia B; Kuzmin, Vladislav S; Abramochkin, Denis V

    2016-03-01

    Diadenosine polyphosphates (Ap(n)As) are endogenously produced molecules which have been identified in various tissues of mammalian organism, including myocardium. Ap(n)As contribute to the blood clotting and are also widely accepted as regulators of blood vascular tone. Physiological role of Ap(n)As in cardiac muscle has not been completely elucidated. The present study aimed to investigate the effects of diadenosine tetra- (Ap4A) and penta- (Ap5A) polyphosphates on contractile function and action potential (AP) waveform in rat supraventricular and ventricular myocardium. We have also demonstrated the effects of A4pA and Ap5A in myocardial sleeves of pulmonary veins (PVs), which play a crucial role in genesis of atrial fibrillation. APs were recorded with glass microelectrodes in multicellular myocardial preparations. Contractile activity was measured in isolated Langendorff-perfused rat hearts. Both Ap4A and Ap5A significantly reduced contractility of isolated Langendorff-perfused heart and produced significant reduction of AP duration in left and right auricle, interatrial septum, and especially in right ventricular wall myocardium. Ap(n)As also shortened APs in rat pulmonary veins and therefore may be considered as potential proarrhythmic factors. Cardiotropic effects of Ap4A and Ap5A were strongly antagonized by selective blockers of P2 purine receptors suramin and pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS), while P1 blocker DPCPX was not effective. We conclude that Ap(n)As may be considered as new class of endogenous cardioinhibitory compounds. P2 purine receptors play the central role in mediation of Ap4A and Ap5A inhibitory effects on electrical and contractile activity in different regions of the rat heart. PMID:26680209

  3. Attenuation of Ca2+ homeostasis, oxidative stress, and mitochondrial dysfunctions in diabetic rat heart: insulin therapy or aerobic exercise?

    PubMed

    da Silva, Márcia F; Natali, Antônio J; da Silva, Edson; Gomes, Gilton J; Teodoro, Bruno G; Cunha, Daise N Q; Drummond, Lucas R; Drummond, Filipe R; Moura, Anselmo G; Belfort, Felipe G; de Oliveira, Alessandro; Maldonado, Izabel R S C; Alberici, Luciane C

    2015-07-15

    We tested the effects of swimming training and insulin therapy, either alone or in combination, on the intracellular calcium ([Ca(2+)]i) homeostasis, oxidative stress, and mitochondrial functions in diabetic rat hearts. Male Wistar rats were separated into control, diabetic, or diabetic plus insulin groups. Type 1 diabetes mellitus was induced by streptozotocin (STZ). Insulin-treated groups received 1 to 4 UI of insulin daily for 8 wk. Each group was divided into sedentary or exercised rats. Trained groups were submitted to swimming (90 min/day, 5 days/wk, 8 wk). [Ca(2+)]i transient in left ventricular myocytes (LVM), oxidative stress in LV tissue, and mitochondrial functions in the heart were assessed. Diabetes reduced the amplitude and prolonged the times to peak and to half decay of the [Ca(2+)]i transient in LVM, increased NADPH oxidase-4 (Nox-4) expression, decreased superoxide dismutase (SOD), and increased carbonyl protein contents in LV tissue. In isolated mitochondria, diabetes increased Ca(2+) uptake, susceptibility to permeability transition pore (MPTP) opening, uncoupling protein-2 (UCP-2) expression, and oxygen consumption but reduced H2O2 release. Swimming training corrected the time course of the [Ca(2+)]i transient, UCP-2 expression, and mitochondrial Ca(2+) uptake. Insulin replacement further normalized [Ca(2+)]i transient amplitude, Nox-4 expression, and carbonyl content. Alongside these benefits, the combination of both therapies restored the LV tissue SOD and mitochondrial O2 consumption, H2O2 release, and MPTP opening. In conclusion, the combination of swimming training with insulin replacement was more effective in attenuating intracellular Ca(2+) disruptions, oxidative stress, and mitochondrial dysfunctions in STZ-induced diabetic rat hearts. PMID:25997948

  4. Effect of static magnetic field and/or cadmium in the antioxidant enzymes activity in rat heart and skeletal muscle.

    PubMed

    Amara, Salem; Garrel, Catherine; Favier, Alain; Ben Rhouma, Khémais; Sakly, Mohsen; Abdelmelek, Hafedh

    2009-12-01

    Currently, environmental and industrial pollution along with increase and causes multiple stress conditions, the combined exposure to magnetic field and other toxic agents is recognised as an important research area, with a view to better protecting human health against their probable unfavourable effects. In the present study, we investigated the effect of co-exposure to static magnetic field (SMF) and cadmium (Cd) on the antioxidant enzymes activity and the malondialdehyde (MDA) concentration in rat skeletal and cardiac muscles. The exposure of rats to SMF (128 mT, 1 h/day during 30 consecutive days) decreased the activities of glutathione peroxidase (GPx) and the superoxide dismutase (CuZn-SOD) in heart muscle. Sub-chronic exposure to SMF increased the MDA concentration in rat cardiac muscle. Cd treatment (CdCl2, 40 mg/l, per os) during 4 weeks decreased the activities of catalase (CAT) in skeletal muscle and the CuZn-SOD in the heart. Moreover, Cd administration increased MDA concentration in the both structures. The combined effect of SMF (128 mT, 1 h/day during 30 consecutive days) and Cd (40 mg/l, per os) disrupt the antioxidant enzymes activity in rat skeletal and cardiac muscles. Moreover, we noted a huge increase in MDA concentration in the heart and skeletal muscle compared to control group. Thus it is possible that the SMF- and/or Cd-induced depletion of antioxidant enzymes activity in muscle tissues might, like the enhanced lipid peroxidation, importantly contribute to oxidative damage. The combined effect of SMF and Cd altered significantly the antioxidant enzymatic capacity and induced lipid peroxidation in both skeletal and cardiac muscle.

  5. Erythroblast transformation-specific 2 correlates with vascular smooth muscle cell apoptosis in rat heterotopic heart transplantation model

    PubMed Central

    Liu, Xiaojuan; Yan, Daliang; Li, Yangcheng; Sha, Xilin; Wu, Kunpeng; Zhao, Jianhua; Yang, Chen; Zhang, Chao

    2016-01-01

    Background Cardiac allograft vasculopathy (CAV) decreases the long-term survival of heart transplantation recipients. Vascular smooth muscle cell (VSMC) apoptosis is an important pathological feature of CAV. Erythroblast transformation-specific 2 (Ets-2), as a transcription factor, participates in cell apoptosis and plays an important role in organ transplantation. Methods Hearts from Wistar-Furth (WF:RT1u) rats were heterotopically transplanted into Lewis (Lew:RT1l) rats without immunosuppression. Additional syngeneic heterotopic cardiac transplantations were performed in Lewis rats. HE staining was used to identify CAV. Ets-2 expression was examined by western blot. Ets-2 tissue location was examined by immunohistochemical assay and double immunostaining. Cleaved caspase 3 expression was detected by western blot. Co-localization of Ets-2 and cleaved caspase 3 was detected by double immunostaining. Ets-2, p53, cleaved caspase 3 and Bcl-xl expression in rat VSMC line A7R5 was examined after Ets-2 siRNA transfection. TUNEL assay was applied to detect A7R5 apoptosis with or without ETS-2 siRNA transfection. Immunoprecipitation was performed to explore the interaction between Ets-2 and p53. Results Ets-2 expression decreased in the allograft group but had no obvious change in the isograft group. Meanwhile, the phenomenon of CAV was observed in the allograft group and there is neointima formation in the isograft group which is not obvious compared with allograft group. Additionally, Ets-2 expression was opposite to VSMC apoptosis in the allograft group. In vitro, Ets-2 siRNA transfection in A7R5cells resulted in enhanced cell apoptosis. Finally, Ets-2 interacted with p53. Conclusions Ets-2 might inhibit VSMC apoptosis via p53 pathway. The results further elucidate the molecular mechanism of VSMC apoptosis after heart transplantation during CAV and provide theoretical basis for seeking new specific drug targets for CAV prevention and treatment.

  6. Erythroblast transformation-specific 2 correlates with vascular smooth muscle cell apoptosis in rat heterotopic heart transplantation model

    PubMed Central

    Liu, Xiaojuan; Yan, Daliang; Li, Yangcheng; Sha, Xilin; Wu, Kunpeng; Zhao, Jianhua; Yang, Chen; Zhang, Chao

    2016-01-01

    Background Cardiac allograft vasculopathy (CAV) decreases the long-term survival of heart transplantation recipients. Vascular smooth muscle cell (VSMC) apoptosis is an important pathological feature of CAV. Erythroblast transformation-specific 2 (Ets-2), as a transcription factor, participates in cell apoptosis and plays an important role in organ transplantation. Methods Hearts from Wistar-Furth (WF:RT1u) rats were heterotopically transplanted into Lewis (Lew:RT1l) rats without immunosuppression. Additional syngeneic heterotopic cardiac transplantations were performed in Lewis rats. HE staining was used to identify CAV. Ets-2 expression was examined by western blot. Ets-2 tissue location was examined by immunohistochemical assay and double immunostaining. Cleaved caspase 3 expression was detected by western blot. Co-localization of Ets-2 and cleaved caspase 3 was detected by double immunostaining. Ets-2, p53, cleaved caspase 3 and Bcl-xl expression in rat VSMC line A7R5 was examined after Ets-2 siRNA transfection. TUNEL assay was applied to detect A7R5 apoptosis with or without ETS-2 siRNA transfection. Immunoprecipitation was performed to explore the interaction between Ets-2 and p53. Results Ets-2 expression decreased in the allograft group but had no obvious change in the isograft group. Meanwhile, the phenomenon of CAV was observed in the allograft group and there is neointima formation in the isograft group which is not obvious compared with allograft group. Additionally, Ets-2 expression was opposite to VSMC apoptosis in the allograft group. In vitro, Ets-2 siRNA transfection in A7R5cells resulted in enhanced cell apoptosis. Finally, Ets-2 interacted with p53. Conclusions Ets-2 might inhibit VSMC apoptosis via p53 pathway. The results further elucidate the molecular mechanism of VSMC apoptosis after heart transplantation during CAV and provide theoretical basis for seeking new specific drug targets for CAV prevention and treatment. PMID:27621856

  7. Use of 5-Bromodeoxyuridine and irradiation for the estimation of the myoblast and myocyte content of primary rat heart cell cultures

    SciTech Connect

    Masse, M.J.O.; Harary, I.

    1980-11-01

    A method for killing dividing cells was adapted for the elimination of dividing heart muscle cells (myoblasts) in cultures. We have used this method to demonstrate their presence and to estimate their number as well as the number of nondividing heart muscle cells (myocytes) in the neo-natal rat heart. Cells were cultivated in BUdR (5-bromodeoxyuridine) 10/sup -4/ M for 3 days and then irradiated with long uv light. The selective elimination of dividing cells led to a loss of myosin Ca/sup 2 +/-activated ATPase in the cultures. The percent of ATPase left after irradiation was 32% of the control in cultures derived from 1-day postnatal rats and 48% in cultures from 4-day postnatal rats. This reflects an in vivo shift of myoblasts to myocytes in the muscle cell population as the rat ages.

  8. Hearing Profile in Patients with Dilated and Hypertrophic Cardiomyopathies

    PubMed Central

    El-Zarea, Gehan Abd El-Rahman; Hassan, Yasser Elsayed Mohamed; Mahmoud, Ahmed Mohamed Ahmed

    2016-01-01

    Introduction Cardiomyopathy may cause disruptions in the micro-vascular system of the stria vascularis in the cochlea, and, subsequently, may result in cochlear degeneration. Degeneration in the stria vascularis affects the physical and chemical processes in the organ of Corti, thereby causing a possible hearing impairment. The objective of this study was to assess the hearing profiles of patients with dilated and hypertrophic cardiomyopathies to determine the relationship between the degree of hearing loss and the degree and duration of the disease and to compare the dilated and hypertrophic cardiomyopathies as regards hearing profile. Methods In this case control study, we studied 21 patients (cases/study group/group 1) and 15 healthy individuals (controls/group 2). Six patients (group 1a) had hypertrophic cardiomyopathy (HCM), and 15 patients (group 1b) had dilated cardiomyopathy (DCM). The data were analyzed using the t-test, chi-squared test, Kruskal-Wallis test, and the Multiple Mann-Whitney test. Results The results of this study showed that 80% of those patients with DCM (group 1b) had bilateral sensorineural hearing loss (SNHL), and 100% of the patients with HCM (group 1a) had mild to severe bilateral sloping SNHL. Distortion Product Otoacoustic Emissions (DPOAEs) were present in 14% of the study group and in 100 % of the control group. The results of the measurements of auditory brainstem response (ABR) showed that 50% of the study group had abnormal latencies compared to the control group, and there was no correlation between the duration of the disease and the degree of hearing loss or DPOAE. Fifty percent of the patients with HCM and 35% of the patients with DCM had positive family histories of similar conditions, and 35% of those with HCM had a positive family history of sudden death. Conclusion The results of this study suggested that the link between heart disease and hearing loss and early identification of hearing loss in patients with

  9. Histone deacetylase inhibitor, CG200745, attenuates cardiac hypertrophy and fibrosis in DOCA-induced hypertensive rats

    PubMed Central

    Lee, Eunjo; Song, Min-ji; Lee, Hae-Ahm; Kang, Seol-Hee; Kim, Mina; Yang, Eun Kyoung; Lee, Do Young; Ro, Seonggu; Cho, Joong Myung

    2016-01-01

    CG200745 is a novel inhibitor of histone deacetylases (HDACs), initially developed for treatment of various hematological and solid cancers. Because it is water-soluble, it can be administered orally. We hypothesized that the HDAC inhibitor, CG200745, attenuates cardiac hypertrophy and fibrosis in deoxycorticosterone acetate (DOCA)-induced hypertensive rats. For establishment of hypertension, 40 mg/kg of DOCA was subcutaneously injected four times weekly into Sprague-Dawley rats. All the rats used in this study including those in the sham group had been unilaterally nephrectomized and allowed free access to drinking water containing 1% NaCl. Systolic blood pressure was measured by the tail-cuff method. Blood chemistry including sodium, potassium, glucose, triglyceride, and cholesterol levels was analyzed. Sections of the heart were visualized after trichrome and hematoxylin and eosin stain. The expression of hypertrophic genes such as atrial natriuretic peptide A (Nppa) and atrial natriuretic peptide B (Nppb) in addition to fibrotic genes such as Collagen-1, Collagen-3, connective tissue growth factor (Ctgf), and Fibronectin were measured by quantitative real-time PCR (qRT-PCR). Injection of DOCA increased systolic blood pressure, heart weight, and cardiac fibrosis, which was attenuated by CG200745. Neither DOCA nor CG200745 affected body weight, vascular contraction and relaxation responses, and blood chemistry. Injection of DOCA increased expression of both hypertrophic and fibrotic genes, which was abrogated by CG200745. These results indicate that CG200745 attenuates cardiac hypertrophy and fibrosis in DOCA-induced hypertensive rats.

  10. Histone deacetylase inhibitor, CG200745, attenuates cardiac hypertrophy and fibrosis in DOCA-induced hypertensive rats

    PubMed Central

    Lee, Eunjo; Song, Min-ji; Lee, Hae-Ahm; Kang, Seol-Hee; Kim, Mina; Yang, Eun Kyoung; Lee, Do Young; Ro, Seonggu; Cho, Joong Myung

    2016-01-01

    CG200745 is a novel inhibitor of histone deacetylases (HDACs), initially developed for treatment of various hematological and solid cancers. Because it is water-soluble, it can be administered orally. We hypothesized that the HDAC inhibitor, CG200745, attenuates cardiac hypertrophy and fibrosis in deoxycorticosterone acetate (DOCA)-induced hypertensive rats. For establishment of hypertension, 40 mg/kg of DOCA was subcutaneously injected four times weekly into Sprague-Dawley rats. All the rats used in this study including those in the sham group had been unilaterally nephrectomized and allowed free access to drinking water containing 1% NaCl. Systolic blood pressure was measured by the tail-cuff method. Blood chemistry including sodium, potassium, glucose, triglyceride, and cholesterol levels was analyzed. Sections of the heart were visualized after trichrome and hematoxylin and eosin stain. The expression of hypertrophic genes such as atrial natriuretic peptide A (Nppa) and atrial natriuretic peptide B (Nppb) in addition to fibrotic genes such as Collagen-1, Collagen-3, connective tissue growth factor (Ctgf), and Fibronectin were measured by quantitative real-time PCR (qRT-PCR). Injection of DOCA increased systolic blood pressure, heart weight, and cardiac fibrosis, which was attenuated by CG200745. Neither DOCA nor CG200745 affected body weight, vascular contraction and relaxation responses, and blood chemistry. Injection of DOCA increased expression of both hypertrophic and fibrotic genes, which was abrogated by CG200745. These results indicate that CG200745 attenuates cardiac hypertrophy and fibrosis in DOCA-induced hypertensive rats. PMID:27610034

  11. Histone deacetylase inhibitor, CG200745, attenuates cardiac hypertrophy and fibrosis in DOCA-induced hypertensive rats.

    PubMed

    Lee, Eunjo; Song, Min-Ji; Lee, Hae-Ahm; Kang, Seol-Hee; Kim, Mina; Yang, Eun Kyoung; Lee, Do Young; Ro, Seonggu; Cho, Joong Myung; Kim, Inkyeom

    2016-09-01

    CG200745 is a novel inhibitor of histone deacetylases (HDACs), initially developed for treatment of various hematological and solid cancers. Because it is water-soluble, it can be administered orally. We hypothesized that the HDAC inhibitor, CG200745, attenuates cardiac hypertrophy and fibrosis in deoxycorticosterone acetate (DOCA)-induced hypertensive rats. For establishment of hypertension, 40 mg/kg of DOCA was subcutaneously injected four times weekly into Sprague-Dawley rats. All the rats used in this study including those in the sham group had been unilaterally nephrectomized and allowed free access to drinking water containing 1% NaCl. Systolic blood pressure was measured by the tail-cuff method. Blood chemistry including sodium, potassium, glucose, triglyceride, and cholesterol levels was analyzed. Sections of the heart were visualized after trichrome and hematoxylin and eosin stain. The expression of hypertrophic genes such as atrial natriuretic peptide A (Nppa) and atrial natriuretic peptide B (Nppb) in addition to fibrotic genes such as Collagen-1, Collagen-3, connective tissue growth factor (Ctgf), and Fibronectin were measured by quantitative real-time PCR (qRT-PCR). Injection of DOCA increased systolic blood pressure, heart weight, and cardiac fibrosis, which was attenuated by CG200745. Neither DOCA nor CG200745 affected body weight, vascular contraction and relaxation responses, and blood chemistry. Injection of DOCA increased expression of both hypertrophic and fibrotic genes, which was abrogated by CG200745. These results indicate that CG200745 attenuates cardiac hypertrophy and fibrosis in DOCA-induced hypertensive rats. PMID:27610034

  12. Phosphorus-31 NMR magnetization transfer measurements of metabolic reaction rates in the rat heart and kidney in vivo

    SciTech Connect

    Koretsky, A.P.

    1984-08-01

    This dissertation is concerned with the measurement of the rates of ATP synthesis in the rat kidney and of the creatine kinase catalyzed reaction in the rat heart in situ. Chronically implanted detection coils, employing a balanced matching configuration of capacitors in the tuned circuit, were used to obtain /sup 31/P NMR spectra from heart, kidney, and liver in situ. Gated spectra of heart obtained at systole and diastole and the effects of fructose on kidney and liver were studied. The ability to observe other nuclei using implanted coils is illustrated with /sup 39/K NMR spectra from kidney and muscle. The theoretical considerations of applying magnetization transfer techniques to intact organs are discussed with emphasis on the problems associated with multiple exchange reactions and compartmentation of reactants. Experimental measurements of the ATP synthesis rate (13 ..mu..mol/min/gm tissue) were compared to whole kidney oxygen consumption and Na/sup +/ reabsorption rates to derive ATP/O (0.8 to 1.7) and Na/sup +//ATP (4 to 10) values. The problems associated with ATP synthesis rate measurements in kidney, e.g., the heterogeneity of the inorganic phosphate resonance, are discussed and experiments to overcome these problems proposed.

  13. Role of sulfurous mineral water and sodium hydrosulfide as potent inhibitors of fibrosis in the heart of diabetic rats.

    PubMed

    El-Seweidy, Mohamed M; Sadik, Nermin A H; Shaker, Olfat G

    2011-02-01

    This study examined the downstream signaling whereby hyperglycemia may lead to myocardial fibrosis and apoptosis in the left ventricle of diabetic rats. The effects of sulfurous mineral water or sodium hydrosulfide (NaHS) as possible modulators were also examined. Sulfurous mineral water (as drinking water) and NaHS (14μmol/kg/day, IP) were administered for 7 week to rats with streptozotocin (STZ)-induced diabetes. Hyperglycemia, overproduction of glycated hemoglobin (HbA1C) and serum decline in insulin, C-peptide and insulin like growth factor-I (IGF-I) were observed in diabetic rats. Up-regulation of gene expressions of nuclear factor (NF-κB), profibrogenic growth factor such as transforming growth factor-β1 (TGF-β1), matrix metalloproteniase-2 (MMP-2), procollagen-1 and Fas ligand (Fas-L) were observed in the left ventricle of diabetic rats. A linear positive correlation between TGF-β1 and MMP-2 was also detected in diabetic group. An increase in hydroxyproline level and a disturbance in oxidative balance were detected in heart of diabetic rats. Sulfurous mineral water and NaHS treatment possibly, by improving cardiac GSH level, counteracted the enhanced expression of NF-κB, the profibrogenic and apoptotic parameters. Histopathological examination was in accordance with the biochemical and molecular findings of this study. We suggest a novel therapeutic approach of sulfurous mineral water and exogenous supplementation of H(2)S in diabetic cardiomyopathy.

  14. Diastolic filling in a physical model of obstructive hypertrophic cardiomyopathy

    NASA Astrophysics Data System (ADS)

    Schovanec, Joseph; Samaee, Milad; Lai, Hong Kuan; Santhanakrishnan, Arvind

    2015-11-01

    Hypertrophic Cardiomyopathy (HCM) is an inherited heart disease that affects as much as one in 500 individuals, and is the most common cause of sudden death in young athletes. The myocardium becomes abnormally thick in HCM and deforms the internal geometry of the left ventricle (LV). Previous studies have shown that a vortex is formed during diastolic filling, and further that the dilated LV morphology seen in systolic heart failure results in altering the filling vortex from elliptical to spherical shape. We have also previously shown that increasing LV wall stiffness decreases the filling vortex circulation. However, alterations to intraventricular filling fluid dynamics due to an obstructive LV morphology and locally elevated wall stiffness (in the hypertrophied region) have not been previously examined from a mechanistic standpoint. We conducted an experimental study using an idealized HCM physical model and compared the intraventricular flow fields obtained from 2D PIV to a baseline LV physical model with lower wall stiffness and anatomical geometry. The obstruction in the HCM model leads to earlier breakdown of the filling vortex as compared to the anatomical LV. Intraventricular filling in both models under increased heart rates will be discussed.

  15. Nuclear β-adrenergic receptors modulate gene expression in adult rat heart

    PubMed Central

    Vaniotis, George; Del Duca, Danny; Trieu, Phan; Rohlicek, Charles V.; Hébert, Terence E.; Allen, Bruce G.

    2016-01-01

    Both β1- and β3-adrenergic receptors (β1ARs and β3ARs) are present on nuclear membranes in adult ventricular myocytes. These nuclear-localized receptors are functional with respect to ligand binding and effector activation. In isolated cardiac nuclei, the non-selective βAR agonist isoproterenol stimulated de novo RNA synthesis measured using assays of transcription initiation (Boivin et al., 2006 Cardiovasc Res. 71:69–78). In contrast, stimulation of endothelin receptors, another G protein-coupled receptor (GPCR) that localizes to the nuclear membrane, resulted in decreased RNA synthesis. To investigate the signalling pathway(s) involved in GPCR-mediated regulation of RNA synthesis, nuclei were isolated from intact adult rat hearts and treated with receptor agonists in the presence or absence of inhibitors of different mitogen-activated protein kinase (MAPK) and PI3K/PKB pathways. Components of p38, JNK, and ERK1/2 MAP kinase cascades as well as PKB were detected in nuclear preparations. Inhibition of PKB with triciribine, in the presence of isoproterenol, converted the activation of the βAR from stimulatory to inhibitory with regards to RNA synthesis, while ERK1/2, JNK and p38 inhibition reduced both basal and isoproterenol-stimulated activity. Analysis by qPCR indicated an increase in the expression of 18 S rRNA following isoproterenol treatment and a decrease in NFκB mRNA. Further qPCR experiments revealed that isoproterenol treatment also reduced the expression of several other genes involved in the activation of NFκB, while ERK1/2 and PKB inhibition substantially reversed this effect. Our results suggest that GPCRs on the nuclear membrane regulate nuclear functions such as gene expression and this process is modulated by activation/inhibition of downstream protein kinases within the nucleus. PMID:20732414

  16. Paeonol Protects Rat Heart by Improving Regional Blood Perfusion during No-Reflow

    PubMed Central

    Ma, Lina; Chuang, Chia-Chen; Weng, Weiliang; Zhao, Le; Zheng, Yongqiu; Zhang, Jinyan; Zuo, Li

    2016-01-01

    No-reflow phenomenon, defined as inadequate perfusion of myocardium without evident artery obstruction, occurs at a high incidence after coronary revascularization. The mechanisms underlying no-reflow is only partially understood. It is commonly caused by the swelling of endothelial cells, neutrophil accumulation, and vasoconstriction, which are all related to acute inflammation. Persistent no-reflow can lead to hospitalization and mortality. However, an effective preventive intervention has not yet been established. We have previously found that paeonol, an active extraction from the root of Paeonia suffruticosa, can benefit the heart function by inhibiting tissue damage after ischemia, reducing inflammation, and inducing vasodilatation. To further investigate the potential cardioprotective action of paeonol on no-reflow, healthy male Wistar rats were randomly divided into four groups: sham, ischemia-reperfusion (I/R) injury (left anterior descending coronary artery was ligated for 4 h followed by reperfusion for 8 h), and I/R injury pretreated with paeonol at two different doses. Real-time myocardial contrast echocardiography was used to monitor regional blood perfusion and cardiac functions. Our data indicated that paeonol treatment significantly reduces myocardial infarct area and no-reflow area (n = 8; p < 0.05). Regional myocardial perfusion (A·β) and cardiac functions such as ejection fraction, stroke volume, and fractional shortening were elevated by paeonol (n = 8; p < 0.05). Paeonol also lowered the serum levels of lactate dehydrogenase, creatine kinase, cardiac troponin T, and C-reactive protein, as indices of myocardial injury. Paeonol exerts beneficial effects on attenuating I/R-associated no-reflow injuries, and may be considered as a potential preventive treatment for cardiac diseases or post-coronary revascularization in which no-reflow often occurs. PMID:27493631

  17. Measurement of matrix free Mg2+ concentration in rat heart mitochondria by using entrapped fluorescent probes.

    PubMed Central

    Rutter, G A; Osbaldeston, N J; McCormack, J G; Denton, R M

    1990-01-01

    1. The concentration of free Mg2+ ([Mg2+]m) within the matrix of isolated rat heart mitochondria was measured after loading of the mitochondria with the fluorescent Mg2+ indicators mag-indo-1 and mag-fura-2. No detectable change in total mitochondrial magnesium content occurred during loading with the indicators. Apparent Kd values for Mg2+ of 3.7 mM and 2.3 mM were obtained for mag-indo-1 and mag-fura-2 respectively within mitochondria permeabilized to bivalent cations with ionomycin and the uncoupler carbonyl cyanide p-trifluoromethoxyphenylhydrazone. These values are 2.7- and 1.8-fold greater respectively than those obtained for the free acid forms of the dyes in incubation medium. 2. Based on the above Kd values, mitochondrial matrix Mg2+ concentrations were found to lie in the range 0.8-1.5 mM in the absence, or immediately after the addition, of a respiratory substrate. 3. Incubation of mitochondria in the presence of respiratory substrate, but in the absence of external Mg2+, led to a time-dependent decline in [Mg2+]m to about half the initial values after 5 min. This was accompanied by a fall in the total mitochondrial magnesium content from 12.7 to 7.0 nmol/mg of protein. 4. ADP (0.5 mM), ATP (0.5 mM) or 10 mM-NaCl had no significant effect on the fall in [Mg2+], whereas 1 microM-nigericin blocked, and 0.3 microM-valinomycin accelerated, the fall. 5. External Mg2+ concentrations above 1 mM progressively inhibited and reversed the decline in free and total mitochondrial Mg2+. PMID:2244870

  18. Hesperidin Produces Cardioprotective Activity via PPAR-γ Pathway in Ischemic Heart Disease Model in Diabetic Rats

    PubMed Central

    Agrawal, Yogeeta O.; Sharma, Pankaj Kumar; Shrivastava, Birendra; Ojha, Shreesh; Upadhya, Harshita M.; Arya, Dharamvir Singh; Goyal, Sameer N.

    2014-01-01

    The present study investigated the effect of hesperidin, a natural flavonoid, in cardiac ischemia and reperfusion (I/R) injury in diabetic rats. Male Wistar rats with diabetes were divided into five groups and were orally administered saline once daily (IR-sham and IR-control), Hesperidin (100 mg/kg/day; IR-Hesperidin), GW9962 (PPAR-γ receptor antagonist), or combination of both for 14 days. On the 15th day, in the IR-control and IR-treatment groups, rats were subjected to left anterior descending (LAD) coronary artery occlusion for 45 minutes followed by a one-hour reperfusion. Haemodynamic parameters were recorded and rats were sacrificed; hearts were isolated for biochemical, histopathological, ultrastructural and immunohistochemistry. In the IR-control group, significant ventricular dysfunctions were observed along with enhanced expression of pro-apoptotic protein Bax. A decline in cardiac injury markers lactate dehydrogenase activity, CK-MB and increased content of thiobarbituric acid reactive substances, a marker of lipid peroxidation, and TNF-α were observed. Hesperidin pretreatment significantly improved mean arterial pressure, reduced left ventricular end-diastolic pressure, and improved both inotropic and lusitropic function of the heart (+LVdP/dt and –LVdP/dt) as compared to IR-control. Furthermore, hesperidin treatment significantly decreased the level of thiobarbituric acid reactive substances and reversed the activity of lactate dehydrogenase towards normal value. Hesperidin showed anti-apoptotic effects by upregulating Bcl-2 protein and decreasing Bax protein expression. Additionally, histopathological and ultrastructural studies reconfirmed the protective action of hesperidin. On the other hand, GW9662, selective PPAR-γ receptor antagonist, produced opposite effects and attenuated the hesperidin induced improvements. The study for the first time evidence the involvement of PPAR-γ pathway in the cardioprotective activity of hesperidin in I

  19. Alpha lipoic acid protects the heart against myocardial post ischemia-reperfusion arrhythmias via KATP channel activation in isolated rat hearts.

    PubMed

    Dudek, Magdalena; Knutelska, Joanna; Bednarski, Marek; Nowiński, Leszek; Zygmunt, Małgorzata; Bilska-Wilkosz, Anna; Iciek, Małgorzata; Otto, Monika; Żytka, Iwona; Sapa, Jacek; Włodek, Lidia; Filipek, Barbara

    2014-06-01

    The cardiovascular effects of alpha lipoic acid were evaluated in isolated rat hearts exposed to ischemia-reperfusion injury in vitro. Alpha-lipoic acid raised the level of sulfane sulfur playing an important role in the release of hydrogen sulfide. H2S was shown to prevent the post-reperfusion arrhythmias and to protect the cardiomyocytes from death caused by hypoxia. The activation of potassium ATP-sensitive channels (K(ATP) channels) is one of the most important mechanisms of action of hydrogen sulfide in the cardiovascular system. The aim of this study was to investigate whether alpha lipoic acid can prevent the occurrence of post-reperfusion arrhythmias in vitro using a Langendorff model of ischemia-reperfusion in rats affecting the K(ATP) channels. Alpha lipoic acid significantly improved post-reperfusion cardiac function (reducing incidence of arrhythmias), especially in a dose of 10(-7)M. These cardiovascular effects of this compound on the measured parameters were reversed by glibenclamide, a selective K(ATP) blocker. Alpha lipoic acid increased the level of sulfane sulfur in the hearts. This may suggest that the positive effects caused by alpha lipoic acid in the cardiovascular system are not only related to its strong antioxidant activity, and the influence on the activity of such enzymes as aldehyde dehydrogenase 2, as previously suggested, but this compound can affect K(ATP) channels. It is possible that this indirect effect of alpha lipoic acid is connected with changes in the release of sulfane sulfur and hydrogen sulfide.

  20. Changes in the Enzymic Capacity of the Rat Kidney and Heart Due to Unilateral Nephrectomy and Deoxycorticosterone Induced Hypertension

    PubMed Central

    Mangnall, D.; Bartley, W.

    1970-01-01

    Changes in the chemical and enzymic composition of the kidney and heart of rats after unilateral nephrectomy and deoxycorticosterone implantation were studied during the 3 week period following operation. The remaining kidney doubled in weight and the heart mass increased by 25 per cent during this time. The initial response in the kidney was an increase in protein and RNA, but after 6 days DNA also increased and approximately doubled by 21 days after operation. No increase in blood urea was observed from 3 days after operation to the end of the experimental period. In the hypertrophying kidney the enzymes NADH cytochrome “c” oxidoreductase, succinate cytochrome “c” oxidoreductase, pyruvate carboxylase, glucose-6-phosphate dehydrogenase, PEP carboxykinase and glutaminase all increased in specific activity with greatest increase usually having occurred by the sixth day after the nephrectomy. Cytochrome oxidase alone showed a decrease in specific activity. At the end of the experiment (21 days after the nephrectomy) the enzyme activities (with the exception of cytochrome oxidase) were between 130-280 per cent of the activities present in the 2 control kidneys. In contrast there was only about 80 per cent of the cytochrome oxidase activity as compared with the 2 control kidneys. The growth of the kidney is discussed with respect to attainment of compensation for removal of its partner. The initial response of the heart was an immediate increase in RNA, DNA and protein and mitochondrial enzymes, although increases in heart weight were not observed until after day 3. Glucose-6-phosphate dehydrogenase activity closely followed the growth of the heart. The changes are discussed in relation to growth of the heart. PMID:4321628

  1. Exogenous superoxide dismutase and catalase promote recovery of function in isolated rat heart after regional ischemia and may be transported from capillaries into myocytes.

    PubMed

    Koke, J R; Christodoulides, N J; Chudej, L L; Bittar, N

    1990-08-10

    The effects of infusing superoxide dismutase (SOD) and catalase (CAT) into the coronary circulation were investigated in isolated, working rat hearts prior to and during a 15 minute episode of regional ischemia followed by 30 minutes reperfusion. Aortic output, left ventricular pressure and dP/dT were recorded. Compared to untreated hearts, SOD and CAT significantly improved function during reperfusion, but had no effect during the pre-ischemic or the ischemic period. To investigate possible transport of SOD and CAT into rat myocytes, cryotome sections of isolated, Langendorff perfused rat hearts were exposed to rabbit antibody prepared against the exogenous SOD and CAT. Bound antibody was detected by the indirect-fluorescent antibody test. The interior of myocytes from rat hearts exposed to SOD and CAT bound antibodies prepared against these enzymes, whereas myocytes from rat hearts not exposed to exogenous SOD and CAT only bound the CAT antibodies. This indicates the anti-SOD we prepared is specific for exogenous SOD, and also suggests exogenous SOD can gain access to the cytoplasm of myocytes from the coronary circulation. PMID:2274050

  2. Effects of combined chelation treatment with pyridoxal isonicotinoyl hydrazone analogs and deferoxamine in hypertransfused rats and in iron-loaded rat heart cells.

    PubMed

    Link, Gabriela; Ponka, Prem; Konijn, Abraham M; Breuer, William; Cabantchik, Z Ioav; Hershko, Chaim

    2003-05-15

    Although iron chelation therapy with deferoxamine (DFO) results in improved life expectancy of patients with thalassemia, compliance with parenteral DFO treatment is unsatisfactory, underlining the need for alternative drugs and innovative ways of drug administration. We examined the chelating potential of pyridoxal isonicotinoyl hydrazone (PIH) analogs, alone or in combination with DFO, using hypertransfused rats with labeled hepatocellular iron stores and cultured iron-loaded rat heart cells. Our in vivo studies using 2 representative PIH analogs, 108-o and 109-o, have shown that PIH analogs given orally are 2.6 to 2.8 times more effective in mobilizing hepatocellular iron in rats, on a weight-per-weight basis, than parenteral DFO administered intraperitoneally. The combined effect of DFO and 108-o on hepatocellular iron excretion was additive, and response at a dose range of 25 to 200 mg/kg was linear. In vitro studies in heart cells showed that DFO was more effective in heart cell iron mobilization than all PIH analogs studied. Response to joint chelation with DFO and PIH analogs was similar to an increase in the equivalent molar dose of DFO alone, rather than the sum of the separate effects of the PIH analog and DFO. This finding was most likely the result of iron transfer from PIH analogs to DFO, a conclusion supported directly by iron-shuttle experiments using fluorescent DFO. These findings provide a rationale for the combined, simultaneous use of iron-chelating drugs and may have useful, practical implications for designing novel strategies of iron chelation therapy.

  3. Infective endocarditis in hypertrophic cardiomyopathy

    PubMed Central

    Dominguez, Fernando; Ramos, Antonio; Bouza, Emilio; Muñoz, Patricia; Valerio, Maricela C.; Fariñas, M. Carmen; de Berrazueta, José Ramón; Zarauza, Jesús; Pericás Pulido, Juan Manuel; Paré, Juan Carlos; de Alarcón, Arístides; Sousa, Dolores; Rodriguez Bailón, Isabel; Montejo-Baranda, Miguel; Noureddine, Mariam; García Vázquez, Elisa; Garcia-Pavia, Pablo

    2016-01-01

    Abstract Infective endocarditis (IE) complicating hypertrophic cardiomyopathy (HCM) is a poorly known entity. Although current guidelines do not recommend IE antibiotic prophylaxis (IEAP) in HCM, controversy remains. This study sought to describe the clinical course of a large series of IE HCM and to compare IE in HCM patients with IE patients with and without an indication for IEAP. Data from the GAMES IE registry involving 27 Spanish hospitals were analyzed. From January 2008 to December 2013, 2000 consecutive IE patients were prospectively included in the registry. Eleven IE HCM additional cases from before 2008 were also studied. Clinical, microbiological, and echocardiographic characteristics were analyzed in IE HCM patients (n = 34) and in IE HCM reported in literature (n = 84). Patients with nondevice IE (n = 1807) were classified into 3 groups: group 1, HCM with native-valve IE (n = 26); group 2, patients with IEAP indication (n = 696); group 3, patients with no IEAP indication (n = 1085). IE episode and 1-year follow-up data were gathered. One-year mortality in IE HCM was 42% in our study and 22% in the literature. IE was more frequent, although not exclusive, in obstructive HCM (59% and 74%, respectively). Group 1 exhibited more IE predisposing factors than groups 2 and 3 (62% vs 40% vs 50%, P < 0.01), and more previous dental procedures (23% vs 6% vs 8%, P < 0.01). Furthermore, Group 1 experienced a higher incidence of Streptococcus infections than Group 2 (39% vs 22%, P < 0.01) and similar to Group 3 (39% vs 30%, P = 0.34). Overall mortality was similar among groups (42% vs 36% vs 35%, P = 0.64). IE occurs in HCM patients with and without obstruction. Mortality of IE HCM is high but similar to patients with and without IEAP indication. Predisposing factors, previous dental procedures, and streptococcal infection are higher in IE HCM, suggesting that HCM patients could benefit from IEAP. PMID:27368014

  4. Aortic biomechanics in hypertrophic cardiomyopathy

    PubMed Central

    Badran, Hala Mahfouz; Soltan, Ghada; Faheem, Nagla; Elnoamany, Mohamed Fahmy; Tawfik, Mohamed; Yacoub, Magdi

    2015-01-01

    Background: Ventricular-vascular coupling is an important phenomenon in many cardiovascular diseases. The association between aortic mechanical dysfunction and left ventricular (LV) dysfunction is well characterized in many disease entities, but no data are available on how these changes are related in hypertrophic cardiomyopathy (HCM). Aim of the work: This study examined whether HCM alone is associated with an impaired aortic mechanical function in patients without cardiovascular risk factors and the relation of these changes, if any, to LV deformation and cardiac phenotype. Methods: 141 patients with HCM were recruited and compared to 66 age- and sex-matched healthy subjects as control group. Pulse pressure, aortic strain, stiffness and distensibility were calculated from the aortic diameters measured by M-mode echocardiography and blood pressure obtained by sphygmomanometer. Aortic wall systolic and diastolic velocities were measured using pulsed wave Doppler tissue imaging (DTI). Cardiac assessment included geometric parameters and myocardial deformation (strain and strain rate) and mechanical dyssynchrony. Results: The pulsatile change in the aortic diameter, distensibility and aortic wall systolic velocity (AWS') were significantly decreased and aortic stiffness index was increased in HCM compared to control (P < .001) In HCM AWS' was inversely correlated to age(r = − .32, P < .0001), MWT (r = − .22, P < .008), LVMI (r = − .20, P < .02), E/Ea (r = − .16, P < .03) LVOT gradient (r = − 19, P < .02) and severity of mitral regurg (r = − .18, P < .03) but not to the concealed LV deformation abnormalities or mechanical dyssynchrony. On multivariate analysis, the key determinant of aortic stiffness was LV mass index and LVOT obstruction while the role LV dysfunction in aortic stiffness is not evident in this population. Conclusion: HCM is associated with abnormal aortic mechanical properties. The severity of cardiac

  5. 3D in vivo imaging of rat hearts by high frequency ultrasound and its application in myofiber orientation wrapping

    PubMed Central

    Qin, Xulei; Wang, Silun; Shen, Ming; Zhang, Xiaodong; Lerakis, Stamatios; Wagner, Mary B.; Fei, Baowei

    2015-01-01

    Cardiac ultrasound plays an important role in the imaging of hearts in basic cardiovascular research and clinical examinations. 3D ultrasound imaging can provide the geometry or motion information of the heart. Especially, the wrapping of cardiac fiber orientations to the ultrasound volume could supply useful information on the stress distributions and electric action spreading. However, how to acquire 3D ultrasound volumes of the heart of small animals in vivo for cardiac fiber wrapping is still a challenging problem. In this study, we provide an approach to acquire 3D ultrasound volumes of the rat hearts in vivo. The comparison between both in vivo and ex vivo geometries indicated 90.1% Dice similarity. In this preliminary study, the evaluations of the cardiac fiber orientation wrapping errors were 24.7° for the acute angle error and were 22.4° for the inclination angle error. This 3D ultrasound imaging and fiber orientation estimation technique have potential applications in cardiac imaging. PMID:26412926

  6. Transmission electron microscopy of malignant neurogenic rat cells during invasion into embryonic chick heart fragments in vitro.

    PubMed

    Mørk, S J; Laerum, O D; De Ridder, L

    1983-01-01

    Invasion of chemically induced brain tumour cells from BD IX-rats into precultured fragments of embryonic chick heart (PHF) was studied by transmission electron microscopy. The malignant cells from monolayer cultures were suspended and allowed to form aggregates for 24 hours on a gyratory shaker. The single aggregates were allowed ro attach to a single PHF and thereafter incubated in a confronting culture on a gyratory shaker. Invasion into the PHF started with cytoplasmic cell extensions between PHF cells and vanishing of heart cell junctions. Irreversible intracellular alterations in heart cells followed the disruption of intracellular contact by the malignant neurogenic cells. The latter exhibited fewer microvilli when invading the PHF than when located at the periphery. No junctions connecting heart cells with neurogenic cells were observed. Malignant cells were lying between the PHF and no extensions were seen in PHF cells. Hetero/autophagosomes were regularly present in the malignant cells and also in PHF cells. The aggregates of the 13 tumourigenic neurogenic cell lines tested, all produced the same alterations in the PHF cells.

  7. The effect of maternal ethanol ingestion on fetal rat heart vitamin A: a model for fetal alcohol syndrome.

    PubMed

    DeJonge, M H; Zachman, R D

    1995-04-01

    Ethanol consumption during pregnancy can cause fetal alcohol syndrome (FAS). Although the exact mechanism is unknown, nutritional alterations caused by ethanol exposure may be an etiologic factor in FAS. The congenital heart defects seen in FAS are similar to those found in vitamin A teratogenesis. Because ethanol ingestion alters vitamin A metabolism, we hypothesized that the cardiac manifestations seen in FAS result from an alteration in vitamin A metabolism or function in the developing fetus. Twenty-day gestation fetal rat hearts from ethanol-exposed and control pregnancies were analyzed for 1) levels of endogenous retinol, retinyl palmitate, and retinoic acid by quantitative HPLC; 2) binding activity levels of both retinol by cellular retinol binding protein and retinoic acid by cellular retinoic acid binding protein using specific competitive binding assays; and 3) relative abundance of cellular retinol binding protein and retinoic acid receptor alpha, beta, and gamma subtype message as expressed in mRNA. Levels of retinol and retinyl palmitate were significantly higher (p < 0.01) and the level of retinoic acid was significantly lower (p < 0.02) in the ethanol-exposed fetal hearts. Binding activity levels of cellular retinol binding protein and cellular retinoic acid binding protein were not different in the two groups. The message for retinoic acid receptor alpha (3.7 kb) was increased (p < 0.01) and the message for retinoic acid receptor beta was decreased (p < 0.05) in the ethanol-exposed hearts.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7596680

  8. 3D in vivo imaging of rat hearts by high frequency ultrasound and its application in myofiber orientation wrapping

    NASA Astrophysics Data System (ADS)

    Qin, Xulei; Wang, Silun; Shen, Ming; Zhang, Xiaodong; Lerakis, Stamatios; Wagner, Mary B.; Fei, Baowei

    2015-03-01

    Cardiac ultrasound plays an important role in the imaging of hearts in basic cardiovascular research and clinical examinations. 3D ultrasound imaging can provide the geometry or motion information of the heart. Especially, the wrapping of cardiac fiber orientations to the ultrasound volume could supply useful information on the stress distributions and electric action spreading. However, how to acquire 3D ultrasound volumes of the heart of small animals in vivo for cardiac fiber wrapping is still a challenging problem. In this study, we provide an approach to acquire 3D ultrasound volumes of the rat hearts in vivo. The comparison between both in vivo and ex vivo geometries indicated 90.1% Dice similarity. In this preliminary study, the evaluations of the cardiac fiber orientation wrapping errors were 24.7° for the acute angle error and were 22.4° for the inclination angle error. This 3D ultrasound imaging and fiber orientation estimation technique have potential applications in cardiac imaging.

  9. [Dynamics of the cAMP and cGMP content of the heart in transient coronary insufficiency in rats].

    PubMed

    Litvitskiĭ, P F; Vinnitskiĭ, L I; Zhidkov, I L; Zuev, M B; Vorob'eva, N T

    1984-01-01

    Experiments made on 127 white random-bred male rats weighing 200 +/- 10 g with transitory coronary insufficiency (TCI) with varying duration of myocardial ischemia (MI) have revealed consistent changes in the heart cAMP and cGMP. During MI, there was a biphasic variation in the concentration of cyclic nucleotides: an initial appreciable increase in the concentration was replaced by its lowering. At the same time the time course of cGMP content was more mobile in nature as compared to cAMP Reperfusion made at an early period (within the first 40 min) did not normally bring about the normalization of heart content of cyclic nucleotides whose concentration time course depended on the duration of the preceding MI. The pattern of changes in the concentration of cyclic nucleotides in the heart in TCI correlated to a significant degree with the previously described time course of the activity of the sympath- and cholinergic mechanisms by which heart work, contractile function and rhythm are controlled during TCI.

  10. Calcium influx inhibition: possible mechanism of the negative effect of tetrahydropalmatine on left ventricular pressure in isolated rat heart.

    PubMed

    Chan, P; Chiu, W T; Chen, Y J; Wu, P J; Cheng, J T

    1999-05-01

    The active ingredient dl-tetrahydropalmatine (THP) isolated from the traditional Chinese herb Corydalis racemosa has been found to have antihypertensive effects. However, severe cardiac and neurological toxic effects were reported from using this herb for the treatment of pain. In an isolated perfused rat heart model, THP at the concentration of 100 microM was found to have a negative effect (-45%) on left ventricular pressure and this effect was produced concentration-dependently from concentrations lower than 50 microM. In isolated cardiomyocytes, radioactive calcium influx was also inhibited significantly by THP at the concentration of 100 microM and this effect was also in a concentration-dependent manner (-39%). In a patient with latent heart disease, the use of Corydalis should probably be detrimental, the toxic effect was probably due to calcium influx inhibition.

  11. Effects of freeze-dried red wine on cardiac function and ECG of the Langendorff-perfused rat heart.

    PubMed

    Ferrara, Antonella; Fusi, Fabio; Gorelli, Beatrice; Sgaragli, Giampietro; Saponara, Simona

    2014-02-01

    The effect of freeze-dried red wine (FDRW) on cardiac function and electrocardiogram (ECG) in Langendorff-isolated rat hearts was investigated. FDRW significantly decreased left ventricular pressure and coronary perfusion pressure, the latter being dependent on the activation of both phosphatidylinositol 3-kinase and eNOS. FDRW did not affect the QRS and QT interval in the ECG, although at 56 μg of gallic acid equivalents/mL, it prolonged PQ interval and induced a second-degree atrioventricular block in 3 out of 6 hearts. This is the first study demonstrating that at concentrations resembling a moderate consumption of red wine, FDRW exhibited negative inotropic and coronary vasodilating activity leaving unaltered ECG, whereas at very high concentrations, it induced arrhythmogenic effects.

  12. Lovastatin prevents angiotensin II-induced cardiac hypertrophy in cultured neonatal rat heart cells.

    PubMed

    Oi, S; Haneda, T; Osaki, J; Kashiwagi, Y; Nakamura, Y; Kawabe, J; Kikuchi, K

    1999-07-01

    Angiotensin II activates p21ras, and mediates cardiac hypertrophic growth through the type 1 angiotensin II receptor in cardiac myocytes. An inhibitor of 3-hydroxy-3-methyglutaryl-coenzyme A (HMG-CoA) reductase has been shown to block the post-translational farnesylation of p21ras and inhibit protein synthesis in several cell types. Primary cultures of neonatal cardiac myocytes were used to determine whether HMG-CoA reductase inhibitors, lovastatin, simvastatin and pravastatin inhibit the angiotensin II-induced hypertrophic growth. Angiotensin II (10(-6) M) significantly increased protein-DNA ratio, RNA-DNA ratio, ratios of protein synthesis and mitogen-activated protein (MAP) kinase activity. Lipid-soluble HMG-CoA reductase inhibitors, lovastatin (10(-6) M) and simvastatin (10(-6) M) partially and significantly inhibited the angiotensin II-induced increases in these parameters, but a water-soluble HMG-CoA reductase inhibitor, pravastatin (10(-6) M) did not. Mevalonate (10(-4) M) overcame the inhibitory effects of lovastatin and simvastatin on angiotensin II-induced increases in these parameters. A selective protein kinase C inhibitor, calphostin C (10(-6) M) partially and significantly prevented angiotensin II-induced increases in these parameters, and treatment with both lovastatin and calphostin C inhibited completely. Angiotensin II increased p21ras activity and membrane association, and lovastatin inhibited them. These studies demonstrate that a lipid-soluble HMG-CoA reductase inhibitor, lovastatin, may prevent angiotensin II-induced cardiac hypertrophy, at least in part, through p21ras/MAP kinase pathway, which is linked to mevalonate metabolism.

  13. Chronic electroacupuncture of the ST36 point improves baroreflex function and haemodynamic parameters in heart failure rats.

    PubMed

    Lima, J W; Hentschke, V S; Rossato, D D; Quagliotto, E; Pinheiro, L; Almeida, E; Dal Lago, P; Lukrafka, J L

    2015-12-01

    Electroacupuncture (EA) has been used to treat many diseases, including heart failure (HF). This study aimed to evaluate the effects of chronic stimulation in the ST36 acupuncture point on haemodynamic parameters and baroreflex function in rats with HF. Cardiovascular parameters assessed were heart rate (HR), blood pressure (BP), and the reflex cardiovascular response of HR triggered by stimulation of baroreceptors in animals with HF subsequent to acute myocardial infarction (AMI). Male Wistar rats were divided into three groups: Sham Control - animals without HF and without EA; HF Control group - animals with HF and without EA; and HF EA group - animals with HF that received the EA protocol. Six weeks after surgical induction of AMI, the EA protocol (8 weeks, 5 times a week) was performed. The protocol was applied with EA at the ST36 point, frequency of 2 Hz, pulse of 0.3 ms and intensity of 1-3 mA for 30 min. Haemodynamic parameters and baroreceptor function were assessed. There was no difference between groups in the variables HR, systolic blood pressure (SBP) and diastolic blood pressure (DBP), which were evaluated with awake animals (p>0.05). There was an increase in the mean arterial pressure (MAP) in the HF EA group compared to the HF Control group (p<0.05). The maximum gain of the baroreflex heart rate response (Gain) was higher in the HF EA group than the HF Control and Sham Control groups. Chronic EA in the ST36 point increased the MAP and baroreflex sensitivity in rats with HF.