Sample records for induced hypertension pih

  1. PIH1D1, a subunit of R2TP complex, inhibits doxorubicin-induced apoptosis.

    PubMed

    Inoue, Mika; Saeki, Makio; Egusa, Hiroshi; Niwa, Hitoshi; Kamisaki, Yoshinori

    2010-12-17

    We have previously reported that the two components of R2TP complex, RNA polymerase II-associated protein 3 (RPAP3), and Reptin, regulate apoptosis. Here we characterize another component of the complex, PIH1 domain containing protein 1 (PIH1D1). PIH1D1 interacts with both RPAP3 and Monad in HEK293 or U2OS cells. PIH1D1 transcripts were abundant in lung, leukocyte, and placenta. The reduction in endogenous PIH1D1 by siRNA enhanced apoptosis and caspase-3 activation induced by doxorubicin in U2OS cells. These results suggest that PIH1D1 may also function as a novel modulator of apoptosis pathway. PMID:21078300

  2. Pathophysiology of placentation abnormalities in pregnancy-induced hypertension

    PubMed Central

    Furuya, Mitsuko; Ishida, Junji; Aoki, Ichiro; Fukamizu, Akiyoshi

    2008-01-01

    During embryogenesis and development, the fetus obtains oxygen and nutrients from the mother through placental microcirculation. The placenta is a distinctive organ that develops and differentiates per se, and that organizes fetal growth and maternal condition in the entire course of gestation. Several life-threatening diseases during pregnancy, such as pregnancy-induced hypertension (PIH) and eclampsia, are closely associated with placental dysfunction. Genetic susceptibilities and poor placentation have been investigated intensively to understand the pathophysiology of PIH. It is currently thought that “poor placentation hypothesis”, in which extravillous trophoblasts fail to invade sufficiently the placental bed, explains in part maternal predisposition to this disease. Cumulative studies have suggested that hypoxic micromilieu of fetoplacental site, shear stress of uteroplacental blood flow, and aberrantly secreted proinflammatory substances into maternal circulation synergistically contribute to the progression of PIH. For example, soluble form of vascular endothelial growth factor receptor-1 (sVEGFR-1) and soluble form of CD105 are elevated in circulation of PIH mothers. However, it remains to be poorly understood the pathological events in the placenta during the last half of gestation as maternal systemic disorders get worse. For better understanding and effective therapeutic approaches to PIH, it is important to clarify pathological course of PIH-associated changes in the placenta. In this review, current understanding of placental development and the pathophysiology of PIH placenta are summarized. In addition, recent findings of vasoactive signalings in PIH and rodent PIH models are discussed. PMID:19337544

  3. Serum lipids and malondialdehyde levels in primiparous patients with pregnancy induced hypertension

    Microsoft Academic Search

    Shruti Mohanty; Nalini Nayak; N. N. Nanda; Pragna Rao

    2006-01-01

    Background  Pregnancy induced hypertension (PIH) contributes to 15.6% maternal mortality in India. In Behrampur, Orissa, maternal deaths\\u000a due to PIH was 32%, which is twice the national incidence. Hence in this population, some factors associated with severity\\u000a of PIH were studied. Serum lipid concentrations and malondialdehyde (MDA) levels were correlated with severity of PIH and\\u000a birth weight of the neonate.\\u000a \\u000a \\u000a \\u000a Patients

  4. Fundus changes in pregnancy induced hypertension

    PubMed Central

    Reddy, Sagili Chandrasekhara; Nalliah, Sivalingam; George, Sheila Rani a/pKovil; Who, Tham Seng

    2012-01-01

    AIM To determine the prevalence of retinal changes in pregnancy induced hypertension (PIH) and any association between the retinal changes and blood pressure, proteinuria, and severity of the disease. METHODS All the patients admitted with diagnosis of PIH were included in this study. Age, race, gravida, gestation period, blood pressure, and proteinuria were noted from the case records. After taking history for any eye symptoms, fundus examination was done after dilating the pupils with direct ophthalmoscope in the ward itself. All the findings were noted on a data sheet, and were analyzed using SPSS programme. RESULTS A total of 78 patients of PIH were examined. Majority (75.6%) were Malays. The mean age of patients was 30.2 years (range 21-45 years). The gestation period ranged from 25 weeks to 41 weeks; 34 (43.5%) were primi gravida. Thirty (38.4%) patients had mild preeclampsia, 46 (59%) had severe preeclampsia and 2 (2.5%) had eclampsia. Retinal changes (hypertensive retinopathy) were noted in 46 (59%) patients --- grade I in 41 (52.6%) and grade II in 5 (6.4%). Haemorrhages or exudates or retinal detachment were not seen in any patient. There was statistically significant positive association of retinal changes and blood pressure (P =0.001), proteinuria (P =0.018) and severity of the PIH (P =0.024). CONCLUSION Retinal changes (grade I and II hypertensive retinopathy) were seen in 59% of patients with PIH and they were significantly associated with blood pressure, proteinuria and severity of the disease. Fundus examination helps in assessing the severity of PIH.

  5. Linear and nonlinear interaction analyses of heart rate and blood pressure in pregnancy induced hypertension

    Microsoft Academic Search

    A. Vossl; M. Baumert; V. Baier; H. Stepan; T. Walther; R. Faber

    2003-01-01

    Hypertensive pregnancy disorders have a deep impact on gestation and are a major cause of maternal and fetal mortality. This study was conducted to proof whether changes in the cardiovascular regulation in pregnancy induced hypertension (PIH) can be quantified by heart rate and blood pressure interaction analyses in comparison to healthy pregnancies (CON). Blood pressure recordings of 20 CON and

  6. Drug-induced hypertension

    MedlinePLUS

    ... induced hypertension are the same as those of primary hypertension, and may include: Anxiety Chest pain Confusion Excessive perspiration Headache Muscle tremors Nausea and vomiting Pale skin or redness Tiredness ...

  7. Parent-Offspring Conflict and the Persistence of Pregnancy-Induced Hypertension in Modern Humans

    PubMed Central

    Lykke, Jacob; Boomsma, Jacobus J.

    2013-01-01

    Preeclampsia is a major cause of perinatal mortality and disease affecting 5–10% of all pregnancies worldwide, but its etiology remains poorly understood despite considerable research effort. Parent-offspring conflict theory suggests that such hypertensive disorders of pregnancy may have evolved through the ability of fetal genes to increase maternal blood pressure as this enhances general nutrient supply. However, such mechanisms for inducing hypertension in pregnancy would need to incur sufficient offspring health benefits to compensate for the obvious risks for maternal and fetal health towards the end of pregnancy in order to explain why these disorders have not been removed by natural selection in our hunter-gatherer ancestors. We analyzed >750,000 live births in the Danish National Patient Registry and all registered medical diagnoses for up to 30 years after birth. We show that offspring exposed to pregnancy-induced hypertension (PIH) in trimester 1 had significantly reduced overall later-life disease risks, but increased risks when PIH exposure started or developed as preeclampsia in later trimesters. Similar patterns were found for first-year mortality. These results suggest that early PIH leading to improved postpartum survival and health represents a balanced compromise between the reproductive interests of parents and offspring, whereas later onset of PIH may reflect an unbalanced parent-offspring conflict at the detriment of maternal and offspring health. PMID:23451092

  8. Parent-offspring conflict and the persistence of pregnancy-induced hypertension in modern humans.

    PubMed

    Hollegaard, Birgitte; Byars, Sean G; Lykke, Jacob; Boomsma, Jacobus J

    2013-01-01

    Preeclampsia is a major cause of perinatal mortality and disease affecting 5-10% of all pregnancies worldwide, but its etiology remains poorly understood despite considerable research effort. Parent-offspring conflict theory suggests that such hypertensive disorders of pregnancy may have evolved through the ability of fetal genes to increase maternal blood pressure as this enhances general nutrient supply. However, such mechanisms for inducing hypertension in pregnancy would need to incur sufficient offspring health benefits to compensate for the obvious risks for maternal and fetal health towards the end of pregnancy in order to explain why these disorders have not been removed by natural selection in our hunter-gatherer ancestors. We analyzed >750,000 live births in the Danish National Patient Registry and all registered medical diagnoses for up to 30 years after birth. We show that offspring exposed to pregnancy-induced hypertension (PIH) in trimester 1 had significantly reduced overall later-life disease risks, but increased risks when PIH exposure started or developed as preeclampsia in later trimesters. Similar patterns were found for first-year mortality. These results suggest that early PIH leading to improved postpartum survival and health represents a balanced compromise between the reproductive interests of parents and offspring, whereas later onset of PIH may reflect an unbalanced parent-offspring conflict at the detriment of maternal and offspring health. PMID:23451092

  9. Maternal chronic HBV infection would not increase the risk of pregnancy-induced hypertension--results from pregnancy cohort in Liuyang rural China.

    PubMed

    Huang, Xin; Tan, Hongzhuan; Li, Xun; Zhou, Shujin; Wen, Shi Wu; Luo, Meiling

    2014-01-01

    The relationship between maternal HBV (hepatitis B virus) infection and pregnancy-induced hypertension (PIH) is inconclusive. Few studies have been conducted in rural areas of China. In order to examine the association between maternal chronic HBV infection and risk of PIH in Liuyang rural area China, we enrolled 6,195 eligible pregnant women in 2010-2011 in selected 14 towns of Liuyang on their first prenatal visit to local maternity care unit. A total of 461 subjects (7.44% (95%CI: 6.79%, 8.10%)) were identified with positive HBsAg status (exposed group) and 5734 were non-HBV carriers (unexposed group). Multivariate log-binomial regression models were used to estimate the risk of PIH, gestational hypertension (GH), and preeclampsia (PE) in relation to maternal chronic HBV infection. There are total of 455 subjects diagnosed with PIH (7.34% (95%CI: 6.70%, 7.99%)), including 371 GH (5.99% (95%CI: 5.40%, 6.58%)) and 81 PE (1.31% (95%CI: 1.07%, 1.64%)). The crude risk ratio between PIH, GH, PE and maternal HBV infection were 1.20 (95%CI: 0.88, 1.64), 1.30(95%CI: 0.93, 1.81) and 0.79 (95%CI: 0.32, 1.93), respectively. After adjustment for gravidity history, abortion history, family history of Diabetes Mellitus (DM) and family history of hypertension, positive HBsAg status was still not significantly associated with PIH (RR = 1.18, 95%CI: 0.87, 1.62), GH (RR = 1.27, 95%CI: 0.91, 1.78) or PE (RR = 0.79, 95%CI: 0.32, 1.95). Additional adjustment for maternal age, marital status, parity history, family history of DM, Body Mass Index at first antenatal visit, folic acid supplementation, smoking status during pregnancy and economic status of living area, multivariate analysis provided similar results. In conclusion, our study found that maternal chronic HBV infection prevalence rate is 7.4% among Liuyang rural area and there is no significant association between maternal HBV infection and the risk of PIH, GH or PE. PMID:25479003

  10. Maternal Chronic HBV Infection Would Not Increase the Risk of Pregnancy-Induced Hypertension – Results from Pregnancy Cohort in Liuyang Rural China

    PubMed Central

    Huang, Xin; Tan, Hongzhuan; Li, Xun; Zhou, Shujin; Wen, Shi Wu; Luo, Meiling

    2014-01-01

    The relationship between maternal HBV (hepatitis B virus) infection and pregnancy-induced hypertension (PIH) is inconclusive. Few studies have been conducted in rural areas of China. In order to examine the association between maternal chronic HBV infection and risk of PIH in Liuyang rural area China, we enrolled 6,195 eligible pregnant women in 2010–2011 in selected 14 towns of Liuyang on their first prenatal visit to local maternity care unit. A total of 461 subjects (7.44% (95%CI: 6.79%, 8.10%)) were identified with positive HBsAg status (exposed group) and 5734 were non-HBV carriers (unexposed group). Multivariate log-binomial regression models were used to estimate the risk of PIH, gestational hypertension (GH), and preeclampsia (PE) in relation to maternal chronic HBV infection. There are total of 455 subjects diagnosed with PIH (7.34% (95%CI: 6.70%, 7.99%)), including 371 GH (5.99% (95%CI: 5.40%, 6.58%)) and 81 PE (1.31% (95%CI: 1.07%, 1.64%)). The crude risk ratio between PIH, GH, PE and maternal HBV infection were 1.20 (95%CI: 0.88, 1.64), 1.30(95%CI: 0.93, 1.81) and 0.79 (95%CI: 0.32, 1.93), respectively. After adjustment for gravidity history, abortion history, family history of Diabetes Mellitus (DM) and family history of hypertension, positive HBsAg status was still not significantly associated with PIH (RR?=?1.18, 95%CI: 0.87, 1.62), GH (RR?=?1.27, 95%CI: 0.91, 1.78) or PE (RR?=?0.79, 95%CI: 0.32, 1.95). Additional adjustment for maternal age, marital status, parity history, family history of DM, Body Mass Index at first antenatal visit, folic acid supplementation, smoking status during pregnancy and economic status of living area, multivariate analysis provided similar results. In conclusion, our study found that maternal chronic HBV infection prevalence rate is 7.4% among Liuyang rural area and there is no significant association between maternal HBV infection and the risk of PIH, GH or PE. PMID:25479003

  11. Drug-induced hypertension: an unappreciated cause of secondary hypertension.

    PubMed

    Grossman, Ehud; Messerli, Franz H

    2012-01-01

    A myriad variety of therapeutic agents or chemical substances can induce either a transient or persistent increase in blood pressure, or interfere with the blood pressure-lowering effects of antihypertensive drugs. Some agents cause either sodium retention or extracellular volume expansion, or activate directly or indirectly the sympathetic nervous system. Other substances act directly on arteriolar smooth muscle or do not have a defined mechanism of action. Some medications that usually lower blood pressure may paradoxically increase blood pressure, or an increase in pressure may be encountered after their discontinuation. In general, drug-induced pressure increases are small and transient: however, severe hypertension involving encephalopathy, stroke, and irreversible renal failure have been reported. The deleterious effect of therapeutic agents is more pronounced in patients with preexisting hypertension, in those with renal failure, and in the elderly. Careful evaluation of a patient's drug regimen may identify chemically induced hypertension and obviate unnecessary evaluation and facilitate antihypertensive therapy. Once chemical-induced hypertension has been identified, discontinuation of the causative agent is recommended, although hypertension can often be managed by specific therapy and dose adjustment if continued use of the offending agent is mandatory. The present review summarizes the therapeutic agents or chemical substances that elevate blood pressure and their mechanisms of action. PMID:22195528

  12. Alcohol-induced hypertension: Mechanism and prevention

    PubMed Central

    Husain, Kazim; Ansari, Rais A; Ferder, Leon

    2014-01-01

    Epidemiological, preclinical and clinical studies established the association between high alcohol consumption and hypertension. However the mechanism through which alcohol raises blood pressure remains elusive. Several possible mechanisms have been proposed such as an imbalance of the central nervous system, impairment of the baroreceptors, enhanced sympathetic activity, stimulation of the renin-angiotensin-aldosterone system, increased cortisol levels, increased vascular reactivity due to increase in intracellular calcium levels, stimulation of the endothelium to release vasoconstrictors and loss of relaxation due to inflammation and oxidative injury of the endothelium leading to inhibition of endothelium-dependent nitric oxide production. Loss of relaxation due to inflammation and oxidative injury of the endothelium by angiotensin II leading to inhibition of endothelium-dependent nitric oxide production is the major contributors of the alcohol-induced hypertension. For the prevention of alcohol-induced hypertension is to reduce the amount of alcohol intake. Physical conditioning/exercise training is one of the most important strategies to prevent/treat chronic alcohol-induced hypertension on physiological basis. The efficacious pharmacologic treatment includes the angiotensin-converting enzyme (ACE) inhibitors or angiotensin II type 1 receptor blockers (ARBs) which have antioxidant activity and calcium channel blockers. The most effective prevention and treatment of alcohol-induced hypertension is physical exercise and the use of ACE inhibitors or ARBs in the clinic PMID:24891935

  13. Pathogenesis of calcineurin inhibitor–induced hypertension

    PubMed Central

    Hoorn, Ewout J.; Walsh, Stephen B.; McCormick, James A.; Zietse, Robert; Unwin, Robert J.; Ellison, David H.

    2014-01-01

    This article reviews the current understanding of the mechanisms of calcineurin inhibitor–induced hypertension. Already early after the introduction of cyclosporine in the 1980s, vasoconstriction, sympathetic excitation and sodium retention by the kidney had been shown to play a role in this form of hypertension. The vasoconstrictive effects of calcineurin inhibitors are related to interference with the balance of vasoactive substances, including endothelin and nitric oxide. Until recently, the renal site of the sodium-retaining effect of calcineurin inhibitors was unknown. We and others have shown that calcineurin inhibitors increase the activity of the thiazide-sensitive sodium chloride cotransporter through an effect on the kinases WNK and SPAK. Here, we review the pertinent literature on the hypertensinogenic effects of calcineurin inhibitors, including neural, vascular and renal effects, and we propose an integrated model of calcineurin inhibitor–induced hypertension. PMID:22573529

  14. RPAP3 splicing variant isoform 1 interacts with PIH1D1 to compose R2TP complex for cell survival.

    PubMed

    Yoshida, Miki; Saeki, Makio; Egusa, Hiroshi; Irie, Yasuyuki; Kamano, Yuya; Uraguchi, Shinya; Sotozono, Maki; Niwa, Hitoshi; Kamisaki, Yoshinori

    2013-01-01

    We previously characterized RNA polymerase II-associated protein 3 (RPAP3) as a cell death enhancer. Here we report the identification and characterization of splicing isoform of RPAP3, isoform 1 and 2. We investigated the interaction between RPAP3 and PIH1 domain containing protein 1 (PIH1D1), and found that RPAP3 isoform 1, but not isoform 2, interacted with PIH1D1. Furthermore, knockdown of RPAP3 isoform 1 by small interfering RNA down-regulated PIH1D1 protein level without affecting PIH1D1 mRNA. RPAP3 isoform 2 potentiated doxorubicin-induced cell death in human breast cancer T-47 cells although isoform 1 showed no effect. These results suggest that R2TP complex is composed of RPAP3 isoform 1 for its stabilization, and that RPAP3 isoform 2 may have a dominant negative effect on the survival potency of R2TP complex. PMID:23159623

  15. Serum lecithin: cholesterol acyltransferase activity, HDL2 and HDL3 composition in hypertensive mothers and their small for gestational age newborns.

    PubMed

    Loukidi-Bouchenak, B; Lamri-Senhadji, M Y; Merzouk, S; Merzouk, H; Belarbi, B; Prost, J; Belleville, J; Bouchenak, M

    2008-05-01

    The aim of this study was to determine serum lecithin:cholesterol acyltransferase (LCAT) activity in parallel with HDL2 and HDL3 amounts and composition in pregnancy induced hypertension (PIH) and chronic hypertensive (CH) mothers and in their small for gestational age (SGA) newborns. LCAT activity was assayed by conversion of [3H] cholesterol to labelled cholesteryl ester. HDL2 and HDL3 were separated by ultracentrifugation. At term, cholesterol values were similar in PIH, CH and controls. However, higher levels of triglycerides were observed in PIH and CH (+20% and +21%, respectively) as compared with normotensive control mothers (NC). HDL2 and HDL3-phospholipids, HDL2-cholesterol concentrations and LCAT activity were lower in PIH and CH mothers than in NC mothers. Similar changes were also observed in SGA newborns of PHI mothers and in SGA newborns of CH mothers when compared to appropriate for gestational age newborns of control mothers (AGA-NC). In addition, SGA newborns showed low HDL2 and HDL3 apoA-I contents. Maternal hypertension and foetal intrauterine growth retardation are associated with profound abnormalities in HDL metabolism, consistent with an atherogenic risk. SGA lipoprotein profiles appear to implicate later metabolic diseases. PMID:17605041

  16. Laser-Induced Mouse Model of Chronic Ocular Hypertension

    E-print Network

    Sakaguchi, Donald S.

    Laser-Induced Mouse Model of Chronic Ocular Hypertension Sinisa D. Grozdanic,1,2 Daniel M. Betts,1) is considered a primary risk factor for the initiation and progression of glaucomatous neuropathy.2 However of a mouse model in glaucoma studies.16 A procedure for the reliable induction of chronic ocular hypertension

  17. Schistosomiasis-Induced Experimental Pulmonary Hypertension

    PubMed Central

    Graham, Brian B.; Mentink-Kane, Margaret M.; El-Haddad, Hazim; Purnell, Shawn; Zhang, Li; Zaiman, Ari; Redente, Elizabeth F.; Riches, David W. H.; Hassoun, Paul M.; Bandeira, Angela; Champion, Hunter C.; Butrous, Ghazwan; Wynn, Thomas A.; Tuder, Rubin M.

    2010-01-01

    The mechanisms underlying schistosomiasis-induced pulmonary hypertension (PH), one of the most common causes of PH worldwide, remain unclear. We sought to determine whether Schistosoma mansoni causes experimental PH associated with pulmonary vascular remodeling in an interleukin (IL)-13-dependent manner. IL-13R?1 is the canonical IL-13 signaling receptor, whereas IL-13R?2 is a competitive nonsignaling decoy receptor. Wild-type, IL-13R?1?/?, and IL-13R?2?/? C57BL/6J mice were percutaneously infected with S. mansoni cercariae, followed by i.v. injection of eggs. We assessed PH with right ventricular catheterization, histological evaluation of pulmonary vascular remodeling, and detection of IL-13 and transforming growth factor-? signaling. Infected mice developed pulmonary peri-egg granulomas and arterial remodeling involving predominantly the vascular media. In addition, gain-of-function IL-13R?2?/? mice had exacerbated vascular remodeling and PH. Mice with loss of IL-13R?1 function did not develop PH and had reduced pulmonary vascular remodeling. Moreover, the expression of resistin-like molecule-?, a target of IL-13 signaling, was increased in infected wild-type and IL-13R?2?/? but not IL-13R?1?/? mice. Phosphorylated Smad2/3, a target of transforming growth factor-? signaling, was increased in both infected mice and humans with the disease. Our data indicate that experimental schistosomiasis causes PH and potentially relies on up-regulated IL-13 signaling. PMID:20671265

  18. Spaceflight-Induced Intracranial Hypertension: An Overview

    NASA Technical Reports Server (NTRS)

    Traver, William J.

    2011-01-01

    This slide presentation is an overview of the some of the known results of spaceflight induced intracranial hypertension. Historical information from Gemini 5, Apollo, and the space shuttle programs indicated that some vision impairment was reported and a comparison between these historical missions and present missions is included. Optic Disc Edema, Globe Flattening, Choroidal Folds, Hyperopic Shifts and Raised Intracranial Pressure has occurred in Astronauts During and After Long Duration Space Flight. Views illustrate the occurrence of Optic Disc Edema, Globe Flattening, and Choroidal Folds. There are views of the Arachnoid Granulations and Venous return, and the question of spinal or venous compliance issues is discussed. The question of increased blood flow and its relation to increased Cerebrospinal fluid (CSF) is raised. Most observed on-orbit papilledema does not progress, and this might be a function of plateau homeostasis for the higher level of intracranial pressure. There are seven cases of astronauts experiencing in flight and post flight symptoms, which are summarized and follow-up is reviewed along with a comparison of the treatment options. The question is "is there other involvement besides vision," and other Clinical implications are raised,

  19. Central modulation of cyclosporine-induced hypertension.

    PubMed

    El-Gowelli, Hanan M; El-Mas, Mahmoud M

    2015-03-01

    Arterial hypertension is a considerable side effect that accompanies the clinical use of immunosuppressant drugs such as cyclosporine (CSA). In addition to promoting graft rejection, uncontrolled hypertension is a major risk factor for atherosclerosis, left ventricular hypertrophy, heart failure, and premature death. Most, if not all, reports that reviewed the hypertensive effect of CSA and underlying mechanisms focused on the roles of peripheral vasoactive machinaries, perhaps because of the limited capacity of CSA to diffuse to brain tissues and the lack of any appreciable effect for centrally administered CSA on blood pressure (BP) or central sympathetic outflow. This review focuses primarily on evidence that supports a modulatory role for central neural pathways, as go-between afferent and efferent sympathetic circuits, in the elicitation of the hypertensive action of CSA. Other areas covered briefly in the review include (1) an outline of peripheral mechanisms that contribute to the hypertensive action of CSA, and (2) comparisons of the BP effects of CSA and other calcineurin-dependent (tacrolimus) and independent (sirolimus) immunosuppressants. The knowledge of these mechanisms, central and peripheral, may permit the identification of new therapeutic strategies against CSA hypertension. PMID:25430438

  20. Mitochondrial injury and dysfunction in hypertension-induced cardiac damage.

    PubMed

    Eirin, Alfonso; Lerman, Amir; Lerman, Lilach O

    2014-12-01

    Hypertension remains an important modifiable risk factor for cardiovascular disease, associated with increased morbidity and mortality. Deciphering the mechanisms involved in the pathogenesis of hypertension is critical, as its prevalence continues increasing worldwide. Mitochondria, the primary cellular energy producers, are numerous in parenchymal cells of the heart, kidney, and brain, major target organs in hypertension. These membrane-bound organelles not only maintain cellular respiration but also modulate several functions of the cell including proliferation, apoptosis, generation of reactive oxygen species, and intracellular calcium homeostasis. Therefore, mitochondrial damage and dysfunction compromise overall cell functioning. In recent years, significant advances increased our understanding of mitochondrial morphology, bioenergetics, and homeostasis, and in turn of their role in several diseases, so that mitochondrial abnormalities and dysfunction have been identified in experimental models of hypertension. In this review, we summarize current knowledge of the contribution of dysfunctional mitochondria to the pathophysiology of hypertension-induced cardiac damage, as well as available evidence of mitochondrial injury-induced damage in other organs. Finally, we discuss the capability of antihypertensive therapy to ameliorate hypertensive mitochondrial injury, and the potential position of mitochondria as therapeutic targets in patients with hypertension. PMID:25385092

  1. Mechanisms underlying the hypertensive response induced by capsaicin.

    PubMed

    Dutta, Abhaya; Deshpande, Shripad B

    2010-11-19

    Acute ingestion of large quantity of chili peppers (rich source of capsaicin) produced hypertensive crisis in a patient. The hypertensive response was explained on the basis of decreased vasodilator substance calcitonin gene-related peptide (CGRP) from sensory nerve terminals by capsaicin. Here we present our experimental observations in anaesthetized rats regarding the mechanisms underlying hypertensive response induced by capsaicin. Our results demonstrate non-involvement of adrenergic and angiotensinergic mechanisms and also the cardiac changes in producing the response. Thus, the direct action of capsaicin on vascular smooth muscle or the activation of endothelin is proposed. PMID:20223533

  2. 76 FR 76432 - Notice of Proposed Information for Public Comment for: Capture Energy Efficiency Measures for PIH

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-07

    ...Public Comment for: Capture Energy Efficiency Measures for PIH AGENCY: Office...HUD is creating the Capture Energy Efficiency Measures for PIH (CEEMP) data...Title of Proposal: Capture Energy Efficiency Measures for PIH...

  3. Excellent Tolerance to Cilnidipine in Hypertensives with Amlodipine - Induced Edema

    PubMed Central

    Shetty, Ranjan; Vivek, G; Naha, Kushal; Tumkur, Anil; Raj, Abhinav; Bairy, K L

    2013-01-01

    Background: Ankle edema is a common adverse effect of amlodipine, an L-type calcium channel blocker (CCB). Cilnidipine is a newer L/N-type CCB, approved for treatment of essential hypertension. Aim: This study was designed to determine whether cilnidipine can produce resolution of amlodipine-induced edema while maintaining adequate control of hypertension. Materials and Methods: A prospective study was performed on 27 patients with essential hypertension with amlodipine-induced edema. Concomitant nephropathy, cardiac failure, hepatic cirrhosis, or other causes of edema, and secondary hypertension were excluded by appropriate tests. Amlodipine therapy was substituted in all the cases with an efficacy-equivalent dose of cilnidipine. Clinical assessment of ankle edema and measurement of bilateral ankle circumference, body weight, blood pressure, and pulse rate were performed at onset of the study and after 4 weeks of cilnidipine therapy. Results: At completion of the study, edema had resolved in all the patients. There was a significant decrease in bilateral ankle circumference and body weight (P < 0.001). There was no significant change in mean arterial blood pressure and pulse rate. Conclusions: Therapy with cilnidipine resulted in complete resolution of amlodipine-induced edema in all the cases without significant worsening of hypertension or tachycardia. Cilnidipine is an acceptable alternative antihypertensive for patients with amlodipine-induced edema. PMID:23378956

  4. Indomethacin attenuates exercise-induced proteinuria in hypertensive miniature swine.

    PubMed

    O'Hagan, K P; Hora, D F; Zambraski, E J

    1992-10-01

    Exercise-induced proteinuria may be increased in hypertensives. The mechanisms underlying the increased proteinuria are not known, and it has not been determined whether animal models of hypertension exhibit a similar response. We investigated whether indomethacin (Indo) altered exercise-induced proteinuria in normal and hypertensive deoxycorticosterone acetate (DOCA) Yucatan miniature swine (YMS). Five normal and four DOCA YMS underwent 30 min of treadmill exercise at 80% of maximal heart rate. Cumulative (exercise + recovery) albumin excretion in the DOCA YMS was 25-fold (P < 0.01) greater than observed in the normal YMS. Indo had no effect on resting or exercise-induced proteinuria in the normal YMS. However, Indo decreased the slightly elevated proteinuria at rest, and normalized the exaggerated exercise-induced proteinuria in the DOCA YMS. The antiproteinuric effect of Indo in the DOCA YMS was not associated with altered exercise, recovery blood pressure, or glomerular filtration rate. Thus hypertensive DOCA YMS exhibit an exaggerated exercise-induced proteinuria. It is suggested that eicosanoids are involved in this abnormal renal proteinuric response to exercise. PMID:1415809

  5. Role of Nitric Oxide in Cocaine-Induced Acute Hypertension

    Microsoft Academic Search

    Wa Mo; Ashok K. Singh; Jose A. L. Arruda; George Dunea

    1998-01-01

    Cocaine causes acute hypertension by blocking catecholamine reuptake. There is evidence that it also impairs the peripheral endothelial nitric oxide system, which is normally vasodilatory. We further explored the role of nitric oxide in cocaine-induced vasoconstriction in anesthetized rats, and in vitro by using isolated carotid artery segments. Cocaine administered intravenously in rats increased mean arterial pressure by 30 to

  6. Hypertension

    MedlinePLUS

    ... or secondary. Most people with hypertension have the primary form. This type of high blood pressure is caused by high-salt diets, being overweight, ... can cause secondary hypertension may include: Cushing syndrome Primary ... can also cause high blood pressure, as this tricks the kidneys into thinking blood ...

  7. [Hypertension].

    PubMed

    Ohishi, Mitsuru

    2014-04-01

    Hypertension is well known to one of the risk factors to reduce cognitive function, however, it is still unclear whether anti-hypertensive therapy is effective to prevent development of dementia or Alzheimer's disease. Epidemiological studies suggested antihypertensive therapy from the middle-age could reduce risk of dementia. The meta-analysis including HYVET also suggested blood pressure lowering from the elderly might be also effective to prevent development of dementia. The network meta-analysis and the cohort study using mega-data bank suggested ARB might be effective to prevent development of dementia or Alzheimer's disease compared to administration with other anti-hypertensive drugs. Although the further major clinical investigation is required, anti-hypertensive treatment might be useful to manage hypertensive patients with dementia. PMID:24796098

  8. Elastase-induced intracranial aneurysms in hypertensive mice

    PubMed Central

    Nuki, Yoshitsugu; Tsou, Tsung-Ling; Kurihara, Chie; Kanematsu, Miyuki; Kanematsu, Yasuhisa; Hashimoto, Tomoki

    2009-01-01

    Mechanisms of formation and growth of intracranial aneurysms are poorly understood. To investigate the pathophysiology of intracranial aneurysms, an animal model of intracranial aneurysm yielding high incidence of large aneurysm formation within a short incubation period is needed. We combined two well-known clinical factors associated with human intracranial aneurysms—hypertension and the degeneration of elastic lamina— to induce intracranial aneurysm formation in mice. Roles of matrix metalloproteinases (MMPs) in this model were investigated utilizing doxycycline, a broad-spectrum MMP inhibitor, and MMP knockout mice. Hypertension was induced by continuous infusion of angiotensin-II for two weeks. The disruption of elastic lamina was achieved by a single stereotaxic injection of elastase into the cerebrospinal fluid at the right basal cistern. 77% of the mice that received 35 milli-units of elastase and 1000 ng/kg/min angiotensin-II developed intracranial aneurysms in two weeks. There were dose-dependent effects of elastase and angiotensin-II on the incidence of aneurysms. Histologically, intracranial aneurysms observed in this model closely resembled human intracranial aneurysms. Doxycycline, a broad-spectrum MMP inhibitor, reduced the incidence of aneurysm to 10%. MMP-9 knockout mice, but not MMP-2 knockout mice, had reduced the incidence of intracranial aneurysms. In summary, a stereotaxic injection of elastase into the basal cistern in hypertensive mice resulted in intracranial aneurysms that closely resembled human intracranial aneurysms. The intracranial aneurysm formation in this model appeared to be dependent on MMP activation. PMID:19884566

  9. Hypertension superimposed on type II diabetes in Goto Kakizaki rats induces progressive nephropathy

    Microsoft Academic Search

    Ulf Janssen; Stephen G. Riley; Athina Vassiliadou; Jürgen Floege; Aled O. Phillips

    2003-01-01

    Hypertension superimposed on type II diabetes in Goto Kakizaki rats induces progressive nephropathy.BackgroundType II diabetes in the Goto Kakizaki (GK) rats (derived from Wistar rats) is not associated with the development of obesity, hyperlipidemia, hypertension, or pronounced renal functional changes. The aim of this study was to investigate the effect of superimposed hypertension on renal function and morphology under conditions

  10. Calcimimetic NPS R-568 induces hypotensive effect in spontaneously hypertensive rats

    Microsoft Academic Search

    Apolonia Rybczyníska; Konrad Boblewski; Artur Lehmann; Czeslawa Orlewska; Henryk Foks; Krystyna Drewnowska; Anzelm Hoppe

    2005-01-01

    Background: The discovery of calcium receptors and calcimimetics created the possibility of “pharmacologic parathyroidectomy” (phPTX), which decreased secretion of parathormone (PTH). Parathyroid glands of spontaneously hypertensive rats (SHR) and of patients with primary hyperparathyroidism and hypertension secrete parathyroid hypertensive factor (PHF). Parathyroidectomy decreases blood pressure in these rats and in patients. The present study determined whether phPTX induced by calcimimetics

  11. Clinical management of drug-induced hypertension: 2013 Practical Recommendations of the Italian Society of Hypertension (SIIA).

    PubMed

    Virdis, Agostino; Ghiadoni, Lorenzo; Taddei, Stefano

    2014-03-01

    Results from recent observational studies conducted in our country and including approximately 160,000 patients with hypertension, reported that only 37 % of patients achieve effective blood pressure control under treatment. These data confirm that blood pressure control amongst the hypertensive population is still largely unsatisfactory in Italy. For this reason, the Italian Society of Hypertension aims to generate a number of interventions to improve blood pressure control in Italy, including integrated actions with General Practitioners, the implementation of hypertension awareness in the general population, a larger use of home blood pressure measurements, and a survey aimed at identifying all clinical and excellence centers for hypertension diagnosis and treatment throughout the whole national territory. Many therapeutic agents or chemical substances can induce a persistent or transient increase in blood pressure or interfere with the effect of antihypertensive drugs, causing sodium retention and expansion of the extra-cellular volume, activating the sympathetic nervous system and inducing vasoconstriction. This aspect represents one of the most common cause of secondary forms of hypertension, which often is under-evaluated by the physicians. In this review article, the potential causes of secondary forms of hypertension caused by use/abuse of drugs or substances are summarized. PMID:24535939

  12. Hypertension

    PubMed Central

    LePine, Todd

    2012-01-01

    Hypertension is responsible for roughly one-in-six adult deaths annually in the United States and is associated with five of the top nine causes of death.1 Ten trillion dollars is the estimated annual cost worldwide of the direct and indirect effects of hypertension.2,3 In the U.S. alone, costs estimated at almost $74 billion in 2009 placed a huge economic burden on the health care system.4 The prevalence of hypertension increases with advancing age to the point where more than half of people 60 to 69 years of age and at least three-fourths of those 70 years of age and older are affected.5 Most individuals with hypertension do not have it adequately controlled.1,6 Medication noncompliance due to avoidance of side effects is suggested to be a primary factor.6 The epidemic incidence of hypertension and its significant cost to society indicate that a well-tolerated, cost-effective approach to treatment is urgently needed. PMID:24278815

  13. Cardiovascular effects induced by linalool in normotensive and hypertensive rats.

    PubMed

    Anjos, Paulo J C; Lima, Aline O; Cunha, Patrícia S; De Sousa, Damião P; Onofre, Alexandre S C; Ribeiro, Thais P; Medeiros, Isac A; Antoniolli, Angelo R; Quintans-Júnior, Lucindo J; Santosa, Márcio R V

    2013-01-01

    Linalool is a monoterpene alcohol and constituent of several Brazilian aromatic medicinal plants, popularly used against hypertension. Cardiovascular effects induced by linalool were evaluated. In normotensive rats, (+/-)-linalool [1, 5, 10, and 20 mg/kg body weight (BW); intravenous (i.v.)]-induced hypotension was associated with tachycardia, which was attenuated by atropine (2 mg/kg BW) and N(G)-nitro-L-arginine methyl ester (20 mg/kg BW), but was not modified after indomethacin (5 mg/kg BW) administration. In hypertensive rats, linalool [200 mg/kg BW; oral (v.o.)] reduced blood pressure without changing the heart rate. In intact rings of rat mesenteric artery precontracted with 10 microM phenylephrine, linalool (from 6.4 x 10(-6) to 6.4 x 10(-3) M) induced relaxations in a concentration-dependent manner [E(max) = (115 +/- 13)%] that were not changed after atropine administration [E(max) = (105 +/- 2)%], and were not different from those obtained in endothelium-denuded rings precontracted with phenylephrine [E(max) = (108 +/- 7)%] or 80 mM KCl [E(max) = (113 +/- 7)%] or tetraethylammonium incubation [E(max) = (105 +/- 12)%]. Linalool (1.9 x 10(-3) M) antagonized the contractions induced by CaCl2 (3 x 10(-6)-10(-2) M) (maximal inhibition, 81%). Furthermore, linalool inhibited the contractions induced by 10 microM phenylephrine or 20 mM caffeine. In conclusion, these results demonstrate that linalool reduces blood pressure probably due to a direct effect on the vascular smooth muscle leading to vasodilation. PMID:23923614

  14. Effects of Induced Hypertension on Transcranial Doppler Ultrasound Velocities in Patients After Subarachnoid Hemorrhage

    Microsoft Academic Search

    E. M. Manno; D. R. Gress; L. H. Schwamm; M. N. Diringer; C. S. Ogilvy

    Background and Purpose—Transcranial doppler ultrasound (TCD) is used after subarachnoid hemorrhage to detect cerebral vasospasm and is often treated with induced hypertension. Cerebral autoregulation, however, may be disturbed in this population, raising the possibility that TCD velocities may be elevated by induced hypertension. To study this possibility, we performed continuous TCD monitoring of the middle cerebral artery during the induction

  15. Heart rate and blood pressure variabilities are increased in pregnancy-induced hypertension

    Microsoft Academic Search

    Eeva M. K. Ekholm; Kari U. O. Tahvanainen; Taina Metsälä

    1997-01-01

    Objective: Our purpose was to study whether cardiovascular changes in pregnancy-induced hypertension are associated with the increase in sympathetic control of hemodynamics and change in sympathovagal balance. Study Design: Fourteen women with pregnancy-induced hypertension and 16 women with uncomplicated pregnancies of similar duration were studied. Electrocardiographic signals and arterial blood pressure (Finapres monitor, Ohmeda) were continuously measured noninvasively throughout the

  16. Major inducing factors of hypertensive complications and the interventions required to reduce their prevalence: an epidemiological study of hypertension in a rural population in China

    PubMed Central

    2011-01-01

    Background The complications of hypertension cause severe health problems in rural areas in China. We (i) screened the major factors inducing hypertensive complications and provided intervention measures; and (ii) verified the efficacy of the New Rural Cooperative Medical Scheme (NRCMS; a medical insurance scheme for rural residents) for hypertension management. Methods A survey was conducted in the villages of Yunnan (an underdeveloped province in southwest China). The NRCMS was initiated there in 2005. Data were collected through questionnaires, physical examination, electrocardiography, as well as blood and urine tests. To detect factors inducing hypertension complications, a generalized estimating equations model was developed. Multivariable logistic regression was used to analyze influencing factors for hypertension control. Results Poor management of hypertension was observed in women. Being female, old, poorly educated, a smoker, ignorant of the dangerousness of hypertension, and having uncontrolled hypertension made patients more prone to hypertension complications. Combination therapy with ?2 drugs helped control hypertension, but most rural patients disliked multidrug therapy because they considered it to be expensive and inconvenient. The NRCMS contributed little to reduce the prevalence of complications and improve control of hypertension. Conclusions The present study suggested that the NRCMS needs to be reformed to concentrate on early intervention in hypertension and to concentrate on women. To increase hypertension control in rural areas in China, compound products containing effective and inexpensive drugs (and not multidrug therapy) are needed. PMID:21569365

  17. Regulation of Hypoxia-induced Pulmonary Hypertension by Vascular Smooth Muscle Hypoxia-Inducible Factor-1?

    PubMed Central

    Ball, Molly K.; Waypa, Gregory B.; Mungai, Paul T.; Nielsen, Jacqueline M.; Czech, Lyubov; Dudley, V. Joseph; Beussink, Lauren; Dettman, Robert W.; Berkelhamer, Sara K.; Steinhorn, Robin H.; Shah, Sanjiv J.

    2014-01-01

    Rationale: Chronic hypoxia induces pulmonary vascular remodeling, pulmonary hypertension, and right ventricular hypertrophy. At present, little is known about mechanisms driving these responses. Hypoxia-inducible factor-1? (HIF-1?) is a master regulator of transcription in hypoxic cells, up-regulating genes involved in energy metabolism, proliferation, and extracellular matrix reorganization. Systemic loss of a single HIF-1? allele has been shown to attenuate hypoxic pulmonary hypertension, but the cells contributing to this response have not been identified. Objectives: We sought to determine the contribution of HIF-1? in smooth muscle on pulmonary vascular and right heart responses to chronic hypoxia. Methods: We used mice with homozygous conditional deletion of HIF-1? combined with tamoxifen-inducible smooth muscle–specific Cre recombinase expression. Mice received either tamoxifen or vehicle followed by exposure to either normoxia or chronic hypoxia (10% O2) for 30 days before measurement of cardiopulmonary responses. Measurements and Main Results: Tamoxifen-induced smooth muscle–specific deletion of HIF-1? attenuated pulmonary vascular remodeling and pulmonary hypertension in chronic hypoxia. However, right ventricular hypertrophy was unchanged despite attenuated pulmonary pressures. Conclusions: These results indicate that HIF-1? in smooth muscle contributes to pulmonary vascular remodeling and pulmonary hypertension in chronic hypoxia. However, loss of HIF-1 function in smooth muscle does not affect hypoxic cardiac remodeling, suggesting that the cardiac hypertrophy response is not directly coupled to the increase in pulmonary artery pressure. PMID:24251580

  18. The Pih1-Tah1 Cochaperone Complex Inhibits Hsp90 Molecular Chaperone ATPase Activity*

    PubMed Central

    Eckert, Kelvin; Saliou, Jean-Michel; Monlezun, Laura; Vigouroux, Armelle; Atmane, Noureddine; Caillat, Christophe; Quevillon-Chéruel, Sophie; Madiona, Karine; Nicaise, Magali; Lazereg, Sylvie; Van Dorsselaer, Alain; Sanglier-Cianférani, Sarah; Meyer, Philippe; Moréra, Solange

    2010-01-01

    Hsp90 (heat shock protein 90) is an ATP-dependent molecular chaperone regulated by collaborating proteins called cochaperones. This machinery is involved in the conformational activation of client proteins like signaling kinases, transcription factors, or ribonucleoproteins (RNP) such as telomerase. TPR (TetratricoPeptide Repeat)-containing protein associated with Hsp90 (Tah1) and protein interacting with Hsp90 (Pih1) have been identified in Saccharomyces cerevisiae as two Hsp90 cochaperones involved in chromatin remodeling complexes and small nucleolar RNP maturation. Tah1 possesses a minimal TPR domain and binds specifically to the Hsp90 C terminus, whereas Pih1 displays no homology to other protein motifs and has been involved in core RNP protein interaction. While Pih1 alone was unstable and was degraded from its N terminus, we showed that Pih1 and Tah1 form a stable heterodimeric complex that regulates Hsp90 ATPase activity. We used different biophysical approaches such as analytical ultracentrifugation, microcalorimetry, and noncovalent mass spectrometry to characterize the Pih1-Tah1 complex and its interaction with Hsp90. We showed that the Pih1-Tah1 heterodimer binds to Hsp90 with a similar affinity and the same stoichiometry as Tah1 alone. However, the Pih1-Tah1 complex antagonizes Tah1 activity on Hsp90 and inhibits the chaperone ATPase activity. We further identified the region within Pih1 responsible for interaction with Tah1 and inhibition of Hsp90, allowing us to suggest an interaction model for the Pih1-Tah1/Hsp90 complex. These results, together with previous reports, suggest a role for the Pih1-Tah1 cochaperone complex in the recruitment of client proteins such as core RNP proteins to Hsp90. PMID:20663878

  19. Complement C1q-induced activation of ?-catenin signalling causes hypertensive arterial remodelling

    PubMed Central

    Sumida, Tomokazu; Naito, Atsuhiko T.; Nomura, Seitaro; Nakagawa, Akito; Higo, Tomoaki; Hashimoto, Akihito; Okada, Katsuki; Sakai, Taku; Ito, Masamichi; Yamaguchi, Toshihiro; Oka, Toru; Akazawa, Hiroshi; Lee, Jong-Kook; Minamino, Tohru; Offermanns, Stefan; Noda, Tetsuo; Botto, Marina; Kobayashi, Yoshio; Morita, Hiroyuki; Manabe, Ichiro; Nagai, Toshio; Shiojima, Ichiro; Komuro, Issei

    2015-01-01

    Hypertension induces structural remodelling of arteries, which leads to arteriosclerosis and end-organ damage. Hyperplasia of vascular smooth muscle cells (VSMCs) and infiltration of immune cells are the hallmark of hypertensive arterial remodelling. However, the precise molecular mechanisms of arterial remodelling remain elusive. We have recently reported that complement C1q activates ?-catenin signalling independent of Wnts. Here, we show a critical role of complement C1-induced activation of ?-catenin signalling in hypertensive arterial remodelling. Activation of ?-catenin and proliferation of VSMCs were observed after blood-pressure elevation, which were prevented by genetic and chemical inhibition of ?-catenin signalling. Macrophage depletion and C1qa gene deletion attenuated the hypertension-induced ?-catenin signalling, proliferation of VSMCs and pathological arterial remodelling. Our findings unveil the link between complement C1 and arterial remodelling and suggest that C1-induced activation of ?-catenin signalling becomes a novel therapeutic target to prevent arteriosclerosis in patients with hypertension. PMID:25716000

  20. Complement C1q-induced activation of ?-catenin signalling causes hypertensive arterial remodelling.

    PubMed

    Sumida, Tomokazu; Naito, Atsuhiko T; Nomura, Seitaro; Nakagawa, Akito; Higo, Tomoaki; Hashimoto, Akihito; Okada, Katsuki; Sakai, Taku; Ito, Masamichi; Yamaguchi, Toshihiro; Oka, Toru; Akazawa, Hiroshi; Lee, Jong-Kook; Minamino, Tohru; Offermanns, Stefan; Noda, Tetsuo; Botto, Marina; Kobayashi, Yoshio; Morita, Hiroyuki; Manabe, Ichiro; Nagai, Toshio; Shiojima, Ichiro; Komuro, Issei

    2015-01-01

    Hypertension induces structural remodelling of arteries, which leads to arteriosclerosis and end-organ damage. Hyperplasia of vascular smooth muscle cells (VSMCs) and infiltration of immune cells are the hallmark of hypertensive arterial remodelling. However, the precise molecular mechanisms of arterial remodelling remain elusive. We have recently reported that complement C1q activates ?-catenin signalling independent of Wnts. Here, we show a critical role of complement C1-induced activation of ?-catenin signalling in hypertensive arterial remodelling. Activation of ?-catenin and proliferation of VSMCs were observed after blood-pressure elevation, which were prevented by genetic and chemical inhibition of ?-catenin signalling. Macrophage depletion and C1qa gene deletion attenuated the hypertension-induced ?-catenin signalling, proliferation of VSMCs and pathological arterial remodelling. Our findings unveil the link between complement C1 and arterial remodelling and suggest that C1-induced activation of ?-catenin signalling becomes a novel therapeutic target to prevent arteriosclerosis in patients with hypertension. PMID:25716000

  1. Cirrhosis ameliorates monocrotaline-induced pulmonary hypertension in rats.

    PubMed

    Le Pavec, J; Perros, F; Eddahibi, S; Decante, B; Dorfmuller, P; Sitbon, O; Lebrec, D; Humbert, M; Mazmanian, M; Herve, P

    2009-09-01

    Common bile duct ligation (CBDL) induces biliary cirrhosis and pulmonary vasodilatation. We tested whether CBDL ameliorates monocrotaline (MCT)-induced pulmonary hypertension (PH) in rats. Five groups of rats were studied: controls; rats dosed with MCT (60 mg.kg(-1) subcutaneously); CBDL; rats dosed with MCT followed by CBDL on day 7; and rats dosed with MCT followed by CBDL (day 7) and L-NAME therapy between days 24 and 28. 28-day survival was 26% in the MCT group and 72% in the MCT+CBDL group. Pulmonary vascular resistance measured on days 21 and 28 increased in the MCT and MCT+CBDL+L-NAME groups, but returned to normal in the MCT+CBDL group on day 28. Pulmonary artery (PA) medial hypertrophy persisted in MCT+CBDL rats. PA inflammation increased in MCT+CBDL rats, with accumulation of both intra- and perivascular macrophages. Exhaled nitric oxide (NO) levels decreased in the MCT group and increased in the MCT+CBDL group, which showed upregulation of inducible NO synthase and normal endothelial NO synthase. Blood endothelin (ET)-1 increased in CBDL, MCT, and MCT+CBDL rats. Levels of ET(B) receptors increased and ET(A) receptors decreased in the MCT+CBDL group, whereas the opposite changes occurred in the MCT group. Biliary cirrhosis induces pulmonary vasodilation that ameliorates MCT-induced PH and improves survival. Upregulation of inducible NO synthase and ET(B) receptor and downregulation of ET(A) receptor may be involved. PMID:19324959

  2. Pih1d3 is required for cytoplasmic preassembly of axonemal dynein in mouse sperm

    PubMed Central

    Dong, Fenglan; Shinohara, Kyosuke; Botilde, Yanick; Nabeshima, Ryo; Asai, Yasuko; Fukumoto, Akemi; Hasegawa, Toshiaki; Matsuo, Moe; Takeda, Hiroyuki; Shiratori, Hidetaka; Nakamura, Tetsuya

    2014-01-01

    Axonemal dynein complexes are preassembled in the cytoplasm before their transport to cilia, but the mechanism of this process remains unclear. We now show that mice lacking Pih1d3, a PIH1 domain–containing protein, develop normally but manifest male sterility. Pih1d3?/? sperm were immotile and fragile, with the axoneme of the flagellum lacking outer dynein arms (ODAs) and inner dynein arms (IDAs) and showing a disturbed 9+2 microtubule organization. Pih1d3 was expressed specifically in spermatogenic cells, with the mRNA being most abundant in pachytene spermatocytes. Pih1d3 localized to the cytoplasm of spermatogenic cells but was not detected in spermatids or mature sperm. The levels of ODA and IDA proteins were reduced in the mutant testis and sperm, and Pih1d3 was found to interact with an intermediate chain of ODA as well as with Hsp70 and Hsp90. Our results suggest that Pih1d3 contributes to cytoplasmic preassembly of dynein complexes in spermatogenic cells by stabilizing and promoting complex formation by ODA and IDA proteins. PMID:24421334

  3. TIMP3 is the primary TIMP to regulate agonist-induced vascular remodelling and hypertension

    E-print Network

    MacMillan, Andrew

    3 is the primary TIMP to regulate agonist- induced vascular remodelling and hypertension Ratnadeep March 2013; online publish-ahead-of-print 21 March 2013 Time for primary review: 31 days Aims Hypertension is accompanied by structural remodelling of vascular extracellular matrix (ECM). Tissue inhibitor

  4. The role of constrictor prostanoids in the development of aortic coarctation-induced hypertension in male and female rats

    E-print Network

    Baltzer, Wendy Irene

    2005-02-17

    function and arterial blood pressure (MAP) during development of aortic coarctation-induced hypertension (HT). M and F rats, (15-18 wks.) in four groups: normotensive (NT), hypertensive (HT), ovariectomized (OVX), and OVX estrogen-replaced (OE), underwent...

  5. IgG receptor Fc?RIIB plays a key role in obesity-induced hypertension.

    PubMed

    Sundgren, Nathan C; Vongpatanasin, Wanpen; Boggan, Brigid-Meghan D; Tanigaki, Keiji; Yuhanna, Ivan S; Chambliss, Ken L; Mineo, Chieko; Shaul, Philip W

    2015-02-01

    There is a well-recognized association between obesity, inflammation, and hypertension. Why obesity causes hypertension is poorly understood. We previously demonstrated using a C-reactive protein (CRP) transgenic mouse that CRP induces hypertension that is related to NO deficiency. Our prior work in cultured endothelial cells identified the Fc? receptor IIB (Fc?RIIB) as the receptor for CRP whereby it antagonizes endothelial NO synthase. Recognizing known associations between CRP and obesity and hypertension in humans, in the present study we tested the hypothesis that Fc?RIIB plays a role in obesity-induced hypertension in mice. Using radiotelemetry, we first demonstrated that the hypertension observed in transgenic mouse-CRP is mediated by the receptor, indicating that Fc?RIIB is capable of modifying blood pressure. We then discovered in a model of diet-induced obesity yielding equal adiposity in all study groups that whereas Fc?RIIB(+/+) mice developed obesity-induced hypertension, Fc?RIIB(-/-) mice were fully protected. Levels of CRP, the related pentraxin serum amyloid P component which is the CRP-equivalent in mice, and total IgG were unaltered by diet-induced obesity; Fc?RIIB expression in endothelium was also unchanged. However, whereas IgG isolated from chow-fed mice had no effect, IgG from high-fat diet-fed mice inhibited endothelial NO synthase in cultured endothelial cells, and this was an Fc?RIIB-dependent process. Thus, we have identified a novel role for Fc?RIIB in the pathogenesis of obesity-induced hypertension, independent of processes regulating adiposity, and it may entail an IgG-induced attenuation of endothelial NO synthase function. Approaches targeting Fc?RIIB may potentially offer new means to treat hypertension in obese individuals. PMID:25368023

  6. Chemotherapy-induced pulmonary hypertension: role of alkylating agents.

    PubMed

    Ranchoux, Benoît; Günther, Sven; Quarck, Rozenn; Chaumais, Marie-Camille; Dorfmüller, Peter; Antigny, Fabrice; Dumas, Sébastien J; Raymond, Nicolas; Lau, Edmund; Savale, Laurent; Jaïs, Xavier; Sitbon, Olivier; Simonneau, Gérald; Stenmark, Kurt; Cohen-Kaminsky, Sylvia; Humbert, Marc; Montani, David; Perros, Frédéric

    2015-02-01

    Pulmonary veno-occlusive disease (PVOD) is an uncommon form of pulmonary hypertension (PH) characterized by progressive obstruction of small pulmonary veins and a dismal prognosis. Limited case series have reported a possible association between different chemotherapeutic agents and PVOD. We evaluated the relationship between chemotherapeutic agents and PVOD. Cases of chemotherapy-induced PVOD from the French PH network and literature were reviewed. Consequences of chemotherapy exposure on the pulmonary vasculature and hemodynamics were investigated in three different animal models (mouse, rat, and rabbit). Thirty-seven cases of chemotherapy-associated PVOD were identified in the French PH network and systematic literature analysis. Exposure to alkylating agents was observed in 83.8% of cases, mostly represented by cyclophosphamide (43.2%). In three different animal models, cyclophosphamide was able to induce PH on the basis of hemodynamic, morphological, and biological parameters. In these models, histopathological assessment confirmed significant pulmonary venous involvement highly suggestive of PVOD. Together, clinical data and animal models demonstrated a plausible cause-effect relationship between alkylating agents and PVOD. Clinicians should be aware of this uncommon, but severe, pulmonary vascular complication of alkylating agents. PMID:25497573

  7. Dexamethasone reverses monocrotaline-induced pulmonary arterial hypertension in rats.

    PubMed

    Price, L C; Montani, D; Tcherakian, C; Dorfmüller, P; Souza, R; Gambaryan, N; Chaumais, M-C; Shao, D M; Simonneau, G; Howard, L S; Adcock, I M; Wort, S J; Humbert, M; Perros, F

    2011-04-01

    Pulmonary arterial hypertension (PAH) is associated with dysregulated bone morphogenetic protein receptor (BMPR)-II signaling and pulmonary vascular inflammation. We evaluated the effects of dexamethasone on monocrotaline (MCT)-induced PAH in rats for potential reversal of PAH at late time-points. Saline-treated control, MCT-exposed, MCT-exposed and dexamethasone-treated rats (5 mg·kg?¹·day?¹, 1.25 mg·kg?¹ and 2.5 mg·kg?¹·48 h?¹) were evaluated at day 28 and day 35 following MCT for haemodynamic parameters, right ventricular hypertrophy, morphometry, immunohistochemistry, and IL6 and BMPR2 expression. Dexamethasone improved haemodynamics and pulmonary vascular remodelling, preventing PAH development at early (day 1-14 and 1-28) and reversing PAH at late (day 14-28 and 21-35) time-points following MCT, as well as improving survival in MCT-exposed rats compared with controls. Both MCT-induced pulmonary IL6 overexpression and interleukin (IL)-6-expressing adventitial inflammatory cell infiltration were reduced with dexamethasone. This was associated with pulmonary BMPR2 downregulation following MCT, which was increased with dexamethasone, in whole lung and control pulmonary artery smooth muscle cells. Dexamethasone also reduced proliferation of rat pulmonary artery smooth muscle cells in vitro. Experimental PAH can be prevented and reversed by dexamethasone, and survival is improved. In this model, mechanisms may involve reduction of IL-6-expressing inflammatory cells, restoration of pulmonary BMPR2 expression and reduced proliferation of vascular smooth muscle cells. PMID:20693255

  8. Ambient air pollution and pregnancy-induced hypertensive disorders: a systematic review and meta-analysis.

    PubMed

    Pedersen, Marie; Stayner, Leslie; Slama, Rémy; Sørensen, Mette; Figueras, Francesc; Nieuwenhuijsen, Mark J; Raaschou-Nielsen, Ole; Dadvand, Payam

    2014-09-01

    Pregnancy-induced hypertensive disorders can lead to maternal and perinatal morbidity and mortality, but the cause of these conditions is not well understood. We have systematically reviewed and performed a meta-analysis of epidemiological studies investigating the association between exposure to ambient air pollution and pregnancy-induced hypertensive disorders including gestational hypertension and preeclampsia. We searched electronic databases for English language studies reporting associations between ambient air pollution and pregnancy-induced hypertensive disorders published between December 2009 and December 2013. Combined risk estimates were calculated using random-effect models for each exposure that had been examined in ?4 studies. Heterogeneity and publication bias were evaluated. A total of 17 articles evaluating the impact of nitrogen oxides (NO2, NOX), particulate matter (PM10, PM2.5), carbon monoxide (CO), ozone (O3), proximity to major roads, and traffic density met our inclusion criteria. Most studies reported that air pollution increased risk for pregnancy-induced hypertensive disorders. There was significant heterogeneity in meta-analysis, which included 16 studies reporting on gestational hypertension and preeclampsia as separate or combined outcomes; there was less heterogeneity in findings of the 10 studies reporting solely on preeclampsia. Meta-analyses showed increased risks of hypertensive disorders in pregnancy for all pollutants except CO. Random-effect meta-analysis combined odds ratio associated with a 5-?g/m3 increase in PM2.5 was 1.57 (95% confidence interval, 1.26-1.96) for combined pregnancy-induced hypertensive disorders and 1.31 (95%confidence interval, 1.14-1.50) for preeclampsia [corrected]. Our results suggest that exposure to air pollution increases the risk of pregnancy-induced hypertensive disorders. PMID:24935943

  9. Dietary potassium and magnesium supplementation in cyclosporine-induced hypertension and nephrotoxicity

    Microsoft Academic Search

    Anna-Kaisa Pere; Leena Lindgren; Päivi Tuomainen; Leena Krogerus; Pekka Rauhala; Juha Laakso; Heikki Karppanen; Heikki Vapaatalo; Juhani Ahonen; Eero M A Mervaala

    2000-01-01

    Dietary potassium and magnesium supplementation in cyclosporine-induced hypertension and nephrotoxicity.BackgroundCyclosporine A (CsA)-induced hypertension and nephrotoxicity are aggravated by high sodium intake. Accumulating evidence suggests that potassium and magnesium supplementation could protect against the detrimental effects of dietary salt. In the present study, we tested the hypothesis of whether concurrent supplementation with potassium and magnesium could protect against the development of

  10. Urantide alleviates monocrotaline induced pulmonary arterial hypertension in Wistar rats.

    PubMed

    Mei, Yifang; Jin, Hong; Tian, Wei; Wang, Hao; Wang, Han; Zhao, Yanping; Zhang, Zhiyi; Meng, Fanchao

    2011-08-01

    Pulmonary arterial hypertension (PAH) is a serious disorder with poor prognosis. Urotensin II (UII) has been confirmed to be powerful vasoconstrictor than endothelin-1, which may play an important role in PAH development. The aim of this study is to observe the effects of urantide, a UII receptor antagonist, on monocrotaline (MCT) induced PAH in rats. 60 male Wistar rats were divided into six groups. For early treatment experiment, rats were divided into normal control group, MCT(4w) model group (MCT + saline × 3 wks from the 8th day of MCT injection) and urantide early treatment group (MCT + urantide 10 ?g/kg/d × 3 wks, 1 week after MCT injection once). For late treatment experiment, rats were divided as controls, MCT(6w) model group (MCT + saline × 2 wks, 4 weeks after MCT injection once) and urantide late treatment group (MCT + urantide 10 ?g/kg/d × 2 wks, 4 weeks after MCT injection once). At the end of experiments, mean pulmonary arterial pressures (mPAP) and mean blood pressure (MBP) of rats in each group were measured by catheterization. Right ventricular weight ratio was also weighed. Relaxation effects of urantide on intralobar pulmonary arterial rings of normal control and MCT(4w) model rats were investigated. Pulmonary artery remodeling was detected by hematoxylin and eosin (HE) staining and immunohistochemistry analysis. Serum nitric oxide (NO) levels in all six groups were assayed by ELISA kits. Urantide markedly reduced the mPAP levels of MCT induced PAH in both early and late treatment groups. It didn't change the MBP. Urantide dose-dependently relaxed the pulmonary arterial rings of normal control and MCT(4w) model rats. Moreover, N(G)-Nitro-l-arginine Methyl Ester (l-NAME) blocked the dilation response induced by urantide. In addition, urantide inhibited the pulmonary vascular remodeling remarkably. Serum NO level elevated in both early and late treatment rats with urantide infusion. These results suggest that urantide effectively alleviated MCT induced rats PAH may through relaxing pulmonary arteries and inhibiting pulmonary vascular remodeling. NO pathway might be one of the mechanisms in urantide induced pulmonary artery dilation. Thus, it is expected that urantide may be a novel therapy for PAH. PMID:21396478

  11. Structural basis for phosphorylation-dependent recruitment of Tel2 to Hsp90 by Pih1.

    PubMed

    Pal, Mohinder; Morgan, Marc; Phelps, Sarah E L; Roe, S Mark; Parry-Morris, Sarah; Downs, Jessica A; Polier, Sigrun; Pearl, Laurence H; Prodromou, Chrisostomos

    2014-06-10

    Client protein recruitment to the Hsp90 system depends on cochaperones that bind the client and Hsp90 simultaneously and facilitate their interaction. Hsp90 involvement in the assembly of snoRNPs, RNA polymerases, PI3-kinase-like kinases, and chromatin remodeling complexes depends on the TTT (Tel2-Tti1-Tti2), and R2TP complexes-consisting of the AAA-ATPases Rvb1 and Rvb2, Tah1 (Spagh/RPAP3 in metazoa), and Pih1 (Pih1D1 in humans)-that together provide the connection to Hsp90. The biochemistry underlying R2TP function is still poorly understood. Pih1 in particular, at the heart of the complex, has not been described at a structural level, nor have the multiple protein-protein interactions it mediates been characterized. Here we present a structural and biochemical analysis of Hsp90-Tah1-Pih1, Hsp90-Spagh, and Pih1D1-Tel2 complexes that reveal a domain in Pih1D1 specific for binding CK2 phosphorylation sites, and together define the structural basis by which the R2TP complex connects the Hsp90 chaperone system to the TTT complex. PMID:24794838

  12. Structural Basis for Phosphorylation-Dependent Recruitment of Tel2 to Hsp90 by Pih1

    PubMed Central

    Pal, Mohinder; Morgan, Marc; Phelps, Sarah E.L.; Roe, S. Mark; Parry-Morris, Sarah; Downs, Jessica A.; Polier, Sigrun; Pearl, Laurence H.; Prodromou, Chrisostomos

    2014-01-01

    Summary Client protein recruitment to the Hsp90 system depends on cochaperones that bind the client and Hsp90 simultaneously and facilitate their interaction. Hsp90 involvement in the assembly of snoRNPs, RNA polymerases, PI3-kinase-like kinases, and chromatin remodeling complexes depends on the TTT (Tel2-Tti1-Tti2), and R2TP complexes—consisting of the AAA-ATPases Rvb1 and Rvb2, Tah1 (Spagh/RPAP3 in metazoa), and Pih1 (Pih1D1 in humans)—that together provide the connection to Hsp90. The biochemistry underlying R2TP function is still poorly understood. Pih1 in particular, at the heart of the complex, has not been described at a structural level, nor have the multiple protein-protein interactions it mediates been characterized. Here we present a structural and biochemical analysis of Hsp90-Tah1-Pih1, Hsp90-Spagh, and Pih1D1-Tel2 complexes that reveal a domain in Pih1D1 specific for binding CK2 phosphorylation sites, and together define the structural basis by which the R2TP complex connects the Hsp90 chaperone system to the TTT complex. PMID:24794838

  13. Aging exacerbates hypertension-induced cerebral microhemorrhages in mice: role of resveratrol treatment in vasoprotection.

    PubMed

    Toth, Peter; Tarantini, Stefano; Springo, Zsolt; Tucsek, Zsuzsanna; Gautam, Tripti; Giles, Cory B; Wren, Jonathan D; Koller, Akos; Sonntag, William E; Csiszar, Anna; Ungvari, Zoltan

    2015-06-01

    Recent studies demonstrate that aging exacerbates hypertension-induced cognitive decline, but the specific age-related mechanisms remain elusive. Cerebral microhemorrhages (CMHs) are associated with rupture of small intracerebral vessels and are thought to progressively impair neuronal function. To determine whether aging exacerbates hypertension-induced CMHs young (3 months) and aged (24 months) mice were treated with angiotensin II plus L-NAME. We found that the same level of hypertension leads to significantly earlier onset and increased incidence of CMHs in aged mice than in young mice, as shown by neurological examination, gait analysis, and histological assessment of CMHs in serial brain sections. Hypertension-induced cerebrovascular oxidative stress and redox-sensitive activation of matrix metalloproteinases (MMPs) were increased in aging. Treatment of aged mice with resveratrol significantly attenuated hypertension-induced oxidative stress, inhibited vascular MMP activation, significantly delayed the onset, and reduced the incidence of CMHs. Collectively, aging promotes CMHs in mice likely by exacerbating hypertension-induced oxidative stress and MMP activation. Therapeutic strategies that reduce microvascular oxidative stress and MMP activation may be useful for the prevention of CMHs, protecting neurocognitive function in high-risk elderly patients. PMID:25677910

  14. Angiographic changes to induced hypertension in cerebral vasospasm. Case report.

    PubMed

    De Araujo, L C; Zappulla, R A; Yang, W C; Hollin, S A

    1978-08-01

    A case of cerebral vasospasm complicating intracranial aneurysm surgery is presented. Angiographic findings under hypertension and normotension revealed a paradoxical response of involved vessels suggesting that normal autoregulation is either lost or overcome by spasm. PMID:671087

  15. Obesity-induced hypertension: interaction of neurohumoral and renal mechanisms.

    PubMed

    Hall, John E; do Carmo, Jussara M; da Silva, Alexandre A; Wang, Zhen; Hall, Michael E

    2015-03-13

    Excess weight gain, especially when associated with increased visceral adiposity, is a major cause of hypertension, accounting for 65% to 75% of the risk for human primary (essential) hypertension. Increased renal tubular sodium reabsorption impairs pressure natriuresis and plays an important role in initiating obesity hypertension. The mediators of abnormal kidney function and increased blood pressure during development of obesity hypertension include (1) physical compression of the kidneys by fat in and around the kidneys, (2) activation of the renin-angiotensin-aldosterone system, and (3) increased sympathetic nervous system activity. Activation of the renin-angiotensin-aldosterone system is likely due, in part, to renal compression, as well as sympathetic nervous system activation. However, obesity also causes mineralocorticoid receptor activation independent of aldosterone or angiotensin II. The mechanisms for sympathetic nervous system activation in obesity have not been fully elucidated but may require leptin and activation of the brain melanocortin system. With prolonged obesity and development of target organ injury, especially renal injury, obesity-associated hypertension becomes more difficult to control, often requiring multiple antihypertensive drugs and treatment of other risk factors, including dyslipidemia, insulin resistance and diabetes mellitus, and inflammation. Unless effective antiobesity drugs are developed, the effect of obesity on hypertension and related cardiovascular, renal and metabolic disorders is likely to become even more important in the future as the prevalence of obesity continues to increase. PMID:25767285

  16. A novel adipocytokine, omentin, inhibits monocrotaline-induced pulmonary arterial hypertension in rats.

    PubMed

    Kazama, Kyosuke; Okada, Muneyoshi; Yamawaki, Hideyuki

    2014-09-12

    Omentin is a novel adipocytokine mainly expressed in visceral rather than subcutaneous adipose tissue. Several epidemiological studies demonstrated the negative relationship between blood omentin level and occurrence of obesity, type 2 diabetes and hypertension. Increases of inflammatory responses, contractile reactivity and structural remodeling of vascular wall contribute to hypertension development. Our in vitro studies previously demonstrated that omentin inhibited those hypertension-related pathological processes. In addition, our in vivo study demonstrated that intravenously injected omentin acutely inhibited agonists-induced increases of blood pressure in rats. However, the chronic effects of omentin on hypertension development are not determined. In the present study, we tested the hypothesis that chronic omentin treatment may inhibit pulmonary arterial (PA) hypertension (PAH). PAH was induced by a single intraperitoneal injection of monocrotaline (MCT: 60 mg/kg) to rats. Omentin (18 ?g/kg/day) was intraperitoneally treated for 14 days. Chronic omentin treatment inhibited MCT-induced increases in PA pressure. Omentin inhibited MCT-induced right ventricular hypertrophy as well as increase of lung to body weight ratio. Histologically, omentin inhibited MCT-induced PA hyperplasia. Further, omentin inhibited the impairment of both endothelium-dependent and -independent relaxations mediated by acetylcholine and sodium nitroprusside, respectively. In conclusion, we for the first time demonstrate that chronic omentin treatment inhibits MCT-induced PAH in rats via inhibiting vascular structural remodeling and abnormal contractile reactivity. PMID:25152392

  17. Role of the sympathetic nervous system during the development of obesity-induced hypertension in rabbits

    Microsoft Academic Search

    Vladan Antic; Francesca Kiener-Belforti; Aldo Tempini; Bruce N. Van Vliet; Jean-Pierre Montani

    2000-01-01

    We have previously reported that weight gain induced by high-fat diet (HFD) leads to an increase in mean arterial pressure (MAP, +14%) and heart rate (HR, +31%) in the adult rabbit. In the present study, we tested the hypothesis that an increased activity of the sympathetic nervous system may contribute to the development of obesity-induced hypertension. A combination of ?-

  18. Spice up the hypertension diet - curcumin and piperine prevent remodeling of aorta in experimental L-NAME induced hypertension

    PubMed Central

    2011-01-01

    Background Increase of blood pressure is accompanied by functional and morphological changes in the vascular wall. The presented study explored the effects of curcuma and black pepper compounds on increased blood pressure and remodeling of aorta in the rat model of experimental NO-deficient hypertension. Methods Wistar rats were administered for 6 weeks clear water or L-NAME (40 mg/kg/day) dissolved in water, piperine (20 mg/kg/day), curcumin (100 mg/kg/day) or their combination in corn oil by oral gavage. The systolic blood pressure was measured weekly. Histological slices of thoracic aorta were stained with hematoxylin and eosin, Mallory's phosphotungstic acid hematoxylin (PTAH), orcein, picrosirius red and van Gieson staining and with antibodies against smooth muscle cells actin. Microscopic pictures were digitally processed and morphometrically evaluated. Results The increase of blood pressure caused by L-NAME was partially prevented by piperine and curcumin, but the effect of their combination was less significant. Animals with hypertension had increased wall thickness and cross-sectional area of the aorta, accompanied by relative increase of PTAH positive myofibrils and decrease of elastin, collagen and actin content. Piperine was able to decrease the content of myofibrils and slightly increase actin, while curcumin also prevented elastin decrease. The combination of spices had similar effects on aortic morphology as curcumin itself. Conclusions Administration of piperine or curcumin, less their combination, is able to partially prevent the increase of blood pressure caused by chronic L-NAME administration. The spices modify the remodeling of the wall of the aorta induced by hypertension. Our results show that independent administration of curcumin is more effective in preventing negative changes in blood vessel morphology accompanying hypertensive disease. PMID:22005253

  19. beta-Adrenergic and cholinergic receptors in hypertension-induced hypertrophy

    SciTech Connect

    Vatner, D.E.; Kirby, D.A.; Homcy, C.J.; Vatner, S.F.

    1985-05-01

    Perinephritic hypertension was produced in dogs by wrapping one kidney with silk and removing the contralateral kidney 1 week later. Mean arterial pressure rose from 104 +/- 3 to 156 +/- 11 mm Hg, while left ventricular free wall weight, normalized for body weight, was increased by 49%. Muscarinic, cholinergic receptor density measured with (/sup 3/H)-quinuclidinyl benzilate, fell in hypertensive left ventricles (181 +/- 19 fmol/mg, n = 6; p less than 0.01) as compared with that found in normal left ventricles (272 +/- 16 fmol/mg, n = 8), while receptor affinity was not changed. The beta-adrenergic receptor density, measured by binding studies with (/sup 3/H)-dihydroalprenolol, rose in the hypertensive left ventricles (108 +/- 10 fmol/mg, n = 7; p less than 0.01) as compared with that found in normal left ventricles (68.6 +/- 5.2 fmol/mg, n = 15), while beta-adrenergic receptor affinity decreased in the hypertensive left ventricles (10.4 +/- 1.2 nM) compared with that found in the normal left ventricles (5.0 +/- 0.7 nM). Plasma norepinephrine levels were similar in the two groups, but myocardial norepinephrine levels were depressed (p less than 0.05) in dogs with hypertension. Moderate left ventricular hypertrophy induced by long-term aortic banding in dogs resulted in elevations in beta-adrenergic receptor density (115 +/- 14 fmol/mg) and decreases in affinity (10.4 +/- 2.2 nM) similar to those observed in the dogs with left ventricular hypertrophy induced by hypertension. Thus, these results suggest that perinephritic hypertension in the dog induces divergent effects on cholinergic and beta-adrenergic receptor density. The increased beta-adrenergic receptor density and decreased affinity may be a characteristic of left ventricular hypertrophy rather than hypertension.

  20. Maternal Obesity and Energy Intake as Risk Factors of Pregnancy-induced Hypertension among Iranian Women

    PubMed Central

    Kazemian, Elham; Dorosty-Motlagh, Ahmad Reza; Eshraghian, Mohammad Reza; Bagheri, Minoo

    2014-01-01

    ABSTRACT Pregnancy-induced hypertension is causing striking maternal, foetal and neonatal mortality and morbidity in the world. A case-control study was conducted on 113 women with gestational hypertension and 150 healthy pregnant women at Shahid Akbarabadi Hospital of obstetrics and gynaecology in south of Tehran. Women who were obese (OR 4.44; 95% CI 1.84-10.72) before pregnancy were more likely to develop gestational hypertension. Proportion of having excessive gestational weight gain was positively and significantly associated with development of gestational hypertension (OR 2.70; 95% CI 1.19-6.13). Furthermore, findings revealed that women who were in the highest quartile of mid-arm-circumference had a 3-fold increased risk of gestational hypertension compared to women in the lowest quartile (OR 8.93; 95% CI 2.16-36.93). We found that having been in the highest quartile of energy intake positively correlated with increased risk of gestational hypertension (OR 9.66; 95% CI 3.30-28.21). The results suggest pre-pregnancy obesity, excessive gestational weight gain, and increased intake of energy as potential risk factors of developing gestational hypertension. PMID:25395911

  1. PIH1D1 interacts with mTOR complex 1 and enhances ribosome RNA transcription.

    PubMed

    Kamano, Yuya; Saeki, Makio; Egusa, Hiroshi; Kakihara, Yoshito; Houry, Walid A; Yatani, Hirofumi; Kamisaki, Yoshinori

    2013-10-11

    PIH1D1 is the defining component of the R2TP complex. Recently, R2TP has been reported to stabilize mTOR (mammalian target of rapamycin), an important regulator of cell growth and protein synthesis. Two complexes of mTOR, mTORC1 and mTORC2, have been identified. We demonstrate that immunoprecipitation (IP) of PIH1D1 results in the co-IP of Raptor (mTORC1 specific), but not Rictor (mTORC2 specific), and that knockdown of PIH1D1 decreases mTORC1 assembly, S6 kinase phosphorylation (indicator of mTORC1 activity), and rRNA transcription without affecting mTORC2 in human breast cancer MCF-7 cells. In addition, we provide evidence that PIH1D1 is overexpressed in various breast cancer cell lines. These findings collectively suggest that PIH1D1 may have an important role in mTORC1 regulation in breast cancers. PMID:24036451

  2. Rosuvastatin, sildenafil and their combination in monocrotaline-induced pulmonary hypertension in rat.

    PubMed

    Jasi?ska-Stroschein, Magdalena; Owczarek, Jacek; Weso?owska, Anna; Orszulak-Michalak, Daria

    2014-09-01

    There is considerable interest in the pleiotropic effects of statins and their potential role in the treatment of pulmonary hypertension. Previous experimental findings indicate that a combination of lipophilic statins with phosphodiesterase type-5 inhibitor, sildenafil, can offer preventive effects on rat monocrotaline-induced pulmonary hypertension. The present study is aimed to assess whether therapeutic regimen provides any benefits. Seven days after pulmonary hypertension induction, hydrophilic rosuvastatin and sildenafil were given for 14 days to male Wistar outbred rats. Right ventricular pressure, right ventricle mass and three biomarkers were evaluated after 21 days: brain natriuretic peptide, high-density lipoprotein cholesterol and vascular endothelial growth factor. The present study demonstrates that administration of hydrophilic statin with sildenafil results in reduction of pulmonary vascular remodeling and right ventricular pressure. The results of biochemical measurements may suggest that statins play a positive role in right ventricle function or the process of angiogenesis in pulmonary hypertension development. PMID:25296680

  3. Pregnancy-induced hypertension complicated by postpartum renal failure and pancreatitis: a case report.

    PubMed

    Marcovici, Iacob; Marzano, David

    2002-05-01

    Reported causes of pancreatitis in pregnancy include: gallstone disease, hyperlipidemia, alcohol ingestion, viral, and idiopathic. Few reports associate pancreatitis with pregnancy-induced hypertension. A 35-year-old women with pregnancy-induced hypertension and spontaneous rupture of membranes was admitted for induction of labor. Her postpartum course was complicated by acute renal failure that responded well to treatment with Lasix and Albumin. Subsequently, the patient developed acute pancreatitis and recovered following conservative treatment. It is possible that the pancreatic ischemia due to generalized vasoconstriction of preeclampsia and loop diuretics in the setting of oliguria with renal failure, had a synergistic effect on the pancreas. Therefore, we suggest that in postpartum women with pregnancy-induced hypertension and acute renal failure, diuretics should be cautiously used because they may increase the risk of pancreatitis. PMID:12012278

  4. Resistance to mineralocorticoid-induced hypertensive vascular disease.

    PubMed

    Sciotti, V; Gallant, S

    1987-08-01

    To support our contention that the Wistar-Furth rat is resistant to mineralocorticoid hypertension, we assessed the effects of deoxycorticosterone (DOC) administration or renal artery stenosis on the development of hypertension in the Sprague-Dawley and Wistar-Furth rat strains. Weekly administration of mineralocorticoid in the form of DOC pivalate resulted in rapid, severe hypertensive cardiovascular disease in Sprague-Dawley rats. Within 5 weeks the mean conscious systolic blood pressures in steroid-treated and control rats were 186 +/- 4 and 118 +/- 5 mm Hg, respectively. In contrast, blood pressures of Wistar-Furth rats were only moderately elevated, even after 10 weeks of DOC pivalate administration (136 +/- 2 vs 116 +/- 2 mm Hg for controls). Furthermore, none of the steroid-treated Wistar-Furth animals exhibited cardiovascular lesions. In parallel studies, littermates of these rat strains were subjected to renal artery stenosis and blood pressures were determined weekly in conscious rats. Silver clip constriction of the left renal artery, in the presence of the contralateral kidney, resulted in a rapid, sustained elevation of blood pressure in both Sprague-Dawley and Wistar-Furth rat strains (177 +/- 4 and 176 +/- 5 mm Hg, respectively). Corticosteroid levels were also determined in DOC-treated Sprague-Dawley and Wistar-Furth rats. The regimen employed resulted in a 10-fold increase in DOC levels as compared with controls, and the levels achieved were comparable in both strains. Thus, the Wistar-Furth rat appears to be selectively resistant to mineralocorticoid hypertensive vascular disease and thus affords a model for studying mechanisms of steroid hypertension. PMID:3610293

  5. The Stability of the Small Nucleolar Ribonucleoprotein (snoRNP) Assembly Protein Pih1 in Saccharomyces cerevisiae Is Modulated by Its C Terminus*

    PubMed Central

    Paci, Alexandr; Liu, Xiao Hu; Huang, Hao; Lim, Abelyn; Houry, Walid A.; Zhao, Rongmin

    2012-01-01

    Pih1 is an unstable protein and a subunit of the R2TP complex that, in yeast Saccharomyces cerevisiae, also contains the helicases Rvb1, Rvb2, and the Hsp90 cofactor Tah1. Pih1 and the R2TP complex are required for the box C/D small nucleolar ribonucleoprotein (snoRNP) assembly and ribosomal RNA processing. Purified Pih1 tends to aggregate in vitro. Molecular chaperone Hsp90 and its cochaperone Tah1 are required for the stability of Pih1 in vivo. We had shown earlier that the C terminus of Pih1 destabilizes the protein and that the C terminus of Tah1 binds to the Pih1 C terminus to form a stable complex. Here, we analyzed the secondary structure of the Pih1 C terminus and identified two intrinsically disordered regions and five hydrophobic clusters. Site-directed mutagenesis indicated that one predicted intrinsically disordered region IDR2 is involved in Tah1 binding, and that the C terminus of Pih1 contains multiple destabilization or degron elements. Additionally, the Pih1 N-terminal domain, Pih11–230, was found to be able to complement the physiological role of full-length Pih1 at 37 °C. Pih11–230 as well as a shorter Pih1 N-terminal fragment Pih11–195 is able to bind Rvb1/Rvb2 heterocomplex. However, the sequence between the two disordered regions in Pih1 significantly enhances the Pih1 N-terminal domain binding to Rvb1/Rvb2. Based on these data, a model of protein-protein interactions within the R2TP complex is proposed. PMID:23139418

  6. The stability of the small nucleolar ribonucleoprotein (snoRNP) assembly protein Pih1 in Saccharomyces cerevisiae is modulated by its C terminus.

    PubMed

    Paci, Alexandr; Liu, Xiao Hu; Huang, Hao; Lim, Abelyn; Houry, Walid A; Zhao, Rongmin

    2012-12-21

    Pih1 is an unstable protein and a subunit of the R2TP complex that, in yeast Saccharomyces cerevisiae, also contains the helicases Rvb1, Rvb2, and the Hsp90 cofactor Tah1. Pih1 and the R2TP complex are required for the box C/D small nucleolar ribonucleoprotein (snoRNP) assembly and ribosomal RNA processing. Purified Pih1 tends to aggregate in vitro. Molecular chaperone Hsp90 and its cochaperone Tah1 are required for the stability of Pih1 in vivo. We had shown earlier that the C terminus of Pih1 destabilizes the protein and that the C terminus of Tah1 binds to the Pih1 C terminus to form a stable complex. Here, we analyzed the secondary structure of the Pih1 C terminus and identified two intrinsically disordered regions and five hydrophobic clusters. Site-directed mutagenesis indicated that one predicted intrinsically disordered region IDR2 is involved in Tah1 binding, and that the C terminus of Pih1 contains multiple destabilization or degron elements. Additionally, the Pih1 N-terminal domain, Pih1(1-230), was found to be able to complement the physiological role of full-length Pih1 at 37 °C. Pih1(1-230) as well as a shorter Pih1 N-terminal fragment Pih1(1-195) is able to bind Rvb1/Rvb2 heterocomplex. However, the sequence between the two disordered regions in Pih1 significantly enhances the Pih1 N-terminal domain binding to Rvb1/Rvb2. Based on these data, a model of protein-protein interactions within the R2TP complex is proposed. PMID:23139418

  7. Ciclosporin-induced hypertension is associated with increased sodium transporter of the loop of Henle (NKCC2)

    Microsoft Academic Search

    Elisabet Ars; Elena Guillen-Gomez; Josep Maria Campistol; Laia Sanz; Wladimiro Jimenez; Mark Alan Knepper; Ferran Torres; Roser Torra; JoseAurelio Ballarin; Patricia Fernandez-Llama

    2007-01-01

    Background. Hypertension induced by cyclosporine is associated with renal sodium and water retention. Using immunoblotting of kidney homogenates, we investigated the regulation of sodium and water transport proteins in a rat model of cyclosporine- induced hypertension. Methods. Rats were treated with cyclosporine (25 mg\\/ kg\\/day intraperitoneally) during 7 days. Control rats received vehicle. Results. Cyclosporine-treated rats had an increase in

  8. Structure of Minimal Tetratricopeptide Repeat Domain Protein Tah1 Reveals Mechanism of Its Interaction with Pih1 and Hsp90*

    PubMed Central

    Jiménez, Beatriz; Ugwu, Francisca; Zhao, Rongmin; Ortí, Leticia; Makhnevych, Taras; Pineda-Lucena, Antonio; Houry, Walid A.

    2012-01-01

    Tah1 and Pih1 are novel Hsp90 interactors. Tah1 acts as a cofactor of Hsp90 to stabilize Pih1. In yeast, Hsp90, Tah1, and Pih1 were found to form a complex that is required for ribosomal RNA processing through their effect on box C/D small nucleolar ribonucleoprotein assembly. Tah1 is a minimal tetratricopeptide repeat protein of 111 amino acid residues that binds to the C terminus of the Hsp90 molecular chaperone, whereas Pih1 consists of 344 residues of unknown fold. The NMR structure of Tah1 has been solved, and this structure shows the presence of two tetratricopeptide repeat motifs followed by a C helix and an unstructured region. The binding of Tah1 to Hsp90 is mediated by the EEVD C-terminal residues of Hsp90, which bind to a positively charged channel formed by Tah1. Five highly conserved residues, which form a two-carboxylate clamp that tightly interacts with the ultimate Asp-0 residue of the bound peptide, are also present in Tah1. Tah1 was found to bind to the C terminus of Pih1 through the C helix and the unstructured region. The C terminus of Pih1 destabilizes the protein in vitro and in vivo, whereas the binding of Tah1 to Pih1 allows for the formation of a stable complex. Based on our data, a model for an Hsp90-Tah1-Pih1 ternary complex is proposed. PMID:22179618

  9. Portopulmonary hypertension.

    PubMed

    Mukhtar, Nizar A; Fix, Oren K

    2011-09-01

    The development of pulmonary arterial hypertension in the setting of portal hypertension is known as portopulmonary hypertension. Portal hypertension is thought to predispose patients to disturbances in the homeostatic regulation of numerous neurohumoral and vasoactive mediators that induce the development of pulmonary arterial hypertension. Portopulmonary hypertension is pathologically indistinguishable from idiopathic pulmonary arterial hypertension and is characterized by the development of vasoconstriction, vascular remodeling, and thrombosis within the pulmonary vasculature. Although described in patients with both cirrhotic and noncirrhotic portal hypertension, portopulmonary hypertension is most prevalent among patients with end-stage liver disease, and its severity seems to be independent of the etiology or severity of liver disease. All liver transplant candidates must be screened for the presence of portopulmonary hypertension because of the high perioperative mortality risk of liver transplantation associated with this condition. Primary screening for portopulmonary hypertension consists of Doppler-estimated pulmonary artery systolic pressure measurement during echocardiography. However, the diagnosis of portopulmonary hypertension is based on unique hemodynamic criteria as determined by right heart catheterization. Untreated portopulmonary hypertension portends a poor prognosis, and the efficacy of current treatment modalities is limited. At present, the primary goals of therapy are to provide symptomatic relief, prolong survival, and improve pulmonary hemodynamics to facilitate safe and successful liver transplantation. PMID:21325952

  10. Resolution of pulmonary hypertension complication during venovenous perfusion-induced systemic hyperthermia application.

    PubMed

    Ballard-Croft, Cherry; Wang, Dongfang; Jones, Cameron; Wang, Jingkun; Pollock, Robert; Jubak, Bob; Topaz, Stephen; Zwischenberger, Joseph B

    2013-01-01

    We are developing a venovenous perfusion-induced systemic hyperthermia (vv-PISH) system for advanced cancer treatment. The vv-PISH system consistently delivered hyperthermia to adult healthy swine, but significant pulmonary hypertension developed during the heating phase. The goal of this study was to develop a method to prevent pulmonary hypertension. We hypothesized that pulmonary hypertension results from decreased priming solution air solubility, which causes pulmonary gas embolism. Healthy adult sheep (n = 3) were used to establish a standard vv-PISH sheep model without priming solution preheating. In subsequent sheep (n = 7), the priming solution was preheated (42-46°C) and the hyperthermia circuit flushed with CO2. All sheep survived the experiment and achieved 2 hours of 42°C hyperthermia. In the group lacking priming solution preheating, significant pulmonary hypertension (35-44 mm?Hg) developed. In the sheep with priming solution preheating, pulmonary artery pressure was very stable without pulmonary hypertension. Blood electrolytes were in physiologic range, and complete blood counts were unaffected by hyperthermia. Blood chemistries revealed no significant liver or kidney damage. Our simple strategy of priming solution preheating completely resolved the problem of pulmonary hypertension as a milestone toward developing a safe and easy-to-use vv-PISH system for cancer treatment. PMID:23820278

  11. Posterior reversible encephalopathy syndrome from induced hypertension during endovascular thoracoabdominal aortic aneurysm repair.

    PubMed

    Oderich, Gustavo S; Pereira, Alexandre A; Rabinstein, Alejandro A; Mendes, Bernardo C; Pulido, Juan N

    2015-04-01

    Endovascular repair of thoracoabdominal aortic aneurysm has been increasingly performed using fenestrated and branched endografts. Spinal cord injury is a complication of complex endovascular aortic repair, especially in patients with extensive aortic involvement. Maneuvers commonly used to avoid spinal cord injury include cerebrospinal fluid drainage and induced hypertension. Posterior reversible encephalopathy syndrome is associated with abnormal cerebral autoregulation through endothelial and blood-brain barrier dysfunction; the pathophysiology involves vasogenic edema, and severe hypertension is a recognized trigger. We report on a patient who developed posterior reversible encephalopathy syndrome associated with induced hypertension used to prevent spinal cord injury during endovascular repair of a type II thoracoabdominal aortic aneurysm using fenestrated and branched stent grafts. PMID:24365121

  12. Antihypertensive Effect of Radix Paeoniae Alba in Spontaneously Hypertensive Rats and Excessive Alcohol Intake and High Fat Diet Induced Hypertensive Rats

    PubMed Central

    Su-Hong, Chen; Qi, Chen; Bo, Li; Jian-Li, Gao; Jie, Su; Gui-Yuan, Lv

    2015-01-01

    Radix Paeoniae Alba (Baishao, RPA) has long been used in traditional Chinese medicine formulation to treat hypertension by repression the hyperfunction of liver. However, whether the RPA itself has the antihypertensive effect or not is seldom studied. This study was to evaluate the protective effect of RPA on hypertensive rats. Alcohol in conjunction with a high fat diet- (ACHFD-) induced hypertensive rats and spontaneously hypertensive rats (SHR) was constantly received either RPA extract (25 or 75?mg/kg) or captopril (15?mg/kg) all along the experiments. As a result, RPA extract (75?mg/kg) could significantly reduce systolic blood pressure of both ACHFD-induced hypertensive rats and SHR after 9-week or 4-week treatment. In ACHFD-induced hypertensive rats, the blood pressure was significantly increased and the lipid profiles in serum including triglyceride, total cholesterol, LDL-cholesterol, and HDL-cholesterol were significantly deteriorated. Also, hepatic damage was manifested by a significant increase in alanine transaminase (ALT) and aspartate transaminase (AST) in serum. The RPA extract significantly reversed these parameters, which revealed that it could alleviate the liver damage of rats. In SHR, our result suggested that the antihypertensive active of RPA extract may be related to its effect on regulating serum nitric oxide (NO) and endothelin (ET) levels. PMID:25784949

  13. Hepatoprotective Effect of Silymarin (Silybum marianum) on Hepatotoxicity Induced by Acetaminophen in Spontaneously Hypertensive Rats.

    PubMed

    Freitag, Abel Felipe; Cardia, Gabriel Fernando Esteves; da Rocha, Bruno Ambrósio; Aguiar, Rafael Pazzinatto; Silva-Comar, Francielli Maria de Souza; Spironello, Ricardo Alexandre; Grespan, Renata; Caparroz-Assef, Silvana Martins; Bersani-Amado, Ciomar Aparecida; Cuman, Roberto Kenji Nakamura

    2015-01-01

    This study was aimed to investigate the effect of Silymarin (SLM) on the hypertension state and the liver function changes induced by acetaminophen (APAP) in spontaneously hypertensive rat (SHR). Animals normotensive (N) or hypertensive (SHR) were treated or not with APAP (3?g/kg, oral) or previously treated with SLM. Twelve hours after APAP administration, plasmatic levels of liver function markers: alanine aminotransferase (ALT), aspartate aminotransferase (AST), glucose (GLU), gamma glutamyl transferase (?-GT), and alkaline phosphatase (ALP) of all groups, were determined. Liver injury was assessed using histological studies. Samples of their livers were then used to determine the myeloperoxidase (MPO) activity and nitric oxide (NO) production and were also sectioned for histological analysis. No differences were observed for ALT, ?-GT, and GLU levels between SHR and normotensive rats groups. However, AST and ALP levels were increased in hypertensive animals. APAP treatment promoted an increase in ALT and AST in both SHR and N. However, only for SHR, ?-GT levels were increased. The inflammatory response evaluated by MPO activity and NO production showed that SHR was more susceptible to APAP effect, by increasing leucocyte infiltration. Silymarin treatment (Legalon) restored the hepatocyte functional and histopathological alterations induced by APAP in normotensive and hypertensive animals. PMID:25821491

  14. Hepatoprotective Effect of Silymarin (Silybum marianum) on Hepatotoxicity Induced by Acetaminophen in Spontaneously Hypertensive Rats

    PubMed Central

    Cardia, Gabriel Fernando Esteves; da Rocha, Bruno Ambrósio; Aguiar, Rafael Pazzinatto; Spironello, Ricardo Alexandre; Caparroz-Assef, Silvana Martins; Bersani-Amado, Ciomar Aparecida; Cuman, Roberto Kenji Nakamura

    2015-01-01

    This study was aimed to investigate the effect of Silymarin (SLM) on the hypertension state and the liver function changes induced by acetaminophen (APAP) in spontaneously hypertensive rat (SHR). Animals normotensive (N) or hypertensive (SHR) were treated or not with APAP (3?g/kg, oral) or previously treated with SLM. Twelve hours after APAP administration, plasmatic levels of liver function markers: alanine aminotransferase (ALT), aspartate aminotransferase (AST), glucose (GLU), gamma glutamyl transferase (?-GT), and alkaline phosphatase (ALP) of all groups, were determined. Liver injury was assessed using histological studies. Samples of their livers were then used to determine the myeloperoxidase (MPO) activity and nitric oxide (NO) production and were also sectioned for histological analysis. No differences were observed for ALT, ?-GT, and GLU levels between SHR and normotensive rats groups. However, AST and ALP levels were increased in hypertensive animals. APAP treatment promoted an increase in ALT and AST in both SHR and N. However, only for SHR, ?-GT levels were increased. The inflammatory response evaluated by MPO activity and NO production showed that SHR was more susceptible to APAP effect, by increasing leucocyte infiltration. Silymarin treatment (Legalon) restored the hepatocyte functional and histopathological alterations induced by APAP in normotensive and hypertensive animals.

  15. Long-term therapy of interferon-alpha induced pulmonary arterial hypertension with different PDE-5 inhibitors: a case report

    PubMed Central

    Jochmann, Nicoline; Kiecker, Felix; Borges, Adrian C; Hofmann, Maja A; Eddicks, Stephan; Sterry, Wolfram; Baumann, Gert; Trefzer, Uwe

    2005-01-01

    background Interferon alpha2 is widely used in hepatitis and high-risk melanoma. Interferon-induced pulmonary arterial hypertension as a side effect is rare. Case presentation We describe a melanoma patient who developed severe pulmonary arterial hypertension 30 months after initiation of adjuvant interferon alpha2b therapy. Discontinuation of interferon did not improve pulmonary arterial hypertension. This patient could be treated successfully with phosphodiesterase-5 inhibitor therapy. Conclusion This is only the 5th case of interferon-induced pulmonary arterial hypertension and the first documented case where pulmonary arterial hypertension was not reversible after termination of interferon alpha2 therapy. If interferon alpha2 treated patients develop respiratory symptoms, pulmonary arterial hypertension should be considered in the differential diagnosis. For these patients phosphodiesterase-5 inhibitors, e.g. sildenafil or vardenafil, could be an effective therapeutic approach. PMID:16138923

  16. Excess PTH in CRF induces pulmonary calcification, pulmonary hypertension and right ventricular hypertrophy

    Microsoft Academic Search

    Mohammad Akmal; Robert R Barndt; Azizullah N Ansari; John G Mohler; Shaul G Massry

    1995-01-01

    Excess PTH in CRF induces pulmonary calcification, pulmonary hypertension and right ventricular hypertrophy. Calcification of the lungs occurs in chronic renal failure (CRF) and may adversely affect both pulmonary and right ventricular function. The present study examined the role of excess parathyroid hormone (PTH) in the genesis of pulmonary calcifications in dogs with experimental CRF and evaluated calcium content of

  17. Effect of Magnesium Lithospermate B in Rats with Sodium-Induced Hypertension and Renal Failure

    Microsoft Academic Search

    Takako Yokozawa; Tae Woong Lee; Hikokichi Oura; Gen-ichiro Nonaka; Itsuo Nishioka

    1992-01-01

    To evaluate the antihypertensive effect of magnesium lithospermate B isolated from Salviae miltiorrhizae radix, determinations of blood pressure and urinary excretions of sodium, potassium, prostaglandin E2 (PGE2) and kallikrein, which have been proposed to play an important role in the regulation of blood pressure, were made in rats with sodium-induced hypertension and renal failure. In rats given magnesium lithospermate B,

  18. Overfeeding-Induced Obesity in Spontaneously Hypertensive Rats: An Animal Model of the Human Metabolic Syndrome

    Microsoft Academic Search

    Anja Miesel; Helge Müller; Margot Thermann; Marc Heidbreder; Peter Dominiak; Walter Raasch

    2010-01-01

    Background\\/Aims: The metabolic syndrome (MS) has become an epidemiological problem in Western countries. We developed a diet-induced obese rat model that mimics all the symptoms of MS in humans, but whose insulin resistance, hyperphagia and hyperleptinemia are caused by nutrition rather than genetic modifications. Methods: Spontaneously hypertensive rats (SHR) were allowed for 12 weeks to choose between a cafeteria diet

  19. The Role of NADPH Oxidase in Chronic Intermittent Hypoxia-Induced Pulmonary Hypertension in Mice

    PubMed Central

    Nisbet, Rachel E.; Graves, Anitra S.; Kleinhenz, Dean J.; Rupnow, Heidi L.; Reed, Alana L.; Fan, Tai-Hwang M.; Mitchell, Patrick O.; Sutliff, Roy L.; Hart, C. Michael

    2009-01-01

    Obstructive sleep apnea, characterized by intermittent periods of hypoxemia, is an independent risk factor for the development of pulmonary hypertension. However, the exact mechanisms of this disorder remain to be defined. Enhanced NADPH oxidase expression and superoxide (O2?·) generation in the pulmonary vasculature play a critical role in hypoxia-induced pulmonary hypertension. Therefore, the current study explores the hypothesis that chronic intermittent hypoxia (CIH) causes pulmonary hypertension, in part, by increasing NADPH oxidase–derived reactive oxygen species (ROS) that contribute to pulmonary vascular remodeling and hypertension. To test this hypothesis, male C57Bl/6 mice and gp91phox knockout mice were exposed to CIH for 8 hours per day, 5 days per week for 8 weeks. CIH mice were placed in a chamber where the oxygen concentration was cycled between 21% and 10% O2 45 times per hour. Exposure to CIH for 8 weeks increased right ventricular systolic pressure (RVSP), right ventricle (RV):left ventricle (LV) + septum (S) weight ratio, an index of RV hypertrophy, and thickness of the right ventricular anterior wall as measured by echocardiography. CIH exposure also caused pulmonary vascular remodeling as demonstrated by increased muscularization of the distal pulmonary vasculature. CIH-induced pulmonary hypertension was associated with increased lung levels of the NADPH oxidase subunits, Nox4 and p22phox, as well as increased activity of platelet-derived growth factor receptor ? and its associated downstream effector, Akt kinase. These CIH-induced derangements were attenuated in similarly treated gp91phox knockout mice. These findings demonstrate that NADPH oxidase–derived ROS contribute to the development of pulmonary vascular remodeling and hypertension caused by CIH. PMID:18952568

  20. Gender differences in the attenuation of salt-induced hypertension by angiotensin (1-7)

    Microsoft Academic Search

    Danita Eatman; Min Wang; Robin R. Socci; Myrtle Thierry-Palmer; Nerimiah Emmett; Mohamed A. Bayorh

    2001-01-01

    Chronic infusion of angiotensin (1-7) [Ang-(1-7)] lowers blood pressure in spontaneously hypertensive rats (SHR). To assess the role of Ang-(1-7) in salt-induced hypertension, Ang-(1-7) (24 ?g\\/kg\\/hr) or saline was administered chronically via osmotic minipump into the jugular vein of 5–6 wk-old male (M) and female (F) Dahl salt-sensitive rats placed on a high-salt (8% NaCl) diet for 2 weeks. Blood

  1. Pharmacological treatment of antipsychotic-induced dyslipidemia and hypertension.

    PubMed

    Tse, Lurdes; Procyshyn, Ric M; Fredrikson, Diane H; Boyda, Heidi N; Honer, William G; Barr, Alasdair M

    2014-05-01

    Second-generation antipsychotics (SGAs) are associated with significant comorbid metabolic abnormalities. Adjunct medications may be prescribed to treat these metabolic side effects, but the evidence supporting this practice (especially for the management of antipsychotic-associated dyslipidemia and hypertension) is limited. The purpose of this review was to evaluate the effects of adjunct medications on triglyceride, total cholesterol, low-density lipoprotein, high-density lipoprotein, and blood pressure levels in participants taking SGAs for psychosis. Studies were systematically searched and evaluated. Studies were included for review if participants were taking SGAs and if lipid and/or blood pressure levels were included as outcome measures. Statins, conventional lipid-lowering agents, fluvoxamine, ramelteon, topiramate, valsartan, telmisartan, omega-3 fatty acids, metformin (including both immediate-release and extended-release formulations), and a combination of metformin-sibutramine seemed to have beneficial effects on lipid levels. Valsartan, telmisartan, and topiramate appeared to be effective for controlling increases in blood pressure. The literature on adjunct medications for the treatment of antipsychotic-associated dyslipidemia and hypertension is not exhaustive, and long-term randomized-controlled trials would offer valuable results. PMID:24169026

  2. Antioxidant effects of bovine lactoferrin on dexamethasone-induced hypertension in rat.

    PubMed

    Safaeian, Leila; Zabolian, Hadi

    2014-01-01

    Dexamethasone- (Dex-) induced hypertension is associated with enhanced oxidative stress. Lactoferrin (LF) is an iron-binding glycoprotein with antihypertensive properties. In this study, we investigated the effect of chronic administration of LF on oxidative stress and hypertension upon Dex administration. Male Wistar rats were treated by Dex (30? ? g/kg/day subcutaneously) or saline for 14 days. Oral bovine LF (30, 100, 300?mg/kg) was given from day 8 to 14 in a reversal study. In a prevention study, rats received 4 days of LF treatment followed by Dex and continued during the test period. Systolic blood pressure (SBP) was measured using tail-cuff method. Thymus weight was used as a marker of glucocorticoid activity. Plasma hydrogen peroxide (H2O2) concentration and ferric reducing antioxidant power (FRAP) value were determined. Dexamethasone significantly increased SBP and plasma H2O2 level and decreased thymus and body weights. LF lowered (P < 0.01) and dose dependently prevented (P < 0.001) Dex-induced hypertension. LF prevented body weight loss and significantly reduced the elevated plasma H2O2 and increased FRAP values. Chronic administration of LF strongly reduced the blood pressure and production of ROS and improved antioxidant capacity in Dex-induced hypertension, suggesting the role of inhibition of oxidative stress as another mechanism of antihypertensive action of LF. PMID:24587916

  3. Discrete PIH proteins function in the cytoplasmic preassembly of different subsets of axonemal dyneins

    PubMed Central

    Yamamoto, Ryosuke; Hirono, Masafumi

    2010-01-01

    Axonemal dyneins are preassembled in the cytoplasm before being transported into cilia and flagella. Recently, PF13/KTU, a conserved protein containing a PIH (protein interacting with HSP90) domain, was identified as a protein responsible for dynein preassembly in humans and Chlamydomonas reinhardtii. This protein is involved in the preassembly of outer arm dynein and some inner arm dyneins, possibly as a cofactor of molecular chaperones. However, it is not known which factors function in the preassembly of other inner arm dyneins. Here, we analyzed a novel C. reinhardtii mutant, ida10, and found that another conserved PIH family protein, MOT48, is responsible for the formation of another subset of inner arm dyneins. A variety of organisms with motile cilia and flagella typically have three to four PIH proteins, including potential homologues of MOT48 and PF13/KTU, whereas organisms without them have no, or only one, such protein. These findings raise the possibility that multiple PIH proteins are commonly involved in the preassembly of different subsets of axonemal dyneins. PMID:20603327

  4. Phosphorylation-Dependent PIH1D1 Interactions Define Substrate Specificity of the R2TP Cochaperone Complex

    PubMed Central

    Ho?ejší, Zuzana; Stach, Lasse; Flower, Thomas G.; Joshi, Dhira; Flynn, Helen; Skehel, J. Mark; O’Reilly, Nicola J.; Ogrodowicz, Roksana W.; Smerdon, Stephen J.; Boulton, Simon J.

    2014-01-01

    Summary The R2TP cochaperone complex plays a critical role in the assembly of multisubunit machines, including small nucleolar ribonucleoproteins (snoRNPs), RNA polymerase II, and the mTORC1 and SMG1 kinase complexes, but the molecular basis of substrate recognition remains unclear. Here, we describe a phosphopeptide binding domain (PIH-N) in the PIH1D1 subunit of the R2TP complex that preferentially binds to highly acidic phosphorylated proteins. A cocrystal structure of a PIH-N domain/TEL2 phosphopeptide complex reveals a highly specific phosphopeptide recognition mechanism in which Lys57 and 64 in PIH1D1, along with a conserved DpSDD phosphopeptide motif within TEL2, are essential and sufficient for binding. Proteomic analysis of PIH1D1 interactors identified R2TP complex substrates that are recruited by the PIH-N domain in a sequence-specific and phosphorylation-dependent manner suggestive of a common mechanism of substrate recognition. We propose that protein complexes assembled by the R2TP complex are defined by phosphorylation of a specific motif and recognition by the PIH1D1 subunit. PMID:24656813

  5. Phosphorylation-dependent PIH1D1 interactions define substrate specificity of the R2TP cochaperone complex.

    PubMed

    Ho?ejší, Zuzana; Stach, Lasse; Flower, Thomas G; Joshi, Dhira; Flynn, Helen; Skehel, J Mark; O'Reilly, Nicola J; Ogrodowicz, Roksana W; Smerdon, Stephen J; Boulton, Simon J

    2014-04-10

    The R2TP cochaperone complex plays a critical role in the assembly of multisubunit machines, including small nucleolar ribonucleoproteins (snoRNPs), RNA polymerase II, and the mTORC1 and SMG1 kinase complexes, but the molecular basis of substrate recognition remains unclear. Here, we describe a phosphopeptide binding domain (PIH-N) in the PIH1D1 subunit of the R2TP complex that preferentially binds to highly acidic phosphorylated proteins. A cocrystal structure of a PIH-N domain/TEL2 phosphopeptide complex reveals a highly specific phosphopeptide recognition mechanism in which Lys57 and 64 in PIH1D1, along with a conserved DpSDD phosphopeptide motif within TEL2, are essential and sufficient for binding. Proteomic analysis of PIH1D1 interactors identified R2TP complex substrates that are recruited by the PIH-N domain in a sequence-specific and phosphorylation-dependent manner suggestive of a common mechanism of substrate recognition. We propose that protein complexes assembled by the R2TP complex are defined by phosphorylation of a specific motif and recognition by the PIH1D1 subunit. PMID:24656813

  6. Exercise-induced hypertension among healthy firefighters-a comparison between two different definitions.

    PubMed

    Leiba, Adi; Baur, Dorothee M; Kales, Stefanos N

    2013-01-01

    Different studies have yielded conflicting results regarding the association of hypertensive response to exercise and cardiovascular morbidity. We compared two different definitions of exaggerated hypertensive response to exercise and their association with cardio-respiratory fitness in a population of healthy firefighters. We examined blood pressure response to exercise in 720 normotensive male career firefighters. Fitness was measured as peak metabolic equivalent tasks (METs) achieved during maximal exercise treadmill tests. Abnormal hypertensive response was defined either as systolic blood pressure ? 200 mm Hg; or alternatively, as responses falling in the upper tertile of blood pressure change from rest to exertion, divided by the maximal workload achieved. Using the simple definition of a 200 mm Hg cutoff at peak exercise less fit individuals (METs ? 12) were protected from an exaggerated hypertensive response (OR 0.45, 95%CI 0.30-0.67). However, using the definition of exercise-induced hypertension that corrects for maximal workload, less fit firefighters had almost twice the risk (OR 1.8, 95%CI 1.3-2.47). Blood pressure change corrected for maximal workload is better correlated with cardiorespiratory fitness. Systolic blood pressure elevation during peak exercise likely represents an adaptive response, whereas elevation out of proportion to the maximal workload may indicate insufficient vasodilation and a maladaptive response. Prospective studies are needed to best define exaggerated blood pressure response to exercise. PMID:23246464

  7. NFATc3 is required for chronic hypoxia-induced pulmonary hypertension in adult and neonatal mice.

    PubMed

    Bierer, R; Nitta, C H; Friedman, J; Codianni, S; de Frutos, S; Dominguez-Bautista, J A; Howard, T A; Resta, T C; Bosc, L V Gonzalez

    2011-12-01

    Pulmonary hypertension occurs with prolonged exposure to chronic hypoxia in both adults and neonates. The Ca(2+)-dependent transcription factor, nuclear factor of activated T cells isoform c3 (NFATc3), has been implicated in chronic hypoxia-induced pulmonary arterial remodeling in adult mice. Therefore, we hypothesized that NFATc3 is required for chronic hypoxia-induced pulmonary hypertension in adult and neonatal mice. The aim of this study was to determine whether 1) NFATc3 mediates chronic hypoxia-induced increases in right ventricular systolic pressure in adult mice; 2) NFATc3 is activated in neonatal mice exposed to chronic hypoxia; and 3) NFATc3 is involved in chronic hypoxia-induced right ventricular hypertrophy and pulmonary vascular remodeling in neonatal mice. Adult mice were exposed to hypobaric hypoxia for 2, 7, and 21 days. Neonatal mouse pups were exposed for 7 days to hypobaric chronic hypoxia within 2 days after delivery. Hypoxia-induced increases in right ventricular systolic pressure were absent in NFATc3 knockout adult mice. In neonatal mice, chronic hypoxia caused NFAT activation in whole lung and nuclear accumulation of NFATc3 in both pulmonary vascular smooth muscle and endothelial cells. In addition, heterozygous NFATc3 neonates showed less right ventricular hypertrophy and pulmonary artery wall thickness in response to chronic hypoxia than did wild-type neonates. Our results suggest that NFATc3 mediates pulmonary hypertension and vascular remodeling in both adult and neonatal mice. PMID:21908592

  8. Pulmonary hypertension

    MedlinePLUS

    Pulmonary arterial hypertension; Sporadic primary pulmonary hypertension; Familial primary pulmonary hypertension; Idiopathic pulmonary arterial hypertension; Primary pulmonary hypertension; PPH; Secondary pulmonary hypertension

  9. Loss of functional endothelial connexin40 results in exercise-induced hypertension in mice.

    PubMed

    Morton, Susan K; Chaston, Daniel J; Howitt, Lauren; Heisler, Jillian; Nicholson, Bruce J; Fairweather, Stephen; Bröer, Stefan; Ashton, Anthony W; Matthaei, Klaus I; Hill, Caryl E

    2015-03-01

    During activity, coordinated vasodilation of microcirculatory networks with upstream supply vessels increases blood flow to skeletal and cardiac muscles and reduces peripheral resistance. Endothelial dysfunction in humans attenuates activity-dependent vasodilation, resulting in exercise-induced hypertension in otherwise normotensive individuals. Underpinning activity-dependent hyperemia is an ascending vasodilation in which the endothelial gap junction protein, connexin (Cx)40, plays an essential role. Because exercise-induced hypertension is proposed as a forerunner to clinical hypertension, we hypothesized that endothelial disruption of Cx40 function in mice may create an animal model of this condition. To this end, we created mice in which a mutant Cx40T152A was expressed alongside wildtype Cx40 selectively in the endothelium. Expression of the Cx40T152A transgene in Xenopus oocytes and mouse coronary endothelial cells in vitro impaired both electric and chemical conductance and acted as a dominant-negative against wildtype Cx40, Cx43, and Cx45, but not Cx37. Endothelial expression of Cx40T152A in Cx40T152ATg mice attenuated ascending vasodilation, without effect on radial coupling through myoendothelial gap junctions. Using radiotelemetry, Cx40T152ATg mice showed an activity-dependent increase in blood pressure, which was significantly greater than in wildtype mice, but significantly less than in chronically hypertensive, Cx40knockout mice. The increase in heart rate with activity was also greater than in wildtype or Cx40knockout mice. We conclude that the endothelial Cx40T152A mutation attenuates activity-dependent vasodilation, producing a model of exercise-induced hypertension. These data highlight the importance of endothelial coupling through Cx40 in regulating blood pressure during activity. PMID:25547341

  10. Targeted mutation of SLC4A5 induces arterial hypertension and renal metabolic acidosis.

    PubMed

    Gröger, Nicole; Vitzthum, Helga; Fröhlich, Henning; Krüger, Marcus; Ehmke, Heimo; Braun, Thomas; Boettger, Thomas

    2012-03-01

    The human SLC4A5 gene has been identified as a hypertension susceptibility gene based on the association of single nucleotide polymorphisms with blood pressure (BP) levels and hypertension status. The biochemical basis of this association is unknown particularly since no single gene variant was linked to hypertension in humans. SLC4A5 (NBCe2, NBC4) is expressed in the collecting duct of the kidney and acts as an electrogenic ion-transporter that transports sodium and bicarbonate with a 1:2 or 1:3 stoichiometry allowing bicarbonate reabsorption with relatively minor concurrent sodium uptake. We have mutated the Slc4a5 gene in mice, which caused a persistent increase in systolic and diastolic BP. Slc4a5 mutant mice also displayed a compensated metabolic acidosis and hyporeninemic hypoaldosteronism. Analysis of kidney physiology revealed elevated fluid intake and urine excretion and increased glomerular filtration rate. Transcriptome analysis uncovers possible compensatory mechanisms induced by SLC4A5 mutation, including upregulation of SLC4A7 and pendrin as well as molecular mechanisms associated with hypertension. Induction of metabolic alkalosis eliminated the BP difference between wild-type and Slc4a5 mutant mice. We conclude that the impairment of the function of SLC4A5 favors development of a hypertensive state. We reason that the loss of sodium-sparing bicarbonate reabsorption by SLC4A5 initiates a regulatory cascade consisting of compensatory bicarbonate reabsorption via other sodium-bicarbonate transporters (e.g. SLC4A7) at the expense of an increased sodium uptake. This will ultimately raise BP and cause hypoaldosteronism, thus providing a mechanistic explanation for the linkage of the SLC4A5 locus to hypertension in humans. PMID:22082831

  11. Mechanisms of lead-induced hypertension and cardiovascular disease

    PubMed Central

    Vaziri, Nosratola D.

    2008-01-01

    Lead is a ubiquitous environmental toxin that is capable of causing numerous acute and chronic illnesses. Population studies have demonstrated a link between lead exposure and subsequent development of hypertension (HTN) and cardiovascular disease. In vivo and in vitro studies have shown that chronic lead exposure causes HTN and cardiovascular disease by promoting oxidative stress, limiting nitric oxide availability, impairing nitric oxide signaling, augmenting adrenergic activity, increasing endothelin production, altering the renin-angiotensin system, raising vasoconstrictor prostaglandins, lowering vasodilator prostaglandins, promoting inflammation, disturbing vascular smooth muscle Ca2+ signaling, diminishing endothelium-dependent vasorelaxation, and modifying the vascular response to vasoactive agonists. Moreover, lead has been shown to cause endothelial injury, impede endothelial repair, inhibit angiogenesis, reduce endothelial cell growth, suppress proteoglycan production, stimulate vascular smooth muscle cell proliferation and phenotypic transformation, reduce tissue plasminogen activator, and raise plasminogen activator inhibitor-1 production. Via these and other actions, lead exposure causes HTN and promotes arteriosclerosis, atherosclerosis, thrombosis, and cardiovascular disease. In conclusion, studies performed in experimental animals, isolated tissues, and cultured cells have provided compelling evidence that chronic exposure to low levels of lead can cause HTN, endothelial injury/dysfunction, arteriosclerosis, and cardiovascular disease. More importantly, these studies have elucidated the cellular and molecular mechanisms of lead's action on cardiovascular/renal systems, a task that is impossible to accomplish using clinical and epidemiological investigations alone. PMID:18567711

  12. Arrhythmogenic substrate in hearts of rats with monocrotaline-induced pulmonary hypertension and right ventricular hypertrophy.

    PubMed

    Benoist, David; Stones, Rachel; Drinkhill, Mark; Bernus, Olivier; White, Ed

    2011-06-01

    Mechanisms associated with right ventricular (RV) hypertension and arrhythmias are less understood than those in the left ventricle (LV). The aim of our study was to investigate whether and by what mechanisms a proarrhythmic substrate exists in a rat model of RV hypertension and hypertrophy. Rats were injected with monocrotaline (MCT; 60 mg/kg) to induce pulmonary artery hypertension or with saline (CON). Myocardial levels of mRNA for genes expressing ion channels were measured by real-time RT-PCR. Monophasic action potential duration (MAPD) was recorded in isolated Langendorff-perfused hearts. MAPD restitution was measured, and arrhythmias were induced by burst stimulation. Twenty-two to twenty-six days after treatment, MCT animals had RV hypertension, hypertrophy, and decreased ejection fractions compared with CON. A greater proportion of MCT hearts developed sustained ventricular tachycardias/fibrillation (0.83 MCT vs. 0.14 CON). MAPD was prolonged in RV and less so in the LV of MCT hearts. There were decreased levels of mRNA for K(+) channels. Restitution curves of MCT RV were steeper than CON RV or either LV. Dispersion of MAPD was greater in MCT hearts and was dependent on stimulation frequency. Computer simulations based on ion channel gene expression closely predicted experimental changes in MAPD and restitution. We have identified a proarrhythmic substrate in the hearts of MCT-treated rats. We conclude that steeper RV electrical restitution and rate-dependant RV-LV action potential duration dispersion may be contributing mechanisms and be implicated in the generation of arrhythmias associated with in RV hypertension and hypertrophy. PMID:21398591

  13. Brain-mediated dysregulation of the bone marrow activity in angiotensin II-induced hypertension.

    PubMed

    Jun, Joo Yun; Zubcevic, Jasenka; Qi, Yanfei; Afzal, Aqeela; Carvajal, Jessica Marulanda; Thinschmidt, Jeffrey S; Grant, Maria B; Mocco, J; Raizada, Mohan K

    2012-11-01

    Oxidative stress in the brain is implicated in increased sympathetic drive, inflammatory status, and vascular dysfunctions, associated with development and establishment of hypertension. However, little is known about the mechanism of this impaired brain-vascular communication. Here, we tested the hypothesis that increased oxidative stress in the brain cardioregulatory areas, such as the paraventricular nucleus of the hypothalamus, is driven by mitochondrial reactive oxygen species and leads to increased inflammatory cells (ICs) and decreased/dysfunctional endothelial progenitor cells (EPCs), thereby compromising vasculature repair and accelerating hypertension. Chronic angiotensin II infusion resulted in elevated blood pressure and sympathetic vasomotor drive, decreased spontaneous baroreflex gain, and increased microglia activation in the paraventricular nucleus. This was associated with 46% decrease in bone marrow (BM)-derived EPCs and 250% increase in BM ICs, resulting in 5-fold decrease of EPC/IC ratio in the BM. Treatment with mitochondrial-targeted antioxidant, a scavenger of mitochondrial O(2)(-·), intracerebroventricularly but not subcutaneously attenuated angiotensin II-induced hypertension, decreased activation of microglia in the paraventricular nucleus, and normalized EPCs/ICs. This functional communication between the brain and BM was confirmed by retrograde neuronal labeling from the BM with green fluorescent protein-tagged pseudorabies virus. Administration of green fluorescent protein-tagged pseudorabies virus into the BM resulted in predominant labeling of paraventricular nucleus neurons within 3 days, with some fluorescence in the nucleus tractus solitarius, the rostral ventrolateral medulla, and subfornical organ. Taken together, these data demonstrate that inhibition of mitochondrial reactive oxygen species attenuates angiotensin II-induced hypertension and corrects the imbalance in EPCs/ICs in the BM. They suggest that an imbalance in vascular reparative and ICs may perpetuate vascular pathophysiology in this model of hypertension. PMID:23045460

  14. Brain-Mediated Dysregulation of the Bone Marrow Activity in Angiotensin II-induced Hypertension

    PubMed Central

    Jun, Joo Yun; Zubcevic, Jasenka; Qi, Yanfei; Afzal, Aqeela; Carvajal, Jessica Marulanda; Thinschmidt, Jeffrey S; Grant, Maria B.; Mocco, J; Raizada, Mohan K

    2012-01-01

    Oxidative stress in the brain is implicated in increased sympathetic drive, inflammatory status and vascular dysfunctions, associated with development and establishment of hypertension. However, little is known about the mechanism of this impaired brain-vascular communication. Here, we tested the hypothesis that increased oxidative stress in the brain cardioregulatory areas, such as the paraventricular nucleus (PVN) of the hypothalamus, is driven by mitochondrial reactive oxygen species (ROS) and leads to increased inflammatory cells (ICs) and decreased/dysfunctional endothelial progenitor cells (EPCs), thereby compromising vasculature repair and accelerating hypertension. Chronic angiotensin II (Ang II) infusion resulted in elevated blood pressure and sympathetic vasomotor drive, decreased spontaneous baroreflex gain, and increased microglia activation in the PVN. This was associated with 46% decrease in BM EPCs and 250% increase in BM ICs, resulting in 5 fold decrease of EPCs/ICs ratio in the BM. Treatment with mitoTEMPO, a scavenger of mitochondrial O2?• intracerebroventricularly but not subcutaneously, attenuated Ang II-induced hypertension, decreased activation of microglia in the PVN, and normalized EPCs/ICs. This functional communication between the brain and BM was confirmed by retrograde neuronal labeling from the BM with GFP-tagged pseudorabies virus (PRV). Administration of GFP-PRV into the BM resulted in predominant labeling of PVN neurons within 3 days, with some fluorescence in the NTS, RVLM and SFO. Taken together, these data demonstrate that inhibition of mitochondrial ROS attenuates Ang II-induced hypertension and corrects the imbalance in EPCs/ICs in the BM. They suggest that an imbalance in vascular reparative and ICs may perpetuate vascular pathophysiology in this model of hypertension. PMID:23045460

  15. Oxygen radicals and substance P in perinatal hypoxia-exaggerated, monocrotaline-induced pulmonary hypertension.

    PubMed

    Chen, Kang-Hua; Lai, Yih-Loong; Chen, Mei-Jung

    2012-04-30

    Perinatal hypoxia has been observed to cause more aggressive pulmonary hypertension in human. Several mediators such as reactive oxygen species (ROS) and substance P are believed to be crucial in the mechanism of inducing pulmonary hypertension. This study was designed to test whether substance P and ROS play a role in perinatal hypoxia-exaggerated, monocrotaline (MCT)-induced pulmonary hypertension. Normoxic Wistar rats (weighing 258 ± 9 g, n = 31) were divided into two groups: control (n = 16) and MCT (n = 15). Perinatal hypoxia Wistar rats (weighing 260 ± 19 g, n = 49) were divided into six groups: Hypoxia (n = 8), Hypoxia+MCT (n = 8), Hypoxia+capsaicin (CP)+MCT (n = 7), Hypoxia+MCT+1,3-dimethyl-2-thiourea (DMTU)E (n = 10), Hypoxia+MCT+DMTUL (n = 9), and Hypoxia+MCT+ hexa(sulfobutyl) fullerenes (HSF) (n = 7). Rats in the control group received saline injections. MCT (60 mg/kg, s.c.) was given three weeks prior to the functional examination. Chronic capsaicin pretreatment was performed to deplete substance P. Hydroxyl radical scavenger DMTU (500 mg/kg) was intraperitoneally (i.p.) injected early (DMTUE ) or late (DMTUL ) after MCT. Antioxidant HSF (10 mg/kg, i.p.) was given once daily for three weeks following MCT. MCT treatment caused significant increases in pulmonary arterial pressure (Ppa) and substance P level in lung tissue in normoxic rats. The MCT-induced increase in pulmonary arterial blood pressure was exaggerated by perinatal hypoxia, but this exaggeration was attenuated by either capsaicin pretreatment or antioxidant administrations. These results suggest that both ROS and substance P are involved in perinatal hypoxia-augmented, MCT-induced pulmonary hypertension. PMID:22559732

  16. Interstitial Cells of Cajal in Abdominal Sepsis and Hypertension-Induced Ileus in Rats

    Microsoft Academic Search

    Zheng Lou; Jie Shou Li

    2009-01-01

    Purpose: To evaluate injury to the myenteric interstitial cells of Cajal (ICC-MY) and assess the role of ICC-MY in gastrointestinal motility in rat models of abdominal sepsis and intra-abdominal hypertension (IAH). Materials and Methods: Sprague-Dawley rats were divided into 4 groups; group 1: sham group; group 2: sepsis induced by cecal puncture and ligation; group 3: IAH created by placing

  17. Inhibition of the soluble epoxide hydrolase attenuates monocrotaline-induced pulmonary hypertension in rats

    PubMed Central

    Revermann, Marc; Barbosa-Sicard, Eduardo; Dony, Eva; Schermuly, Ralph T.; Morisseau, Christophe; Geisslinger, Gerd; Fleming, Ingrid; Hammock, Bruce D.; Brandes, Ralf P.

    2010-01-01

    Objectives The soluble epoxide hydrolase (sEH) metabolizes epoxyeicosatrienoic acids (EETs) to their less active dihydroxy derivatives. Because EETs have anti-inflammatory properties, we determined whether or not inhibition of sEH attenuates disease development in the monocrotaline model of pulmonary hypertension in rats. Methods sEH inhibition was achieved using 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (25 mg/l) and cis-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (5 mg/l) administered via drinking water starting 3 days prior to monocrotaline injection (60 mg/kg). Results Monocrotaline induced the development of progressive pulmonary hypertension. sEH inhibition increased the plasma ratio of EETs to DHETs and attenuated the monocrotaline-induced increase in pulmonary artery medial wall thickness as well as the degree of vascular muscularization. Moreover, right ventricular pressure was significantly lower in the group treated with sEH inhibitors. Pulmonary sEH protein expression and sEH activity, as well as pulmonary cytochrome P450 epoxygenase activity were all impaired in monocrotaline-treated rats as compared with control animals. sEH inhibitors, however, increased the plasma ratio of EETs to dihydroxy epoxyeicosatrienoic acids. Monocrotaline induced the proliferation of pulmonary endothelial and vascular smooth muscle cells in vivo as determined by 5-Bromo-2?-deoxy-Uridine incorporation, and this effect was significantly blunted in animals treated with sEH inhibitors. Proliferation of cultured pulmonary smooth muscle cell, however, was not affected by EETs or sEH inhibitors suggesting that the in-vivo effects are a consequence of a direct EET-mediated protection against the inflammation induced by monocrotaline. Conclusion sEH inhibition reduces pulmonary vascular remodeling and the development of pulmonary hypertension in the monocrotaline model of primary pulmonary hypertension in rats. PMID:19226702

  18. Simvastatin Inhibits Cigarette Smoking-induced Emphysema and Pulmonary Hypertension in Rat Lungs

    Microsoft Academic Search

    Ji-Hyun Lee; Dong-Soon Lee; Eun-Kyung Kim; Kang-Hyeon Choe; Yeon-Mock Oh; Tae-Sun Shim; Sang-Eun Kim; Yun-Song Lee; Sang-Do Lee

    2005-01-01

    Rationale: In cigarette smoking-induced chronic obstructive pulmo- nary disease, structural and functional derangements are character- ized by parenchymal destruction and pulmonary hypertension. Statins are 3-hydroxy-3-methyl-glutaryl-coenzyme-A reductase in- hibitors that have been used as lipid-lowering agents. These drugs also have additional pharmacologic properties, including anti- inflammation, scavenging reactive oxygen species, restoring endo- thelial function, and antithrombogenesis, all of which can counter-

  19. Garlic prevents hypertension induced by chronic inhibition of nitric oxide synthesis

    Microsoft Academic Search

    José Pedraza-Chaverrí; Edilia Tapia; Omar N. Medina-Campos; Martha Franco

    1998-01-01

    It has been reported that garlic activates nitric oxide synthase in vitro and that chronic inhibition of nitric oxide (NO) synthesis by N?-nitro-L-arginine-methyl-ester (L-NAME) induces arterial hypertension in rats. In this work, we studied the effect of oral administration of L-NAME for 4 weeks on control and garlic-fed rats. Basal systolic blood pressure was recorded 4 weeks after garlic supplementation,

  20. Renal angiotensin-converting enzyme is essential for the hypertension induced by nitric oxide synthesis inhibition.

    PubMed

    Giani, Jorge F; Janjulia, Tea; Kamat, Nikhil; Seth, Dale M; Blackwell, Wendell-Lamar B; Shah, Kandarp H; Shen, Xiao Z; Fuchs, Sebastien; Delpire, Eric; Toblli, Jorge E; Bernstein, Kenneth E; McDonough, Alicia A; Gonzalez-Villalobos, Romer A

    2014-12-01

    The kidney is an important source of angiotensin-converting enzyme (ACE) in many species, including humans. However, the specific effects of local ACE on renal function and, by extension, BP control are not completely understood. We previously showed that mice lacking renal ACE, are resistant to the hypertension induced by angiotensin II infusion. Here, we examined the responses of these mice to the low-systemic angiotensin II hypertensive model of nitric oxide synthesis inhibition with L-NAME. In contrast to wild-type mice, mice without renal ACE did not develop hypertension, had lower renal angiotensin II levels, and enhanced natriuresis in response to L-NAME. During L-NAME treatment, the absence of renal ACE was associated with blunted GFR responses; greater reductions in abundance of proximal tubule Na(+)/H(+) exchanger 3, Na(+)/Pi co-transporter 2, phosphorylated Na(+)/K(+)/Cl(-) cotransporter, and phosphorylated Na(+)/Cl(-) cotransporter; and greater reductions in abundance and processing of the ? isoform of the epithelial Na(+) channel. In summary, the presence of ACE in renal tissue facilitates angiotensin II accumulation, GFR reductions, and changes in the expression levels and post-translational modification of sodium transporters that are obligatory for sodium retention and hypertension in response to nitric oxide synthesis inhibition. PMID:25012170

  1. Steroid-Induced Ocular Hypertension in Normal Cattle

    Microsoft Academic Search

    Rosana Gerometta; Steven M. Podos; Oscar A. Candia; Brian Wu; Luis A. Malgor; Thomas Mittag; John Danias

    2004-01-01

    Objectives: To determine whether the bovine eye de- velops elevation of intraocular pressure (IOP) in re- sponse to topical corticosteroid use and to develop a re- liable model of steroid-induced elevation of IOP in an animal. Methods: Intraocular pressure was monitored by Per- kins applanation tonometry in a group of 12 cows re- ceiving topically administered prednisolone acetate in 1

  2. Intrarenal ghrelin receptor antagonism prevents high-fat diet-induced hypertension in male rats.

    PubMed

    Kemp, Brandon A; Howell, Nancy L; Gildea, John J; Padia, Shetal H

    2014-07-01

    Excess weight gain contributes up to 65% of the risk of primary hypertension, and the increase in blood pressure in response to high-fat diet (HFD) is preceded by significant increases in renal tubular sodium (Na(+)) reabsorption. In normal rats, intrarenal ghrelin infusion increases distal nephron-dependent Na(+) reabsorption via activation of the intrarenal ghrelin receptor (GHSR). This study focusses on the role of intrarenal GHSR-mediated Na(+) reabsorption in HFD-induced hypertension. Dahl salt-sensitive rats received standard diet or HFD for 6 weeks. Rats underwent uninephrectomy and osmotic minipump implantation for chronic intrarenal delivery of vehicle (0.25 ?L/h × 28 d), selective GHSR antagonist [D-Lys-3]-growth hormone releasing peptide-6 (0.2?M/d), or GHSR inverse agonist [D-Arg(1), D-Phe(5), D-Trp(7,9), Leu(11)]-substance P (SUB-P) (3.6?M/d). HFD rats with vehicle pumps had significantly increased renal GHSR expression compared with standard diet (0.092 ± 0.005 vs 0.065 ± 0.004 arbitrary units; P < .05), whereas acyl ghrelin levels were similar (16.3±6.2 vs 15.7±8.7 pg/g tissue). HFD rats with vehicle pumps became hypertensive after 2 weeks (P < .05) and showed a significant reduction in 24-hour urine Na(+) before hypertension. At this time, these rats showed an increase in collecting duct ?-epithelial Na(+) channel, thereby providing a potential mechanism for the excess Na(+) reabsorption. In contrast, HFD rats with [D-Lys-3]-growth hormone releasing peptide-6 or SUB-P pumps never became hypertensive and did not show the reduction in urine Na(+). Because SUB-P blocks the constitutive, but not ghrelin-dependent, activity of the GHSR, and HFD-induced ?-epithelial Na(+) channel up-regulation was abolished during GHSR antagonism, these data suggest that HFD increases the constitutive activity of renal GHSR to increase Na(+) reabsorption and induce hypertension in rats. PMID:24797629

  3. Tetrahydrocurcumin Protects against Cadmium-Induced Hypertension, Raised Arterial Stiffness and Vascular Remodeling in Mice

    PubMed Central

    Sangartit, Weerapon; Kukongviriyapan, Upa; Donpunha, Wanida; Pakdeechote, Poungrat; Kukongviriyapan, Veerapol; Surawattanawan, Praphassorn; Greenwald, Stephen E.

    2014-01-01

    Background Cadmium (Cd) is a nonessential heavy metal, causing oxidative damage to various tissues and associated with hypertension. Tetrahydrocurcumin (THU), a major metabolite of curcumin, has been demonstrated to be an antioxidant, anti-diabetic, anti-hypertensive and anti-inflammatory agent. In this study, we investigated the protective effect of THU against Cd-induced hypertension, raised arterial stiffness and vascular remodeling in mice. Methods Male ICR mice received CdCl2 (100 mg/l) via drinking water for 8 weeks. THU was administered intragastrically at dose of 50 or 100 mg/kg/day concurrently with Cd treatment. Results Administration of CdCl2 significantly increased arterial blood pressure, blunted vascular responses to vasoactive agents, increased aortic stiffness, and induced hypertrophic aortic wall remodeling by increasing number of smooth muscle cells and collagen deposition, decreasing elastin, and increasing matrix metalloproteinase (MMP)-2 and MMP-9 levels in the aortic medial wall. Supplementation with THU significantly decreased blood pressure, improved vascular responsiveness, and reversed the structural and mechanical alterations of the aortas, including collagen and elastin deposition. The reduction on the adverse response of Cd treatment was associated with upregulated eNOS and downregulated iNOS protein expressions, increased nitrate/nitrite level, alleviated oxidative stress and enhanced antioxidant glutathione. Moreover, THU also reduced the accumulation of Cd in the blood and tissues. Conclusions Our results suggest that THU ameliorates cadmium-induced hypertension, vascular dysfunction, and arterial stiffness in mice through enhancing NO bioavailability, attenuating oxidative stress, improving vascular remodeling and decreasing Cd accumulation in other tissues. THU has a beneficial effect in moderating the vascular alterations associated with Cd exposure. PMID:25502771

  4. Carbonyl stress induces hypertension and cardio-renal vascular injury in Dahl salt-sensitive rats.

    PubMed

    Chen, Xianguang; Mori, Takefumi; Guo, Qi; Hu, Chunyan; Ohsaki, Yusuke; Yoneki, Yoshimi; Zhu, Wanjun; Jiang, Yue; Endo, Satoshi; Nakayama, Keisuke; Ogawa, Susumu; Nakayama, Masaaki; Miyata, Toshio; Ito, Sadayoshi

    2013-04-01

    One major precursor of carbonyl stress, methylglyoxal (MG), is elevated in the plasma of chronic kidney disease (CKD) patients, and this precursor contributes to the progression of vascular injury, hypertension and renal injury in diabetic nephropathy patients. This molecule induces salt-sensitive hypertension via a reactive oxygen species-mediated pathway. We examined the role of MG in the pathogenesis of hypertension and cardio-renal injury in Dahl salt-sensitive (Dahl S) rats, which is a rat model of CKD. Nine-week-old Dahl S rats were fed a 1% NaCl diet, and 1% MG was added to their drinking water for up to 12 weeks. Blood pressure and cardio-renal injuries were compared with rats treated with tap water alone. The angiotensin II receptor blocker (ARB), candesartan (10?mg?kg(-1)?day(-1)), was administered to MG Dahl S rats to determine the impact of this drug on the pathogenesis of MG-induced CKD. A progressive increase in systolic blood pressure was observed (123±1-148±5?mm?Hg) after 12 weeks of MG administration. MG administration significantly increased urinary albumin excretion, glomerular sclerosis, tubular injury, myocardial collagen content and cardiac perivascular fibrosis. MG also enhanced the renal expression of N?-carboxyethyl-lysine (an advanced glycation end product), 8-hydroxydeoxyguanosine (a marker of oxidative stress), macrophage (ED-1) positive cells (a marker of inflammation) and nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase activity. Candesartan treatment for 4 weeks significantly reduced these parameters. These results suggest that MG-induced hypertension and cardio-renal injury and increased inflammation and carbonyl and oxidative stress, which were partially preventable by an ARB. PMID:23364337

  5. The PAI-1 Antagonist TM5441 Attenuates L-NAME-Induced Hypertension and Vascular Senescence

    PubMed Central

    Boe, Amanda E.; Eren, Mesut; Murphy, Sheila B.; Kamide, Christine E.; Ichimura, Atsuhiko; Terry, David; McAnally, Danielle; Smith, Layton H.; Miyata, Toshio; Vaughan, Douglas E.

    2014-01-01

    Background Long-term inhibition of nitric oxide synthase (NOS) by L-arginine analogues such as N?-nitro-L-arginine methyl ester (L-NAME) has been shown to induce senescence in vitro and systemic hypertension and arteriosclerosis in vivo. We previously reported that PAI-1-deficient mice (PAI-1?/?) are protected against L-NAME-induced pathologies. In this study, we investigated whether a novel, orally active PAI-1 antagonist (TM5441) has a similar protective effect against L-NAME treatment. Additionally, we studied whether L-NAME can induce vascular senescence in vivo and investigated the role of PAI-1 in this process. Methods and Results Wild-type (WT) mice received either L-NAME or L-NAME and TM5441 for 8 weeks. Systolic blood pressure was measured every 2 weeks. We found that TM5441 attenuated the development of hypertension and cardiac hypertrophy compared to animals that had received L-NAME alone. Additionally, TM5441-treated mice had a 34% reduction in periaortic fibrosis relative to animals on L-NAME alone. Finally, we investigated the development of vascular senescence by measuring p16Ink4a expression and telomere length in aortic tissue. We found that L-NAME increased p16Ink4a expression levels and decreased telomere length, both of which were prevented with TM5441 co-treatment. Conclusions Pharmacological inhibition of PAI-1 is protective against the development of hypertension, cardiac hypertrophy, and periaortic fibrosis in mice treated with L-NAME. Furthermore, PAI-1 inhibition attenuates the arterial expression of p16Ink4a and maintains telomere length. PAI-1 appears to play a pivotal role in vascular senescence, and these findings suggest that PAI-1 antagonists may provide a novel approach in preventing vascular aging and hypertension. PMID:24092817

  6. Heme biosynthesis modulation via ?-aminolevulinic acid administration attenuates chronic hypoxia-induced pulmonary hypertension.

    PubMed

    Alhawaj, Raed; Patel, Dhara; Kelly, Melissa R; Sun, Dong; Wolin, Michael S

    2015-04-01

    This study examines how heme biosynthesis modulation with ?-aminolevulinic acid (ALA) potentially functions to prevent 21-day hypoxia (10% oxygen)-induced pulmonary hypertension in mice and the effects of 24-h organoid culture with bovine pulmonary arteries (BPA) with the hypoxia and pulmonary hypertension mediator endothelin-1 (ET-1), with a focus on changes in superoxide and regulation of micro-RNA 204 (miR204) expression by src kinase phosphorylation of signal transducer and activator of transcription-3 (STAT3). The treatment of mice with ALA attenuated pulmonary hypertension (assessed through echo Doppler flow of the pulmonary valve, and direct measurements of right ventricular systolic pressure and right ventricular hypertrophy), increases in pulmonary arterial superoxide (detected by lucigenin), and decreases in lung miR204 and mitochondrial superoxide dismutase (SOD2) expression. ALA treatment of BPA attenuated ET-1-induced increases in mitochondrial superoxide (detected by MitoSox), STAT3 phosphorylation, and decreases in miR204 and SOD2 expression. Because ALA increases BPA protoporphyrin IX (a stimulator of guanylate cyclase) and cGMP-mediated protein kinase G (PKG) activity, the effects of the PKG activator 8-bromo-cGMP were examined and found to also attenuate the ET-1-induced increase in superoxide. ET-1 increased superoxide production and the detection of protoporphyrin IX fluorescence, suggesting oxidant conditions might impair heme biosynthesis by ferrochelatase. However, chronic hypoxia actually increased ferrochelatase activity in mouse pulmonary arteries. Thus, a reversal of factors increasing mitochondrial superoxide and oxidant effects that potentially influence remodeling signaling related to miR204 expression and perhaps iron availability needed for the biosynthesis of heme by the ferrochelatase reaction could be factors in the beneficial actions of ALA in pulmonary hypertension. PMID:25659899

  7. Neuroinflammation and oxidative stress in rostral ventrolateral medulla contribute to neurogenic hypertension induced by systemic inflammation

    PubMed Central

    2012-01-01

    Background In addition to systemic inflammation, neuroinflammation in the brain, which enhances sympathetic drive, plays a significant role in cardiovascular diseases, including hypertension. Oxidative stress in rostral ventrolateral medulla (RVLM) that augments sympathetic outflow to blood vessels is involved in neural mechanism of hypertension. We investigated whether neuroinflammation and oxidative stress in RVLM contribute to hypertension following chronic systemic inflammation. Methods In normotensive Sprague-Dawley rats, systemic inflammation was induced by infusion of Escherichia coli lipopolysaccharide (LPS) into the peritoneal cavity via an osmotic minipump. Systemic arterial pressure and heart rate were measured under conscious conditions by the non-invasive tail-cuff method. The level of the inflammatory markers in plasma or RVLM was analyzed by ELISA. Protein expression was evaluated by Western blot or immunohistochemistry. Tissue level of superoxide anion (O2·-) in RVLM was determined using the oxidation-sensitive fluorescent probe dihydroethidium. Pharmacological agents were delivered either via infusion into the cisterna magna with an osmotic minipump or microinjection bilaterally into RVLM. Results Intraperitoneal infusion of LPS (1.2?mg/kg/day) for 14?days promoted sustained hypertension and induced a significant increase in plasma level of C-reactive protein, tumor necrosis factor-? (TNF-?), or interleukin-1? (IL-1?). This LPS-induced systemic inflammation was accompanied by activation of microglia, augmentation of IL-1?, IL-6, or TNF-? protein expression, and O2·- production in RVLM, all of which were blunted by intracisternal infusion of a cycloxygenase-2 (COX-2) inhibitor, NS398; an inhibitor of microglial activation, minocycline; or a cytokine synthesis inhibitor, pentoxifylline. Neuroinflammation in RVLM was also associated with a COX-2-dependent downregulation of endothelial nitric oxide synthase and an upregulation of intercellular adhesion molecule-1. Finally, the LPS-promoted long-term pressor response and the reduction in expression of voltage-gated potassium channel, Kv4.3 in RVLM were antagonized by minocycline, NS398, pentoxifylline, or a superoxide dismutase mimetic, tempol, either infused into cisterna magna or microinjected bilaterally into RVLM. The same treatments, on the other hand, were ineffective against LPS-induced systemic inflammation. Conclusion These results suggest that systemic inflammation activates microglia in RVLM to induce COX-2-dependent neuroinflammation that leads to an increase in O2·- production. The resultant oxidative stress in RVLM in turn mediates neurogenic hypertension. PMID:22958438

  8. Critical role of monocyte chemoattractant protein-1 receptor CCR2 on monocytes in hypertension-induced vascular inflammation and remodeling.

    PubMed

    Ishibashi, Minako; Hiasa, Ken-ichi; Zhao, Qingwei; Inoue, Shujiro; Ohtani, Kisho; Kitamoto, Shiro; Tsuchihashi, Miyuki; Sugaya, Takeshi; Charo, Israel F; Kura, Shinobu; Tsuzuki, Teruhisa; Ishibashi, Tatsuro; Takeshita, Akira; Egashira, Kensuke

    2004-05-14

    Activated monocytes are present in the arterial walls of hypertensive patients and animals. Monocyte chemoattractant protein-1 (MCP-1), which controls monocyte function through its receptor (CCR2), is implicated in hypertensive inflammatory changes in the arterial wall. The role of CCR2 expression on monocytes in hypertension-induced vascular remodeling, however, has not been addressed. We hypothesized that CCR2 on monocytes is critical in hypertension-induced vascular inflammation and remodeling. Hypertension was induced by infusion of angiotensin II (Ang II) into wild-type mice, CCR2-deficient (CCR2-/-) mice, and bone marrow-transferred mice with a leukocyte-selective CCR2 deficiency (BMT-CCR2-/-). In wild-type mice, Ang II increased CCR2 intensity in circulating monocytes, which was prevented by an Ang II type-1 (AT1) receptor blocker or blunted in AT1 receptor-deficient mice. Enhanced CCR2 intensity on monocytes was observed in hypertensive patients and rats, and was reduced by treatment with the Ang II receptor blocker, supporting the clinical relevance of the observation in mice. In CCR2-/- and BMT-CCR2-/- mice, Ang II-induced vascular inflammation and vascular remodeling (aortic wall thickening and fibrosis) were blunted as compared with control mice. In contrast, Ang II-induced left ventricular hypertrophy developed in CCR2-/- and BMT-CCR2-/- mice. The present study suggests that CCR2 expression in monocytes has a critical role in vascular inflammation and remodeling in Ang II-induced hypertension, and possibly in other forms of hypertension. PMID:15059935

  9. Association of plasma antibodies against the inducible Hsp70 with hypertension and harsh working conditions

    PubMed Central

    Wu, Tangchun; Ma, Jinxiang; Chen, Sheng; Sun, Yehuan; Xiao, Chengfeng; Gao, Yajuan; Wang, Ruibo; Poudrier, Jacques; Dargis, Michele; Currie, R. William; Tanguay, Robert M.

    2001-01-01

    Autoantibodies against certain stress or heat shock proteins (Hsps) may play a role in the pathogenesis and/or prognosis of some diseases. Using immunoblotting with human recombinant Hsps and univariate and multivariate logistic regression models, we have investigated the presence of antibodies against Hsp70, the inducible member of the 70-kDa family of heat shock proteins, and analyzed its possible association with hypertension and working conditions. Plasma and serum were collected from 764 steel mill workers from 6 work sites exposed to (1) severe noise; (2) severe noise and dust; (3) noise, dust, and heat; (4) noise and heat; (5) severe noise and heat; and (6) office conditions (control). Workers with prolonged exposure to stresses such as noise, dust, and high temperature and a combination of these in the workplace had a high incidence (26.6% to 40.2%) of antibodies to Hsp70 compared to the lowest incidence (18.6%) of antibodies to Hsp70 in the control group of office workers. Moreover, there was a statistical association of antibodies against Hsp70 with hypertension. The statistical correlation between the presence of antibodies to Hsp70 and hypertension is higher in the group of workers with blood pressure of 160/95 mmHg than in the 140/90-mmHg group after excluding possible effects of the workplace stresses. These results suggest that harsh workplace conditions can increase the production of antibodies against Hsp70 and that the presence of antibodies to this stress protein may be associated with hypertension. The precise mechanism for the elevation of antibodies against Hsps by environmental and workplace stresses and their relation to hypertension remains to be established. PMID:11795477

  10. Modulatory effect of sesamol on DOCA-salt-induced oxidative stress in uninephrectomized hypertensive rats.

    PubMed

    Hemalatha, Govindasamy; Pugalendi, Kodukkur Viswanathan; Saravanan, Ramalingam

    2013-07-01

    The present study was undertaken to investigate the antihypertensive and antioxidant effects of sesamol on uninephrectomized deoxycorticosterone acetate (DOCA)-salt-induced hypertensive rats. Hypertension was induced in surgically single-kidney-removed (left) adult male albino Wistar rats, weighing 180-200 g, by injecting DOCA (25 mg/kg BW) subcutaneously twice a week for 6 weeks, with saline instead of tap water for drinking. Rats were treated with three different doses of sesamol (50, 100 and 200 mg/kg BW) post-orally by gavage daily for 6 weeks. Hypertension was revealed by increased systolic and diastolic blood pressure and the toxicity of DOCA-salt was determined using hepatic marker enzymes, aspartate aminotransferase, alanine aminotransferase, alkaline phospatase and gamma-glutamyl transpeptidase; and, lipid peroxidative markers, thiobarbituric acid reactive substances, lipid hydroperoxides and conjugated dienes were assayed. The activities of enzymatic antioxidants, superoxide dismutase, catalase and glutathione peroxidase and the levels of non-enzymatic antioxidants (vitamin C, vitamin E and reduced glutathione) were evaluated in erythrocytes, plasma and tissues. Post-oral administration of sesamol at the dosage of 50 mg/kg BW remarkably decreased systolic and diastolic blood pressure, hepatic marker enzyme activities and lipid peroxidation products and also enhanced the antioxidant activity. The biochemical observations were also supported by histopathological examinations of the rat liver, kidney and heart sections. These results suggest that sesamol possesses antihypertensive and antioxidant effects. PMID:23576423

  11. Effects of tetrahydrobiopterin oral treatment in hypoxia-induced pulmonary hypertension in rat

    PubMed Central

    Francis, Bahaa N.; Hale, Ashley; Channon, Keith M.; Wilkins, Martin R.

    2014-01-01

    Abstract Endothelial nitric oxide synthase (eNOS) plays a major role in maintaining pulmonary vascular homeostasis. Tetrahydrobiopterin (BH4), an essential cofactor that stabilizes the dimerization of eNOS and balances nitric oxide (NO) and superoxide production, may have therapeutic potential in pulmonary hypertension. In the isolated perfused lung, we demonstrated a direct effect of exogenous administration of BH4 on pulmonary NO production, leading to acute vasorelaxation during the plateau phase of hypoxia-induced pulmonary vasoconstriction. In the chronic hypoxia-induced pulmonary hypertension rat model, chronic BH4 oral administration attenuated the pressor response to hypoxia (mean pulmonary artery pressure ± standard error of the mean, 31.8 ± 0.5 mmHg at 100 mg/kg/day; placebo group, 36.3 ± 0.6 mmHg; P < 0.05). During telemetric monitoring, right ventricular systolic pressure was reduced by approximately 50% after 1 week of BH4 treatment at 100 mg/kg/day. BH4 at 100 mg/kg/day reduced right ventricular hypertrophy (from 0.55 ± 0.01 to 0.50 ± 0.01; P < 0.05) and pulmonary vascular muscularization (from 79.2% ± 2% to 65.2% ± 3%; P < 0.01). BH4 treatment enhanced lung eNOS activity and reduced superoxide production, with a net increase in cyclic guanosine monophosphate levels. BH4 is effective in attenuating pulmonary hypertension in the hypoxic rat model when given as a rescue therapy. PMID:25621160

  12. Hypoxia inducible factor signaling and experimental persistent pulmonary hypertension of the newborn

    PubMed Central

    Wedgwood, Stephen; Lakshminrusimha, Satyan; Schumacker, Paul T.; Steinhorn, Robin H.

    2015-01-01

    Background: Mitochondrial reactive oxygen species (ROS) levels and nuclear factor kappa-light-chain-enhancer of activated B cells (NF?B) activity are increased in a lamb model of persistent pulmonary hypertension of the newborn (PPHN). These events can trigger hypoxia inducible factor (HIF) signaling in response to hypoxia, which has been shown to contribute to pulmonary vascular remodeling in rodent models of pulmonary hypertension. However, the role of HIF signaling in chronic intrauterine pulmonary hypertension is not well understood. Aim: To determine if HIF signaling is increased in the lamb model of PPHN, and to identify the underlying mechanisms. Results: PPHN was induced in lambs by antenatal ligation of the ductus arteriosus at 128 days gestation. After 9 days, lungs and pulmonary artery smooth muscle cells (PASMC) were isolated from control and PPHN lambs. HIF-1? expression was increased in PPHN lungs and HIF activity was increased in PPHN PASMC relative to controls. Hypoxia increased HIF activity to a greater degree in PPHN vs. control PASMC. Control PASMC were exposed to cyclic stretch at 1 Hz and 15% elongation for 24 h, as an in vitro model of vascular stress. Stretch increased HIF activity, which was attenuated by inhibition of mitochondrial complex III and NF?B. Conclusion: Increased HIF signaling in PPHN is triggered by stretch, via mechanisms involving mitochondrial ROS and NF?B. Hypoxia substantially amplifies HIF activity in PPHN vascular cells. Targeting these signaling molecules may attenuate and reverse pulmonary vascular remodeling associated with PPHN. PMID:25814954

  13. Cardiovascular Responses Induced by Obstructive Apnea Are Enhanced in Hypertensive Rats Due to Enhanced Chemoreceptor Responsivity

    PubMed Central

    Angheben, Juliana M. M.; Schoorlemmer, Guus H. M.; Rossi, Marcio V.; Silva, Thiago A.; Cravo, Sergio L.

    2014-01-01

    Spontaneously hypertensive rats (SHR), like patients with sleep apnea, have hypertension, increased sympathetic activity, and increased chemoreceptor drive. We investigated the role of carotid chemoreceptors in cardiovascular responses induced by obstructive apnea in awake SHR. A tracheal balloon and vascular cannulas were implanted, and a week later, apneas of 15 s each were induced. The effects of apnea were more pronounced in SHR than in control rats (Wistar Kyoto; WKY). Blood pressure increased by 57±3 mmHg during apnea in SHR and by 28±3 mmHg in WKY (p<0.05, n?=?14/13). The respiratory effort increased by 53±6 mmHg in SHR and by 34±5 mmHg in WKY. The heart rate fell by 209±19 bpm in SHR and by 155±16 bpm in WKY. The carotid chemoreceptors were then inactivated by the ligation of the carotid body artery, and apneas were induced two days later. The inactivation of chemoreceptors reduced the responses to apnea and abolished the difference between SHR and controls. The apnea-induced hypertension was 11±4 mmHg in SHR and 8±4 mmHg in WKY. The respiratory effort was 15±2 mmHg in SHR and 15±2 mmHg in WKY. The heart rate fell 63±18 bpm in SHR and 52±14 bpm in WKY. Similarly, when the chemoreceptors were unloaded by the administration of 100% oxygen, the responses to apnea were reduced. In conclusion, arterial chemoreceptors contribute to the responses induced by apnea in both strains, but they are more important in SHR and account for the exaggerated responses of this strain to apnea. PMID:24466272

  14. 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

  15. Oxidative stress exaggerates skeletal muscle contraction-evoked reflex sympathoexcitation in rats with hypertension induced by angiotensin II.

    PubMed

    Koba, Satoshi; Watanabe, Ryosuke; Kano, Naoko; Watanabe, Tatsuo

    2013-01-01

    Muscle contraction stimulates thin fiber muscle afferents and evokes reflex sympathoexcitation. In hypertension, this reflex is exaggerated. ANG II, which is elevated in hypertension, has been reported to trigger the production of superoxide and other reactive oxygen species. In the present study, we tested the hypothesis that increased ANG II in hypertension exaggerates skeletal muscle contraction-evoked reflex sympathoexcitation by inducing oxidative stress in the muscle. In rats, subcutaneous infusion of ANG II at 450 ng·kg(-1)·min(-1) for 14 days significantly (P < 0.05) elevated blood pressure compared with sham-operated (sham) rats. Electrically induced 30-s hindlimb muscle contraction in decerebrate rats with hypertension evoked larger renal sympathoexcitatory and pressor responses [+1,173 ± 212 arbitrary units (AU) and +35 ± 5 mmHg, n = 10] compared with sham normotensive rats (+419 ± 103 AU and +13 ± 2 mmHg, n = 11). Tempol, a SOD mimetic, injected intra-arterially into the hindlimb circulation significantly reduced responses in hypertensive rats, whereas this compound had no effect on responses in sham rats. Tiron, another SOD mimetic, also significantly reduced reflex renal sympathetic and pressor responses in a subset of hypertensive rats (n = 10). Generation of muscle superoxide, as evaluated by dihydroethidium staining, was increased in hypertensive rats. RT-PCR and immunoblot experiments showed that mRNA and protein for gp91(phox), a NADPH oxidase subunit, in skeletal muscle tissue were upregulated in hypertensive rats. Taken together, hese results suggest that increased ANG II in hypertension induces oxidative stress in skeletal muscle, thereby exaggerating the muscle reflex. PMID:23086992

  16. Improvement of vascular insulin sensitivity by downregulation of GRK2 mediates exercise-induced alleviation of hypertension in spontaneously hypertensive rats.

    PubMed

    Xing, Wenjuan; Li, Youyou; Zhang, Haifeng; Mi, Chunjuan; Hou, Zuoxu; Quon, Michael J; Gao, Feng

    2013-10-15

    Exercise training lowers blood pressure and is a recommended nonpharmacological strategy and useful adjunctive therapy for hypertensive patients. Studies demonstrate that physical activity attenuates progression of hypertension. However, underlying mechanisms remain elusive. Vascular insulin resistance and endothelial dysfunction plays a critical role in the development of hypertension. The present study investigated whether long-term physical exercise starting during the prehypertensive period prevents the development of hypertension via improving vascular insulin sensitivity. Young (4 wk old) prehypertensive spontaneously hypertensive rats (SHRs) and their normotensive Wistar-Kyoto (WKY) control rats were subjected to a 10-wk free-of-loading swim training session (60 min/day, 5 days/wk). Blood pressure, mesenteric arteriolar vasorelaxation, G protein-coupled receptor kinase-2 (GRK2) expression and activity, and insulin-stimulated Akt/endothelial nitric oxide synthase (eNOS) activation were determined. SHRs had higher systolic blood pressure, systemic insulin resistance, and impaired vasodilator actions of insulin in resistance vessels when compared with WKY rats. Systolic blood pressure in SHRs postexercise was significantly lower than that in sedentary rats. Vascular insulin sensitivity in mesenteric arteries was improved after exercise training as evidenced by an increased vasodilator response to insulin. In addition, exercise downregulated vascular GRK2 expression and activity, which further increased insulin-stimulated vascular Akt/eNOS activation in exercised SHRs. Specific small interfering RNA knockdown of GRK2 in endothelium mimicked the effect of exercise-enhanced vascular insulin sensitivity. Likewise, upregulation of GRK2 by Chariot-mediated delivery opposed exercise-induced vascular insulin sensitization. Taken together, our results suggest that long-term exercise beginning at the prehypertensive stage improves vascular insulin sensitivity via downregulation of vascular GRK2 that may help to limit the progression of hypertension. PMID:23913704

  17. Protective effects of hydrogen-rich saline on monocrotaline-induced pulmonary hypertension in a rat model

    Microsoft Academic Search

    Yun Wang; Lei Jing; Xiao-Min Zhao; Ji-Ju Han; Zuo-Li Xia; Shu-Cun Qin; Ya-Ping Wu; Xue-Jun Sun

    2011-01-01

    Background  Hydrogen-rich saline has been reported to have antioxidant and anti-inflammatory effects and effectively protect against organ\\u000a damage. Oxidative stress and inflammation contribute to the pathogenesis and\\/or development of pulmonary hypertension. In\\u000a this study, we investigated the effects of hydrogen-rich saline on the prevention of pulmonary hypertension induced by monocrotaline\\u000a in a rat model.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  In male Sprague-Dawley rats, pulmonary hypertension was

  18. Selective Inactivation of PTEN in Smooth Muscle Cells Synergizes With Hypoxia to Induce Severe Pulmonary Hypertension

    PubMed Central

    Horita, Henrick; Furgeson, Seth B.; Ostriker, Allison; Olszewski, Kyle A.; Sullivan, Timothy; Villegas, Leah R.; Levine, Michelle; Parr, Jane E.; Cool, Carlyne D.; Nemenoff, Raphael A.; Weiser?Evans, Mary C. M.

    2013-01-01

    Background Pulmonary vascular remodeling in pulmonary hypertension (PH) is characterized by increased vascular smooth muscle cell (SMC) and adventitial fibroblast proliferation, small vessel occlusion, and inflammatory cell accumulation. The underlying molecular mechanisms driving progression remain poorly defined. We have focused on loss of the phosphatase PTEN in SMCs as a major driver of pathological vascular remodeling. Our goal was to define the role of PTEN in human PH and in hypoxia?induced PH using a mouse model with inducible deletion of PTEN in SMCs. Methods and Results Staining of human biopsies demonstrated enhanced inactive PTEN selectively in the media from hypertensive patients compared to controls. Mice with induced deletion of PTEN in SMCs were exposed to normoxia or hypoxia for up to 4 weeks. Under normoxia, SMC PTEN depletion was sufficient to induce features of PH similar to those observed in wild?type mice exposed to chronic hypoxia. Under hypoxia, PTEN depletion promoted an irreversible progression of PH characterized by increased pressure, extensive pulmonary vascular remodeling, formation of complex vascular lesions, and increased macrophage accumulation associated with synergistic increases in proinflammatory cytokines and proliferation of both SMCs and nonSMCs. Conclusions Chronic inactivation of PTEN selectively in SMC represents a critical mediator of PH progression, leading to cell autonomous events and increased production of factors correlated to proliferation and recruitment of adventitial and inflammatory cells, resulting in irreversible progression of the disease. PMID:23727701

  19. Pyk2 aggravates hypoxia-induced pulmonary hypertension by activating HIF-1?.

    PubMed

    Fukai, Kuniyoshi; Nakamura, Akihiro; Hoshino, Atsushi; Nakanishi, Naohiko; Okawa, Yoshifumi; Ariyoshi, Makoto; Kaimoto, Satoshi; Uchihashi, Motoki; Ono, Kazunori; Tateishi, Shuhei; Ikeda, Koji; Ogata, Takehiro; Ueyama, Tomomi; Matoba, Satoaki

    2015-04-15

    Pulmonary arterial hypertension (PAH) is a refractory disease characterized by uncontrolled vascular remodeling and elevated pulmonary arterial pressure. Although synthetic inhibitors of some tyrosine kinases have been used to treat PAH, their therapeutic efficacies and safeties remain controversial. Thus, the establishment of novel therapeutic targets based on the molecular pathogenesis underlying PAH is a clinically urgent issue. In the present study, we demonstrated that proline-rich tyrosine kinase 2 (Pyk2), a nonreceptor type protein tyrosine kinase, plays a crucial role in the pathogenesis of pulmonary hypertension (PH) using an animal model of hypoxia-induced PH. Resistance to hypoxia-induced PH was markedly higher in Pyk2-deficient mice than in wild-type mice. Pathological investigations revealed that medial thickening of the pulmonary arterioles, which is a characteristic of hypoxia-induced PH, was absent in Pyk2-deficient mice, suggesting that Pyk2 is involved in the hypoxia-induced aberrant proliferation of vascular smooth muscle cells in hypoxia-induced PH. In vitro experiments using human pulmonary smooth muscle cells showed that hypoxic stress increased the proliferation and migration of cells in a Pyk2-dependent manner. We also demonstrated that Pyk2 plays a crucial role in ROS generation during hypoxic stress and that this Pyk2-dependent generation of ROS is necessary for the activation of hypoxia-inducible factor-1?, a key molecule in the pathogenesis of hypoxia-induced PH. In summary, the results of the present study reveal that Pyk2 plays an important role in the pathogenesis of hypoxia-induced PH. Therefore, Pyk2 may represent a promising therapeutic target for PAH in a clinical setting. PMID:25659487

  20. Manganese Porphyrin Reduces Retinal Injury Induced by Ocular Hypertension in Rats

    PubMed Central

    Dogan, Serdar; Unal, Mustafa; Ozturk, Nihal; Yargicoglu, Piraye; Cort, Aysegul; Spasojevic, Ivan; Batinic-Haberle, Ines; Aslan, Mutay

    2011-01-01

    This study aimed to clarify the possible therapeutic benefit of preferential nitric oxide synthase (NOS) inhibition and catalytic antioxidant Mn (III) meso-tetrakis (N-n-hexylpyridinium-2-yl) porphyrin (MnTnHex-2-PyP5+) treatment in a rat model of elevated intraocular pressure (EIOP). Rats were randomly divided into different experimental groups which received either intraperitoneal MnTnHex-2-PyP5+ (0.1 mg/kg/day), intragastric NOS inhibitor (S-methylthiourea: SMT; 5 mg/kg/day) or both agents for a period of 6 weeks. Ocular hypertension was induced by unilaterally cauterizing three episcleral vessels and the unoperated eye served as control. Neuroprotective effects of given treatments were determined via electrophysiological measurements of visual evoked potentials (VEP) while retina and vitreous levels of MnTnHex-2-PyP5+ were measured via LC-MS/MS. Latencies of all VEP components (P1, N1, P2, N2, P3) were significantly prolonged (p<0.05) in EIOP and returned to control levels following all three treatment protocols. Ocular hypertension significantly increased retinal protein nitration (p<0.001) which returned to baseline levels in all treated groups. NOS-2 expression and nitrate/nitrite levels were significantly greater in non-treated rats with EIOP. Retinal TUNEL staining showed apoptosis in all ocular hypertensive rats. The presented data confirm the role of oxidative injury in EIOP and highlight the protective effect of MnTnHex-2-PyP5+ treatment and NOS inhibition in ocular hypertension. PMID:21669199

  1. Cytosolic Phospholipase A2? Is Critical for Angiotensin II-Induced Hypertension and Associated Cardiovascular Pathophysiology.

    PubMed

    Khan, Nayaab S; Song, Chi Young; Jennings, Brett L; Estes, Anne M; Fang, Xiao R; Bonventre, Joseph V; Malik, Kafait U

    2015-04-01

    Angiotensin II activates cytosolic phospholipase A(2)? (cPLA2?) and releases arachidonic acid from tissue phospholipids, which mediate or modulate ?1 cardiovascular effects of angiotensin II and has been implicated in hypertension. Because arachidonic acid release is the rate limiting step in eicosanoid production, cPLA2? might play a central role in the development of angiotensin II-induced hypertension. To test this hypothesis, we investigated the effect of angiotensin II infusion for 13 days by micro-osmotic pumps on systolic blood pressure and associated pathogenesis in wild type (cPLA2?(+/+)) and cPLA2?(-/-) mice. Angiotensin II-induced increase in systolic blood pressure in cPLA2?(+/+) mice was abolished in cPLA2?(-/-) mice; increased systolic blood pressure was also abolished by the arachidonic acid metabolism inhibitor, 5,8,11,14-eicosatetraynoic acid in cPLA2?(+/+) mice. Angiotensin II in cPLA2?(+/+) mice increased cardiac cPLA2 activity and urinary eicosanoid excretion, decreased cardiac output, caused cardiovascular remodeling with endothelial dysfunction, and increased vascular reactivity in cPLA2?(+/+) mice; these changes were diminished in cPLA2?(-/-) mice. Angiotensin II also increased cardiac infiltration of F4/80(+) macrophages and CD3(+) T lymphocytes, cardiovascular oxidative stress, expression of endoplasmic reticulum stress markers p58(IPK), and CHOP in cPLA2?(+/+) but not cPLA2?(-/-) mice. Angiotensin II increased cardiac activity of ERK1/2 and cSrc in cPLA2?(+/+) but not cPLA2?(-/-) mice. These data suggest that angiotensin II-induced hypertension and associated cardiovascular pathophysiological changes are mediated by cPLA2? activation, most likely through the release of arachidonic acid and generation of eicosanoids with predominant prohypertensive effects and activation of ?1 signaling molecules, including ERK1/2 and cSrc. PMID:25667212

  2. Cardiovascular disease risk factors after early-onset preeclampsia, late-onset preeclampsia, and pregnancy-induced hypertension.

    PubMed

    Veerbeek, Jan H W; Hermes, Wietske; Breimer, Anath Y; van Rijn, Bas B; Koenen, Steven V; Mol, Ben W; Franx, Arie; de Groot, Christianne J M; Koster, Maria P H

    2015-03-01

    Observational studies have shown an increased lifetime risk of cardiovascular disease (CVD) in women who experienced a hypertensive disorder in pregnancy. This risk is related to the severity of the pregnancy-related hypertensive disease and gestational age at onset. However, it has not been investigated whether these differences in CVD risk factors are already present at postpartum cardiovascular screening. We evaluated postpartum differences in CVD risk factors in 3 subgroups of patients with a history of hypertensive pregnancy. We compared the prevalence of common CVD risk factors postpartum among 448 women with previous early-onset preeclampsia, 76 women with previous late-onset preeclampsia, and 224 women with previous pregnancy-induced hypertension. Women with previous early-onset preeclampsia were compared with women with late-onset preeclampsia and pregnancy-induced hypertension and had significantly higher fasting blood glucose (5.29 versus 4.80 and 4.83 mmol/L), insulin (9.12 versus 6.31 and 6.7 uIU/L), triglycerides (1.32 versus 1.02 and 0.97 mmol/L), and total cholesterol (5.14 versus 4.73 and 4.73 mmol/L). Almost half of the early-onset preeclampsia women had developed hypertension, as opposed to 39% and 25% of women in the pregnancy-induced hypertension and late-onset preeclampsia groups, respectively. Our data show differences in the prevalence of common modifiable CVD risk factors postpartum and suggest that prevention strategies should be stratified according to severity and gestational age of onset for the hypertensive disorders of pregnancy. PMID:25561694

  3. Diesel exhaust induced pulmonary and cardiovascular impairment: The role of hypertension intervention

    SciTech Connect

    Kodavanti, Urmila P., E-mail: kodavanti.urmila@epa.gov [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory (NHEERL), Office of Research and Development (ORD), U.S. Environmental Protection Agency - EPA, Research Triangle Park, NC 27711 (United States); Thomas, Ronald F.; Ledbetter, Allen D.; Schladweiler, Mette C.; Bass, Virginia; Krantz, Q. Todd; King, Charly [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory (NHEERL), Office of Research and Development (ORD), U.S. Environmental Protection Agency - EPA, Research Triangle Park, NC 27711 (United States); Nyska, Abraham [Tel Aviv University, Tel Aviv (Israel); Richards, Judy E. [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory (NHEERL), Office of Research and Development (ORD), U.S. Environmental Protection Agency - EPA, Research Triangle Park, NC 27711 (United States); Andrews, Debora [Research Core Unit, NHEERL, ORD, U.S. EPA, Research Triangle Park, NC 27711 (United States); Gilmour, M. Ian [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory (NHEERL), Office of Research and Development (ORD), U.S. Environmental Protection Agency - EPA, Research Triangle Park, NC 27711 (United States)

    2013-04-15

    Exposure to diesel exhaust (DE) and associated gases is linked to cardiovascular impairments; however, the susceptibility of hypertensive individuals is poorly understood. The objectives of this study were (1) to determine cardiopulmonary effects of gas-phase versus whole-DE and (2) to examine the contribution of systemic hypertension in pulmonary and cardiovascular effects. Male Wistar Kyoto (WKY) rats were treated with hydralazine to reduce blood pressure (BP) or L-NAME to increase BP. Spontaneously hypertensive (SH) rats were treated with hydralazine to reduce BP. Control and drug-pretreated rats were exposed to air, particle-filtered exhaust (gas), or whole DE (1500 ?g/m{sup 3}), 4 h/day for 2 days or 5 days/week for 4 weeks. Acute and 4-week gas and DE exposures increased neutrophils and ?-glutamyl transferase (?-GT) activity in lavage fluid of WKY and SH rats. DE (4 weeks) caused pulmonary albumin leakage and inflammation in SH rats. Two-day DE increased serum fatty acid binding protein-3 (FABP-3) in WKY. Marked increases occurred in aortic mRNA after 4-week DE in SH (eNOS, TF, tPA, TNF-?, MMP-2, RAGE, and HMGB-1). Hydralazine decreased BP in SH while L-NAME tended to increase BP in WKY; however, neither changed inflammation nor BALF ?-GT. DE-induced and baseline BALF albumin leakage was reduced by hydralazine in SH rats and increased by L-NAME in WKY rats. Hydralazine pretreatment reversed DE-induced TF, tPA, TNF-?, and MMP-2 expression but not eNOS, RAGE, and HMGB-1. ET-1 was decreased by HYD. In conclusion, antihypertensive drug treatment reduces gas and DE-induced pulmonary protein leakage and expression of vascular atherogenic markers. - Highlights: ? Acute diesel exhaust exposure induces pulmonary inflammation in healthy rats. ? In hypertensive rats diesel exhaust effects are seen only after long term exposure. ? Normalizing blood pressure reverses lung protein leakage caused by diesel exhaust. ? Normalizing blood pressure reverses atherogenic effects of diesel exhaust. ? Diesel exhaust and hydralazine cause similar aorta effect on vascular tone markers.

  4. Protective Effects of Methylsulfonylmethane on Hemodynamics and Oxidative Stress in Monocrotaline-Induced Pulmonary Hypertensive Rats

    PubMed Central

    Mohammadi, Sadollah; Najafi, Moslem; Hamzeiy, Hossein; Maleki-Dizaji, Nasrin; Pezeshkian, Masoud; Sadeghi-Bazargani, Homayon; Darabi, Masoud; Mostafalou, Sara; Bohlooli, Shahab; Garjani, Alireza

    2012-01-01

    Methylsulfonylmethane (MSM) is naturally occurring organic sulfur that is known as a potent antioxidant/anti-inflammatory compound. The aim of this study was to investigate the effect of MSM on hemodynamics functions and oxidative stress in rats with monocrotaline- (MCT-) induced pulmonary arterial hypertension (PAH). Wistar rats were randomly assigned to 38-days treatment. MSM was administered to rats at 100, 200, and 400?mg/kg/day doses 10 days before a single dose of 60?mg/kg, IP, MCT. Hemodynamics of ventricles were determined by Powerlab AD instrument. Blood samples were obtained to evaluate changes in the antioxidative system including activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and the level of reduced glutathione (GSH) and malondialdehyde (MDA). Improvements in cardiopulmonary hemodynamics were observed in the MSM-treated pulmonary arterial hypertensive rats, with a significant reduction in right ventricular systolic pressure (RSVP) and an increase in the mean arterial pressure (MAP). The values of CAT, SOD, GSH-px activities, and GSH were significantly lower in MCT-induced PAH (P < 0.01), but they were recovered to control levels of MSM-treated groups. Our present results suggest that long-term administration of the MSM attenuates MCT-induced PAH in rats through modulation of oxidative stress and antioxidant defense. PMID:23118745

  5. The Modulatory Role of Heme Oxygenase on Subpressor Angiotensin II-Induced Hypertension and Renal Injury

    PubMed Central

    Chandrashekar, Kiran; Lopez-Ruiz, Arnaldo; Juncos, Ramiro; Nath, Karl; Stec, David E.; Vera, Trinity; Liu, Ruisheng; Juncos, Luis A.

    2012-01-01

    Angiotensin II (AngII) causes hypertension (HTN) and promotes renal injury while simultaneously inducing reno-protective enzymes like heme oxygenase-1 (HO-1). We examined the modulatory role of HO on sub-pressor angiotensin II (SP-AngII) induced renal inflammation and injury. We first tested whether the SP-AngII-induced renal dysfunction, inflammation and injury are exacerbated by either preventing (chronic HO-1 inhibition) or reversing (late HO-1 inhibition) SP-AngII-induced HO (using tin protoporphyrin; SnPP). We next examined whether additional chronic or late induction of SP-AngII-induced HO (using cobalt protoporphyrin; CoPP), prevents or ameliorates renal damage. We found that neither chronic nor late SnPP altered blood pressure. Chronic SnPP worsened SP-AngII-induced renal dysfunction, inflammation, injury and fibrosis, whereas late SnPP worsened renal dysfunction but not inflammation. Chronic CoPP prevented HTN, renal dysfunction, inflammation and fibrosis, but surprisingly, not the NGAL levels (renal injury marker). Late CoPP did not significantly alter SP-AngII-induced HTN, renal inflammation or injury, but improved renal function. Thus, we conclude (a) endogenous HO may be an essential determining factor in SP-AngII induced renal inflammation, injury and fibrosis, (b) part of HO's renoprotection may be independent of blood pressure changes; and (c) further induction of HO-1 protects against renal injury, suggesting a possible therapeutic target. PMID:22506099

  6. The Modulatory Role of Heme Oxygenase on Subpressor Angiotensin II-Induced Hypertension and Renal Injury.

    PubMed

    Chandrashekar, Kiran; Lopez-Ruiz, Arnaldo; Juncos, Ramiro; Nath, Karl; Stec, David E; Vera, Trinity; Liu, Ruisheng; Juncos, Luis A

    2012-01-01

    Angiotensin II (AngII) causes hypertension (HTN) and promotes renal injury while simultaneously inducing reno-protective enzymes like heme oxygenase-1 (HO-1). We examined the modulatory role of HO on sub-pressor angiotensin II (SP-AngII) induced renal inflammation and injury. We first tested whether the SP-AngII-induced renal dysfunction, inflammation and injury are exacerbated by either preventing (chronic HO-1 inhibition) or reversing (late HO-1 inhibition) SP-AngII-induced HO (using tin protoporphyrin; SnPP). We next examined whether additional chronic or late induction of SP-AngII-induced HO (using cobalt protoporphyrin; CoPP), prevents or ameliorates renal damage. We found that neither chronic nor late SnPP altered blood pressure. Chronic SnPP worsened SP-AngII-induced renal dysfunction, inflammation, injury and fibrosis, whereas late SnPP worsened renal dysfunction but not inflammation. Chronic CoPP prevented HTN, renal dysfunction, inflammation and fibrosis, but surprisingly, not the NGAL levels (renal injury marker). Late CoPP did not significantly alter SP-AngII-induced HTN, renal inflammation or injury, but improved renal function. Thus, we conclude (a) endogenous HO may be an essential determining factor in SP-AngII induced renal inflammation, injury and fibrosis, (b) part of HO's renoprotection may be independent of blood pressure changes; and (c) further induction of HO-1 protects against renal injury, suggesting a possible therapeutic target. PMID:22506099

  7. Inhibition of Phosphodiesterase-1 Attenuates Cold-Induced Pulmonary Hypertension (CIPH)

    PubMed Central

    Crosswhite, Patrick; Sun, Zhongjie

    2014-01-01

    Chronic exposure to cold caused pulmonary arterial hypertension (CIPH) and increased phosphodiesterase-1C (PDE-1C) expression in pulmonary arteries (PAs) in rats. The purpose of this study is to investigate a hypothesis that inhibition of PDE-1 would decrease inflammatory infiltrates and superoxide production leading to attenuation of CIPH. Three groups of male rats were exposed to moderate cold (5±1°C) continuously while 3 groups were maintained at room temperature (23.5±1°C, warm) (6 rats/group). Following 8-week exposure to cold, 3 groups in each temperature condition received continuous i.v. infusion of 8-IBMX (PDE-1 inhibitor), apocynin (NADPH oxidase inhibitor) or vehicle, respectively, for one week. Cold exposure significantly increased right ventricular (RV) systolic pressure compared to warm groups (33.8±3.2 vs 18.6±0.3 mmHg), indicating that animals developed pulmonary arterial hypertension (CIPH). Notably, treatment with 8-IBMX significantly attenuated the cold-induced increase in RV pressure (23.5±1.8 mmHg). Cold exposure also caused RV hypertrophy while 8-IBMX reversed cold-induced RV hypertrophy. Cold exposure increased PDE-1C protein expression, macrophage infiltration, NADPH oxidase activity, and superoxide production in PAs and resulted in PA remodeling. 8-IBMX abolished cold-induced upregulation of PDE1C in PAs. Interestingly, inhibition of PDE1 eliminated cold-induced macrophage infiltration, NADPH oxidase activation, and superoxide production in PAs and reversed PA remodeling. Inhibition of NADPH oxidase by apocynin abolished cold-induced superoxide production and attenuated CIPH and PA remodeling. Conclusions Inhibition of PDE-1 attenuated CIPH and reversed cold-induced PA remodeling by suppressing macrophage infiltration and superoxide production, suggesting that upregulation of PDE-1C expression may be involved in the pathogenesis of CIPH. PMID:23319544

  8. Contribution of Ras farnesyl transferase, MAP kinase and cytochrome P-450 metabolites to endothelin-1 induced hypertension

    PubMed Central

    Ljuca, Farid; Drevenšek, Gorazd; Zerem, Enver

    2011-01-01

    Endothelin 1 (ET-1) is vasoactive peptide that acts via ET-A receptors coupling inducing vascular smooth muscle cell proliferation and contraction. ET-1 is involved in the development and maintenance of hypertension. Aim of this study was to determine the contribution of Ras farnesyl transferase, mitogen activated protein kinase (MAP kinase) and cytochrome P¬450 (CYP450) metabolites to ET-1 induced hypertension. ET-1 (5 pmol/kg per minute) was chronically infused into to the jugular vein by use of mini-osmotic pump for 9 days in male Sprague-Dawley rats. Mean arterial blood pressure (MABP) in ET-1-treated rats was 154±2 mm Hg (hypertensive rats) compared with 98±3 mm Hg in control (normotensive) rats. Infusion of Ras farnesyl transferase inhibitor FPTIII (138 ng/min), MAP kinase inhibitor PD-98059 (694 ng/min) and CYP450 inhibitor 17-ODYA (189 ng/min) significantly attenuated MABP to 115±2.5 mm Hg, 109±3 mm Hg and 118±1.5 mm Hg, respectively. These results suggest that CYP-450 metabolites and Ras/MAP kinase pathway contribute to the development of ET-1 induced hypertension. Further investigation has to be done to confirm whether activation of RAS/MAP kinase pathway by arachidonic acid metabolites plays an important role in the development of ET-1 induced hypertension. PMID:21619553

  9. 20-HETE induces remodeling of renal resistance arteries independent of blood pressure elevation in hypertension.

    PubMed

    Ding, Yan; Wu, Cheng-Chia; Garcia, Victor; Dimitrova, Irina; Weidenhammer, Adam; Joseph, Gregory; Zhang, Frank; Manthati, Vijay L; Falck, John R; Capdevila, Jorge H; Schwartzman, Michal L

    2013-09-01

    20-Hydroxyeicosatetraenoic acid (20-HETE) is a cytochrome P-450 (Cyp)-derived arachidonic acid metabolite that has been shown to increase smooth muscle contractions and proliferation, stimulate endothelial dysfunction and activation, and promote hypertension. We examined if 20-HETE contributes to microvascular remodeling in hypertension. In Sprague-Dawley rats, administration of the 20-HETE biosynthesis inhibitor HET0016 or the 20-HETE antagonist N-20-hydroxyeicosa-6(Z),15(Z)-dienoic acid (20-HEDE) prevented 5?-dihydrotestosterone (DHT)-induced increases in blood pressure as well as abrogated DHT-induced increases in the media-to-lumen ratio (M/L), media thickness, and collagen IV deposition in renal interlobar arteries. Reserpine prevented blood pressure elevation in DHT-treated rats but did not affect microvascular remodeling (M/L, media thickness, and collagen deposition); under these conditions, treatment with the 20-HETE antagonist attenuated microvascular remodeling, suggesting that 20-HETE contributes to DHT-induced vascular remodeling independent of blood pressure elevation. In Cyp4a14(-/-) mice, which display androgen-driven and 20-HETE-dependent hypertension, treatment with the 20-HETE antagonist abolished remodeling of renal resistance arteries measured as media thickness (24 ± 1 vs. 15 ± 1 ?m) and M/L (0.29 ± 0.03 vs. 0.17 ± 0.01). Moreover, in Cyp4a12 transgenic mice in which the expression of Cyp4a12-20-HETE synthase is driven by a tetracycline-sensitive promoter, treatment with doxycycline resulted in blood pressure elevation (140 ± 4 vs. 92 ± 5 mmHg) and a significant increase in remodeling of renal resistance arteries (media thickness: 23 ± 1 vs. 16 ± 1 ?m; M/L: 0.39 ± 0.04 vs. 0.23 ± 0.02); these increases were abrogated by cotreatment with 20-HEDE. This study demonstrated that 20-HETE is a key regulator of microvascular remodeling in hypertension; its effect is independent of blood pressure elevation and androgen levels. PMID:23825080

  10. [Hydrogen sulfide inhibits Ca(2+)-induced mitochondrial permeability transition pore opening in spontaneously hypertensive rats].

    PubMed

    Strutyns'ka, N A; Dorofeieva, N O; Vavilova, H L; Sahach, V F

    2013-01-01

    In experiments in vivo and in vitro on the mitochondria isolated from the control and spontaneously hypertensive rats (SHR) hearts, we studied the effects of a donor of hydrogen sulfide (H2S), NaHS, and H2S biosynthesis substrate, L-cysteine, on the sensitivity of the mitochondrial permeability transition pore (mPTP) opening to its natural inductor, Ca2+. We found that NaHS (10(-4), 10(-5) and 5 10(-5) mol/l) influenced the mitochondrial swelling in a concentration-dependent manner in control and spontaneously hypertensive rats. The H2S donor NaHS used in physiological concentrations (10(-6), 10(-5) and 5 10(-5) mol/l) exerted the inhibiting effect on the Ca(2+)-induced mPTP opening in control hearts (corresponding values of such effect were 31, 76, and 100%, respectively), while in spontaneously hypertensive rats hearts the protector effect of NaHS was observed only at its concentration of 10(-5) - 10(-4) mol/l. In experiments in vivo, single intraperitoneal injections of L-cysteine (10(-3) mol/kg) resulted in a decrease in the sensitivity of mPTP to it's inductor Ca2+ in control rats and SHR. In experiments in vivo in which we used a specific blocker of cystathionine-gamma-lyase, propargylglycine (10(-4) mol/kg), with the further injections of L-cysteine we observed a decrease in the threshold Ca2+ concentration (that induce the mitochondrial swelling) by three orders of magnitude in SHR, but in control rats did not effect of L-cysteine. Thus, both endogenous and exogenous hydrogen sulfide inhibits Ca(2+)-induced mitochondrial permeability transition pore opening, indicating its protective effect on pore formation in spontaneously hypertensive rats hearts. Therefore, our studies are indicative of the involvement of H2S in modulation of changes in the permeability of mitochondrial membranes, which can be an important regulatory factor in the development of cardiovascular diseases. PMID:23713344

  11. Novel retro-inverso Peptide inhibitor reverses Angiotensin receptor autoantibody-induced hypertension in the rabbit.

    PubMed

    Li, Hongliang; Kem, David C; Zhang, Ling; Huang, Bing; Liles, Campbell; Benbrook, Alexandria; Gali, Hariprasad; Veitla, Vineet; Scherlag, Benjamin J; Cunningham, Madeleine W; Yu, Xichun

    2015-04-01

    Activating autoantibodies to the angiotensin II type 1 receptor (AT1R) have been implicated in hypertensive disorders. We investigated whether AT1R antibodies produced in immunized rabbits will activate AT1R and contribute to hypertension by a direct contractile effect on the vasculature and whether they can be blocked by a novel decoy peptide. A multiple antigenic peptide containing the AT1R epitope AFHYESQ, which is the receptor-binding epitope of AT1R-activating autoantibodies, was used to immunize 6 rabbits. AT1R antibody activity was analyzed in AT1R-transfected cells, and their contractile effects were assayed using isolated perfused rat cremaster resistance arterioles. A retro-inverso d-amino acid epitope-mimetic peptide was tested for AT1R antibody inhibition in vitro and in vivo. All immunized animals produced high AT1R antibody titers and developed elevated blood pressure. No changes in measured blood chemistry values were observed after immunization. Rabbit anti-AT1R sera induced significant AT1R activation in transfected cells and vasoconstriction in the arteriole assay, both of which were blocked by losartan and the retro-inverso d-amino acid peptide. A single intravenous bolus injection of the retro-inverso d-amino acid peptide (1 mg/kg) into immunized rabbits dropped the mean arterial pressure from 122±11 to 82±6 mm?Hg. Rabbit anti-AT1R sera partially suppressed angiotensin II-induced contraction of isolated rat cremaster arterioles, and the pressor response to angiotensin II infusion was attenuated in immunized animals. In conclusion, AT1R-activating autoantibodies and the retro-inverso d-amino acid peptide, respectively, have important etiologic and therapeutic implications in hypertensive subjects who harbor these autoantibodies. PMID:25691619

  12. Abnormal pressure natriuresis in the dog model of obesity-induced hypertension.

    PubMed

    Granger, J P; West, D; Scott, J

    1994-01-01

    Obesity is considered to be a major factor in the pathogenesis of hypertension in industrialized countries. Recent studies have suggested that the kidneys may play an important role in the development of obesity-induced hypertension. The purpose of this study was to determine whether obesity-induced hypertension is associated with abnormalities in the pressure-natriuresis relation. Renal function studies were performed in anesthetized control dogs (body weight, 20.2 +/- 0.8 kg) and obese dogs (body weight, 26.4 +/- 0.7 kg) that were maintained on a high-fat diet for 5 to 6 weeks. Mean arterial pressure averaged 122 +/- 5 mm Hg in the control group (n = 6) and 148 +/- 7 mm Hg in the obese group (n = 8). The effects of renal perfusion pressure on renal hemodynamics as well as sodium and water excretions were examined at five levels of renal perfusion pressure ranging from 75 to 165 mm Hg. Pressure-natriuretic and diuretic responses were reduced in the obese dogs by 40% to 50%. The renal blood flow and glomerular filtration rate autoregulatory responses and fractional lithium excretion responses to changes in renal perfusion pressure were similar in the control and obese dog groups. Associated with the attenuated natriuretic response to renal perfusion pressure in the obese dogs were significant elevations in plasma renin activity (4.3 +/- 1.6 versus 1.6 +/- 0.5 ng angiotensin I/mL per hour), plasma aldosterone concentration (34.4 +/- 6.4 versus 15.3 +/- 3.2 ng/dL), and plasma insulin concentration (30.5 +/- 6.8 versus 20.9 +/- 2.9 IU/mL).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8282380

  13. Aldosterone acting through the central nervous system sensitizes angiotensin II-induced hypertension.

    PubMed

    Xue, Baojian; Zhang, Zhongming; Roncari, Camila F; Guo, Fang; Johnson, Alan Kim

    2012-10-01

    Previous studies have shown that preconditioning rats with a nonpressor dose of angiotensin II (Ang II) sensitizes the pressor response produced by later treatment with a higher dose of Ang II and that Ang II and aldosterone (Aldo) can modulate each other's pressor effects through actions involving the central nervous system. The current studies tested whether Aldo can cross-sensitize the pressor actions of Ang II to enhance hypertension by employing an induction-delay-expression experimental design. Male rats were implanted for telemetered blood pressure recording. During induction, subpressor doses of either subcutaneous or intracerebroventricular Aldo were delivered for 1 week. Rats were then rested for 1 week (delay) to assure that any exogenous Aldo was metabolized. After this, Ang II was given subcutaneously for 2 weeks (expression). During induction and delay, Aldo had no sustained effect on blood pressure. However, during expression, Ang II-induced hypertension was greater in the groups receiving subcutaneous or intracerebroventricular Aldo during induction in comparison with those groups receiving vehicle. Central administration of mineralocorticoid receptor antagonist blocked sensitization. Brain tissue collected at the end of delay and expression showed increased mRNA expression of several renin-angiotensin-aldosterone system components in cardiovascular-related forebrain regions of cross-sensitized rats. Cultured subfornical organ neurons preincubated with Aldo displayed greater increases in [Ca2+]i after Ang II treatment, and there was a greater Fra-like immunoreactivity present at the end of expression in cardiovascular-related forebrain structures. Taken together, these results indicate that Aldo pretreatment cross-sensitizes the development of Ang II-induced hypertension probably by mechanisms that involve the central nervous system. PMID:22949534

  14. SPIRONOLACTONE PREVENTS CHLORTHALIDONE-INDUCED SYMPATHETIC ACTIVATION AND INSULIN RESISTANCE IN HYPERTENSIVE PATIENTS

    PubMed Central

    Raheja, Prafull; Price, Angela; Wang, Zhongyun; Arbique, Debbie; Adams-Huet, Beverley; Auchus, Richard J.; Vongpatanasin, Wanpen

    2012-01-01

    Recent studies from our laboratory indicate that chlorthalidone triggers persistent activation of the sympathetic nervous system and promotes insulin resistance in hypertensive patients, independent of serum potassium. Mechanisms underlying these adverse effects of chlorthalidone remain unknown but increasing evidence in rodents suggests the role of angiotensin and aldosterone excess in inducing both sympathetic overactivity and insulin resistance. Accordingly, we conducted studies in 17 subjects with untreated stage I hypertension, measuring sympathetic nerve activity (SNA) at baseline, after 12 weeks of chlorthalidone alone (25 mg/day), chlorthalidone plus spironolactone, and chlorthalidone plus irbesartan, using randomized crossover design. We found that chlorthalidone alone decreased 24-hour ambulatory BP (ABP) from 135±3/84±2 to 124±2/78±2 mm Hg and significantly increased SNA from baseline (from 41±3 vs 49±4 bursts/min, p < 0.01). Addition of spironolactone to chlorthalidone returned SNA value to baseline (42±3 bursts/min, p = NS) while addition of irbesartan failed to alter the SNA response to chlorthalidone in the same subjects (52±2 bursts/min, p < 0.01) despite similar reduction in ABP (121±2/75±2 and 121±2/75±2 mmHg, respectively). Chlorthalidone alone also increased indices of insulin resistance, which was not observed when used in combination with spironolactone. In conclusion, our study demonstrates beneficial effects of spironolactone in attenuating both chlorthalidone-induced sympathetic activation and insulin resistance in humans, independent of BP reduction. Because sympathetic overactivity and insulin resistance contributes to the poor prognosis in patients with cardiovascular disease, combination therapy of chlorthalidone with mineralocorticoid receptor antagonists may constitute a preferable regimen than chlorthalidone alone in hypertensive patients. PMID:22733474

  15. Endogenous biosynthesis of arachidonic acid epoxides in humans: Increased formation in pregnancy-induced hypertension

    SciTech Connect

    Catella, F.; Lawson, J.A.; Fitzgerald, D.J.; FitzGerald, G.A. (Vanderbilt Univ., Nashville, TN (USA))

    1990-08-01

    Arachidonic acid is metabolized by means of P450 isoenzyme(s) to form epoxyeicosatrienoic acids (EETs) and their corresponding dihydroxy derivatives (DHETs). In the present study, we established the presence in human urine of 8,9-, 11,12-, and 14,15-EETs and their corresponding DHETs by developing quantitative assays and using negative ion, chemical ionization GC/MS and octadeuterated internal standards. Urinary excretion of 8,9- and 11,12-DHET increased in healthy pregnant women compared with nonpregnant female volunteers. By contrast, excretion of 11,12-DHET and 14,15-DHET, but not the 8,9-DHET regioisomer, increased even further in patients with pregnancy-induced hypertension. Intravenous administration of (3H)14,15-EET to three dogs markedly increased its DHET in plasma. The terminal half-life ranged from 7.9-12.3 min and the volume of distribution (3.5-5.3 liters) suggested limited distribution outside the plasma compartment. Negligible radioactivity was detected in urine; this fact infers that under physiological circumstances, urinary DHETs largely derive from the kidney. That P450 metabolites of arachidonic acid are formed in humans supports the hypothesis that these metabolites contribute to the physiological response to normal pregnancy and the pathophysiology of pregnancy-induced hypertension.

  16. Protective effects of hydrogen-rich saline on monocrotaline-induced pulmonary hypertension in a rat model

    PubMed Central

    2011-01-01

    Background Hydrogen-rich saline has been reported to have antioxidant and anti-inflammatory effects and effectively protect against organ damage. Oxidative stress and inflammation contribute to the pathogenesis and/or development of pulmonary hypertension. In this study, we investigated the effects of hydrogen-rich saline on the prevention of pulmonary hypertension induced by monocrotaline in a rat model. Methods In male Sprague-Dawley rats, pulmonary hypertension was induced by subcutaneous administration of monocrotaline at a concentration of 6 mg/100 g body weight. Hydrogen-rich saline (5 ml/kg) or saline was administred intraperitoneally once daily for 2 or 3 weeks. Severity of pulmonary hypertension was assessed by hemodynamic index and histologic analysis. Malondialdehyde and 8-hydroxy-desoxyguanosine level, and superoxide dismutase activity were measured in the lung tissue and serum. Levels of pro-inflammatory cytokines (tumor necrosis factor-?, interleukin-6) in serum were determined with enzyme-linked immunosorbent assay. Results Hydrogen-rich saline treatment improved hemodynamics and reversed right ventricular hypertrophy. It also decreased malondialdehyde and 8-hydroxy-desoxyguanosine levels, and increased superoxide dismutase activity in the lung tissue and serum, accompanied by a decrease in pro-inflammatory cytokines. Conclusions These results suggest that hydrogen-rich saline ameliorates the progression of pulmonary hypertension induced by monocrotaline in rats, which may be associated with its antioxidant and anti-inflammatory effects. PMID:21375753

  17. Is hypercalcemic diet a possible antidote to oral contraceptive-induced hypertension?

    PubMed

    Okwusidi, J I; Alabi, K I; Olatunji, L A; Oyesola, T O

    2010-01-01

    Administration of oral contraceptive (OC) has been associated with body fluid retention and in high doses over a long period, promotes hypertension. This present investigation tests the hypothesis that the dietary calcium supplementation increases salt and water excretion in OC (norgestre/ethinylestradiol) treated 32 female albino rats randomly distributed into four (1-4) groups of 8 rats each: Control, OC-treated, OC-treated+ Calcium diet fed and Calcium diet fed only respectively. OC was administered to the appropriate groups by gavage. Experimental diet contained 2.5% calcium supplement. Plasma and urinary [Na+] [K+] were evaluated after 8 weeks of experimentation by flame photometry and plasma [Ca2+] by colorimetric method. OC-treatment induced a significant fall in urinary [Na+]. Water excretion was significantly reduced in these animals (control, 3.1±0.56 Vs OC-treated rats, 1.47±0.16). OC-treated rats had significantly higher plasma [K+] compared to control rats. Calcium supplementation induced increases in plasma [Na+], [K+] and augmented urinary Na+ excretion (OC-treated + Ca2+ diet Vs OC-treated only). Compared with the control rats, high Ca2+ diet fed rats exhibited significant increases in plasma [Na+] and [K+] accompanied by significant decreases in urinary H20 excretion. These results strongly suggest that high dietary Ca2+ supplementation increases salt and water excretion in OC-treated rats and potentially moderates fluid retention and blood pressure in these animals, and may be of clinical significance in OC-induced abnormal fluid retention and perhaps OC-induced hypertension. PMID:22314948

  18. Serelaxin reduces oxidative stress and asymmetric dimethylarginine in angiotensin II-induced hypertension.

    PubMed

    Sasser, Jennifer M; Cunningham, Mark W; Baylis, Chris

    2014-12-15

    Recent findings suggest the therapeutic action of relaxin during hypertension is dependent on nitric oxide synthase (NOS) activation; however, the mechanisms underlying the beneficial effects of relaxin on the NOS system have not been fully elucidated. We hypothesized that the protective effects of relaxin include reducing both oxidative stress and the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA). We examined the effect of Serelaxin [human recombinant relaxin-2 (RLX)] in male Sprague-Dawley rats given high-dose angiotensin (ANG) II (400 ng·kg(-1)·min(-1) sc) for 6 wk or shams. RLX was administered (4 ?g/h sc) to half of the rats in each group after 2 wk of ANG II for the remaining 4 wk. ANG II induced hypertension and proteinuria, reduced NO oxidation products (NOx), and increased oxidative stress (NADPH oxidase activity, thiobarbituric acid-reactive substances, and 8-isoprostane excretion) and plasma ADMA. While RLX had no effect on sham rats, RLX attenuated the ANG II-dependent hypertension (165 ± 5 vs. 135 ± 13 mmHg, P < 0.05) and proteinuria at 6 wk (62 ± 6 vs. 41 ± 4 mg·day(-1)·100 g(-1), P < 0.05) and normalized oxidative stress and circulating ADMA, in association with restored NOx excretion and kidney cortex NOx. We found that RLX had no impact on the ADMA-regulatory enzymes protein arginine methyltransferase and dimethylarginine-dimethylaminohydrolase (DDAH). Furthermore, RLX treatment did not increase DDAH activity in kidney cortex or liver. These data suggest that benefits of RLX treatment include reduced ADMA levels and increased NO bioavailability, possibly due to its antioxidant effects. PMID:25298524

  19. Angiotensin-II-induced reactive oxygen species along the SFO-PVN-RVLM pathway: implications in neurogenic hypertension.

    PubMed

    Braga, V A; Medeiros, I A; Ribeiro, T P; França-Silva, M S; Botelho-Ono, M S; Guimarães, D D

    2011-09-01

    Neurogenic hypertension has been the subject of extensive research worldwide. This review is based on the premise that some forms of neurogenic hypertension are caused in part by the formation of angiotensin-II (Ang-II)-induced reactive oxygen species along the subfornical organ-paraventricular nucleus of the hypothalamus-rostral ventrolateral medulla pathway (SFO-PVN-RVLM pathway). We will discuss the recent contribution of our laboratory and others regarding the mechanisms by which neurons in the SFO (an important circumventricular organ) are activated by Ang-II, how the SFO communicates with two other important areas involved in sympathetic activity regulation (PVN and RVLM) and how Ang-II-induced reactive oxygen species participate along the SFO-PVN-RVLM pathway in the pathogenesis of neurogenic hypertension. PMID:21755262

  20. Intracerebroventricular infusion of the (Pro)renin receptor antagonist PRO20 attenuates deoxycorticosterone acetate-salt-induced hypertension.

    PubMed

    Li, Wencheng; Sullivan, Michelle N; Zhang, Sheng; Worker, Caleb J; Xiong, Zhenggang; Speth, Robert C; Feng, Yumei

    2015-02-01

    We previously reported that binding of prorenin to the (pro)renin receptor (PRR) plays a major role in brain angiotensin II formation and the development of deoxycorticosterone acetate (DOCA)-salt hypertension. Here, we designed and developed an antagonistic peptide, PRO20, to block prorenin binding to the PRR. Fluorescently labeled PRO20 bound to both mouse and human brain tissues with dissociation constants of 4.4 and 1.8 nmol/L, respectively. This binding was blocked by coincubation with prorenin and was diminished in brains of neuron-specific PRR-knockout mice, indicating specificity of PRO20 for PRR. In cultured human neuroblastoma cells, PRO20 blocked prorenin-induced calcium influx in a concentration- and AT(1) receptor-dependent manner. Intracerebroventricular infusion of PRO20 dose-dependently inhibited prorenin-induced hypertension in C57Bl6/J mice. Furthermore, acute intracerebroventricular infusion of PRO20 reduced blood pressure in both DOCA-salt and genetically hypertensive mice. Chronic intracerebroventricular infusion of PRO20 attenuated the development of hypertension and the increase in brain hypothalamic angiotensin II levels induced by DOCA-salt. In addition, chronic intracerebroventricular infusion of PRO20 improved autonomic function and spontaneous baroreflex sensitivity in mice treated with DOCA-salt. In summary, PRO20 binds to both mouse and human PRRs and decreases angiotensin II formation and hypertension induced by either prorenin or DOCA-salt. Our findings highlight the value of the novel PRR antagonist, PRO20, as a lead compound for a novel class of antihypertensive agents and as a research tool to establish the validity of brain PRR antagonism as a strategy for treating hypertension. PMID:25421983

  1. Effects of rolipram and roflumilast, phosphodiesterase-4 inhibitors, on hypertension-induced defects in memory function in rats.

    PubMed

    Jabaris, Sobhana George Sugin Lal; Sumathy, Haridass; Kumar, Ramadass Satiesh; Narayanan, Shridhar; Thanikachalam, Sadagopan; Babu, Chidambaram Saravana

    2015-01-01

    Hypertension (HT) is a prevailing risk factor for cognitive impairment, the most common cause of vascular dementia; yet, no possible mechanism underlying the cognitive impairment induced by hypertension has been identified so far. Inhibition of PDE-4 has been shown to increase phosphorylation of cAMP-response element binding protein in the hippocampus and enhance the memory performance. Here, we examined the effects of PDE-4 inhibitors, rolipram and roflumilast, on the impairment of learning and memory observed in hypertensive rats. We used 2k-1c hypertensive model to induce learning and memory defects. In addition, mRNA expression of PDE-4 sub-types A-D was also assessed in the hippocampus tissue. Systolic blood pressure (SBP) was measured by tail-cuff method was significantly increased in 2k-1c rats when compared to sham operated rats; this effect was reversed by clonidine, whereas, PDE-4 inhibitors did not. PDE-4 inhibitors significantly reversed time induced memory deficit in novel object recognition task (NORT). Further, the retention latency on the second day in the elevated plus maze model was significantly shortened after repeated administration of rolipram and roflumilast. Plasma and brain concentrations of rolipram, roflumilast and roflumilast N-oxide were also measured after the NORT and showed linear increase in plasma and brain concentrations. The PDE4B and PDE4D gene expression was significantly enhanced in hypertensive rats compared with sham operated however PDE4A and PDE4C remained unaltered. Repeated treatment with PDE-4 inhibitors caused down regulation of PDE4B and PDE4D in hypertensive rats. These results suggest that inhibition of PDE-4 ameliorates HT-induced impairment of learning and memory functions. PMID:25446433

  2. Effect of Lysyl Oxidase Inhibition on Angiotensin II-Induced Arterial Hypertension, Remodeling, and Stiffness

    PubMed Central

    Eberson, Lance S.; Sanchez, Pablo A.; Majeed, Beenish A.; Tawinwung, Supannikar; Secomb, Timothy W.; Larson, Douglas F.

    2015-01-01

    It is well accepted that angiotensin II (Ang II) induces altered vascular stiffness through responses including both structural and material remodeling. Concurrent with remodeling is the induction of the enzyme lysyl oxidase (LOX) through which ECM proteins are cross-linked. The study objective was to determine the effect of LOX mediated cross-linking on vascular mechanical properties. Three-month old mice were chronically treated with Ang II with or without the LOX blocker, ? -aminopropionitrile (BAPN), for 14 days. Pulse wave velocity (PWV) from Doppler measurements of the aortic flow wave was used to quantify in vivo vascular stiffness in terms of an effective Young’s modulus. The increase in effective Young’s modulus with Ang II administration was abolished with the addition of BAPN, suggesting that the material properties are a major controlling element in vascular stiffness. BAPN inhibited the Ang II induced collagen cross-link formation by 2-fold and PWV by 44% (P<0.05). Consistent with this observation, morphometric analysis showed that BAPN did not affect the Ang II mediated increase in medial thickness but significantly reduced the adventitial thickness. Since the hypertensive state contributes to the measured in vivo PWV stiffness, we removed the Ang II infusion pumps on Day 14 and achieved normal arterial blood pressures. With pump removal we observed a decrease of the PWV in the Ang II group to 25% above that of the control values (P=0.002), with a complete return to control values in the Ang II plus BAPN group. In conclusion, we have shown that the increase in vascular stiffness with 14 day Ang II administration results from a combination of hypertension-induced wall strain, adventitial wall thickening and Ang II mediated LOX ECM cross-linking, which is a major material source of vascular stiffening, and that the increased PWV was significantly inhibited with co-administration of BAPN. PMID:25875748

  3. Hydrogen sulfide is involved in dexamethasone-induced hypertension in rat.

    PubMed

    d'Emmanuele di Villa Bianca, Roberta; Mitidieri, Emma; Donnarumma, Erminia; Tramontano, Teresa; Brancaleone, Vincenzo; Cirino, Giuseppe; Bucci, Mariarosaria; Sorrentino, Raffaella

    2015-04-30

    Glucocorticoid (GC)-induced hypertension is a common clinical problem still poorly understood. The presence of GC receptor (GR) in vascular smooth muscle and endothelial cells suggests a direct role for GC in vasculature. In response to hemodynamic shear stress, endothelium tonically releases nitric oxide (NO), endothelial-derived hyperpolarizing factor (EDHF) and prostacyclin contributing to vascular homeostasis. Recently, hydrogen sulfide (H2S) has been proposed as a candidate for EDHF. H2S is endogenously mainly formed from L-cysteine by the action of cystathionine-?-synthase (CBS) and cystathionine-?-lyase (CSE). It plays many physiological roles and contributes to cardiovascular function. Here we have evaluated the role played by H2S in mesenteric arterial bed and in carotid artery harvested from rats treated with vehicle or dexamethasone (DEX; 1.5?mg/kg/day) for 8 days. During treatments systolic blood pressure was significantly increased in conscious rats. EDHF contribution was evaluated in ex-vivo by performing a concentration-response curve induced by acetylcholine (Ach) in presence of a combination of indomethacin and L-NG-Nitroarginine methyl ester in both vascular districts. EDHF-mediated relaxation was significantly reduced in DEX-treated group in both mesenteric bed and carotid artery. EDHF-mediated relaxation was abolished by pre-treatment with both apamin and charybdotoxin, inhibitors of small and big calcium-dependent potassium channels respectively, or with propargylglycine, inhibitor of CSE. Western blot analysis revealed a marked reduction in CBS and CSE expression as well as H2S production in homogenates of mesenteric arterial bed and carotid artery from DEX-treated rats. In parallel, H2S plasma levels were significantly reduced in DEX group compared with vehicle. In conclusion, an impairment in EDHF/H2S signaling occurs in earlier state of GC-induced hypertension in rats suggesting that counteracting this dysfunction may be beneficial to manage DEX-associated increase in blood pressure. PMID:25461303

  4. Selective endothelin-A receptor blockade attenuates endotoxin-induced pulmonary hypertension and pulmonary vascular dysfunction

    PubMed Central

    2014-01-01

    Abstract Endothelin-1 is a potent mediator of sepsis-induced pulmonary hypertension (PH). The pulmonary vascular effects of selective blockade of endothelin receptor subtype A (ETAR) during endotoxemia remain unknown. We hypothesized that selective ETAR antagonism attenuates endotoxin-induced PH and improves pulmonary artery (PA) vasoreactivity. Adult male Sprague-Dawley rats (250–450 g) received lipopolysaccharide (LPS; Salmonella typhimurium; 20 mg/kg intraperitoneally) or vehicle 6 hours before hemodynamic assessment and tissue harvest. The selective ETAR antagonist sitaxsentan (10 or 20 mg/kg) or vehicle was injected intravenously 3 hours after receipt of LPS. Right ventricular systolic pressure, mean arterial pressure (MAP), cardiac output (CO), oxygenation (P/F ratio), and serum bicarbonate were measured. Bronchoalveolar lavage (BAL) cell differential and lung wet-to-dry ratios were obtained. Endothelium-dependent and endothelium-independent vasorelaxations were determined in isolated PA rings. PA interleukin (IL)-1?, IL-6, tumor necrosis factor ? (TNF-?), and inducible nitric oxide synthase (iNOS) messenger RNA (mRNA) were measured. LPS caused PH, decreased MAP, CO, and serum bicarbonate, and increased PA IL-1?, IL-6, TNF-?, and iNOS mRNA. Sitaxsentan attenuated sepsis-induced PH and increased MAP. The P/F ratio, CO, serum bicarbonate, and BAL neutrophilia were not affected by sitaxsentan. In isolated PA rings, while not affecting phenylephrine-induced vasocontraction or endothelium-dependent relaxation, sitaxsentan dose-dependently attenuated LPS-induced alterations in endothelium-independent relaxation. PA cytokine mRNA levels were not significantly attenuated by ETAR blockade. We conclude that ETAR blockade attenuates endotoxin-induced alterations in systemic and PA pressures without negatively affecting oxygenation. This protective effect appears to be mediated not by attenuation of sepsis-induced cardiac dysfunction, acidosis, or alveolar inflammation but rather by improved endothelium-independent vasorelaxation. PMID:25006449

  5. Phenylalanine improves dilation and blood pressure in GTP cyclohydrolase inhibition-induced hypertensive rats.

    PubMed

    Mitchell, Brett M; Dorrance, Anne M; Webb, R Clinton

    2004-06-01

    GTP cyclohydrolase (GTPCH), the rate-limiting enzyme in the production of the nitric oxide synthase cofactor tetrahydrobiopterin (BH4), is partly regulated by the GTPCH feedback regulatory protein (GFRP). GFRP can inhibit GTPCH by end-product negative feedback, and L-phenylalanine (L-Phe) reverses this inhibition and increases BH4 biosynthesis in vitro. We hypothesized that L-Phe would increase endothelium-dependent relaxation and decrease blood pressure in rats made hypertensive by GTPCH inhibition. Di-amino-hydroxypyrimidine (DAHP, 10 mmol/L), a known inhibitor of GTPCH, was given with or without L-Phe or D-Phe (2 mmol/L) in the drinking water of rats for 3 days and blood pressure was measured via tail-cuff. Endothelium-intact aortic segments were hung in organ chambers for measurement of isometric force generation. Systolic blood pressure was increased significantly in DAHP-treated rats compared with controls. The addition of L-Phe attenuated the hypertensive effect, whereas D-Phe had no effect. Acetylcholine- and A23187-induced relaxation was decreased in aortas from DAHP-treated rats compared with controls, but was restored in aortas from DAHP+L-Phe-treated rats. Following NOS inhibition, sensitivity to sodium nitroprusside was increased in aortas from DAHP-treated rats, but restored in DAHP+L-Phe-treated rats. These results suggest that L-Phe can reverse GTPCH inhibition in vivo leading to increased vasodilation and decreased blood pressure. PMID:15167268

  6. Cerebral microvascular inflammation in DOCA salt-induced hypertension: role of angiotensin II and mitochondrial superoxide.

    PubMed

    Rodrigues, Stephen F; Granger, Daniel Neil

    2012-02-01

    Angiotensin II-mediated hypertension (HTN) is accompanied by a pro-inflammatory and pro-thrombotic state in the cerebral microvasculature. Whether comparable phenotypic changes are elicited in other models of HTN remains unclear. Using wild-type mice with deoxycorticosterone acetate (DOCA) salt-induced HTN and intravital microscopy, we observed significant increases in the adhesion of both leukocytes and platelets in cerebral venules, compared with uninephrectomized control mice, without an accompanying increase in blood-brain barrier permeability. The cell-cell interactions in hypertensive mice were more pronounced after ischemic stroke, but no difference in infarct size was detected. The blood cell recruitment was largely prevented in the following groups of DOCA salt mice: losartan (angiotensin II AT1 receptor blocker) treated, AT1 receptor knockout mice, tempol (a membrane-permeable oxygen radical scavenger) treated, and mito-TEMPO (a mitochondria-targeted antioxidant) treated. A similar pattern of protection was noted in mice subjected to ischemic stroke. The blunted cell recruitment responses were not accompanied by reductions in blood pressure (BP). These findings implicate mitochondria-derived oxygen radicals and angiotensin II in the cerebral inflammation associated with DOCA salt HTN and suggests that BP per se is not a critical determinant of the phenotypic changes that accompany HTN, even after ischemic stroke. PMID:21971354

  7. Leaf methanol extract of Bidens pilosa prevents and attenuates the hypertension induced by high-fructose diet in Wistar rats

    Microsoft Academic Search

    Théophile Dimo; Silvere V Rakotonirina; Paul V Tan; Jacqueline Azay; Etienne Dongo; Gérard Cros

    2002-01-01

    Chronic fructose treatment in rats has repeatedly been shown to elevate blood pressure in association with insulin resistance and hyperinsulinemia. The purpose of the current study was to investigate the effect of the leaf methanol extract of Bidens pilosa on systolic blood pressure (SBP) and plasma glucose, insulin, cholesterol, triglycerides and creatinine levels in rats with fructose-induced hypertension. Wistar rats

  8. Elevated Transglutaminase 2 Activity is Associated with Hypoxia-Induced Experimental Pulmonary Hypertension in Mice

    PubMed Central

    DiRaimondo, Thomas R.; Klock, Cornelius; Warburton, Rod; Herrera, Zachary; Penumatsa, Krishna; Toksoz, Deniz; Hill, Nicholas; Khosla, Chaitan; Fanburg, Barry

    2013-01-01

    Previous studies in human patients and animal models have suggested that transglutaminase 2 (TG2) is upregulated in pulmonary hypertension (PH), a phenomenon that appears to be associated with the effects of serotonin (5-hydroxytryptamine; 5-HT) in this disease. Using chemical tools to interrogate and inhibit TG2 activity in vivo, we have shown that pulmonary TG2 undergoes marked post-translational activation in a mouse model of hypoxia-induced PH. We have also identified irreversible fluorinated TG2 inhibitors that may find use as non-invasive positron emission tomography probes for diagnosis and management of this debilitating, lifelong disorder. Pharmacological inhibition of TG2 attenuated the elevated right ventricular pressure but had no effect on hypertrophy of the right ventricle of the heart. A longitudinal study of pulmonary TG2 activity in PH patients is warranted. PMID:24152195

  9. Role of digitalis-like substance in the hypertension of streptozotocin-induced diabetes and simulated weightlessness in rats

    NASA Technical Reports Server (NTRS)

    Pamnani, M. B.; Chen, S.; Haddy, F. J.; Yuan, C.; Mo, Z.

    1998-01-01

    We have examined the role of plasma Na+-K+ pump inhibitor (SPI) in the hypertension of streptozotocin induced insulin dependent diabetes (IDDM) in reduced renal mass rats. The increase in blood pressure (BP) was associated with an increase in extracellular fluid volume (ECFV), and SPI and a decrease in myocardial Na+,K+ATPase (NKA) activity, suggesting that increased SPI, which inhibits cardiovascular muscle (CVM) cell NKA activity, may be involved in the mechanism of IDDM-hypertension. In a second study, using prolonged suspension resulted in a decrease in cardiac NKA activity, suggesting that cardiovascular deconditioning following space flight might in part result from insufficient SPI.

  10. Deamidated Lipocalin?2 Induces Endothelial Dysfunction and Hypertension in Dietary Obese Mice

    PubMed Central

    Song, Erfei; Fan, Pengcheng; Huang, Bosheng; Deng, Han?Bing; Cheung, Bernard Man Yung; Félétou, Michel; Vilaine, Jean?Paul; Villeneuve, Nicole; Xu, Aimin; Vanhoutte, Paul M.; Wang, Yu

    2014-01-01

    Background Lipocalin?2 is a proinflammatory adipokine upregulated in obese humans and animals. A pathogenic role of lipocalin?2 in hypertension has been suggested. Mice lacking lipocalin?2 are protected from dietary obesity?induced cardiovascular dysfunctions. Administration of lipocalin?2 causes abnormal vasodilator responses in mice on a high?fat diet (HFD). Methods and Results Wild?type and lipocalin?2 knockout mice were fed with standard chow or HFD. Immunoassays were performed for evaluating the circulating and tissue contents of lipocalin?2. The relaxation and contraction of arteries were studied using a wire myograph. Blood pressure was monitored with implantable radio telemetry. Dietary obesity promoted the accumulation of lipocalin?2 protein in blood and arteries. Deficiency of this adipokine protected mice from dietary obesity?induced elevation of blood pressure. Mass spectrometry analysis revealed that human and murine lipocalin?2 were modified by polyamination. Polyaminated lipocalin?2 was rapidly cleared from the circulation. Adipose tissue was a major site for lipocalin?2 deamidation. The circulating levels and the arterial accumulation of deamidated lipocalin?2 were significantly enhanced by treatment with linoleic acid (18:2n?6), which bound to lipocalin?2 with high affinity and prevented its interactions with matrix metalloproteinase 9 (MMP9). Combined administration of linoleic acid with lipocalin?2 caused vascular inflammation and endothelial dysfunction and raised the blood pressure of mice receiving standard chow. A human lipocalin?2 mutant with cysteine 87 replaced by alanine (C87A) contained less polyamines and exhibited a reduced capacity to form heterodimeric complexes with MMP9. After treatment, C87A remained in the circulation for a prolonged period of time and evoked endothelial dysfunction in the absence of linoleic acid. Conclusions Polyamination facilitates the clearance of lipocalin?2, whereas the accumulation of deamidated lipocalin?2 in arteries causes vascular inflammation, endothelial dysfunction, and hypertension. PMID:24721803

  11. The Complex Regulation of Tanshinone IIA in Rats with Hypertension-Induced Left Ventricular Hypertrophy

    PubMed Central

    Pang, Hui; Han, Bing; Yu, Tao; Peng, Zhen

    2014-01-01

    Tanshinone IIA has definite protective effects on various cardiovascular diseases. However, in hypertension-induced left ventricular hypertrophy (H-LVH), the signaling pathways of tanshinone IIA in inhibition of remodeling and cardiac dysfunction remain unclear. Two-kidney, one-clip induced hypertensive rats (n?=?32) were randomized to receive tanshinone IIA (5, 10, 15 mg/kg per day) or 5% glucose injection (GS). Sham-operated rats (n?=?8) received 5%GS as control. Cardiac function and dimensions were assessed by using an echocardiography system. Histological determination of the fibrosis and apoptosis was performed using hematoxylin eosin, Masson’s trichrome and TUNEL staining. Matrix metalloproteinase 2 (MMP2) and tissue inhibitor of matrix metalloproteinases type 2 (TIMP2) protein expressions in rat myocardial tissues were detected by immunohistochemistry. Rat cardiomyocytes were isolated by a Langendorff perfusion method. After 48 h culture, the supernatant and cardiomyocytes were collected to determine the potential related proteins impact on cardiac fibrosis and apoptosis. Compared with the sham rats, the heart tissues of H-LVH (5%GS) group suffered severely from the oxidative damage, apoptosis of cardiomyocytes and extracellular matrix (ECM) deposition. In the H-LVH group, tanshinone IIA treated decreased malondialdehyde (MDA) content and increased superoxide dismutase (SOD) activity. Tanshinone IIA inhibited cardiomyocytes apoptosis as confirmed by the reduction of TUNEL positive cardiomyocytes and the down-regulation of Caspase-3 activity and Bax/Bcl-2 ratio. Meanwhile, plasma apelin level increased with down-regulation of APJ receptor. Tanshinone IIA suppressed cardiac fibrosis through regulating the paracrine factors released by cardiomyocytes and the TGF-?/Smads signaling pathway activity. In conclusion, our in vivo study showed that tanshinone IIA could improve heart function by enhancing myocardial contractility, inhibiting ECM deposition, and limiting apoptosis of cardiomyocytes and oxidative damage. PMID:24647357

  12. Attenuation of salt-induced hypertension by aqueous calyx extract of Hibiscus sabdariffa.

    PubMed

    Mojiminiyi, F B O; Audu, Z; Etuk, E U; Ajagbonna, O P

    2012-01-01

    The aqueous calyx extract of Hibiscus sabdariffa (HS) has a folk reputation as an antihypertensive agent. On account of its antioxidant properties and probably high K+ concentration, we hypothesized that HS may attenuate the development of salt-induced hypertension. Sprague-Dawley rats (n=8 each) were treated for 12 weeks as follows: control (normal diet + water), salt-loaded (8% salt diet + water), HS (normal diet + 6 mg/ml HS), salt+HS (8% salt diet + 6 mg/ml HS) and furosemide (normal diet+ 0.25mg/Kg furosemide). Their blood pressure and heart rates were measured and responses to noradrenalin and acetylcholine (0.01 mg/kg respectively) were estimated. The cationic concentration of 6 mg/ml HS was determined. The Na+ and K+ concentrations of 6 mg/ml HS were 3.6 and 840 mmol/l respectively. The mean arterial pressure (MAP±SEM; mmHg) of salt loaded rats (184.6±29.8) was significantly higher than control (113.2±3.0; P<0.05), HS (90.0±7.4; P<0.001) salt+HS (119.4±8.9; P<0.05) and furosemide (94.9±11.5; P<0.01). The MAP of salt+HS and control rats did not differ significantly and the effect of HS was comparable to furosemide. The pressor response to noradrenalin or vasodilator response to acetylcholine remained similar in all groups. These results suggest that HS attenuated the development of salt-induced hypertension and this attenuation may be associated with its high K+ content or high potassium: sodium ratio and not with altered pressor/depressor response to noradrenalin or acetylcholine. Also the effects of HS and furosemide on blood pressure are comparable. PMID:23652235

  13. The Beneficial Effect of Suramin on Monocrotaline-Induced Pulmonary Hypertension in Rats

    PubMed Central

    Izikki, Mohamed; Mercier, Olaf; Lecerf, Florence; Lubert Guin, Lauriane; Hoang, Eric; Dorfmüller, Peter; Perros, Frédéric; Humbert, Marc; Simonneau, Gerald; Dartevelle, Philippe; Fadel, Elie; Eddahibi, Saadia

    2013-01-01

    Background Pulmonary hypertension (PH) is a progressive disorder characterized by an increase in pulmonary artery pressure and structural changes in the pulmonary vasculature. Several observations indicate that growth factors play a key role in PH by modulating pulmonary artery smooth muscle cell (PA-SMC) function. In rats, established monocrotaline-induced PH (MCT-PH) can be reversed by blocking platelet-derived growth factor receptors (PDGF-R), epidermal growth factor receptors (EGF-R), or fibroblast growth factor receptors (FGF-R). All these receptors belong to the receptor tyrosine kinase (RTK) family. Methods and Results We evaluated whether RTK blockade by the nonspecific growth factor inhibitor, suramin, reversed advanced MCT-PH in rats via its effects on growth-factor signaling pathways. We found that suramin inhibited RTK and ERK1/2 phosphorylation in cultured human PA-SMCs. Suramin inhibited PA-SMC proliferation induced by serum, PDGF, FGF2, or EGF in vitro and ex vivo. Treatment with suramin from day 1 to day 21 after monocrotaline injection attenuated PH development, as shown by lower values for pulmonary artery pressure, right ventricular hypertrophy, and distal vessel muscularization on day 21 compared to control rats. Treatment with suramin from day 21 to day 42 after monocrotaline injection reversed established PH, thereby normalizing the pulmonary artery pressure values and vessel structure. Suramin treatment suppressed PA-SMC proliferation and attenuated both the inflammatory response and the deposition of collagen. Conclusions RTK blockade by suramin can prevent MCT-PH and reverse established MCT-PH in rats. This study suggests that an anti-RTK strategy that targets multiple RTKs could be useful in the treatment of pulmonary hypertension. PMID:24143201

  14. Thymosin Beta 4 Protects Mice from Monocrotaline-Induced Pulmonary Hypertension and Right Ventricular Hypertrophy

    PubMed Central

    Wu, Liling; Gupta, Sudhiranjan

    2014-01-01

    Pulmonary hypertension (PH) is a progressive vascular disease of pulmonary arteries that impedes ejection of blood by the right ventricle. As a result there is an increase in pulmonary vascular resistance and pulmonary arterial pressure causing right ventricular hypertrophy (RVH) and RV failure. The pathology of PAH involves vascular cell remodeling including pulmonary arterial endothelial cell (PAEC) dysfunction and pulmonary arterial smooth muscle cell (PASMC) proliferation. Current therapies are limited to reverse the vascular remodeling. Investigating a key molecule is required for development of new therapeutic intervention. Thymosin beta-4 (T?4) is a ubiquitous G-actin sequestering protein with diverse biological function and promotes wound healing and modulates inflammatory responses. However, it remains unknown whether T?4 has any protective role in PH. The purpose of this study is to evaluate the whether T?4 can be used as a vascular-protective agent. In monocrotaline (MCT)-induced PH mouse model, we showed that mice treated with T?4 significantly attenuated the systolic pressure and RVH, compared to the MCT treated mice. Our data revealed for the first time that T?4 selectively targets Notch3-Col 3A-CTGF gene axis in preventing MCT-induced PH and RVH. Our study may provide pre-clinical evidence for T?4 and may consider as vasculo-protective agent for the treatment of PH induced RVH. PMID:25412097

  15. Effect of Chronic Sodium Nitrite Therapy on Monocrotaline-Induced Pulmonary Hypertension

    PubMed Central

    Pankey, Edward A.; Badejo, Adeleke M.; Casey, David B.; Lasker, George F.; Riehl, Russel A.; Murthy, Subramanyam N.; Nossaman, Bobby D.; Kadowitz, Philip J.

    2012-01-01

    Pulmonary hypertension (PH) is a rare disorder that without treatment is progressive and often fatal within 3 years. The treatment of PH involves the use of a diverse group of drugs and lung transplantation. Although nitrite was once thought to be an inactive metabolite of endothelial-derived nitric oxide (NO), there is increasing evidence that nitrite may be useful in the treatment of PH, but the mechanism by which nitrite exerts its beneficial effect remains uncertain. The purpose of this study was to investigate the effect of chronic sodium nitrite treatment in a PH model in the rat. Following induction of PH with a single injection of monocrotaline, 60 mg; daily ip injections of sodium nitrite (3 mg/kg) starting on day 14 and continuing for 21 days, resulted in a significantly lower pulmonary arterial pressure on day 35 when compared to values in untreated animals with monocrotaline-induced PH. In monocrotaline-treated rats, daily treatment with ip nitrite injections for 21 days decreased right ventricular mass and pathologic changes in small pulmonary arteries. Nitrite therapy did not change systemic arterial pressure or cardiac output when values were measured on day 35. The decreases in pulmonary arterial pressure in response to iv injections of sodium nitroprusside, sodium nitrite, and BAY 41-8543 were not different in rats with monocrotaline-induced pulmonary hypertension and rats with chronic nitrite therapy when compared to responses in animals in which pulmonary arterial pressure was increased with U46619. These findings are consistent with the hypothesis that the mechanisms that convert nitrite to vasoactive NO, activate soluble guanylyl cyclase and mediate the vasodilator response to NO or an NO derivative are not impaired. The present data are consistent with the results of a previous study in monocrotaline-induced PH in which systemic arterial pressure and cardiac output were not evaluated and are consistent with the hypothesis that nitrite is effective in the treatment of monocrotaline-induced PH in the rodent. PMID:22426035

  16. Pressure natriuresis and angiotensin II in reduced kidney mass, salt-induced hypertension.

    PubMed

    Hall, J E; Mizelle, H L; Brands, M W; Hildebrandt, D A

    1992-01-01

    In normal subjects, high sodium intake causes little change in mean arterial pressure (MAP). However, MAP is sodium sensitive after reduction of kidney mass. The present study examined the role of increased renal artery pressure and decreased angiotensin II (ANG II) formation in maintaining sodium balance during high sodium intake in dogs with reduced kidney mass. In seven dogs with pressure natriuresis intact, increasing sodium intake from 36 to 466 meq/day for 7 days raised MAP from 91 +/- 2 to 106 +/- 2 mmHg. Sodium excretion increased promptly and cumulative sodium balance increased by only 80 +/- 26 meq after 7 days of high sodium intake. When renal perfusion pressure was servo-controlled to prevent pressure natriuresis, comparable increases in sodium intake raised MAP from 88 +/- 2 to 128 +/- 4 mmHg after 7 days. Sodium excretion rose to match intake, but cumulative sodium balance increased by 226 +/- 34 meq after 7 days. In dogs in which ANG II levels were held constant by converting enzyme inhibition and constant ANG II infusion (2 ng.kg-1.min-1 iv), raising sodium intake for 7 days elevated MAP from 126 +/- 2 to 146 +/- 4 mmHg after 7 days while increasing cumulative sodium balance by 212 +/- 29 meq. When renal perfusion pressure was servo-controlled and ANG II levels held constant, raising sodium intake elevated MAP from 125 +/- 3 to 166 +/- 11 mmHg and increased cumulative sodium balance by 399 +/- 128 meq. These data indicate that pressure natriuresis and decreased ANG II formation are important in minimizing sodium retention and hypertension during high sodium intake. However, other mechanisms can increase sodium excretion independent of pressure natriuresis and suppression of ANG II during salt-induced hypertension. PMID:1733341

  17. Adventitial fibroblasts induce a distinct proinflammatory/profibrotic macrophage phenotype in pulmonary hypertension.

    PubMed

    El Kasmi, Karim C; Pugliese, Steven C; Riddle, Suzette R; Poth, Jens M; Anderson, Aimee L; Frid, Maria G; Li, Min; Pullamsetti, Soni S; Savai, Rajkumar; Nagel, Maria A; Fini, Mehdi A; Graham, Brian B; Tuder, Rubin M; Friedman, Jacob E; Eltzschig, Holger K; Sokol, Ronald J; Stenmark, Kurt R

    2014-07-15

    Macrophage accumulation is not only a characteristic hallmark but is also a critical component of pulmonary artery remodeling associated with pulmonary hypertension (PH). However, the cellular and molecular mechanisms that drive vascular macrophage activation and their functional phenotype remain poorly defined. Using multiple levels of in vivo (bovine and rat models of hypoxia-induced PH, together with human tissue samples) and in vitro (primary mouse, rat, and bovine macrophages, human monocytes, and primary human and bovine fibroblasts) approaches, we observed that adventitial fibroblasts derived from hypertensive pulmonary arteries (bovine and human) regulate macrophage activation. These fibroblasts activate macrophages through paracrine IL-6 and STAT3, HIF1, and C/EBP? signaling to drive expression of genes previously implicated in chronic inflammation, tissue remodeling, and PH. This distinct fibroblast-activated macrophage phenotype was independent of IL-4/IL-13-STAT6 and TLR-MyD88 signaling. We found that genetic STAT3 haplodeficiency in macrophages attenuated macrophage activation, complete STAT3 deficiency increased macrophage activation through compensatory upregulation of STAT1 signaling, and deficiency in C/EBP? or HIF1 attenuated fibroblast-driven macrophage activation. These findings challenge the current paradigm of IL-4/IL-13-STAT6-mediated alternative macrophage activation as the sole driver of vascular remodeling in PH, and uncover a cross-talk between adventitial fibroblasts and macrophages in which paracrine IL-6-activated STAT3, HIF1?, and C/EBP? signaling are critical for macrophage activation and polarization. Thus, targeting IL-6 signaling in macrophages by completely inhibiting C/EBP? or HIF1? or by partially inhibiting STAT3 may hold therapeutic value for treatment of PH and other inflammatory conditions characterized by increased IL-6 and absent IL-4/IL-13 signaling. PMID:24928992

  18. Inducible deletion of connexin 40 in adult mice causes hypertension and disrupts pressure control of renin secretion.

    PubMed

    Gerl, Melanie; Vöckl, Josef; Kurt, Birgül; van Veen, Toon A B; Kurtz, Armin; Wagner, Charlotte

    2015-03-01

    Genetic loss-of-function defects of connexin 40 in renal juxtaglomerular cells are associated with renin-dependent hypertension. The dysregulation of renin secretion results from an intrarenal displacement of renin cells and an interruption of the negative feedback control of renin secretion by blood pressure. It is unknown whether this phenotype is secondary to developmental defects of juxtaglomerular renin cells due to connexin 40 malfunction, or whether acute functional defects of connexin 40 in the normal adult kidney can also lead to a similar dysregulation of renin secretion and hypertension. To address this question, we generated mice with an inducible deletion of connexin 40 in the adult kidney by crossing connexin 40-floxed mice with mice harboring a ubiquitously expressed tamoxifen-inducible Cre recombinase. Tamoxifen treatment in these mice strongly reduced connexin 40 mRNA and protein expression in the kidneys. These mice displayed persistent hypertension with renin expression shifted from the media layer of afferent arterioles to juxtaglomerular periglomerular cells. Control of renin secretion by the perfusion pressure was abolished in vitro, whereas in vivo plasma renin concentrations were increased. Thus, interruption of the connexin 40 gene in the adult kidney produced very similar changes in the renin system as had embryonic deletion. Hence, impairments of connexin 40 function in the normal adult kidney can cause renin-dependent hypertension. PMID:25229336

  19. Pathological mechanisms of alcohol-induced hepatic portal hypertension in early stage fibrosis rat model

    PubMed Central

    Li, Jian; Niu, Jian-Zhao; Wang, Ji-Feng; Li, Yu; Tao, Xiao-Hua

    2005-01-01

    AIM: To study the role of hepatic sinusoidal capillarization and perisinusoidal fibrosis in rats with alcohol-induced portal hypertension and to discuss the pathological mechanisms of alcohol-induced hepatic portal hypertension. METHODS: Fifty SD rats were divided into control group (n=20) and model group (n=30). Alcoholic liver fibrosis rat model was induced by intragastric infusion of a mixture containing alcohol, corn oil and pyrazole (1 000:250:3). Fifteen rats in each group were killed at wk 16. The diameter and pressure of portal vein were measured. Plasma hyaluronic acid (HA), type IV collagen (CoIV) and laminin (LN) were determined by radioimmunoassay. Liver tissue was fixed in formalin (10%) and 6-?m thick sections were routinely stained with Mallory and Sirius Red. Liver tissue was treated with rabbit polyclonal antibody against LN and ColIV. Hepatic non-parenchymal cells were isolated, total protein was extracted and separated by SDS-PAGE. MMP-2 and TIMP-1 protein expression was estimated by Western blotting. RESULTS: The diameter (2.207 ± 0.096 vs 1.528 ± 0.054 mm, P<0.01) and pressure (11.014±0.395 vs 8.533±0.274 mmHg, P<0.01) of portal vein were significantly higher in model group than those in the control group. Plasma HA (129.97±16.10 vs 73.09±2.38 ng/mL, P<0.01), ColIV (210.49±4.36 vs 89.65±4.42 ng/mL, P<0.01) and LN (105.00±7.29 vs 55.70±4.32 ng/mL, P<0.01) were upregulated in model group. Abundant collagen deposited around the central vein of lobules, hepatic sinusoids and hepatocytes in model group. ColI and ColIII increased remarkably and perisinusoids were almost surrounded by ColIII. Immunohistochemical staining showed that ColIV protein level (0.130±0.007 vs 0.032±0.004, P<0.01) and LN protein level (0.152±0.005 vs 0.029±0.005, P<0.01) were up-regulated remarkably in model group. MMP-2 protein expression (2.306±1.089 vs 0.612±0.081, P<0.01) and TIMP-1 protein expression (3.015±1.364 vs 0.446±0.009, P<0.01) in freshly isolated hepatic non-parenchymal cells were up-regulated in model group and TIMP-1 protein expression was evidently higher than MMP-2 protein expression (2.669±0.170 vs 1.695±0.008, P<0.05). CONCLUSION: Hepatic sinusoidal capillarization and peri-sinusoidal fibrosis are responsible for alcohol-induced portal hypertension in rats. PMID:16425420

  20. Attenuated muscle metaboreflex-induced pressor response during postexercise muscle ischemia in renovascular hypertension.

    PubMed

    Spranger, Marty D; Kaur, Jasdeep; Sala-Mercado, Javier A; Machado, Tiago M; Krishnan, Abhinav C; Alvarez, Alberto; O'Leary, Donal S

    2015-04-01

    During dynamic exercise, muscle metaboreflex activation (MMA; induced via partial hindlimb ischemia) markedly increases mean arterial pressure (MAP), and MAP is sustained when the ischemia is maintained following the cessation of exercise (postexercise muscle ischemia, PEMI). We previously reported that the sustained pressor response during PEMI in normal individuals is driven by a sustained increase in cardiac output (CO) with no peripheral vasoconstriction. However, we have recently shown that the rise in CO with MMA is significantly blunted in hypertension (HTN). The mechanisms sustaining the pressor response during PEMI in HTN are unknown. In six chronically instrumented canines, hemodynamic responses were observed during rest, mild exercise (3.2 km/h), MMA, and PEMI in the same animals before and after the induction of HTN [Goldblatt two kidney, one clip (2K1C)]. In controls, MAP, CO and HR increased with MMA (+52 ± 6 mmHg, +2.1 ± 0.3 l/min, and +37 ± 7 beats per minute). After induction of HTN, MAP at rest increased from 97 ± 3 to 130 ± 4 mmHg, and the metaboreflex responses were markedly attenuated (+32 ± 5 mmHg, +0.6 ± 0.2 l/min, and +11 ± 3 bpm). During PEMI in HTN, HR and CO were not sustained, and MAP fell to normal recovery levels. We conclude that the attenuated metaboreflex-induced HR, CO, and MAP responses are not sustained during PEMI in HTN. PMID:25632024

  1. Role of vascular endothelial growth factor signaling in Schistosoma-induced experimental pulmonary hypertension

    PubMed Central

    2014-01-01

    Abstract There is significant evidence that Th2 (T helper 2)-mediated inflammation supports the pathogenesis of both human and experimental animal models of pulmonary hypertension (PH). A key immune regulator is vascular endothelial growth factor (VEGF), which is produced by Th2 inflammation and can itself contribute to Th2 pulmonary responses. In this study, we interrogated the role of VEGF signaling in a murine model of schistosomiasis-induced PH with a phenotype of significant intrapulmonary Th2 inflammation, vascular remodeling, and elevated right ventricular pressures. We found that VEGF receptor blockade partially suppressed the levels of the Th2 inflammatory cytokines interleukin (IL)-4 and IL-13 in both the lung and the liver after Schistosoma mansoni exposure and suppressed pulmonary vascular remodeling. These findings suggest that VEGF positively contributes to schistosomiasis-induced vascular inflammation and remodeling, and they also provide evidence for a VEGF-dependent signaling pathway necessary for pulmonary vascular remodeling and inflammation in this model. PMID:25006448

  2. Megakaryocytic Leukemia 1 (MKL1) Regulates Hypoxia Induced Pulmonary Hypertension in Rats

    PubMed Central

    Yuan, Zhibin; Chen, Jian; Chen, Dewei; Xu, Gang; Xia, Minjie; Xu, Yong; Gao, Yuqi

    2014-01-01

    Hypoxia induced pulmonary hypertension (HPH) represents a complex pathology that involves active vascular remodeling, loss of vascular tone, enhanced pulmonary inflammation, and increased deposition of extracellular matrix proteins. Megakaryocytic leukemia 1 (MKL1) is a transcriptional regulator known to influence cellular response to stress signals in the vasculature. We report here that in response to chronic hypobaric hypoxia, MKL1 expression was up-regulated in the lungs in rats. Short hairpin RNA (shRNA) mediated depletion of MKL1 significantly ameliorated the elevation of pulmonary arterial pressure in vivo with a marked alleviation of vascular remodeling. MKL1 silencing also restored the expression of NO, a key vasoactive molecule necessary for the maintenance of vascular tone. In addition, hypoxia induced pulmonary inflammation was dampened in the absence of MKL1 as evidenced by normalized levels of pro-inflammatory cytokines and chemokines as well as reduced infiltration of pro-inflammatory immune cells in the lungs. Of note, MKL1 knockdown attenuated fibrogenesis in the lungs as indicated by picrosirius red staining. Finally, we demonstrate that MKL1 mediated transcriptional activation of type I collagen genes in smooth muscle cells under hypoxic conditions. In conclusion, we data highlight a previously unidentified role for MKL1 in the pathogenesis of HPH and as such lay down groundwork for future investigation and drug development. PMID:24647044

  3. Attenuation of the extract from Moringa oleifera on monocrotaline-induced pulmonary hypertension in rats.

    PubMed

    Chen, Kang-Hu; Chen, Yi-Jui; Yang, Chao-Hsun; Liu, Kuo-Wei; Chang, Junn-Liang; Pan, Shwu-Fen; Lin, Tzer-Bin; Chen, Mei-Jung

    2012-02-29

    The purpose of this study was to determine the effects of an extract from Moringa oleifera (MO) on the development of monocrotaline (MCT)-induced pulmonary hypertension (PH) in Wistar rats. An ethanol extraction was performed on dried MO leaves, and HPLC analysis identified niaziridin and niazirin in the extract. PH was induced with a single subcutaneous injection of MCT (60 mg/kg) which resulted in increases in pulmonary arterial blood pressure (Ppa) and in thickening of the pulmonary arterial medial layer in the rats. Three weeks after induction, acute administration of the MO extract to the rats decreased Ppa in a dose-dependent manner that reached statistical significance at a dose of 4.5 mg of freeze-dried extract per kg body weight. The reduction in Ppa suggested that the extract directly relaxed the pulmonary arteries. To assay the effects of chronic administration of the MO extract on PH, control, MCT and MCT+MO groups were designated. Rats in the control group received a saline injection; the MCT and MCT+MO groups received MCT to induce PH. During the third week after MCT treatment, the MCT+MO group received daily i.p. injections of the MO extract (4.5 mg of freeze-dried extract/kg of body weight). Compared to the control group, the MCT group had higher Ppa and thicker medial layers in the pulmonary arteries. Chronic treatments with the MO extract reversed the MCT-induced changes. Additionally, the MCT group had a significant elevation in superoxide dismutase activity when normalized by the MO extract treatments. In conclusion, the MO extract successfully attenuated the development of PH via direct vasodilatation and a potential increase in antioxidant activity. PMID:22242951

  4. Arginase inhibition prevents bleomycin-induced pulmonary hypertension, vascular remodeling, and collagen deposition in neonatal rat lungs.

    PubMed

    Grasemann, Hartmut; Dhaliwal, Rupinder; Ivanovska, Julijana; Kantores, Crystal; McNamara, Patrick J; Scott, Jeremy A; Belik, Jaques; Jankov, Robert P

    2015-03-15

    Arginase is an enzyme that limits substrate l-arginine bioavailability for the production of nitric oxide by the nitric oxide synthases and produces l-ornithine, which is a precursor for collagen formation and tissue remodeling. We studied the pulmonary vascular effects of arginase inhibition in an established model of repeated systemic bleomycin sulfate administration in neonatal rats that results in pulmonary hypertension and lung injury mimicking the characteristics typical of bronchopulmonary dysplasia. We report that arginase expression is increased in the lungs of bleomycin-exposed neonatal rats and that treatment with the arginase inhibitor amino-2-borono-6-hexanoic acid prevented the bleomycin-induced development of pulmonary hypertension and deposition of collagen. Arginase inhibition resulted in increased l-arginine and l-arginine bioavailability and increased pulmonary nitric oxide production. Arginase inhibition also normalized the expression of inducible nitric oxide synthase, and reduced bleomycin-induced nitrative stress while having no effect on bleomycin-induced inflammation. Our data suggest that arginase is a promising target for therapeutic interventions in neonates aimed at preventing lung vascular remodeling and pulmonary hypertension. PMID:25595650

  5. Partners In Health and Brigham & Women's Hospitalist Program Background: Partners In Health (PIH) is a health and social justice organization with a

    E-print Network

    Derisi, Joseph

    Partners In Health and Brigham & Women's Hospitalist Program Background: Partners In Health (PIH) is a health and social justice organization with a mission to build high quality, comprehensive public health systems

  6. Salt-induced hypertension in a mouse model of Liddle syndrome is mediated by epithelial sodium channels in the brain.

    PubMed

    Van Huysse, James W; Amin, Md Shahrier; Yang, Baoli; Leenen, Frans H H

    2012-09-01

    Neural precursor cell expressed and developmentally downregulated 4-2 protein (Nedd4-2) facilitates the endocytosis of epithelial Na channels (ENaCs). Both mice and humans with a loss of regulation of ENaC by Nedd4-2 have salt-induced hypertension. ENaC is also expressed in the brain, where it is critical for hypertension on a high-salt diet in salt-sensitive rats. In the present studies we assessed whether Nedd4-2 knockout (-/-) mice have the following: (1) increased brain ENaC; (2) elevated cerebrospinal fluid (CSF) sodium on a high-salt diet; and (3) enhanced pressor responses to CSF sodium and hypertension on a high-salt diet, both mediated by brain ENaC. Prominent choroid plexus and neuronal ENaC staining was present in -/- but not in wild-type mice. In chronically instrumented mice, ICV infusion of Na-rich artificial CSF increased mean arterial pressure 3-fold higher in -/- than in wild-type mice. ICV infusion of the ENaC blocker benzamil abolished this enhancement. In telemetered -/- mice on a high-salt diet (8% NaCl), CSF [Na(+)], mean arterial pressure, and heart rate increased significantly, mean arterial pressure by 30 to 35 mmHg. These mean arterial pressure and heart rate responses were largely prevented by ICV benzamil but only to a minor extent by SC benzamil at the ICV rate. We conclude that increased ENaC expression in the brain of Nedd4-2 -/- mice mediates their hypertensive response to a high-salt diet by causing increased sodium levels in the CSF, as well as hyperresponsiveness to CSF sodium. These findings highlight the possible causative contribution of central nervous system ENaC in the etiology of salt-induced hypertension. PMID:22802227

  7. Hypoxia-induced glucose-6-phosphate dehydrogenase overexpression and -activation in pulmonary artery smooth muscle cells: implication in pulmonary hypertension.

    PubMed

    Chettimada, Sukrutha; Gupte, Rakhee; Rawat, Dhwajbahadur; Gebb, Sarah A; McMurtry, Ivan F; Gupte, Sachin A

    2015-02-01

    Severe pulmonary hypertension is a debilitating disease with an alarmingly low 5-yr life expectancy. Hypoxia, one of the causes of pulmonary hypertension, elicits constriction and remodeling of the pulmonary arteries. We now know that pulmonary arterial remodeling is a consequence of hyperplasia and hypertrophy of pulmonary artery smooth muscle (PASM), endothelial, myofibroblast, and stem cells. However, our knowledge about the mechanisms that cause these cells to proliferate and hypertrophy in response to hypoxic stimuli is still incomplete, and, hence, the treatment for severe pulmonary arterial hypertension is inadequate. Here we demonstrate that the activity and expression of glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme of the pentose phosphate pathway, are increased in hypoxic PASM cells and in lungs of chronic hypoxic rats. G6PD overexpression and -activation is stimulated by H2O2. Increased G6PD activity contributes to PASM cell proliferation by increasing Sp1 and hypoxia-inducible factor 1? (HIF-1?), which directs the cells to synthesize less contractile (myocardin and SM22?) and more proliferative (cyclin A and phospho-histone H3) proteins. G6PD inhibition with dehydroepiandrosterone increased myocardin expression in remodeled pulmonary arteries of moderate and severe pulmonary hypertensive rats. These observations suggest that altered glucose metabolism and G6PD overactivation play a key role in switching the PASM cells from the contractile to synthetic phenotype by increasing Sp1 and HIF-1?, which suppresses myocardin, a key cofactor that maintains smooth muscle cell in contractile state, and increasing hypoxia-induced PASM cell growth, and hence contribute to pulmonary arterial remodeling and pathogenesis of pulmonary hypertension. PMID:25480333

  8. Salt-Induced Hypertension in a Mouse Model of Liddle's Syndrome is Mediated by Epithelial Sodium Channels in the Brain

    PubMed Central

    Van Huysse, James W.; Amin, Md. Shahrier; Yang, Baoli; Leenen, Frans H. H.

    2012-01-01

    Neural precursor cell expressed and developmentally downregulated 4-2 protein (Nedd4-2) facilitates the endocytosis of epithelial Na channels (ENaC). Both mice and humans with a loss of regulation of ENaC by Nedd4-2 have salt-induced hypertension. ENaC is also expressed in the brain, where it is critical for hypertension on high salt diet in salt-sensitive rats. In the present studies we assessed whether Nedd4-2 knockout (?/?) mice have: 1) increased brain ENaC; 2) elevated CSF sodium on high salt diet; and 3) enhanced pressor responses to CSF sodium and hypertension on high salt diet, both mediated by brain ENaC. Prominent choroid plexus and neuronal ENaC staining was present in ?/? but not in wild-type (W/T) mice. In chronically instrumented mice, intracerebroventricular (icv) infusion of Na-rich aCSF increased MAP 3-fold higher in ?/? than W/T. Icv infusion of the ENaC blocker benzamil abolished this enhancement. In telemetered ?/? mice on high salt diet (8% NaCl), CSF [Na+], MAP and HR increased significantly, MAP by 30-35 mmHg. These MAP and HR responses were largely prevented by icv benzamil, but only to a minor extent by sc benzamil at the icv rate. We conclude that increased ENaC expression in the brain of Nedd 4-2 ?/? mice mediates their hypertensive response to high salt diet, by causing increased sodium levels in the CSF as well as hyper-responsiveness to CSF sodium. These findings highlight the possible causative contribution of CNS ENaC in the etiology of salt-induced hypertension. PMID:22802227

  9. Pyrrolidine Dithiocarbamate Restores Endothelial Cell Membrane Integrity and Attenuates Monocrotaline-Induced Pulmonary Artery Hypertension

    PubMed Central

    Huang, Jing; Kaminski, Pawel M.; Edwards, John G.; Yeh, Albert; Wolin, Michael S.; Frishman, William H.; Gewitz, Michael H.; Mathew, Rajamma

    2008-01-01

    Monocrotaline (MCT)-induced pulmonary artery hypertension (PAH) in rats is preceded by an inflammatory response, progressive endothelial cell membrane disruption, reduction in the expression of caveolin-1 and reciprocal activation of STAT3 (PY-STAT3). Superoxide and NF-?B have been implicated in PAH. To evaluate the role of caveolin-1, PY-STAT3 activation and superoxide in PAH, MCT-injected rats were treated daily with pyrrolidine dithiocarbamate (PDTC, starting on day 1, 3 and 14 × 2 wks) an inhibitor of inflammation and NF-?B activation. Hemodynamic data, the expression of inhibitory (I)-?B?, caveolin-1 and Tie2 (a membrane protein), activation of PY-STAT3 and NF-?B, and superoxide chemiluminescence were examined. Rats developed progressive PAH at 2 wks post-MCT. There were progressive reduction in the expression of caveolin-1, Tie2 and activation of PY-STAT3 in the lungs. Reduction in I-?B? expression was present at 2 and 4 wks post-MCT. Superoxide chemiluminescence and NF-?B activation were observed only at 2 wks post-MCT and both decreased by 4 wks post-MCT despite progressive PAH. PDTC (starting on day 1 and 3) rescued caveolin-1 and Tie2, reversed MCT-induced PY-STAT3 activation, and attenuated PAH. In addition, PDTC restored I-?B? expression and reduced superoxide chemiluminescence at 2 wks, but did not inhibit NF-?B activation despite attenuation of PAH. PDTC had no effect on established PAH. Increased superoxide chemiluminescence and NF-?B activation appear to be a transient phenomenon in the MCT model. Thus, the disruption of endothelial cell membrane integrity resulting in cav-1 loss and reciprocal activation of PY-STAT3 plays a key role in the MCT-induced PAH. PMID:18390833

  10. Ultrastructural Changes Associated With Dexamethasone-Induced Ocular Hypertension in Mice

    PubMed Central

    Overby, Darryl R.; Bertrand, Jacques; Tektas, Ozan-Yüksel; Boussommier-Calleja, Alexandra; Schicht, Martin; Ethier, C. Ross; Woodward, David F.; Stamer, W. Daniel; Lütjen-Drecoll, Elke

    2014-01-01

    Purpose. To determine whether dexamethasone (DEX)-induced ocular hypertension (OHT) in mice mimics the hallmarks of steroid-induced glaucoma (SIG) in humans, including reduced conventional outflow facility (C), increased extracellular matrix (ECM), and myofibroblasts within the outflow pathway. Methods. Osmotic mini-pumps were implanted subcutaneously into C57BL/6J mice for systemic delivery of DEX (3–4 mg/kg/d, n = 31 mice) or vehicle (n = 28). IOP was measured weekly by rebound tonometry. After 3 to 4 weeks, mice were euthanized and eyes enucleated for ex vivo perfusion to measure C, for electron microscopy to examine the trabecular meshwork (TM) and Schlemm's canal (SC), or for immunohistochemistry to examine type IV collagen and ?-smooth muscle actin. The length of basement membrane material (BMM) was measured along the anterior-posterior extent of SC by electron microscopy. Ultrastructural changes in BMM of DEX-treated mice were compared against archived human SIG specimens. Results. Dexamethasone increased IOP by 2.6 ± 1.6 mm Hg (mean ± SD) over 3 to 4 weeks and decreased C by 52% ± 17% versus controls. Intraocular pressure elevation correlated with decreased C. Dexamethasone treatment led to increased fibrillar material in the TM, plaque-like sheath material surrounding elastic fibers, and myofibroblasts along SC outer wall. The length of BMM underlying SC was significantly increased in mice with DEX and in humans with SIG, and in mice decreased C correlated with increased BMM. Conclusions. Dexamethasone-induced OHT in mice mimics hallmarks of human SIG within 4 weeks of DEX treatment. The correlation between reduced C and newly formed ECM motivates further study using DEX-treated mice to investigate the pathogenesis of conventional outflow obstruction in glaucoma. PMID:25028360

  11. Role of VPAC2 receptor in monocrotaline-induced pulmonary hypertension in rats.

    PubMed

    Koga, Motokazu; Mizuno, Yusuke; Watanabe, Itaru; Kawakami, Hiromasa; Goto, Takahisa

    2014-08-15

    Pulmonary hypertension (PH) is associated with significant morbidity and mortality. Vasoactive intestinal peptide (VIP) and pituitary adenylyl cyclase activating peptide (PACAP) have pulmonary vasodilatory and positive inotropic effects via receptors VPAC1 and VPAC2, which possess a similar affinity for both peptides, and PAC1, a PACAP-preferring receptor. VIP is a promising option for PH treatment; however, various physiological effects of VIP have limited its clinical use. We investigated the effects of VPAC1 and VPAC2 selective agonists VIP and PACAP to explore more appropriate means of treatment for PH. We examined hemodynamic changes in right ventricular systolic pressure (RVSP), systemic blood pressure (SBP), total pulmonary resistance index (TPRI), total systemic resistance index, and cardiac index (CI) in response to their agonists with monocrotaline (MCT)-induced PH and explored involvement of VIP/PACAP expression and receptors in PH. Sprague-Dawley rats were divided into the MCT group (administered MCT 60 mg/kg) and control group. In MCT-induced PH, decreased VIP and PACAP were associated with upregulation of VPAC1, VPAC2, and PAC1 in lung tissues. Intravenous injection of VPAC2-selective agonist BAY 55-9837 and VIP, but not [Ala(11,22,28)]VIP, improved the CI. The decrease in SBP with VPAC2 agonist was significantly less than that in the control. Although they decreased SBP, these agonists hardly affected RVSP in the control. Activation of VPAC2 receptor with BAY 55-9837 effectively improved RVSP, TPRI, and CI in MCT-induced PH, suggesting a VPAC2 agonist as a possible promising treatment for PH. PMID:24947028

  12. Gender difference in diet-induced obesity hypertension: implication of renal ? 2-adrenergic receptors

    Microsoft Academic Search

    Gwenn Coatmellec-Taglioni; Jean-Pierre Dausse; Yves Giudicelli; Catherine Ribière

    2002-01-01

    Although the pathogenesis of the obesity-related hypertension is not fully understood, prevalence of the cardiovascular complications is much higher in obese men than obese women. In a recent study, we reported that male rats fed a cafeteria diet, while becoming obese, developed hypertension and important changes in their renal ?2-adrenergic receptor subtypes distributions. The aim of the present study was

  13. Adipose-derived stem cells attenuate pulmonary arterial hypertension and ameliorate pulmonary arterial remodeling in monocrotaline-induced pulmonary hypertensive rats.

    PubMed

    Luo, Li; Lin, Taijie; Zheng, Suli; Xie, Zhenguo; Chen, Ming; Lian, Guili; Xu, Changsheng; Wang, Huajun; Xie, Liangdi

    2014-10-01

    Abstract We investigated the effect of adipose-derived stem cells (ADSCs) transplantation effects on structural remodeling and pulmonary artery pressure in monocrotaline (MCT)-induced pulmonary hypertensive rats. In the first experiment, 32 male Sprague-Dawley (SD) rats were randomly divided into four groups (n?=?8/group): 3 ADSCs treated groups and normal control (Ctrl). ADSCs were administered through the left jugular vein at 10(5), 10(6) and 10(7) cells, respectively, and a cell density of 10(6)cells/ml was shown to be optimal. The GFP-tagged ADSCs were identified in the lungs and differentiated into endothelial-like cells. In the second experiment, 96 male SD rats were randomly divided into three groups (n?=?32/group): Ctrl, MCT-induced pulmonary arterial hypertension (PAH), and PAH treated with ADSCs (ADSCs). Two weeks post-MCT administration, the ADSCs group received 1?×?10(6) ADSCs via the external jugular vein. Compared to PAH rats, mean pulmonary arterial pressure was decreased in rats at 1, 2, and 3 weeks after ADSCs-treatment (18.63?±?2.15?mmHg versus 24.53?±?2.90?mmHg; 23.07?±?2.84?mmHg versus 33.18?±?2.30?mmHg; 22.98?±?2.34?mmHg versus 36.38?±?3.28?mmHg, p?hypertension and ameliorate pulmonary arterial remodeling. PMID:25271670

  14. Altered lymphatic function and architecture in salt-induced hypertension assessed by near-infrared fluorescence imaging

    NASA Astrophysics Data System (ADS)

    Kwon, Sunkuk; Agollah, Germaine D.; Chan, Wenyaw; Sevick-Muraca, Eva M.

    2012-08-01

    The lymphatic system plays an important role in maintaining the fluid homeostasis between the blood vascular and interstitial tissue compartment and there is recent evidence that its transport capabilities may regulate blood pressure in salt-induced hypertension. Yet, there is little known how the lymphatic contractile function and architecture responds to dietary salt-intake. Thus, we longitudinally characterized lymphatic contractile function and vessel remodeling noninvasively using dynamic near-infrared fluorescence imaging in animal models of salt-induced hypertension. The lymphatics of mice and rats were imaged following intradermal injection of indocyanine green to the ear tip or the base of the tail before and during two weeks of either a high salt diet (HSD) or normal chow. Our noninvasive imaging data demonstrated dilated lymphatic vessels in the skin of mice and rats on a HSD as compared to their baseline levels. In addition, our dynamic imaging results showed increased lymphatic contraction frequency in HSD-fed mice and rats. Lymphatic contractile function and vessel remodeling occurs in response to salt-induced hypertension suggesting a possible role for the lymphatics in the regulation of vascular blood pressure.

  15. Maintenance of GLUT4 expression in smooth muscle prevents hypertension-induced changes in vascular reactivity.

    PubMed

    Atkins, Kevin B; Seki, Yoshinori; Saha, Jharna; Eichinger, Felix; Charron, Maureen J; Brosius, Frank C

    2015-02-01

    Previous studies have shown that expression of GLUT4 is decreased in arterial smooth muscle of hypertensive rats and mice and that total body overexpression of GLUT4 in mice prevents enhanced arterial reactivity in hypertension. To demonstrate that the effect of GLUT4 overexpression on vascular responses is dependent on vascular smooth muscle GLUT4 rather than on some systemic effect we developed and tested smooth-muscle-specific GLUT4 transgenic mice (SMG4). When made hypertensive with angiotensin II, both wild-type and SMG4 mice exhibited similarly increased systolic blood pressure. Responsiveness to phenylephrine, serotonin, and prostaglandin F2? was significantly increased in endothelium-intact aortic rings from hypertensive wild-type mice but not in aortae of SMG4 mice. Inhibition of Rho-kinase equally reduced serotonin-stimulated contractility in aortae of hypertensive wild-type and SMG4-mice. In addition, acetylcholine-stimulated relaxation was significantly decreased in aortic rings of hypertensive wild-type mice, but not in rings of SMG4 mice. Inhibition of either prostacylin receptors or cyclooxygenase-2 reduced relaxation in rings of hypertensive SMG4 mice. Inhibition of cyclooxygenase-2 had no effect on relaxation in rings of hypertensive wild-type mice. Cyclooxygenase-2 protein expression was decreased in hypertensive wild-type aortae but not in hypertensive SMG4 aortae compared to nonhypertensive controls. Our results demonstrate that smooth muscle expression of GLUT4 exerts a major effect on smooth muscle contractile responses and endothelium-dependent vasorelaxation and that normal expression of GLUT4 in vascular smooth muscle is required for appropriate smooth muscle and endothelial responses. PMID:25677552

  16. Maintenance of GLUT4 expression in smooth muscle prevents hypertension-induced changes in vascular reactivity

    PubMed Central

    Atkins, Kevin B; Seki, Yoshinori; Saha, Jharna; Eichinger, Felix; Charron, Maureen J; Brosius, Frank C

    2015-01-01

    Previous studies have shown that expression of GLUT4 is decreased in arterial smooth muscle of hypertensive rats and mice and that total body overexpression of GLUT4 in mice prevents enhanced arterial reactivity in hypertension. To demonstrate that the effect of GLUT4 overexpression on vascular responses is dependent on vascular smooth muscle GLUT4 rather than on some systemic effect we developed and tested smooth-muscle-specific GLUT4 transgenic mice (SMG4). When made hypertensive with angiotensin II, both wild-type and SMG4 mice exhibited similarly increased systolic blood pressure. Responsiveness to phenylephrine, serotonin, and prostaglandin F2? was significantly increased in endothelium-intact aortic rings from hypertensive wild-type mice but not in aortae of SMG4 mice. Inhibition of Rho-kinase equally reduced serotonin-stimulated contractility in aortae of hypertensive wild-type and SMG4-mice. In addition, acetylcholine-stimulated relaxation was significantly decreased in aortic rings of hypertensive wild-type mice, but not in rings of SMG4 mice. Inhibition of either prostacylin receptors or cyclooxygenase-2 reduced relaxation in rings of hypertensive SMG4 mice. Inhibition of cyclooxygenase-2 had no effect on relaxation in rings of hypertensive wild-type mice. Cyclooxygenase-2 protein expression was decreased in hypertensive wild-type aortae but not in hypertensive SMG4 aortae compared to nonhypertensive controls. Our results demonstrate that smooth muscle expression of GLUT4 exerts a major effect on smooth muscle contractile responses and endothelium-dependent vasorelaxation and that normal expression of GLUT4 in vascular smooth muscle is required for appropriate smooth muscle and endothelial responses. PMID:25677552

  17. Rhodiola-water extract induces ?-endorphin secretion to lower blood pressure in spontaneously hypertensive rats.

    PubMed

    Lee, Wei-Jing; Chung, Hsien-Hui; Cheng, Yung-Ze; Lin, Hung Jung; Cheng, Juei-Tang

    2013-10-01

    Rhodiola rosea (Rhodiola) is grown at high altitudes and northern latitudes. It is mainly used clinically as an adaptogen, but antihypertensive effects have been reported for the extract. These have not been well investigated, so in the present study, we evaluated the effect of Rhodiola-water extract on blood pressure in spontaneously hypertensive rats (SHRs) and investigated the potential mechanism(s) for this action. In conscious male SHRs, systolic blood pressure (SBP) and heart rate were recorded using the tail-cuff method. Plasma ?-endorphin was measured by enzyme-linked immunosorbent assay. Rhodiola-water extract decreased SBP in SHRs in a dose-dependent manner, and this action was more significant than that in normal group named Wistar-Kyoto (WKY) rats. This reduction of SBP in SHRs was inhibited by pretreatment with the selective opioid ?-receptor antagonist, cyprodime, but not by naloxonazine, an antagonist specific to opioid ?1-receptor. Also, the SBP-lowering action of Rhodiola-water extract was attenuated in adrenalectomized SHRs. Moreover, Rhodiola-water extract dose-dependently increased ?-endorphin release in SHRs, and the elevation of ?-endorphin in SHRs was higher than that in WKY. Thus, we suggest that Rhodiola-water extract can induce release of ?-endorphin to lower SBP in SHRs. PMID:23192943

  18. Pulmonary hypertension induced in dogs by hypoxia at different high-altitude levels.

    PubMed

    Glaus, T M; Hässig, M; Baumgartner, C; Reusch, C E

    2003-12-01

    Chronic natural hypoxia at 2300 m altitude induces mild pulmonary hypertension (PH) in healthy dogs. The influence of more severe hypoxia on the same group of dogs was evaluated by re-examining such dogs at 3500 m, after they had regularly exercised at this altitude level for half a year. Despite severe hypoxaemia at 3500 m (PaO2 52+/-5 mmHg), none of the dogs developed erythrocytosis, and their PCV at 3500 m (48% +/- 4%) did not differ from that at 2300 m (49% +/- 4%). There was a tendency towards an elevated systemic BP, with a significant increase in diastolic BP (105 +/- 13 mmHg at 3500 m versus 98 +/- 17 at 2300 m). Tricuspid regurgitation (TR) was detected in 7 dogs at 3500 m compared to 8 dogs at 2300 m. The mean TR Vmax was significantly higher at 3500 m, and all 7 dogs had systolic PH at 3500 m (33.6-54.8 mmHg), when PH was defined as TR Vmax > or = 2.8 m/s, i.e. a peak pressure gradient > 30 mmHg. Hence, in dogs, increasing altitude and the concomitant hypoxia result in a progressively more pronounced PH and an elevated systemic BP. Intermittent severe hypoxaemia of around 50 mmHg may not cause erythrocytosis in healthy dogs, even over a prolonged period. PMID:14672455

  19. Sleep and Pregnancy-Induced Hypertension: A Possible Target for Intervention?

    PubMed Central

    Haney, Alyssa; Buysse, Daniel J.; Okun, Michele

    2013-01-01

    Sleep disturbances in the general population are associated with elevated blood pressure. This may be due to several mechanisms, including sympathetic activation and hypothalamic-pituitary-adrenal (HPA) axis disturbance. Elevated blood pressure in pregnancy can have devastating effects on both maternal and fetal health and is associated with increased risk for preeclampsia and poor delivery outcomes. Preliminary evidence suggests that mechanisms linking sleep and blood pressure in the general population may also hold in the pregnant population. However, the effects of disturbed sleep on physiologic mechanisms that may directly influence blood pressure in pregnancy have not been well studied. The role that sleep disturbance plays in gestational blood pressure elevation and its subsequent consequences warrant further investigation. This review evaluates the current literature on sleep disturbance and elevated blood pressure in pregnancy and proposes possible treatment interventions. Citation: Haney A; Buysse DJ; Okun M. Sleep and pregnancy-induced hypertension: a possible target for intervention? J Clin Sleep Med 2013;9(12):1349-1356. PMID:24340300

  20. Renal vascular cytochrome P450-derived eicosanoids in androgen-induced hypertension.

    PubMed

    Singh, Harpreet; Schwartzman, Michal L

    2008-01-01

    Androgen has been linked to higher incidence of cardiovascular disease based on the simple observation that men have more cardiovascular and renal events than women at similar ages. The Cytochrome P450 (CYP)-derived eicosanoids, 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs) have been implicated in the regulation of blood pressure via their vasoactive properties as vasoconstrictors and vasodilators, respectively, as well as via inhibition and activation of endothelial nitric oxide synthase. Since, 20-HETE and EETs have opposing vascular effects, their relative levels may determine vascular resistance and tone. We characterized the renal vascular production of 20-HETE and EETs in male and female rats before and after treatment with 5 alpha -dihydrotestosterone (DHT). In renal interlobar arteries from male rats, the ratio between 20-HETE and EETs levels was 2-fold higher than that observed in arteries from female rats (1.86 +/- 0.22 vs. 0.85 +/- 0.13). Importantly, treatment with DHT significantly increased this ratio by 85 and 230% in arteries from male and female rats, respectively. Moreover, DHT treatment eliminated the difference in the ratio of 20-HETE to EETs between males and females. DHT treatment increased blood pressure in both male and female rats by 21.3 +/- 4.0 and 15.3 +/- 5.1 mmHg, respectively. The primary enzyme responsible for 20-HETE synthesis in the renal vasculature, CYP4A8, was significantly induced by treatment with DHT while the major epoxygenase in the kidney, CYP2C23, was down regulated by DHT. We conclude that increased vascular tone brought about by downregulation of CYP2C23 and decreased levels of vasodilatory EETs and by induction of CYP4A8 and enhanced production of 20-HETE may constitute important factors in androgen-induced hypertension. PMID:18276983

  1. Emission-particle-induced ventilatory abnormalities in a rat model of pulmonary hypertension.

    PubMed Central

    Gardner, Sarah Y; McGee, John K; Kodavanti, Urmila P; Ledbetter, Allen; Everitt, Jeffrey I; Winsett, Darrell W; Doerfler, Donald L; Costa, Daniel L

    2004-01-01

    Preexistent cardiopulmonary disease in humans appears to enhance susceptibility to the adverse effects of ambient particulate matter. Previous studies in this laboratory have demonstrated enhanced inflammation and mortality after intratracheal instillation (IT) and inhalation (INH) of residual oil fly ash (ROFA) in a rat model of pulmonary hypertension induced by monocrotaline (MCT). The present study was conducted to examine the effects of ROFA in this model on ventilatory function in unanesthetized, unrestrained animals. Sixty-day-old male CD rats were injected with MCT (60 mg/kg) or vehicle (VEH) intraperitoneally 10 days before IT of ROFA (8.3 mg/kg) or saline (SAL) (control) or nose-only INH of ROFA [15 mg/m3 for 6 hr on 3 consecutive days or air (control)]. At 24 and 72 hr after exposure, rats were studied individually in a simultaneous gas uptake/whole-body plethysmograph. Lungs were removed at 72 hr for histology. Pulmonary test results showed that tidal volume (VT) decreased 24 hr after IT of ROFA in MCT-treated rats. Breathing frequency, minute volume (VE), and the ventilatory equivalent for oxygen increased in MCT- and VEH-treated rats 24 hr after IT or INH of ROFA and remained elevated 72 hr post-IT. O2 uptake (VO2) decreased after IT of ROFA in MCT-treated rats. Carbon monoxide uptake decreased 24 hr after IT of ROFA, returning to control values in VEH-treated rats but remaining low in MCT-treated rats 72 hr post-IT. ROFA exposure induced histologic changes and abnormalities in several ventilatory parameters, many of which were enhanced by MCT treatment. PMID:15175175

  2. Obesity-induced Hypertension: Role of Sympathetic Nervous System, Leptin, and Melanocortins*

    PubMed Central

    Hall, John E.; da Silva, Alexandre A.; do Carmo, Jussara M.; Dubinion, John; Hamza, Shereen; Munusamy, Shankar; Smith, Grant; Stec, David E.

    2010-01-01

    Excess weight gain contributes to increased blood pressure in most patients with essential hypertension. Although the mechanisms of obesity hypertension are not fully understood, increased renal sodium reabsorption and impaired pressure natriuresis play key roles. Several mechanisms contribute to altered kidney function and hypertension in obesity, including activation of the sympathetic nervous system, which appears to be mediated in part by increased levels of the adipocyte-derived hormone leptin, stimulation of pro-opiomelanocortin neurons, and subsequent activation of central nervous system melanocortin 4 receptors. PMID:20348094

  3. Hypothalamic signaling mechanisms in hypertension.

    PubMed

    Carmichael, Casey Y; Wainford, Richard D

    2015-05-01

    The etiology of hypertension, a critical public health issue affecting one in three US adults, involves the integration of the actions of multiple organ systems, including the central nervous system. Increased activation of the central nervous system, driving enhanced sympathetic outflow and increased blood pressure, has emerged as a major contributor to the pathogenesis of hypertension. The hypothalamus is a key brain site acting to integrate central and peripheral inputs to ultimately impact blood pressure in multiple disease states that evoke hypertension. This review highlights recent advances that have identified novel signal transduction mechanisms within multiple hypothalamic nuclei (e.g., paraventricular nucleus, arcuate nucleus) acting to drive the pathophysiology of hypertension in neurogenic hypertension, angiotensin II hypertension, salt-sensitive hypertension, chronic intermittent hypoxia, and obesity-induced hypertension. Increased understanding of hypothalamic activity in hypertension has the potential to identify novel targets for future therapeutic interventions designed to treat hypertension. PMID:25860531

  4. Insight into molecular mechanisms of ultrafine carbon particle induced cardiovascular impairments in spontaneously hypertensive rats.

    EPA Science Inventory

    Rationale: Exposure to ambient particulate matter is a risk factor for cardiopulmonary disease as identified in several epidemiological studies. Radio telemetric analysis detected increased heart rate and blood pressure in Spontaneously Hypertensive Rats (SHR) following inhalatio...

  5. Protective actions of estrogen on angiotensin II-induced hypertension: role of central nitric oxide.

    PubMed

    Xue, Baojian; Singh, Minati; Guo, Fang; Hay, Meredith; Johnson, Alan Kim

    2009-11-01

    The present study tested the hypotheses that 1) nitric oxide (NO) is involved in attenuated responses to ANG II in female mice, and 2) there is differential expression of neuronal NO synthase (nNOS) in the subfornical organ (SFO) and paraventricular nucleus (PVN) in response to systemic infusions of ANG II in males vs. females. Aortic blood pressure (BP) was measured in conscious mice with telemetry implants. N(G)-nitro-l-arginine methyl ester (l-NAME; 100 microg x kg(.-1)day(-1)), an inhibitor of NOS, was administrated into the lateral cerebral ventricle for 14 days before and during ANG II pump implantation. Central infusion of l-NAME augmented the pressor effects of systemic ANG II in females (Delta21.5 + or - 2.2 vs. Delta9.2 + or - 1.5 mmHg) but not in males (Delta29.4 + or - 2.5 vs. Delta30.1 + or - 2.5 mmHg). Central administration of N(5)-(1-imino-3-butenyl)-l-ornithine (l-VNIO), a selective nNOS inhibitor, also significantly potentiated the increase in BP induced by ANG II in females (Delta17.5 + or - 3.2 vs. Delta9.2 + or - 1.5 mmHg). In gonadectomized mice, central l-NAME infusion did not affect the pressor response to ANG II in either males or females. Ganglionic blockade after ANG II infusion resulted in a greater reduction in BP in central l-NAME- or l-VNIO-treated females compared with control females. Western blot analysis of nNOS protein expression indicated that levels were approximately 12-fold higher in both the SFO and PVN of intact females compared with those in intact males. Seven days of ANG II treatment resulted in a further increase in nNOS protein expression only in intact females (PVN, to approximately 51-fold). Immunohistochemical studies revealed colocalization of nNOS and estrogen receptors in the SFO and PVN. These results suggest that NO attenuates the increase in BP induced by ANG II through reduced sympathetic outflow in females and that increased nNOS protein expression associated with the presence of female sex hormones plays a protective role against ANG II-induced hypertension in female mice. PMID:19734362

  6. Endocannabinoid-mediated modulation of Gq/11 protein-coupled receptor signaling-induced vasoconstriction and hypertension.

    PubMed

    Szekeres, Mária; Nádasy, György L; Turu, Gábor; Soltész-Katona, Eszter; Benyó, Zoltán; Offermanns, Stefan; Ruisanchez, Éva; Szabó, Eszter; Takáts, Zoltán; Bátkai, Sándor; Tóth, Zsuzsanna E; Hunyady, László

    2015-03-01

    Activation of G protein-coupled receptors (GPCRs) can induce vasoconstriction via calcium signal-mediated and Rho-dependent pathways. Earlier reports have shown that diacylglycerol produced during calcium signal generation can be converted to an endocannabinoid, 2-arachidonoylglycerol (2-AG). Our aim was to provide evidence that GPCR signaling-induced 2-AG production and activation of vascular type1 cannabinoid receptors (CB1R) is capable of reducing agonist-induced vasoconstriction and hypertension. Rat and mouse aortic rings were examined by myography. Vascular expression of CB1R was demonstrated with immunohistochemistry. Rat aortic vascular smooth muscle cells (VSMCs) were cultured for calcium measurements and 2-AG-determination. Inhibition or genetic loss of CB1Rs enhanced vasoconstriction induced by angiotensin II (AngII) or phenylephrine (Phe), but not by prostaglandin(PG)F2?. AngII-induced vasoconstriction was augmented by inhibition of diacylglycerol lipase (tetrahydrolipstatin) and was attenuated by inhibition of monoacylglycerol lipase (JZL184) suggesting a functionally relevant role for endogenously produced 2-AG. In G?q/11-deficient mice vasoconstriction was absent to AngII or Phe, which activate Gq/11-coupled receptors, but was maintained in response to PGF2?. In VSMCs, AngII-stimulated 2-AG-formation was inhibited by tetrahydrolipstatin and potentiated by JZL184. CB1R inhibition increased the sustained phase of AngII-induced calcium signal. Pharmacological or genetic loss of CB1R function augmented AngII-induced blood pressure rise in mice. These data demonstrate that vasoconstrictor effect of GPCR agonists is attenuated via Gq/11-mediated vascular endocannabinoid formation. Agonist-induced endocannabinoid-mediated CB1R activation is a significant physiological modulator of vascular tone. Thus, the selective modulation of GPCR signaling-induced endocannabinoid release has a therapeutic potential in case of increased vascular tone and hypertension. PMID:25595485

  7. Impact of interleukin-6 on hypoxia-induced pulmonary hypertension and lung inflammation in mice

    PubMed Central

    Savale, Laurent; Tu, Ly; Rideau, Dominique; Izziki, Mohamed; Maitre, Bernard; Adnot, Serge; Eddahibi, Saadia

    2009-01-01

    Background Inflammation may contribute to the pathogenesis of various forms of pulmonary hypertension (PH). Recent studies in patients with idiopathic PH or PH associated with underlying diseases suggest a role for interleukin-6 (IL-6). Methods To determine whether endogenous IL-6 contributes to mediate hypoxic PH and lung inflammation, we studied IL-6-deficient (IL-6-/-) and wild-type (IL-6+/+) mice exposed to hypoxia for 2 weeks. Results Right ventricular systolic pressure, right ventricle hypertrophy, and the number and media thickness of muscular pulmonary vessels were decreased in IL-6-/- mice compared to wild-type controls after 2 weeks' hypoxia, although the pressure response to acute hypoxia was similar in IL-6+/+ and IL-6-/- mice. Hypoxia exposure of IL-6+/+ mice led to marked increases in IL-6 mRNA and protein levels within the first week, with positive IL-6 immunostaining in the pulmonary vessel walls. Lung IL-6 receptor and gp 130 (the IL-6 signal transducer) mRNA levels increased after 1 and 2 weeks' hypoxia. In vitro studies of cultured human pulmonary-artery smooth-muscle-cells (PA-SMCs) and microvascular endothelial cells revealed prominent synthesis of IL-6 by PA-SMCs, with further stimulation by hypoxia. IL-6 also markedly stimulated PA-SMC migration without affecting proliferation. Hypoxic IL-6-/- mice showed less inflammatory cell recruitment in the lungs, compared to hypoxic wild-type mice, as assessed by lung protein levels and immunostaining for the specific macrophage marker F4/80, with no difference in lung expression of adhesion molecules or cytokines. Conclusion These data suggest that IL-6 may be actively involved in hypoxia-induced lung inflammation and pulmonary vascular remodeling in mice. PMID:19173740

  8. Nebivolol induces distinct changes in profibrosis microRNA expression compared with atenolol, in salt-sensitive hypertensive rats.

    PubMed

    Ye, Hongmei; Ling, Shukuan; Castillo, Alexander C; Thomas, Bejoy; Long, Bo; Qian, Jinqiao; Perez-Polo, Jose R; Ye, Yumei; Chen, Xiaoping; Birnbaum, Yochai

    2013-05-01

    Nebivolol is a selective ?1-blocker with nitric oxide-enhancing effects. MicroRNAs are small noncoding RNA molecules that downregulate gene expression. We compared the effects of nebivolol and atenolol, a first generation ?1-selective blocker, on left ventricular hypertrophy, fibrosis, and function and microRNA expression in a rodent model of hypertension. Dahl salt-sensitive rats received either low-salt chow (control) or AIN-76A high-salt (8% NaCl) diet and randomized to vehicle (high-salt), nebivolol (20 mg/kg per day), or atenolol (50 mg/kg per day) for 8 weeks. High-salt induced left ventricular hypertrophy and fibrosis and decreased the expression of miR-27a, -29a, and -133a. Nebovolol attenuated deterioration of left ventricular systolic function, remodeling, and fibrosis more than atenolol, despite similar effects on heart rate and blood pressure. Nebivolol, but not atenolol, prevented the decrease in miR-27a and -29a induced by high-salt. Nebivolol and atenolol equally attenuated the decrease in miR-133a. In vitro overexpression of miR-27a,-29a, and -133a inhibited cardiomyocyte hypertrophy and reduced collagen expression. Both miR-27a and -29a target Sp1, and miR-133a targets Cdc42. Pharmacological inhibition of Sp1 and Cdc42 decreased myocardial fibrosis and hypertrophy. Our data support a differential microRNAs expression profile in salt-induced hypertension. Nebivolol substantially attenuated cardiac remodeling, hypertrophy, and fibrosis more than atenolol. These effects are related to attenuation of the hypertension-induced decrease in miR-27a and -29a (with a subsequent decrease in Sp1 expression) and miR-133a (with a subsequent decrease in Cdc42). PMID:23460283

  9. Low level and sub-chronic exposure to methylmercury induces hypertension in rats: nitric oxide depletion and oxidative damage as possible mechanisms

    Microsoft Academic Search

    Denise Grotto; Michele M. de Castro; Gustavo R. M. Barcelos; Solange C. Garcia; Fernando Barbosa Jr

    2009-01-01

    Increased risk of hypertension after methylmercury (MeHg) exposure has been suggested. However, the underlying mechanisms\\u000a are not well explored. In this paper, we have analyzed whether sub-chronic exposure to MeHg increases systolic blood pressure\\u000a even at very low levels. In addition, we analyzed if the methylmercury-induced hypertension is associated with a decreased\\u000a plasmatic nitric oxide levels and with a dysregulation

  10. Central endogenous angiotensin-(1–7) protects against aldosterone/NaCl-induced hypertension in female rats

    PubMed Central

    Zhang, Zhongming; Johnson, Ralph F.; Guo, Fang; Hay, Meredith; Johnson, Alan Kim

    2013-01-01

    In comparison to male rodents, females are protected against angiotensin (ANG) II- and aldosterone (Aldo)-induced hypertension. However, the mechanisms underlying this protective effect are not well understood. ANG-(1–7) is formed from ANG II by angiotensin-converting enzyme 2 (ACE2) and has an antihypertensive effect in the central nervous system (CNS). The present study tested the hypothesis that central ANG-(1–7) plays an important protective role in attenuating the development of Aldo/NaCl-hypertension in female rats. Systemic infusion of Aldo into intact female rats with 1% NaCl as their sole drinking fluid resulted in a slight increase in blood pressure (BP). Intracerebroventricular (icv) infusion of A-779, an ANG-(1–7) receptor (Mas-R) antagonist, significantly augmented the pressor effects of Aldo/NaCl. In contrast, systemic Aldo/NaCl induced a significant increase in BP in ovariectomized (OVX) female rats, and central infusion of ANG-(1–7) significantly attenuated this Aldo/NaCl pressor effect. The inhibitory effect of ANG-(1–7) on the Aldo/NaCl pressor effect was abolished by concurrent infusion of A-779. RT-PCR analyses showed that there was a corresponding change in mRNA expression of several renin-angiotensin system components, estrogen receptors and an NADPH oxidase subunit in the lamina terminalis. Taken together these results suggest that female sex hormones regulate an antihypertensive axis of the brain renin-angiotensin system involving ACE2/ANG-(1–7)/Mas-R that plays an important counterregulatory role in protecting against the development of Aldo/NaCl-induced hypertension. PMID:23812385

  11. Effects of acute haemodialysis-induced changes in sodium balance upon experimentally hypertensive rats.

    PubMed

    Röckel, A; Brand, A; Bechinger, W; Heidland, A

    1980-01-01

    In two-kidney Goldblatt hypertensive, spontaneously hypertensive, and normotensive control rats, the activity of the renin-angiotensin system was tested during variation of sodium balance. Acute, exactly calculable and selective changes in total body sodium were achieved by haemodialysing conscious rats, using dialysates with high and low sodium contents. The activity of the renin-angiotensin system was evaluated by blood pressure response to angiogtensin II blockade (saralasin bolus injection; 25 micrograms/kg b.w., i.v.) and plasma renin activity. During sodium-depletion, blood pressure maintenance became renin-dependent; sodium-loading caused a decrease of renin-angiotensin activity in renovascular hypertension. A weak direct correlation between depressor response to saralasin and the plasma renin activity could be established in the different sodium-depleted and sodium-loaded states. PMID:6991209

  12. Role of the NADPH oxidases in the subfornical organ in angiotensin II-induced hypertension.

    PubMed

    Lob, Heinrich E; Schultz, David; Marvar, Paul J; Davisson, Robin L; Harrison, David G

    2013-02-01

    Reactive oxygen species and the NADPH oxidases contribute to hypertension via mechanisms that remain undefined. Reactive oxygen species produced in the central nervous system have been proposed to promote sympathetic outflow, inflammation, and hypertension, but the contribution of the NADPH oxidases to these processes in chronic hypertension is uncertain. We therefore sought to identify how NADPH oxidases in the subfornical organ (SFO) of the brain regulate blood pressure and vascular inflammation during sustained hypertension. We produced mice with loxP sites flanking the coding region of the NADPH oxidase docking subunit p22(phox). SFO-targeted injections of an adenovirus encoding cre-recombinase markedly diminished p22(phox), Nox2, and Nox4 mRNA in the SFO, as compared with a control adenovirus encoding red-fluorescent protein injection. Increased superoxide production in the SFO by chronic angiotensin II infusion (490 ng/kg min(-1) × 2 weeks) was blunted in adenovirus encoding cre-recombinase-treated mice, as detected by dihydroethidium fluorescence. Deletion of p22(phox) in the SFO eliminated the hypertensive response observed at 2 weeks of angiotensin II infusion compared with control adenovirus encoding red-fluorescent protein-treated mice (mean arterial pressures=97 ± 15 versus 154 ± 6 mm Hg, respectively; P=0.0001). Angiotensin II infusion also promoted marked vascular inflammation, as characterized by accumulation of activated T-cells and other leukocytes, and this was prevented by deletion of the SFO p22(phox). These experiments definitively identify the NADPH oxidases in the SFO as a critical determinant of the blood pressure and vascular inflammatory responses to chronic angiotensin II, and further support a role of reactive oxygen species in central nervous system signaling in hypertension. PMID:23248154

  13. Role of the NADPH Oxidases in the Subfornical Organ in Angiotensin II-Induced Hypertension

    PubMed Central

    Lob, Heinrich E.; Schultz, David; Marvar, Paul J.; Davisson, Robin L.; Harrison, David G.

    2013-01-01

    Reactive oxygen species (ROS) and the NADPH oxidases contribute to hypertension via mechanisms that remain undefined. ROS produced in the central nervous system have been proposed to promote sympathetic outflow, inflammation and hypertension, but the contribution of the NADPH oxidases to these processes in chronic hypertension is uncertain. We therefore sought to identify how NADPH oxidases in the subfornical organ (SFO) of the brain regulate blood pressure and vascular inflammation during sustained hypertension. We produced mice with loxP sites flanking the coding region of the NADPH oxidase docking subunit p22phox. SFO-targeted injections of an adenovirus encoding cre-recombinase (AdCre) markedly diminished p22phox, Nox2 and Nox4 mRNA in the SFO as compared to a control adenovirus (AdRFP) injection. Increased superoxide production in the SFO by chronic angiotensin II infusion (490 ng/kg/min × 2 weeks), was blunted in AdCre-treated mice as detected by dihydroethidium fluorescence. Deletion of p22phox in the SFO eliminated the hypertensive response observed at two weeks of angiotensin II infusion compared to AdRFP-treated mice (mean arterial pressures = 97±15 vs. 154±6 mmHg respectively, p = 0.0001). Angiotensin II-infusion also promoted marked vascular inflammation, as characterized by accumulation of activated T cells and other leukocytes, and this was prevented by deletion of the SFO p22phox. These experiments definitively identify the NADPH oxidases in the SFO as a critical determinant of the blood pressure and vascular inflammatory responses to chronic angiotensin II, and further support a role of ROS in central nervous system signaling in hypertension. PMID:23248154

  14. Arbutus unedo prevents cardiovascular and morphological alterations in L-NAME-induced hypertensive rats Part I: cardiovascular and renal hemodynamic effects of Arbutus unedo in L-NAME-induced hypertensive rats.

    PubMed

    Afkir, Saida; Nguelefack, Telesphore Benoit; Aziz, Mohamed; Zoheir, Johar; Cuisinaud, Guy; Bnouham, Mohamed; Mekhfi, Hassane; Legssyer, Abdelkhaleq; Lahlou, Saad; Ziyyat, Abderrahim

    2008-03-01

    Hypertension induced by nitric oxide synthase inhibition is associated with functional abnormalities of the heart and kidney. The aim of the present study was to investigate whether chronic treatment with Arbutus unedo leaf (AuL) or root (AuR) aqueous extracts can prevent these alterations. Six groups of rats were used: control group received tap water; N(G)-nitro-l-arginine methyl-ester (L-NAME) group treated with L-NAME at 40 mg/kg/day; AuL and AuR groups received simultaneously L-NAME (40 mg/kg/day) and Au leaves or roots extract at the same concentration 250 mg/kg/day; l-arginine and enalapril groups received simultaneously L-NAME (40 mg/kg/day) and l-arginine at 50mg/kg/day or enalapril at 15 mg/kg/day. Treatment of rats during 4 weeks with L-NAME caused an increase of the systolic blood pressure (SBP) accompanied by a ventricular hypertrophy, an impairment of endothelium-dependent vasorelaxation, an increase of the cardiac baroreflex sensitivity and a decrease of water, sodium and potassium excretion. The co-administration of AuL or AuR extracts with L-NAME reduces the development of increased SBP, ameliorates the vascular reactivity as well as the baroreflex sensitivity and normalizes the renal function. AuR reduces the ventricular hypertrophy but AuL do not. Enalapril associated with L-NAME reverses the majority of alterations induced by L-NAME while l-arginine only lightly ameliorates the vascular reactivity. These results show that chronic treatment with Arbutus extract regress the development of hypertension and ameliorate cardiovascular and renal functions in NO deficient hypertension. PMID:18191352

  15. Maternal citrulline supplementation prevents prenatal N(G)-nitro-L-arginine-methyl ester (L-NAME)-induced programmed hypertension in rats.

    PubMed

    Tain, You-Lin; Huang, Li-Tung; Lee, Chien-Te; Chan, Julie Y H; Hsu, Chien-Ning

    2015-01-01

    Nitric oxide (NO) deficiency induced by the NO synthase (NOS) inhibitor N(G)-nitro-L-arginine-methyl ester (L-NAME) resulted in hypertension. L-citrulline (CIT) can be converted to L-arginine to generate NO. We examined whether maternal CIT supplementation can prevent L-NAME-induced programmed hypertension. Pregnant Sprague-Dawley rats were assigned to four groups: control, L-NAME, control + citrulline (CIT), and L-NAME + citrulline (L-NAME+CIT). Pregnant rats received L-NAME administration at 60 mg/kg/day subcutaneously during pregnancy alone or with additional 0.25% l-citrulline solution in drinking water during the whole period of pregnancy and lactation. Male offspring were sacrificed at 12 wk of age. L-NAME exposure during pregnancy induces hypertension in the 12-wk-old offspring. Maternal CIT therapy prevented L-NAME-induced programmed hypertension, which was associated with a decreased asymmetric dimethylarginine (ADMA) concentration and an increased L-arginine-to-ADMA ratio in the kidney, increased urinary cGMP levels, and decreased renal protein levels of type 3 sodium hydrogen exchanger (NHE3). Together, our data suggest that the beneficial effects of CIT supplementation are attributed to its ability to increase NO level in the kidney and inhibition of NHE3 expression. Our results suggest that supplementing CIT in pregnant women with NO deficiency can improve fetal development and prevent programmed hypertension. PMID:25395680

  16. Nitric Oxide Deficiency in Fenfluramine and Dexfenfluramine-induced Pulmonary Hypertension

    Microsoft Academic Search

    STEPHEN L. ARCHER; KHIER DJABALLAH; MARC HUMBERT; E. KENNETH WEIR; MURIEL FARTOUKH; JOSETTE DALL' AVA-SANTUCCI; JEAN-CHRISTOPHE MERCIER; GERALD SIMONNEAU; A. TUAN DINH-XUAN

    1998-01-01

    Dexfenfluramine and fenfluramine greatly increase the risk of developing pulmonary hypertension (PHT). The mechanism of anorexigen-associated PHT (AA-PHT) and the reason PHT occurs in a mi- nority of people exposed are unknown. Anorexigens are weak pulmonary vasoconstrictors, but they become potent when synthesis of the endogenous vasodilator nitric oxide (NO) is suppressed. We hypothesized NO deficiency predisposes affected individuals to

  17. Sex differences in angiotensin II- and aldosterone-induced hypertension: the central protective effects of estrogen

    PubMed Central

    Xue, Baojian; Hay, Meredith

    2013-01-01

    Premenopausal women have lower blood pressure and a reduced incidence of cardiovascular disease compared with age-matched men. Similar sex differences have been seen across species and in multiple animal models of hypertension. While important progress over the last decade has been made in elucidating some of the mechanisms underlying these differences, there are still significant gaps in our knowledge. Understanding the cellular and molecular mechanisms responsible for sex differences in hypertension will be important for developing sex-specific therapies targeted toward the prevention and treatment of hypertension. Female sex hormones, especially estrogen, have been demonstrated to modulate the renin-angiotensin-aldosterone system (RAAS) and to have beneficial effects on cardiovascular function through actions not only on the kidney, heart, and vasculature, but also on the central nervous system (CNS). This review primarily focuses on the central regulatory actions of estrogen on brain nuclei involved in blood pressure regulation and the interactions between estrogen and the RAAS in the CNS by which estrogen plays an important protective role against the development of hypertension. PMID:23883676

  18. Role of chymase in cigarette smoke-induced pulmonary artery remodeling and pulmonary hypertension in hamsters

    Microsoft Academic Search

    Tao Wang; Su-Xia Han; Shang-Fu Zhang; Yun-Ye Ning; Lei Chen; Ya-Juan Chen; Guang-Ming He; Dan Xu; Jin An; Ting Yang; Xiao-Hong Zhang; Fu-Qiang Wen

    2010-01-01

    BACKGROUND: Cigarette smoking is an important risk factor for pulmonary arterial hypertension (PAH) in chronic obstructive pulmonary disease (COPD). Chymase has been shown to function in the enzymatic production of angiotensin II (AngII) and the activation of transforming growth factor (TGF)-?1 in the cardiovascular system. The aim of this study was to determine the potential role of chymase in cigarette

  19. Prenatal programming of pulmonary hypertension induced by chronic hypoxia or ductal ligation in sheep

    PubMed Central

    2013-01-01

    Abstract Pulmonary hypertension of the newborn is caused by a spectrum of functional and structural abnormalities of the cardiopulmonary circuit. The existence of multiple etiologies and an incomplete understanding of the mechanisms of disease progression have hindered the development of effective therapies. Animal models offer a means of gaining a better understanding of the fundamental basis of the disease. To that effect, a number of experimental animal models are being used to generate pulmonary hypertension in the fetus and newborn. In this review, we compare the mechanisms associated with pulmonary hypertension caused by two such models: in utero ligation of the ductus arteriosus and chronic perinatal hypoxia in sheep fetuses and newborns. In this manner, we make direct comparisons between ductal ligation and chronic hypoxia with respect to the associated mechanisms of disease, since multiple studies have been performed with both models in a single species. We present evidence that the mechanisms associated with pulmonary hypertension are dependent on the type of stress to which the fetus is subjected. Such an analysis allows for a more thorough evaluation of the disease etiology, which can help focus clinical treatments. The final part of the review provides a clinical appraisal of current treatment strategies and lays the foundation for developing individualized therapies that depend on the causative factors. PMID:25006393

  20. Sodium-sensitivity and exercise training-induced blood pressure reduction in older hypertensives

    Microsoft Academic Search

    Jung-Jun Park; Michael D. Brown; Donald R. Dengel; Mark A. Supiano

    2001-01-01

    Exercise training has been shown to reduce blood pressure in patients with hypertension, but individual responses are variable. Blood pressure responses to sodium loading are also heterogeneous. No studies have determined if sodium-sensitivity status differentially affects the blood pressure response to exercise training. Thus, we sought to determine whether blood pressure reductions with exercise training are different between sodium-sensitive (SS)

  1. Chromosome 17 and the inducible nitric oxide synthase gene in human essential hypertension

    Microsoft Academic Search

    Sue Rutherford; Matthew P. Johnson; Robert P. Curtain; Lyn R. Griffiths

    2001-01-01

    Essential hypertension is a common multifactorial trait that results in a significantly increased risk for heart attack and stroke. The condition has a genetic basis, although at present the number of genes is unknown. In order to identify such genes, we are utilising a linkage scanning approach using microsatellite markers and affected sibships. Here we provide evidence for the location

  2. Clinical relevance of the glucocorticoid receptor gene polymorphisms in glucocorticoid–induced ocular hypertension and primary open angle glaucoma

    PubMed Central

    Wang, Xiu-Qing; Duan, Zhao-Xia; He, Xiang-Ge; Zhou, Xi-Yuan

    2015-01-01

    AIM To avoid the side effects of ocular hypertension of glucocorticoid (GC) usage in eye, we must identify susceptible individuals, which exists in about one-third of all population. Further, the majority of all primary open angle glaucoma (POAG) patients show this phenotype. Glucocorticoid receptor (GR) regulates C responsiveness in trabecular meshwork (TM) cells. In this study, single nucleotide polymorphism (SNP) genotyping was used to determine whether there are differences in the BclI (rs41423247) and N363S (rs6195) polymorphisms of the GR gene in healthy and POAG patients, and glucocorticoid-induced ocular hypertension (GIOH) populations. METHODS Three hundred and twenty-seven unrelated Chinese adults, including 111 normal controls, 117 GIOH subjects and 99 POAG patients, were recruited. DNA samples were prepared and the BclI and N363S polymorphisms were screened using real-time polymerase chain reaction (RT-PCR)-restriction fragment length polymorphism (RFLP) analysis. Frequencies of the BclI and N363S polymorphisms were determined and compared using Fisher's exact test and the Chi-squared test. RESULTS Only the BclI polymorphism was identified in the Chinese Han population. The frequency of the G allele was 21.6 % in normal controls, 18.3% in GIOH patients, and 13.64% in the POAG patients. There was no significant difference in polymorphism or allele frequency in the 3 groups. Furthermore, no N363S polymorphism was found in the study subjects. CONCLUSION The BclI polymorphisms in GR gene had no association with GIOH and POAG patients, and N363S polymorphism might not exist in the Chinese Han population. Therefore, the BclI polymorphism might not be responsible for the development of GC-induced ocular hypertension or POAG. PMID:25709928

  3. Prenatal Testosterone Exposure Induces Hypertension in Adult Females via Androgen Receptor-Dependent Protein Kinase C?-Mediated Mechanism.

    PubMed

    Blesson, Chellakkan S; Chinnathambi, Vijayakumar; Hankins, Gary D; Yallampalli, Chandra; Sathishkumar, Kunju

    2015-03-01

    Prenatal exposure to excess testosterone induces hyperandrogenism in adult females and predisposes them to hypertension. We tested whether androgens induce hypertension through transcriptional regulation and signaling of protein kinase C (PKC) in the mesenteric arteries. Pregnant Sprague-Dawley rats were injected with vehicle or testosterone propionate (0.5 mg/kg per day from gestation days 15 to 19, SC) and their 6-month-old adult female offspring were examined. Plasma testosterone levels (0.84±0.04 versus 0.42±0.09 ng/mL) and blood pressures (111.6±1.3 versus 104.5±2.4 mm Hg) were significantly higher in prenatal testosterone-exposed rats compared with controls. This was accompanied with enhanced expression of PKC? mRNA (1.5-fold) and protein (1.7-fold) in the mesenteric arteries of prenatal testosterone-exposed rats. In addition, mesenteric artery contractile responses to PKC activator, phorbol-12,13-dibutyrate, was significantly greater in prenatal testosterone-exposed rats. Treatment with androgen receptor antagonist flutamide (10 mg/kg, SC, BID for 10 days) significantly attenuated hypertension, PKC? expression, and the exaggerated vasoconstriction in prenatal testosterone-exposed rats. In vitro exposure of testosterone to cultured mesenteric artery smooth muscle cells dose dependently upregulated PKC? expression. Analysis of PKC? gene revealed a putative androgen responsive element in the promoter upstream to the transcription start site and an enhancer element in intron-1. Chromatin immunoprecipitation assays showed that androgen receptors bind to these elements in response to testosterone stimulation. Furthermore, luciferase reporter assays showed that the enhancer element is highly responsive to androgens and treatment with flutamide reverses reporter activity. Our studies identified a novel androgen-mediated mechanism for the control of PKC? expression via transcriptional regulation that controls vasoconstriction and blood pressure. PMID:25489059

  4. Role of excitatory amino acid input in rostral ventrolateral medulla neurons in rats with obesity-induced hypertension.

    PubMed

    Suhaimi, Farah Wahida; Yusoff, Nurul Hasnida Mohammad; Dewa, Aidiahmad; Yusof, Ahmad Pauzi M D

    2010-03-01

    Obesity is intimately associated with hypertension; increases in blood pressure are closely related to the magnitude of weight gain. The present study aims to determine whether the excitatory amino acid input to rostral ventrolateral medulla (RVLM) contributes to elevated blood pressure in rats with diet-induced obesity. Male Sprague-Dawley rats weighing 280 to 300 grams were fed with a low-fat diet (10% kcal from fat) or moderately high-fat diet (32% kcal from fat) for 16 weeks. At week 16, rats on the moderate high-fat diet were segregated into obesity-prone and obesity-resistant rats based on body weight distribution. Baseline mean arterial pressure (MAP) was significantly higher in obesity-prone rats as compared to obesity-resistant and rats on a low-fat diet. Bilateral injection of kynurenic acid (KYN) (40 nM) into the RVLM of the obesity-prone rats reduced MAP to levels significantly different from those observed in rats on a low-fat diet and obesity-resistant rats (no change in MAP). At a lower concentration (4 nM), KYN injection did not produce any change in MAP in any group. The results obtained suggest that excitatory amino acid input to the RVLM does contribute to the development of hypertension in rats with diet-induced obesity. PMID:20514927

  5. An afferent vagal nerve pathway links hepatic PPAR? activation to glucocorticoid-induced insulin resistance and hypertension

    PubMed Central

    Bernal-Mizrachi, Carlos; Xiaozhong, Liu; Yin, Li; Knutsen, Russell H.; Howard, Michael J.; Arends, Joop J. A.; DeSantis, Pascual; Coleman, Trey; Semenkovich, Clay F.

    2007-01-01

    Summary Glucocorticoid excess causes insulin resistance and hypertension. Hepatic expression of PPAR? (Ppara) is required for glucocorticoid-induced insulin resistance. Here we demonstrate that afferent fibers of the vagus nerve interface with hepatic Ppara expression to disrupt blood pressure and glucose homeostasis in response to glucocorticoids. Selective hepatic vagotomy decreased hyperglycemia, hyperinsulinemia, hepatic insulin resistance, Ppara expression and phosphoenolpyruvate carboxykinase (PEPCK) enzyme activity in dexamethasone-treated Ppara+/+ mice. Selective vagotomy also decreased blood pressure, adrenergic tone, renin activity, and urinary sodium retention in these mice. Hepatic reconstitution of Ppara in nondiabetic, normotensive dexamethasone-treated Ppara null mice increased glucose, insulin, hepatic PEPCK enzyme activity, blood pressure and renin activity in sham-operated but not hepatic-vagotomized animals. Disruption of vagal afferent fibers by chemical or surgical means prevented glucocorticoid-induced metabolic derangements. We conclude that a dynamic interaction between hepatic Ppara expression and a vagal afferent pathway is essential for glucocorticoid induction of diabetes and hypertension. PMID:17276352

  6. Renoprotective mechanisms of pirfenidone in hypertension-induced renal injury: through anti-fibrotic and anti-oxidative stress pathways.

    PubMed

    Ji, Xu; Naito, Yukiko; Weng, Huachun; Ma, Xiao; Endo, Kosuke; Kito, Naoko; Yanagawa, Nariaki; Yu, Yang; Li, Jie; Iwai, Naoharu

    2013-01-01

    Pirfenidone (PFD) is a novel anti-fibrotic agent that targets TGF?. However, the mechanisms underlying its renoprotective properties in hypertension-induced renal injury are poorly understood. We investigated the renoprotective properties of PFD and clarified its renoprotective mechanisms in a rat hypertension-induced renal injury model. Dahl salt-sensitive rats were fed a high-salt diet with or without 1% PFD for 6 weeks. During the administration period, we examined the effects of PFD on blood pressure and renal function. After the administration, the protein levels of renal TGF?, Smad2/3, TNF?, MMP9, TIMP1, and catalase were examined. In addition, total serum antioxidant activity was measured. Compared to untreated rats, PFD treatment significantly attenuated blood pressure and proteinuria. Histological study showed that PFD treatment improved renal fibrosis. PFD may exert its anti-fibrotic effects via the downregulation of TGF?-Smad2/3 signaling, improvement of MMP9/TIMP1 balance, and suppression of fibroblast proliferation. PFD treatment also increased catalase expression and total serum antioxidant activity. In contrast, PFD treatment did not affect the expression of TNF? protein, macrophage or T-cell infiltration, or plasma interleukin 1? levels. PFD prevents renal injury via its anti-fibrotic and anti-oxidative stress mechanisms. Clarifying the renoprotective mechanisms of PFD will help improve treatment for chronic renal diseases. PMID:24389407

  7. Crocetin reduces the oxidative stress induced reactive oxygen species in the stroke-prone spontaneously hypertensive rats (SHRSPs) brain

    PubMed Central

    Yoshino, Fumihiko; Yoshida, Ayaka; Umigai, Naofumi; Kubo, Koya; Lee, Masaichi-Chang-il

    2011-01-01

    Crocetin is a natural carotenoid compound of gardenia fruits and saffron, which has various effects in biological systems. In this study, we investigated the antioxidant effects of crocetin on reactive oxygen species such as hydroxyl radical using in vitro X-band electron spin resonance and spin trapping. Crocetin significantly inhibited hydroxyl radical generation compared with the control. Moreover, we performed electron spin resonance computed tomography ex vivo with the L-band electron spin resonance imaging system and determined the electron spin resonance signal decay rate in the isolated brain of stroke-prone spontaneously hypertensive rats, a high-oxidative stress model. Crocetin significantly reduced oxidative stress in the isolated brain by acting as a scavenger of reactive oxygen species, especially hydroxyl radical, as demonstrated by in vitro and ex vivo electron spin resonance analysis. The distribution of crocetin was also determined in the plasma and the brain of stroke-prone spontaneously hypertensive rats using high-performance liquid chromatography. After oral administration, crocetin was detected at high levels in the plasma and the brain. Our results suggest that crocetin may participate in the prevention of reactive oxygen species-induced disease due to a reduction of oxidative stress induced by reactive oxygen species in the brain. PMID:22128217

  8. Curcumin Induces Nrf2 Nuclear Translocation and Prevents Glomerular Hypertension, Hyperfiltration, Oxidant Stress, and the Decrease in Antioxidant Enzymes in 5/6 Nephrectomized Rats

    PubMed Central

    Tapia, Edilia; Soto, Virgilia; Ortiz-Vega, Karla Mariana; Zarco-Márquez, Guillermo; Molina-Jijón, Eduardo; Cristóbal-García, Magdalena; Santamaría, José; García-Niño, Wylly Ramsés; Correa, Francisco; Zazueta, Cecilia; Pedraza-Chaverri, José

    2012-01-01

    Renal injury resulting from renal ablation induced by 5/6 nephrectomy (5/6NX) is associated with oxidant stress, glomerular hypertension, hyperfiltration, and impaired Nrf2-Keap1 pathway. The purpose of this work was to know if the bifunctional antioxidant curcumin may induce nuclear translocation of Nrf2 and prevents 5/6NX-induced oxidant stress, renal injury, decrease in antioxidant enzymes, and glomerular hypertension and hyperfiltration. Four groups of rats were studied: (1) control, (2) 5/6NX, (3) 5/6NX +CUR, and (4) CUR (n = 8–10). Curcumin was given by gavage to NX5/6 +CUR and CUR groups (60?mg/kg/day) starting seven days before surgery. Rats were studied 30 days after NX5/6 or sham surgery. Curcumin attenuated 5/6NX-induced proteinuria, systemic and glomerular hypertension, hyperfiltration, glomerular sclerosis, interstitial fibrosis, interstitial inflammation, and increase in plasma creatinine and blood urea nitrogen. This protective effect was associated with enhanced nuclear translocation of Nrf2 and with prevention of 5/6NX-induced oxidant stress and decrease in the activity of antioxidant enzymes. It is concluded that the protective effect of curcumin against 5/6NX-induced glomerular and systemic hypertension, hyperfiltration, renal dysfunction, and renal injury was associated with the nuclear translocation of Nrf2 and the prevention of both oxidant stress and the decrease of antioxidant enzymes. PMID:22919438

  9. Temporal Changes of Angiopoietins and Tie2 Expression in Rat Lungs after Monocrotaline-Induced Pulmonary Hypertension

    PubMed Central

    Cho, Yu Ji; Han, Jae Yoon; Lee, Sang Gab; Jeon, Byeong Tak; Choi, Wan Sung; Hwang, Young Sil; Roh, Gu Seob; Lee, Jong Deog

    2009-01-01

    Angiogenic factors such as vascular endothelial growth factor (VEGF) are implicated in pulmonary hypertension (PH). However, the pathway of angiogenic factor-mediated pathologic angiogenesis in PH remains unclear. In this study, we evaluated the temporal expression of angiopoietin (Ang) 1, Ang2, and their receptor (Tie2) as well as VEGF, endothelial nitric oxide synthase (eNOS), inducible NOS (iNOS), and heme oxygenase 1 (HO1) in the monocrotaline-induced PH model. Histologic evaluation showed pathologic vascular remodeling in the arteries of lung sections 1 wk after monocrotaline treatment. Protein levels of Ang1, Ang2, eNOS, iNOS, HO1, and VEGF were increased 1 wk after monocrotaline treatment but Tie2 protein levels were decreased 2 wk afterward. These results suggest that Ang2 mediates vascular remodeling in PH by decreasing Tie2 expression. Therefore, the Ang–Tie2 system may play a role in the pathophysiology of PH. PMID:19712575

  10. INCREASED HYPOTHALAMIC ANGIOTENSIN-(1-7) LEVELS IN RATS WITH AORTIC COARCTATION-INDUCED HYPERTENSION

    PubMed Central

    Gironacci, Mariela M.; Brosnihan, K. Bridget; Ferrario, Carlos M.; Gorzalczany, Susana; Lopez Verrilli, María A.; Pascual, Mariano; Taira, Carlos; Peña, Clara

    2007-01-01

    Since angiotensin (Ang) (1-7) injected into the brain blocked Ang II pressor actions in rats made hypertensive by aortic coarctation (CH), we examined systemic and tissue angiotensin peptide levels, specifically concentrating on the hypothalamic Ang-(1-7) levels. Plasma, heart and kidney isolated from CH rats showed increased levels of Ang I, Ang II and Ang-(1-7) compared with the normotensive group, with Ang II being the predominant peptide in heart and kidney. In the hypothalamus, equimolar amounts of Ang II and Ang-(1-7) were found in the sham group, whereas only Ang-(1-7) levels increased in CH rats. We conclude that aortic coarctation activates systemic and tissue renin-angiotensin system. The increased central levels of Ang-(1-7) in the CH rats suggest a potential mitigating role of this peptide in central control of the hypertensive process. PMID:17646033

  11. Pioglitazone Prevents Hypertension and Reduces Oxidative Stress in Diet-Induced Obesity

    Microsoft Academic Search

    Anca D. Dobrian; Suzanne D. Schriver; Ali A. Khraibi; Russell L. Prewitt

    2010-01-01

    The objective of this study was to determine the effect of pioglitazone on blood pressure (BP) and oxidative balance in obese, hypertensive, Sprague-Dawley rats and to identify some of the molecular mechanisms involved. After 12 weeks of a moderately high-fat diet, rats diverged into obesity-prone (OP) and obesity-resistant (OR) groups (n6 per group). At the end of the diet, peroxisome

  12. The effects of allicin and enalapril in fructose-induced hyperinsulinemic hyperlipidemic hypertensive rats

    Microsoft Academic Search

    Amitai Elkayam; David Mirelman; Edna Peleg; Meir Wilchek; Talia Miron; Aharon Rabinkov; Sigal Sadetzki; Talma Rosenthal

    2001-01-01

    The effects of a synthetic preparation of an active constituent of garlic, allicin, were studied on blood pressure (BP), triglycerides, and insulin levels in Sprague-Dawley rats in which high fructose feeding elicited hyperinsulinemia, hypertension, and hypertriglyceridemia. Results were compared with those of the antihypertensive drug enalapril. Three groups of male Sprague-Dawley rats were fed a fructose-enriched diet for 5 weeks.

  13. Differential Effects of Endothelin1 Antagonists on Erythropoietin-Induced Hypertension in Renal Failure

    Microsoft Academic Search

    EDITH BROCHU; IRIS KINGMA; JOHN H. GROSE; MARCEL LEBEL

    1999-01-01

    Recently, it was reported that blood vessel immuno- reactive endothelin-1 (irET-1) content is increased in hyper- tensive uremic rats treated with recombinant human erythro- poietin (rhEPO). The present study was designed to evaluate whether ET-1 receptor blockade can prevent the progression of hypertension in renal failure rats receiving rhEPO and, if so, whether selective ETA and nonselective ETA\\/ETB receptor antagonists

  14. Correction of vascular hypercontractility in spontaneously hypertensive rats using shRNAs-induced delta protein kinase C gene silencing.

    PubMed

    Novokhatska, Tetiana; Tishkin, Sergey; Dosenko, Victor; Boldyriev, Alexey; Ivanova, Irina; Strielkov, Ievgen; Soloviev, Anatoly

    2013-10-15

    Potassium conductance in vascular smooth muscle (VSM) is known to be altered in arterial hypertension. High level of protein kinase C (PKC) activity is a common feature for hypertension of different genesis. The main goal of this study was to investigate the efficacy of the RNA interference (RNAi) technique targeting PKC delta-isoform gene as a possible pharmacological tool to restore vasodilator potential in spontaneously hypertensive rats (SHR). Experimental design of the study comprised RNAi and patch-clamp techniques, RT-PCR analysis and standard acetylcholine test. Total outward currents and acetylcholine-induced endothelium-dependent relaxant responses were blunted in SHR. BKCa alpha subunit mRNA expression in SHR was unchanged whereas KV and KATP mRNA expression appeared significantly increased. PKC inhibitor, chelerythrine (100 nM), restored potassium channels activity in SHR. PKC-delta-isoform protein expression and PKC-delta-isoform mRNA expression are 2.5-4 fold increased in VSM from SHR. PKC gene silencing with the short hairpin RNAs (shRNAs)-plasmid delivery system administered intravenously led to an increment in maximal amplitude of acetylcholine-relaxation, restored outward K(+) currents and PKC-delta-isoform mRNA and protein expression. Arterial blood pressure in SHR was normalized following shRNAs administration. We conclude that BKCa channels are likely to be the most PKC-dependent member of K(+) channels family responsible for vascular hypercontractility in SHR while Kv and KATP channels may constitute a reserve mechanism for the maintenance of vasodilator potential under BKCa channelopathy. It is likely that RNAi technique is a good therapeutic approach to inactivate PKC gene and to normalize vascular functions and high arterial blood pressure in SHR. PMID:23973649

  15. Protective effects of 10-nitro-oleic acid in a hypoxia-induced murine model of pulmonary hypertension.

    PubMed

    Klinke, Anna; Möller, Annika; Pekarova, Michaela; Ravekes, Thorben; Friedrichs, Kai; Berlin, Matthias; Scheu, Katrin M; Kubala, Lukas; Kolarova, Hana; Ambrozova, Gabriela; Schermuly, Ralph T; Woodcock, Steven R; Freeman, Bruce A; Rosenkranz, Stephan; Baldus, Stephan; Rudolph, Volker; Rudolph, Tanja K

    2014-07-01

    Pulmonary arterial hypertension (PAH) is characterized by adverse remodeling of pulmonary arteries. Although the origin of the disease and its underlying pathophysiology remain incompletely understood, inflammation has been identified as a central mediator of disease progression. Oxidative inflammatory conditions support the formation of electrophilic fatty acid nitroalkene derivatives, which exert potent anti-inflammatory effects. The current study investigated the role of 10-nitro-oleic acid (OA-NO2) in modulating the pathophysiology of PAH in mice. Mice were kept for 28 days under normoxic or hypoxic conditions, and OA-NO2 was infused subcutaneously. Right ventricular systolic pressure (RVPsys) was determined, and right ventricular and lung tissue was analyzed. The effect of OA-NO2 on cultured pulmonary artery smooth muscle cells (PASMCs) and macrophages was also investigated. Changes in RVPsys revealed increased pulmonary hypertension in mice on hypoxia, which was significantly decreased by OA-NO2 administration. Right ventricular hypertrophy and fibrosis were also attenuated by OA-NO2 treatment. The infiltration of macrophages and the generation of reactive oxygen species were elevated in lung tissue of mice on hypoxia and were diminished by OA-NO2 treatment. Moreover, OA-NO2 decreased superoxide production of activated macrophages and PASMCs in vitro. Vascular structural remodeling was also limited by OA-NO2. In support of these findings, proliferation and activation of extracellular signal-regulated kinases 1/2 in cultured PASMCs was less pronounced on application of OA-NO2.Our results show that the oleic acid nitroalkene derivative OA-NO2 attenuates hypoxia-induced pulmonary hypertension in mice. Thus, OA-NO2 represents a potential therapeutic agent for the treatment of PAH. PMID:24521348

  16. Genetic knockdown of estrogen receptor-alpha in the subfornical organ augments ANG II-induced hypertension in female mice.

    PubMed

    Xue, Baojian; Zhang, Zhongming; Beltz, Terry G; Guo, Fang; Hay, Meredith; Johnson, Alan Kim

    2015-03-15

    The present study tested the hypotheses that 1) ER? in the brain plays a key role in the estrogen-protective effects against ANG II-induced hypertension, and 2) that the subfornical organ (SFO) is a key site where ER? mediates these protective actions. In this study, a "floxed" ER? transgenic mouse line (ER?(flox)) was used to create models in which ER? was knocked down in the brain or just in the SFO. Female mice with ER? ablated in the nervous system (Nestin-ER?(-) mice) showed greater increases in blood pressure (BP) in response to ANG II. Furthermore, females with ER? knockdown specifically in the SFO [SFO adenovirus-Cre (Ad-Cre) injected ER?(flox) mice] also showed an enhanced pressor response to ANG II. Immunohistochemical (IHC), RT-PCR, and Western blot analyses revealed a marked reduction in the expression of ER? in nervous tissues and, in particular, in the SFO. These changes were not present in peripheral tissues in Nestin-ER?(-) mice or Ad-Cre-injected ER?(flox) mice. mRNA expression of components of the renin-angiotensin system in the lamina terminalis were upregulated in Nestin-ER?(-) mice. Moreover, ganglionic blockade on day 7 after ANG II infusions resulted in a greater reduction of BP in Nestin-ER?(-) mice or SFO Ad-Cre-injected mice, suggesting that knockdown of ER? in the nervous system or the SFO alone augments central ANG II-induced increase in sympathetic tone. The results indicate that interfering with the action of estrogen on SFO ER? is sufficient to abolish the protective effects of estrogen against ANG II-induced hypertension. PMID:25552661

  17. Fatty acid nitroalkenes ameliorate glucose intolerance and pulmonary hypertension in high-fat diet-induced obesity

    PubMed Central

    Kelley, Eric E.; Baust, Jeff; Bonacci, Gustavo; Golin-Bisello, Franca; Devlin, Jason E.; St. Croix, Claudette M.; Watkins, Simon C.; Gor, Sonia; Cantu-Medellin, Nadiezhda; Weidert, Eric R.; Frisbee, Jefferson C.; Gladwin, Mark T.; Champion, Hunter C.; Freeman, Bruce A.; Khoo, Nicholas K.H.

    2014-01-01

    Aims Obesity is a risk factor for diabetes and cardiovascular diseases, with the incidence of these disorders becoming epidemic. Pathogenic responses to obesity have been ascribed to adipose tissue (AT) dysfunction that promotes bioactive mediator secretion from visceral AT and the initiation of pro-inflammatory events that induce oxidative stress and tissue dysfunction. Current understanding supports that suppressing pro-inflammatory and oxidative events promotes improved metabolic and cardiovascular function. In this regard, electrophilic nitro-fatty acids display pleiotropic anti-inflammatory signalling actions. Methods and results It was hypothesized that high-fat diet (HFD)-induced inflammatory and metabolic responses, manifested by loss of glucose tolerance and vascular dysfunction, would be attenuated by systemic administration of nitrooctadecenoic acid (OA-NO2). Male C57BL/6j mice subjected to a HFD for 20 weeks displayed increased adiposity, fasting glucose, and insulin levels, which led to glucose intolerance and pulmonary hypertension, characterized by increased right ventricular (RV) end-systolic pressure (RVESP) and pulmonary vascular resistance (PVR). This was associated with increased lung xanthine oxidoreductase (XO) activity, macrophage infiltration, and enhanced expression of pro-inflammatory cytokines. Left ventricular (LV) end-diastolic pressure remained unaltered, indicating that the HFD produces pulmonary vascular remodelling, rather than LV dysfunction and pulmonary venous hypertension. Administration of OA-NO2 for the final 6.5 weeks of HFD improved glucose tolerance and significantly attenuated HFD-induced RVESP, PVR, RV hypertrophy, lung XO activity, oxidative stress, and pro-inflammatory pulmonary cytokine levels. Conclusions These observations support that the pleiotropic signalling actions of electrophilic fatty acids represent a therapeutic strategy for limiting the complex pathogenic responses instigated by obesity. PMID:24385344

  18. High matrix metalloproteinase-9 expression induces angiogenesis and basement membrane degradation in stroke-prone spontaneously hypertensive rats after cerebral infarction

    PubMed Central

    Hou, Huilian; Zhang, Guanjun; Wang, Hongyan; Gong, Huilin; Wang, Chunbao; Zhang, Xuebin

    2014-01-01

    Basement membrane degradation and blood-brain barrier damage appear after cerebral infarction, severely impacting neuronal and brain functioning; however, the underlying pathogenetic mechanisms remain poorly understood. In this study, we induced cerebral infarction in stroke-prone spontaneously hypertensive rats by intragastric administration of high-sodium water (1.3% NaCl) for 7 consecutive weeks. Immunohistochemical and immunofluorescence assays demonstrated that, compared with the non-infarcted contralateral hemisphere, stroke-prone spontaneously hypertensive rats on normal sodium intake and Wistar-Kyoto rats, matrix metalloproteinase-9 expression, the number of blood vessels with discontinuous collagen IV expression and microvessel density were significantly higher, and the number of continuous collagen IV-positive blood vessels was lower in the infarct border zones of stroke-prone spontaneously hypertensive rats given high-sodium water. Linear correlation analysis showed matrix metalloproteinase-9 expression was positively correlated with the number of discontinuously collagen IV-labeled blood vessels and microvessel density in cerebral infarcts of stroke-prone spontaneously hypertensive rats. These results suggest that matrix metalloproteinase-9 upregulation is associated with increased regional angiogenesis and degradation of collagen IV, the major component of the basal lamina, in stroke-prone spontaneously hypertensive rats with high-sodium water-induced focal cerebral infarction. PMID:25206775

  19. Increased oxidative stress and severe arterial remodeling induced by permanent high-flow challenge in experimental pulmonary hypertension

    PubMed Central

    2011-01-01

    Background Involvement of inflammation in pulmonary hypertension (PH) has previously been demonstrated and recently, immune-modulating dendritic cells (DCs) infiltrating arterial lesions in patients suffering from idiopathic pulmonary arterial hypertension (IPAH) and in experimental monocrotaline-induced PH have been reported. Occurrence of perivascular inflammatory cells could be linked to local increase of oxidative stress (OS), as it has been shown for systemic atherosclerosis. The impact of OS on vascular remodeling in PH is still to be determined. We hypothesized, that augmented blood-flow could increase OS and might thereby contribute to DC/inflammatory cell-recruitment and smooth-muscle-cell-proliferation. Methods We applied a monocrotaline-induced PH-model and combined it with permanent flow-challenge. Thirty Sprague-Dawley rats were assigned to following groups: control, monocrotaline-exposure (MCT), monocrotaline-exposure/pneumonectomy (MCT/PE). Results Hemodynamic exploration demonstrated most severe effects in MCT/PE, corresponding in histology to exuberant medial and adventitial remodeling of pulmonary muscular arteries, and intimal remodeling of smaller arterioles; lung-tissue PCR evidenced increased expression of DCs-specific fascin, CD68, proinflammatory cytokines (IL-6, RANTES, fractalkine) in MCT/PE and to a lesser extent in MCT. Major OS enzyme NOX-4 was maximal in MCT/PE. Antioxidative stress enzymes Mn-SOD and glutathion-peroxidase-1 were significantly elevated, while HO-1 showed maximal expression in MCT with significant decrease in MCT/PE. Catalase was decreased in MCT and MCT/PE. Expression of NOX-4, but also of MN-SOD in MCT/PE was mainly attributed to a highly increased number of interstitial and perivascular CXCR4/SDF1 pathway-recruited mast-cells. Stress markers malonedialdehyde and nitrotyrosine were produced in endothelial cells, medial smooth muscle and perivascular leucocytes of hypertensive vasculature. Immunolabeling for OX62, CD68 and actin revealed adventitial and medial DC- and monocyte-infiltration; in MCT/PE, medial smooth muscle cells were admixed with CD68+/vimentin+ cells. Conclusion Our experimental findings support a new concept of immunologic responses to increased OS in MCT/PE-induced PAH, possibly linking recruitment of dendritic cells and OS-producing mast-cells to characteristic vasculopathy. PMID:21906276

  20. Acute and chronic antihypertensive effects of Cinnamomum zeylanicum stem bark methanol extract in L-NAME-induced hypertensive rats

    PubMed Central

    2013-01-01

    Background Previous study showed that the aqueous extract of the stem bark of Cinnamomum zeylanicum possesses antihypertensive and vasodilatory properties. The present work investigates the acute and chronic antihypertensive effects of the methanol extract of Cinnamomum zeylanicum stem bark (MECZ) in L-NAME-induced hypertensive rats. Methods The acute antihypertensive effects of MECZ (5, 10 and 20 mg/kg) administered intravenously were evaluated in rats in which acute arterial hypertension has been induced by intravenous administration of L-NAME (20 mg/kg). For chronic antihypertensive effects, animals were treated with L-NAME (40 mg/kg/day) plus the vehicle or L-NAME (40 mg/kg/day) in combination with captopril (20 mg/kg/day) or MECZ (300 mg/kg/day) and compared with control group receiving only distilled water. All drugs were administered per os and at the end of the experiment that lasted for four consecutive weeks, blood pressure was measured by invasive method and blood samples were collected for the determination of the lipid profile. The heart and aorta were collected, weighed and used for both histological analysis and determination of NO tissue content. Results Acute intravenous administration of C. zeylanicum extract (5, 10 and 20 mg/kg) to L-NAME-induced hypertensive rats provoked a long-lasting decrease in blood pressure. Mean arterial blood pressure decreased by 12.5%, 26.6% and 30.6% at the doses of 5, 10 and 20 mg/kg, respectively. In chronic administration, MECZ and captopril significantly prevented the increase in blood pressure and organs’ weights, as well as tissue histological damages and were able to reverse the depletion in NO tissue’s concentration. The MECZ also significantly lower the plasma level of triglycerides (38.1%), total cholesterol (32.1%) and LDL-cholesterol (75.3%) while increasing that of HDL-cholesterol (58.4%) with a significant low atherogenic index (1.4 versus 5.3 for L-NAME group). Conclusion MECZ possesses antihypertensive and organ protective effects that may result from its ability to increase the production of the endogenous NO and/or to regulate dyslipidemia. PMID:23368533

  1. Cytochrome P4501A1 is Required for Vascular Dysfunction and Hypertension Induced by 2,3,7,8-Tetrachlorodibenzo-p-dioxin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    National Health and Nutrition Examination Survey data show an association between hypertension and exposure to dioxin-like halogenated aromatic hydrocarbons (HAH). Further, chronic exposure of mice to the prototypical HAH, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), induces reactive oxygen species (...

  2. Uridine adenosine tetraphosphate-induced contraction is increased in renal but not pulmonary arteries from DOCA-salt hypertensive rats.

    PubMed

    Matsumoto, Takayuki; Tostes, Rita C; Webb, R Clinton

    2011-08-01

    Uridine adenosine tetraphosphate (Up(4)A) was reported as a novel endothelium-derived contracting factor. Up(4)A contains both purine and pyrimidine moieties, which activate purinergic (P2)X and P2Y receptors. However, alterations in the vasoconstrictor responses to Up(4)A in hypertensive states remain unclear. The present study examined the effects of Up(4)A on contraction of isolated renal arteries (RA) and pulmonary arteries (PA) from DOCA-salt rats using isometric tension recording. RA from DOCA-salt rats exhibited increased contraction to Up(4)A versus arteries from control uninephrectomized rats in the absence and presence of N(G)-nitro-l-arginine (nitric oxide synthase inhibitor). On the other hand, the Up(4)A-induced contraction in PA was similar between the two groups. Up(4)A-induced contraction was inhibited by suramin (nonselective P2 antagonist) but not by diinosine pentaphosphate pentasodium salt hydrate (Ip(5)I; P2X(1) antagonist) in RA from both groups. Furthermore, 2-thiouridine 5'-triphosphate tetrasodium salt (2-ThioUTP; P2Y(2) agonist)-, uridine-5'-(?-thio)-triphosphate trisodium salt (UTP?S; P2Y(2)/P2Y(4) agonist)-, and 5-iodouridine-5'-O-diphosphate trisodium salt (MRS 2693; P2Y(6) agonist)-induced contractions were all increased in RA from DOCA-salt rats. Protein expression of P2Y(2)-, P2Y(4)-, and P2Y(6) receptors in RA was similar between the two groups. In DOCA-salt RA, the enhanced Up(4)A-induced contraction was reduced by PD98059, an ERK pathway inhibitor, and Up(4)A-stimulated ERK activation was increased. These data are the first to indicate that Up(4)A-induced contraction is enhanced in RA from DOCA-salt rats. Enhanced P2Y receptor signaling and activation of the ERK pathway together represent a likely mechanism mediating the enhanced Up(4)A-induced contraction. Up(4)A might be of relevance in the pathophysiology of vascular tone regulation and renal dysfunction in arterial hypertension. PMID:21551273

  3. Uridine adenosine tetraphosphate-induced contraction is increased in renal but not pulmonary arteries from DOCA-salt hypertensive rats

    PubMed Central

    Tostes, Rita C.; Webb, R. Clinton

    2011-01-01

    Uridine adenosine tetraphosphate (Up4A) was reported as a novel endothelium-derived contracting factor. Up4A contains both purine and pyrimidine moieties, which activate purinergic (P2)X and P2Y receptors. However, alterations in the vasoconstrictor responses to Up4A in hypertensive states remain unclear. The present study examined the effects of Up4A on contraction of isolated renal arteries (RA) and pulmonary arteries (PA) from DOCA-salt rats using isometric tension recording. RA from DOCA-salt rats exhibited increased contraction to Up4A versus arteries from control uninephrectomized rats in the absence and presence of NG-nitro-l-arginine (nitric oxide synthase inhibitor). On the other hand, the Up4A-induced contraction in PA was similar between the two groups. Up4A-induced contraction was inhibited by suramin (nonselective P2 antagonist) but not by diinosine pentaphosphate pentasodium salt hydrate (Ip5I; P2X1 antagonist) in RA from both groups. Furthermore, 2-thiouridine 5?-triphosphate tetrasodium salt (2-ThioUTP; P2Y2 agonist)-, uridine-5?-(?-thio)-triphosphate trisodium salt (UTP?S; P2Y2/P2Y4 agonist)-, and 5-iodouridine-5?-O-diphosphate trisodium salt (MRS 2693; P2Y6 agonist)-induced contractions were all increased in RA from DOCA-salt rats. Protein expression of P2Y2-, P2Y4-, and P2Y6 receptors in RA was similar between the two groups. In DOCA-salt RA, the enhanced Up4A-induced contraction was reduced by PD98059, an ERK pathway inhibitor, and Up4A-stimulated ERK activation was increased. These data are the first to indicate that Up4A-induced contraction is enhanced in RA from DOCA-salt rats. Enhanced P2Y receptor signaling and activation of the ERK pathway together represent a likely mechanism mediating the enhanced Up4A-induced contraction. Up4A might be of relevance in the pathophysiology of vascular tone regulation and renal dysfunction in arterial hypertension. PMID:21551273

  4. Central estrogen inhibition of angiotensin II-induced hypertension in male mice and the role of reactive oxygen species.

    PubMed

    Xue, Baojian; Zhao, Yuanzi; Johnson, Alan Kim; Hay, Meredith

    2008-09-01

    It has been shown that reactive oxygen species (ROS) contribute to the central effect of ANG II on blood pressure (BP). Recent studies have implicated an antihypertensive action of estrogen in ANG II-infused female mice. The present study used in vivo telemetry recording and in vitro living mouse brain slices to test the hypothesis that the central activation of estrogen receptors in male mice inhibits ANG II-induced hypertension via the modulation of the central ROS production. In male wild-type mice, the systemic infusion of ANG II induced a significant increase in BP (Delta30.1 +/- 2.5 mmHg). Either central infusion of Tempol or 17beta-estradiol (E2) attenuated the pressor effect of ANG II (Delta10.9 +/- 2.3 and Delta4.5 +/- 1.4 mmHg), and the protective effect of E2 was prevented by the coadministration of an estrogen receptor, antagonist ICI-182780 (Delta23.6 +/- 3.1 mmHg). Moreover, the ganglionic blockade on day 7 after the start of ANG II infusions resulted in a smaller reduction of BP in central Tempol- and in central E2-treated males, suggesting that estrogen inhibits the central ANG II-induced increases in sympathetic outflow. In subfornical organ slices, the application of ANG II resulted in a 21.5 +/- 2.5% increase in ROS production. The coadministration of irbesartan, an ANG II type 1 receptor antagonist, or the preincubation of brain slices with Tempol blocked ANG II-induced increases in ROS production (-1.8 +/- 1.6% and -1.0 +/- 1.8%). The ROS response to ANG II was also blocked by E2 (-3.2 +/- 2.4%). The results suggest that the central actions of E2 are involved in the protection from ANG II-induced hypertension and that estrogen modulation of the ANG II-induced effects may involve interactions with ROS production. PMID:18599599

  5. Molecular chaperone Hsp90 stabilizes Pih1/Nop17 to maintain R2TP complex activity that regulates snoRNA accumulation.

    PubMed

    Zhao, Rongmin; Kakihara, Yoshito; Gribun, Anna; Huen, Jennifer; Yang, Guocheng; Khanna, May; Costanzo, Michael; Brost, Renée L; Boone, Charles; Hughes, Timothy R; Yip, Christopher M; Houry, Walid A

    2008-02-11

    Hsp90 is a highly conserved molecular chaperone that is involved in modulating a multitude of cellular processes. In this study, we identify a function for the chaperone in RNA processing and maintenance. This functionality of Hsp90 involves two recently identified interactors of the chaperone: Tah1 and Pih1/Nop17. Tah1 is a small protein containing tetratricopeptide repeats, whereas Pih1 is found to be an unstable protein. Tah1 and Pih1 bind to the essential helicases Rvb1 and Rvb2 to form the R2TP complex, which we demonstrate is required for the correct accumulation of box C/D small nucleolar ribonucleoproteins. Together with the Tah1 cofactor, Hsp90 functions to stabilize Pih1. As a consequence, the chaperone is shown to affect box C/D accumulation and maintenance, especially under stress conditions. Hsp90 and R2TP proteins are also involved in the proper accumulation of box H/ACA small nucleolar RNAs. PMID:18268103

  6. Exercise-Induced Pulmonary Artery Hypertension in a Patient with Compensated Cardiac Disease: Hemodynamic and Functional Response to Sildenafil Therapy

    PubMed Central

    Nikolaidis, Lazaros; Memon, Nabeel

    2015-01-01

    We describe the case of a 54-year-old man who presented with exertional dyspnea and fatigue that had worsened over the preceding 2 years, despite a normally functioning bioprosthetic aortic valve and stable, mild left ventricular dysfunction (left ventricular ejection fraction, 0.45). His symptoms could not be explained by physical examination, an extensive biochemical profile, or multiple cardiac and pulmonary investigations. However, abnormal cardiopulmonary exercise test results and a right heart catheterization—combined with the use of a symptom-limited, bedside bicycle ergometer—revealed that the patient's exercise-induced pulmonary artery hypertension was out of proportion to his compensated left heart disease. A trial of sildenafil therapy resulted in objective improvements in hemodynamic values and functional class. PMID:25873799

  7. Pulmonary hypertension in CKD.

    PubMed

    Bolignano, Davide; Rastelli, Stefania; Agarwal, Rajiv; Fliser, Danilo; Massy, Ziad; Ortiz, Alberto; Wiecek, Andrzej; Martinez-Castelao, Alberto; Covic, Adrian; Goldsmith, David; Suleymanlar, Gultekin; Lindholm, Bengt; Parati, Gianfranco; Sicari, Rosa; Gargani, Luna; Mallamaci, Francesca; London, Gerard; Zoccali, Carmine

    2013-04-01

    Pulmonary arterial hypertension is a rare disease often associated with positive antinuclear antibody and high mortality. Pulmonary hypertension, which rarely is severe, occurs frequently in patients with chronic kidney disease (CKD). The prevalence of pulmonary hypertension ranges from 9%-39% in individuals with stage 5 CKD, 18.8%-68.8% in hemodialysis patients, and 0%-42% in patients on peritoneal dialysis therapy. No epidemiologic data are available yet for earlier stages of CKD. Pulmonary hypertension in patients with CKD may be induced and/or aggravated by left ventricular disorders and risk factors typical of CKD, including volume overload, an arteriovenous fistula, sleep-disordered breathing, exposure to dialysis membranes, endothelial dysfunction, vascular calcification and stiffening, and severe anemia. No specific intervention trial aimed at reducing pulmonary hypertension in patients with CKD has been performed to date. Correcting volume overload and treating left ventricular disorders are factors of paramount importance for relieving pulmonary hypertension in patients with CKD. Preventing pulmonary hypertension in this population is crucial because even kidney transplantation may not reverse the high mortality associated with established pulmonary hypertension. PMID:23164943

  8. CTGF disrupts alveolarization and induces pulmonary hypertension in neonatal mice: implication in the pathogenesis of severe bronchopulmonary dysplasia

    PubMed Central

    Chen, Shaoyi; Rong, Min; Platteau, Astrid; Hehre, Dorothy; Smith, Heather; Ruiz, Philip; Whitsett, Jeffrey; Bancalari, Eduardo

    2011-01-01

    The pathological hallmarks of bronchopulmonary dysplasia (BPD), one of the most common long-term pulmonary complications associated with preterm birth, include arrested alveolarization, abnormal vascular growth, and variable interstitial fibrosis. Severe BPD is often complicated by pulmonary hypertension characterized by excessive pulmonary vascular remodeling and right ventricular hypertrophy that significantly contributes to the mortality and morbidity of these infants. Connective tissue growth factor (CTGF) is a multifunctional protein that coordinates complex biological processes during tissue development and remodeling. We have previously shown that conditional overexpression of CTGF in airway epithelium under the control of the Clara cell secretory protein promoter results in BPD-like architecture in neonatal mice. In this study, we have generated a doxycycline-inducible double transgenic mouse model with overexpression of CTGF in alveolar type II epithelial (AT II) cells under the control of the surfactant protein C promoter. Overexpression of CTGF in neonatal mice caused dramatic macrophage and neutrophil infiltration in alveolar air spaces and perivascular regions. Overexpression of CTGF also significantly decreased alveolarization and vascular development. Furthermore, overexpression of CTGF induced pulmonary vascular remodeling and pulmonary hypertension. Most importantly, we have also demonstrated that these pathological changes are associated with activation of integrin-linked kinase (ILK)/glucose synthesis kinase-3? (GSK-3?)/?-catenin signaling. These data indicate that overexpression of CTGF in AT II cells results in lung pathology similar to those observed in infants with severe BPD and that ILK/GSK-3?/?-catenin signaling may play an important role in the pathogenesis of severe BPD. PMID:21239535

  9. Water deprivation-induced sodium appetite and differential expression of encephalic c-Fos immunoreactivity in the spontaneously hypertensive rat.

    PubMed

    Pereira-Derderian, Daniela T B; Vendramini, Regina C; Menani, José V; De Luca, Laurival A

    2010-05-01

    The spontaneously hypertensive rat (SHR) has an intense consumption of NaCl solution. Water deprivation (WD) followed by water intake to satiety induces partial rehydration (PR)-the WD-PR protocol-and sodium appetite. In the present work, WD produced similar water intake and no alterations in arterial pressure among spontaneously hypertensive rat (SHR), Wistar-Kyoto, and Holtzman strains. It also increased the number of cells with positive c-Fos immunoreactivity (Fos-IR) in the lamina terminalis and in the hypothalamic supraoptic (SON) and paraventricular (parvocellular, PVNp) nucleus in these strains. The WD and WD-PR produced similar alterations in all strains in serum osmolality and protein, plasma renin activity, and sodium balance. The SHR ingested about 10 times more 0.3 M NaCl than normotensives strains in the sodium appetite test that follows WD-PR. After WD-PR, the Fos-IR persisted, elevated in the lamina terminalis of all strains but notably in the subfornical organ of the SHR. The WD-PR reversed Fos-IR in the SON of all strains and in the PVNp of SHR. It induced Fos-IR in the area postrema and in the nucleus of the solitary tract (NTS), dorsal raphe, parabrachial (PBN), pre-locus coeruleus (pre-LC), suprachiasmatic, and central amygdalar nucleus of all strains. This effect was bigger in the caudal-NTS, pre-LC, and medial-PBN of SHRs. The results indicate that WD-PR increases cell activity in the forebrain and hindbrain areas that control sodium appetite in the rat. They also suggest that increased cell activity in facilitatory brain areas precedes the intense 0.3 M NaCl intake of the SHR in the sodium appetite test. PMID:20200133

  10. Losartan attenuates chronic cigarette smoke exposure-induced pulmonary arterial hypertension in rats: Possible involvement of angiotensin-converting enzyme-2

    Microsoft Academic Search

    Su-Xia Han; Guang-Ming He; Tao Wang; Lei Chen; Yun-Ye Ning; Feng Luo; Jin An; Ting Yang; Jia-Jia Dong; Zeng-lin Liao; Dan Xu; Fu-Qiang Wen

    2010-01-01

    Chronic cigarette smoking induces pulmonary arterial hypertension (PAH) by largely unknown mechanisms. Renin–angiotensin system (RAS) is known to function in the development of PAH. Losartan, a specific angiotensin II receptor antagonist, is a well-known antihypertensive drug with a potential role in regulating angiotensin-converting enzyme-2 (ACE2), a recently found regulator of RAS. To determine the effect of losartan on smoke-induced PAH

  11. PHYSIOLOGY, ENDOCRINOLOGY, AND REPRODUCTION Influence of Aminoguanidine, an Inhibitor of Inducible Nitric Oxide Synthase, on the Pulmonary Hypertensive Response to Microparticle Injections in Broilers1

    Microsoft Academic Search

    R. F. Wideman; O. T. Bowen; G. F. Erf; M. E. Chapman

    The pulmonary hypertensive response to pulmonary vascular obstruction caused by intravenously injected microparticles is amplified by pretreatment with N?nitro-L-arginine methyl ester (L-NAME). The L-NAME prevents the synthesis of the potent vasodilator nitric oxide (NO) by inhibiting both the constitutive (endothe- lial NO synthase (eNOS or NOS-3)) and inducible (induc- ibleNOsynthase(iNOSorNOS-2))formsofNOsynthase. In the present study we used the selective iNOS inhibitor

  12. Positive influence of AT(1) receptor antagonism upon the impaired celiprolol-induced vasodilatation in aorta from spontaneously hypertensive rats.

    PubMed

    Sauvaget, Frédérique; Mallem, Mohamed Yassine; Bucas, Véronique; Gogny, Marc; Desfontis, Jean-Claude; Noireaud, Jacques

    2010-10-10

    We evaluated celiprolol-induced vasodilatation in aorta taken from 12-week-old spontaneously hypertensive rats (SHR) and the effect of AT(1) angiotensin II receptor antagonism on the vasodilatory action of celiprolol in Wistar Kyoto (WKY) rats and SHR. In WKY rats, the celiprolol-induced relaxation was greatly decreased in denuded aorta, and completely abolished in intact aorta by N(omega)-nitro-l-arginine methyl ester (l-NAME, 100 microM). In SHR, celiprolol-induced relaxation was reduced compared to WKY rats (E(max) (value obtained for the highest concentration, 300 microM)=39.1+ or - 3.78%, n=21 vs. 80.4 + or - 3% in WKY rats, n=10; P<0.0001). Endothelium removal or pre-treatment with l-NAME did not alter celiprolol-induced relaxation in SHR. In both strains, relaxation to celiprolol was decreased in the presence of nadolol (a beta(1)/beta(2)-adrenoceptor antagonist, 10 microM). N-[[3-[(2S)-2-hydroxy-3-[[2-[4-[(phenylsulfonyl)amino] phenyl]ethyl]amino] propoxy]phenyl]methyl]-acetamide (L748337, a beta(3)-adrenoceptor antagonist, 7 microM) had no effect. A 12-day treatment with candesartan cilexetil (an AT(1) receptor antagonist, 0.37 or 1mg/kg/day) reduced systolic blood pressure in both strains, but only improved relaxation to celiprolol in SHR, and only at the highest dose (E(max)=64.2+/-3.9%, n=10, P<0.0001 vs. SHR control). In both strains, local aortic AT(1) receptor antagonism with candesartan CV11974 (100 microM) had no effect. The endothelial beta(1)/beta(2) relaxation induced by celiprolol was therefore impaired in SHR aorta and AT(1) receptor antagonism improved the response to celiprolol, in conjunction with a reduction in blood pressure. This work highlights the need to analyse the potential benefit of a combination of celiprolol/AT(1) receptor antagonist in the treatment of hypertension. PMID:20637193

  13. Serum-glucocorticoid regulated kinase 1 regulates macrophage recruitment and activation contributing to monocrotaline-induced pulmonary arterial hypertension.

    PubMed

    Xi, Xin; Liu, Shuang; Shi, Hongtao; Yang, Min; Qi, Yongfen; Wang, Jian; Du, Jie

    2014-12-01

    Sustained inflammation is associated with pulmonary vascular remodeling and arterial hypertension (PAH). Serum-glucocorticoid regulated kinase 1 (SGK1) has been shown to participate in vascular remodeling, but its role in inflammation-associated PAH remains unknown. In this study, the importance of SGK1 expression and activation was investigated on monocrotaline (MCT)-induced PAH, an inflammation-associated experimental model of PAH used in mice and rats. The expression of SGK1 in the lungs of rats with MCT-induced PAH was significantly increased. Furthermore, SGK1 knockout mice were resistant to MCT-induced PAH and showed less elevation of right ventricular systolic pressure and right ventricular hypertrophy and showed reduced pulmonary vascular remodeling in response to MCT injection. Administering the SGK1 inhibitor, EMD638683, to rats also prevented the development of MCT-induced PAH. The expression of SGK1 was shown to take place primarily in alveolar macrophages. EMD638683 treatment suppressed macrophage infiltration and inhibited the proliferation of pulmonary arterial smooth muscle cells (PASMCs) in the lungs of rats with MCT-induced PAH. Co-culture of bone marrow-derived macrophages (BMDMs) from wild-type (WT) mice promoted proliferation of PASMC in vitro, whereas BMDMs from either SGK1 knockout mice or WT mice with EMD638683 treatment failed to induce this response. Collectively, the present results demonstrated that SGK1 is important to the regulation of macrophage activation that contributes to the development of PAH; thus, SGK1 may be a potential therapeutic target for the treatment of PAH. PMID:24825325

  14. Role of the median preoptic nucleus in chronic angiotensin II-induced hypertension.

    PubMed

    Ployngam, Trasida; Collister, John P

    2008-10-31

    Several lines of evidence implicate the median preoptic nucleus (MnPO) as a downstream site of activation following binding of angiotensin II (ANG II) at the subfornical organ and organum vasculosum of the lamina terminalis. We have shown previously that electrolytic lesion of the MnPO attenuated the increased blood pressure response to chronic intravenous infusion of ANG II. However, whether MnPO neurons or fibers that pass through this region contribute to this response is not clear. In the present study, to distinguish the relative importance of MnPO neurons from fibers of passage in the hypertensive response to chronic ANG II administration, male Sprague Dawley rats were randomly assigned to either sham (iSHAM) or ibotenic acid lesion of the MnPO (iMnPOx). In the iMnPOx group, 200 nl of ibotenic acid in phosphate buffer saline (5 microg/microl) was injected into each of 3 predetermined coordinates targeted at the entire MnPO. After a week of recovery, rats were instrumented with venous catheters, and radiotelemetric transducers for the intravenous administration of ANG II and the measurement of mean arterial pressure (MAP) and heart rate, respectively. Rats were given another week to recover. iSHAM and iMnPOx animals were then infused with saline (7 ml 0.9% NaCl/day) for 3 days as a control period, followed by 10 consecutive days of intravenous ANG II infusion (10 ng kg(-1) min(-1)), and finally a recovery period similar to control. Throughout the protocol, a 0.4% NaCl diet and distilled water were provided ad libitum. By day 8 of ANG II infusion, MAP had increased 54+/-2 mm Hg in iSHAM rats (n=8). The hypertensive response to ANG II was significantly attenuated in the iMnPOx rats (n=9), in which MAP had only increased 29+/-3 mm Hg. These results support the hypothesis that neurons of the MnPO are involved in the central neural pathway mediating the chronic hypertensive effects of ANG II. PMID:18760264

  15. Exaggerated natriuresis induced by sodium chloride infusion in essential hypertension is accompanied by an exaggerated urinary 3' 5' guanosine monophosphate excretion.

    PubMed

    Widecka, K; Celiba?a, R; Go?dzik, J; Syrenicz, A; Ciechanowski, K; Czekalski, S

    1993-01-01

    The effects of an intravenous infusion of physiological saline on plasma atrial natriuretic peptide (ANP), guanosine 3' 5' monophosphate (cGMP) concentrations, and on urinary cGMP and sodium excretion were studied in 13 patients with essential hypertension, class I according to WHO criteria, and in 10 healthy subjects. It was found that the groups did not differ as to basal and infusion-induced plasma ANP and cGMP and basal urinary cGMP and sodium excretion, but the sodium chloride infusion resulted in a significantly greater urinary cGMP and sodium excretion and creatinine clearance in hypertensive than in control subjects. The results of this study demonstrate that patients with essential hypertension respond to an intravenous sodium chloride load not only with exaggerated natriuresis, but also with augmented urinary cGMP excretion. The latter finding may in part be due to a greater glomerular filtration of cGMP, but increased renal contribution cannot be excluded. Apart from the possible stronger intrarenal effect of ANP on cGMP production in patients with hypertension, independent direct effect of volume expansion on cGMP excretion and modified activity of other cGMP generating systems may all be responsible for the higher urinary cGMP excretion in essential hypertension. PMID:8414156

  16. Cytochrome P4501A1 is required for vascular dysfunction and hypertension induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin.

    PubMed

    Kopf, Phillip G; Scott, Jason A; Agbor, Larry N; Boberg, Jason R; Elased, Khalid M; Huwe, Janice K; Walker, Mary K

    2010-10-01

    National Health and Nutrition Examination Survey data show an association between hypertension and exposure to dioxin-like halogenated aromatic hydrocarbons (HAHs). Furthermore, chronic exposure of mice to the prototypical HAH, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), induces reactive oxygen species (ROS), endothelial dysfunction, and hypertension. Because TCDD induces cytochrome P4501A1 (CYP1A1) and CYP1A1 can increase ROS, we tested the hypothesis that TCDD-induced endothelial dysfunction and hypertension are mediated by CYP1A1. CYP1A1 wild-type (WT) and knockout (KO) mice were fed one control or TCDD-containing pill (180 ng TCDD/kg, 5 days/week) for 35 days (n = 10-14/genotype/treatment). Blood pressure was monitored by radiotelemetry, and liver TCDD concentration, CYP1A1 induction, ROS, and aortic reactivity were measured at 35 days. TCDD accumulated to similar levels in livers of both genotypes. TCDD induced CYP1A1 in endothelium of aorta and mesentery without detectable expression in the vessel wall. TCDD also induced superoxide anion production, measured by NADPH-dependent lucigenin luminescence, in aorta, heart, and kidney of CYP1A1 WT mice but not KO mice. In contrast, TCDD induced hydrogen peroxide, measured by amplex red assay, to similar levels in aorta of CYP1A1 WT and KO mice but not in heart or kidney. TCDD reduced acetylcholine-dependent vasorelaxation in aortic rings of CYP1A1 WT mice but not in KO mice. Finally, TCDD steadily increased blood pressure after 15 days, which plateaued after 25 days (+20 mmHg) in CYP1A1 WT mice but failed to alter blood pressure in KO mice. These results demonstrate that CYP1A1 is required for TCDD-induced cardiovascular superoxide anion production, endothelial dysfunction, and hypertension. PMID:20634294

  17. Renovascular hypertension

    MedlinePLUS

    Renal hypertension; Hypertension - renovascular; Renal artery occlusion; Stenosis - renal artery; Renal artery stenosis ... Renal artery stenosis is a narrowing or blockage of the arteries that supply blood to the kidneys. The most ...

  18. Malignant hypertension

    MedlinePLUS

    ... for malignant hypertension if you have had: Kidney failure Renal hypertension caused by renal artery stenosis ... An eye examination will reveal changes that indicate high blood ... failure, as well as other complications, may develop. Tests ...

  19. Disulfiram-Induced Reversible Hypertension: A Prospective Case Series and Review of The Literature

    PubMed Central

    Kulkarni, Ranganath R.; Ramdurg, Santosh I.; Bairy, Bhavya K.

    2014-01-01

    Disulfiram (DSF) is one of the recommended aids in the management of selected patients with alcohol dependence. Hypertension (HTN) as an adverse effect of DSF therapy is less understood. In our prospective case series of 7 subjects with co-morbid alcohol and nicotine dependence, a temporal, dose-dependent, and reversible grade 1-3 HTN within 1-6 weeks of initiation of DSF therapy (125-500 mg/day) with no other detectable causes of HTN was noted. Challenges and strategies surrounding diagnosis and treatment along with mean change and percentage rise in blood pressure are described. Literature review and clinical description of case series may suggest neurobiological role in its causation. HTN may be a clinically significant, dose-dependent, and reversible adverse effect of DSF therapy, especially in co-morbid alcohol and nicotine-dependent patients. Awareness amongst clinicians may render better health care delivery to subjects with alcohol dependence. PMID:25336781

  20. Central and peripheral renin-angiotensin systems in ouabain-induced hypertension.

    PubMed

    Cheung, Warren J; Kent, Mary-Anne H; El-Shahat, Esraa; Wang, Hongwei; Tan, Junhui; White, Roselyn; Leenen, Frans H H

    2006-08-01

    Chronic subcutaneous infusion of ouabain causes hypertension via central pathways involving angiotensin type 1 (AT(1)) receptor stimulation. The present study assessed plasma and tissue ANG I and II levels as well as AT1 receptor and angiotensin-converting enzyme (ACE) mRNA levels and binding densities by real-time PCR and in vitro autoradiography in relevant brain nuclei and peripheral tissues (heart and kidney) in rats at 1 and/or 2 wk after start of ouabain infusion at 50 microg/day. After 2 wk (but not after 1 wk), blood pressures significantly increased (+15 mmHg). At 2 wk, plasma ANG I and II levels were markedly suppressed by ouabain. In contrast, in the heart and kidneys, ANG I levels were not affected, and ANG II levels tended to decrease, whereas in the hypothalamus ANG II content clearly increased. At 1 wk, no changes in ACE and AT1 receptor densities were seen. After 2 wk, there were significant decreases in AT(1) receptor mRNA and densities in the organum vasculosum of the lamina terminalis (OVLT), subfornical organ (SFO), and paraventricular nucleus (PVN). ACE densities decreased only in the OVLT and SFO, but ACE mRNA showed more variable responses (decrease in OVLT vs. increase in PVN). In the kidneys, at 2 wk both AT1 receptor and ACE densities were decreased, but mRNA abundance did not change. The heart showed no significant changes. The increase in hypothalamic ANG II content and associated decreases in central AT1 receptor and ACE densities support the involvement of the brain renin-angiotensin system in the central hypertensive mechanism of action of ouabain. PMID:16565308

  1. Collecting duct-specific knockout of renin attenuates angiotensin II-induced hypertension.

    PubMed

    Ramkumar, Nirupama; Stuart, Deborah; Rees, Sara; Hoek, Alfred Van; Sigmund, Curt D; Kohan, Donald E

    2014-10-15

    The physiological and pathophysiological significance of collecting duct (CD)-derived renin, particularly as it relates to blood pressure (BP) regulation, is unknown. To address this question, we generated CD-specific renin knockout (KO) mice and examined BP and renal salt and water excretion. Mice containing loxP-flanked exon 1 of the renin gene were crossed with mice transgenic for aquaporin-2-Cre recombinase to achieve CD-specific renin KO. Compared with controls, CD renin KO mice had 70% lower medullary renin mRNA and 90% lower renin mRNA in microdissected cortical CD. Urinary renin levels were significantly lower in KO mice (45% of control levels) while plasma renin concentration was significantly higher in KO mice (63% higher than controls) during normal-Na intake. While no observable differences were noted in BP between the two groups with varying Na intake, infusion of angiotensin II at 400 ng·kg(-1)·min(-1) resulted in an attenuated hypertensive response in the KO mice (mean arterial pressure 111 ± 4 mmHg in KO vs. 128 ± 3 mmHg in controls). Urinary renin excretion and epithelial Na(+) channel (ENaC) remained significantly lower in the KO mice following ANG II infusion compared with controls. Furthermore, membrane-associated ENaC protein levels were significantly lower in KO mice following ANG II infusion. These findings suggest that CD renin modulates BP in ANG II-infused hypertension and these effects are associated with changes in ENaC expression. PMID:25122048

  2. N-acetylcysteine improves established monocrotaline-induced pulmonary hypertension in rats

    PubMed Central

    2014-01-01

    Background The outcome of patients suffering from pulmonary arterial hypertension (PAH) are predominantly determined by the response of the right ventricle to the increase afterload secondary to high vascular pulmonary resistance. However, little is known about the effects of the current available or experimental PAH treatments on the heart. Recently, inflammation has been implicated in the pathophysiology of PAH. N-acetylcysteine (NAC), a well-known safe anti-oxidant drug, has immuno-modulatory and cardioprotective properties. We therefore hypothesized that NAC could reduce the severity of pulmonary hypertension (PH) in rats exposed to monocrotaline (MCT), lowering inflammation and preserving pulmonary vascular system and right heart function. Methods Saline-treated control, MCT-exposed, MCT-exposed and NAC treated rats (day 14–28) were evaluated at day 28 following MCT for hemodynamic parameters (right ventricular systolic pressure, mean pulmonary arterial pressure and cardiac output), right ventricular hypertrophy, pulmonary vascular morphometry, lung inflammatory cells immunohistochemistry (monocyte/macrophages and dendritic cells), IL-6 expression, cardiomyocyte hypertrophy and cardiac fibrosis. Results The treatment with NAC significantly decreased pulmonary vascular remodeling, lung inflammation, and improved total pulmonary resistance (from 0.71?±?0.05 for MCT group to 0.50?±?0.06 for MCT?+?NAC group, p?

  3. Prevention of hypertensive crises in rats induced by acute and chronic norepinephrine excess.

    PubMed

    Weismann, D; Kleinbrahm, K; Hu, K; Fassnacht, M; Frantz, S; Ertl, G; Allolio, B; Maier, S K G

    2010-10-01

    Calcium Channel Blockers (CCBs), competitive ?-adrenoceptor blockers, and phenoxybenzamine (POB) are used for preoperative treatment of pheochromocytomas. We analyzed the protection from hypertensive crisis provided by these drugs during acute and chronic norepinephrine excess. To ensure adaptive changes during chronic norepinephrine (NE) excess, we continuously exposed male Wistar rats to NE for 3 weeks (osmotic pumps). Afterwards, blood pressure (BP) was continuously measured while NE boli (0-1000 ?g/kg, i.?v.) were administered before and after antihypertensive treatment in anesthetized and catheterized rats. A single dose of urapidil (10 mg/kg), nitrendipine (600 ?g/kg) and POB (10 mg/kg) lowered BP from 212 ± 12 mmHg by 52 ± 7%, 31 ± 9%, and 50 ± 6%, respectively. With NE boli a maximum BP of 235 ± 29, 240 ± 30 and 138 ± 3 mmHg was measured in urapidil, nitrendipine, and POB treated animals (p<0.05). The number of hypertensive episodes (delta BP >30 mmHg) was 3 (3), 1.5 (0-3), and 0 (0-1) (p<0.05). Because of inferiority, urapidil was excluded from further testing. Chronically NE exposed rats were treated with POB (10 mg/kg/d), nifedipine (10 mg/kg/d), or vehicle for 7 days. Marked BP elevations were observed at baseline (167 ± 7, 210 ± 7 , and 217 ± 7 mmHg, p<0.01) and maximum blood pressure was 220 ± 32, 282 ± 26, and 268 ± 40 mmHg (p<0.001) with NE boli. Further stabilization was achieved combining POB pretreatment with a continuous nifedipine infusion, which effectively prevented BP elevations during NE excess. POB was the most effective drug used in monotherapy, but BP stabilization was superior using a combination of POB pretreatment with a continuous nifedipine infusion in this model. PMID:20665428

  4. Microbead-Induced Ocular Hypertensive Mouse Model for Screening and Testing of Aqueous Production Suppressants for Glaucoma

    PubMed Central

    Yang, Qiang; Cho, Kin-Sang; Chen, Huihui; Yu, Dekuang; Wang, Wan-Heng; Luo, Gang; Pang, Iok-Hou; Guo, Wenyi; Chen, Dong Feng

    2012-01-01

    Purpose. To characterize the microbead-induced ocular hypertension (OHT) mouse model and investigate its potential use for preclinical screening and evaluation of ocular hypotensive agents, we tested the model's responses to major antiglaucoma drugs. Methods. Adult C57BL/6J mice were induced to develop OHT unilaterally by intracameral injection of microbeads. The effects of the most commonly used ocular hypotensive drugs, including timolol, brimonidine, brinzolamide, pilocarpine, and latanoprost, on IOP and glaucomatous neural damage were evaluated. Degeneration of retinal ganglion cells (RGCs) and optic nerve axons were quantitatively assessed using immunofluorescence labeling and histochemistry. Thickness of the ganglion cell complex (GCC) was also assessed with spectral-domain optical coherence tomography (SD-OCT). Results. A microbead-induced OHT model promptly responded to drugs, such as timolol, brimonidine, and brinzolamide, that lower IOP through suppressing aqueous humor production and showed improved RGC and axon survival as compared to vehicle controls. Accordingly, SD-OCT detected significantly less reduction of GCC thickness in mice treated with all three aqueous production suppressants as compared to the vehicle contol–treated group. In contrast, drugs that increase aqueous outflow, such as pilocarpine and latanoprost, failed to decrease IOP in the microbead-induced OHT mice. Conclusions. Microbead-induced OHT mice carry dysfunctional aqueous outflow facility and therefore offer a unique model that allows selective screening of aqueous production suppressant antiglaucoma drugs or for studying the mechanisms regulating aqueous humor production. Our data set the stage for using GCC thickness assessed by SD-OCT as an imaging biomarker for noninvasive tracking of neuronal benefits of glaucoma therapy in this model. PMID:22599582

  5. Chronic Hypertension in Pregnancy

    MedlinePLUS

    ... Hypertension? There are 2 types of chronic hypertension: essential hypertension and secondary hypertension. We do not know the cause of essential hypertension, but because hypertension commonly runs in families, we ...

  6. TRPV4 channel contributes to serotonin-induced pulmonary vasoconstriction and the enhanced vascular reactivity in chronic hypoxic pulmonary hypertension

    PubMed Central

    Xia, Yang; Fu, Zhenzhen; Hu, Jinxing; Huang, Chun; Paudel, Omkar; Cai, Shaoxi; Liedtke, Wolfgang

    2013-01-01

    Transient receptor potential vanilloid 4 (TRPV4) is a mechanosensitive channel in pulmonary arterial smooth muscle cells (PASMCs). Its upregulation by chronic hypoxia is associated with enhanced myogenic tone, and genetic deletion of trpv4 suppresses the development of chronic hypoxic pulmonary hypertension (CHPH). Here we further examine the roles of TRPV4 in agonist-induced pulmonary vasoconstriction and in the enhanced vasoreactivity in CHPH. Initial evaluation of TRPV4-selective antagonists HC-067047 and RN-1734 in KCl-contracted pulmonary arteries (PAs) of trpv4?/? mice found that submicromolar HC-067047 was devoid of off-target effect on pulmonary vasoconstriction. Inhibition of TRPV4 with 0.5 ?M HC-067047 significantly reduced the sensitivity of serotonin (5-HT)-induced contraction in wild-type (WT) PAs but had no effect on endothelin-1 or phenylephrine-activated response. Similar shift in the concentration-response curve of 5-HT was observed in trpv4?/? PAs, confirming specific TRPV4 contribution to 5-HT-induced vasoconstriction. 5-HT-induced Ca2+ response was attenuated by HC-067047 in WT PASMCs but not in trpv4?/? PASMCs, suggesting TRPV4 is a major Ca2+ pathway for 5-HT-induced Ca2+ mobilization. Nifedipine also attenuated 5-HT-induced Ca2+ response in WT PASMCs but did not cause further reduction in the presence of HC-067047, suggesting interdependence of TRPV4 and voltage-gated Ca2+ channels in the 5-HT response. Chronic exposure (3–4 wk) of WT mice to 10% O2 caused significant increase in 5-HT-induced maximal contraction, which was partially reversed by HC-067047. In concordance, the enhancement of 5-HT-induced contraction was significantly reduced in PAs of CH trpv4?/? mice and HC-067047 had no further effect on the 5-HT induced response. These results suggest unequivocally that TRPV4 contributes to 5-HT-dependent pharmaco-mechanical coupling and plays a major role in the enhanced pulmonary vasoreactivity to 5-HT in CHPH. PMID:23739180

  7. Effect of Small Hairpin RNA Targeting Endothelin-Converting Enzyme-1 in Monocrotaline-Induced Pulmonary Hypertensive Rats

    PubMed Central

    Son, Jae Sung; Kim, Kwan Chang; Kim, Bo Kyung; Cho, Min-Sun

    2012-01-01

    The purpose of this study was to investigate the therapeutic effects of small hairpin RNA (shRNA) targeting endothelin-converting enzyme (ECE)-1 in monocrotaline (MCT)-induced pulmonary hypertensive rats. Ninty-four Sprague-Dawley rats were divided into three groups: control (n = 24), MCT (n = 35) and shRNA (n = 35). Four-week survival rate in the shRNA group was significantly increased compared to that in the MCT group. The shRNA group showed a significant improvement of right ventricular (RV) pressure compared with the MCT group. The MCT and shRNA groups also showed an increase in RV/(left ventricle + septum) ratio and lung/body weight. Plasma endothelin (ET)-1 concentrations in the shRNA group were lower than those in the MCT group. Medial wall thickness of pulmonary arterioles were increased after MCT injection and was significantly decreased in the shRNA group. The number of intra-acinar muscular pulmonary arteries was decreased in the shRNA group. The mRNA expressions of ET-1 and ET receptor A (ETA) were significantly decreased in the shRNA group in week 4. The protein levels of ETA were decreased in the shRNA group in week 2. The protein levels of tumor necrosis factor-? and vascular endothelial growth factor were decreased in the shRNA group in week 4. In conclusion, the gene silencing with lentiviral vector targeting ECE-1 could be effective against hemodynamic, histopathological and gene expression changes in pulmonary hypertension. PMID:23255850

  8. Early life stress sensitizes rats to angiotensin II-induced hypertension and vascular inflammation in adult life

    PubMed Central

    Loria, Analia S.; Pollock, David M.; Pollock, Jennifer S.

    2010-01-01

    Maternal separation during early life is an established chronic behavioral model of early life stress in rats. It is known that perinatal adverse environments increase activity of the renin-angiotensin system, specifically angiotensin II (ang II), in adulthood. The aim of this study was to investigate whether the effects of early life stress augments the sensitivity of the ang II pathway. Using Wistar Kyoto rats, the maternal separation (MS) protocol was performed separating approximately half of the male pups from their mother 3 hs/day from day 2–14 of life. Pups remaining with the mother at all times were utilized as controls. Maternal separation did not influence the plasma basal parameters such blood glucose, insulin, ang II, ang 1–7 and PRA. Furthermore, body weight, blood pressure and heart rate were similar in MS and control rats. The acute pressor response to ang II was not different in anesthetized MS and control rats. However, the chronic infusion of ang II (65 ng/day, s.c.) elicited an exaggerated hypertensive response in MS compared to control rats (p<0.05). Surprisingly, HR was dramatically increased during the second week of ang II infusion in MS compared with control rats (p<0.05). This enhanced ang II sensitivity was accompanied by a greater vascular inflammatory response in MS vs. control rats. Chronic ang II-infusion increased vascular wall structure in both groups similarly. These data indicate that early life stress sensitizes rats to an increased hemodynamic and inflammatory response during ang II-induced hypertension. PMID:20026758

  9. Autoimmunity in the pathogenesis of hypertension.

    PubMed

    Rodríguez-Iturbe, Bernardo; Pons, Héctor; Quiroz, Yasmir; Lanaspa, Miguel A; Johnson, Richard J

    2014-01-01

    Hypertension affects more than one-third of the adult population of the world. However, the cause of high blood pressure is unknown in the vast majority of patients, classified as patients with essential hypertension. Evidence accumulated over the past decade supports the participation of inflammation in the development of experimental hypertension. Investigations have also demonstrated that immune reactivity to overexpressed heat shock protein 70 (HSP70) is involved in the pathogenesis of salt-induced hypertension. This article reviews, first, the role of T cell-induced inflammation in the arteries, kidney and central nervous system in hypertension and the amelioration of hypertension induced by regulatory T cells. Second, experiments showing that autoimmunity directed to HSP70 in the kidney impairs the pressure natriuresis relationship and has a pivotal role in the pathogenesis of salt sensitive hypertension. Finally, we highlight the clinical evidence that supports the participation of autoimmunity in essential hypertension. PMID:24247285

  10. Alterations of N-3 Polyunsaturated Fatty Acid-Activated K2P Channels in Hypoxia-Induced Pulmonary Hypertension

    PubMed Central

    Nielsen, Gorm; Wandall-Frostholm, Christine; Sadda, Veeranjaneyulu; Oliván-Viguera, Aida; Lloyd, Eric E.; Bryan, Robert M.; Simonsen, Ulf; Köhler, Ralf

    2013-01-01

    Polyunsaturated fatty acid (PUFA)-activated two-pore domain potassium channels (K2P) have been proposed to be expressed in the pulmonary vasculature. However, their physiological or pathophysiological roles are poorly defined. Here we tested the hypothesis that PUFA-activated K2P are involved in pulmonary vasorelaxation and that alterations of channel expression are pathophysiologically linked to pulmonary hypertension. Expression of PUFA-activated K2P in the murine lung was investigated by quantitative reverse-transcription polymerase chain reaction (qRT-PCR), immunohistochemistry (IHC), by patch clamp (PC), and myography. K2P-gene expression was examined in chronic hypoxic mice. QRT-PCR showed that the K2P2.1 and K2P6.1 were the predominantly expressed K2P in the murine lung. IHC revealed protein expression of K2P2.1 and K2P6.1 in the endothelium of pulmonary arteries and of K2P6.1 in bronchial epithelium. PC showed pimozide-sensitive K2P-like K+-current activated by docosahexaenoic acid (DHA) in freshly isolated endothelial cells as well as DHA-induced membrane hyperpolarization. Myography on pulmonary arteries showed that DHA-induced concentration-dependent and instantaneous relaxations that were resistant to endothelial removal and inhibition of NO and prostacyclin synthesis and to a cocktail of blockers of calcium-activated K+ channels but were abolished by high extracellular (30 mM) K+-concentration. Gene expression and protein of K2P2.1 were not altered in chronic hypoxic mice while K2P6.1 was up-regulated by fourfold. In conclusion, the PUFA-activated K2P2.1 and K2P6.1 are expressed in murine lung and functional K2P-like channels contribute to endothelium-hyperpolarization and pulmonary artery relaxation. The increased K2P6.1-gene expression may represent a novel counter-regulatory mechanism in pulmonary hypertension, and suggest that arterial K2P2.1 and K2P6.1 could be novel therapeutic targets. PMID:23724868

  11. Fimasartan, anti-hypertension drug, suppressed inducible nitric oxide synthase expressions via nuclear factor-kappa B and activator protein-1 inactivation.

    PubMed

    Ryu, Suran; Shin, Ji-Sun; Cho, Young-Wuk; Kim, Hyoung Kook; Paik, Soo Heui; Lee, Joo Han; Chi, Yong Ha; Kim, Ji Han; Kim, Je Hak; Lee, Kyung-Tae

    2013-01-01

    Since inhibition of angiotensin II type 1 (AT1) receptor reduces chronic inflammation associated with hypertension, we evaluated the anti-inflammatory potential and the underlying mechanism of fimasartan, a Korean Food and Drug Administration approved anti-hypertension drug, in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Fimasartan suppressed the expressions of inducible nitric oxide synthase (iNOS) by down-regulating its transcription, and subsequently inhibited the productions of nitric oxide (NO). In addition, fimasartan attenuated LPS-induced transcriptional and DNA-binding activities of nuclear factor-kappa B (NF-?B) and activator protein-1 (AP-1). These reductions were accompanied by parallel reductions in the nuclear translocation of NF-?B and AP-1. Taken together, our data suggest that fimasartan down-regulates the expression of the iNOS in macrophages via NF-?B and AP-1 inactivation. PMID:23449332

  12. Comparison of the protective effects of desferrioxamine and ICRF-187 against doxorubicin-induced toxicity in spontaneously hypertensive rats.

    PubMed

    Herman, E H; Zhang, J; Ferrans, V J

    1994-01-01

    Since the iron-mediated formation of free radicals is considered to be a critical factor in the pathogenesis of the toxicity of doxorubicin (DXR), comparisons were made of the protective effects of two iron chelators, ICRF-187 and desferrioxamine (DFO), against the chronic cardiac and renal toxicity induced by DXR in spontaneously hypertensive rats (SHR). Two preparations of DFO were studied: DFO mesylate (DFO-M) and a polymeric form (DFO-P) in which DFO is conjugated to hydroxyethyl starch. Groups of 5 SHR each were given 12 weekly i.v. injections of 1 mg/kg DXR either alone or 30 min after the i.p. injection of 25 mg/kg ICRF-187, 50 mg/kg DFO-M, 50 mg/kg DFO-P, or 100 mg/kg DFO-P. A semiquantitative assessment was made of the cardiomyopathy (Billingham scale) and nephropathy. Renal protection was minimal with DFO-M and moderate with ICRF-187 and both doses of DFO-P. There was no cardiac protection with DFO-M. Both doses of DFO-P provided similar but modest degrees of cardiac protection. DXR-induced mortality was not prevented by either preparation of DFO. ICRF-187 provided a higher degree of protection against the cardiotoxicity and the mortality induced by DXR. Since both DFO and ICRF-187 are highly efficient chelators of iron in vitro, the differences in their in vivo protective effects are thought to be related to their cellular uptake and intracellular distribution and to the relative availability of different intracellular iron pools to these agents. PMID:7987999

  13. Salt-induced nephropathy in obese spontaneously hypertensive rats via paradoxical activation of the mineralocorticoid receptor: role of oxidative stress.

    PubMed

    Nagase, Miki; Matsui, Hiromitsu; Shibata, Shigeru; Gotoda, Takanari; Fujita, Toshiro

    2007-11-01

    Aldosterone is implicated in the pathogenesis of proteinuria and chronic kidney disease. We previously demonstrated the contribution of elevated serum aldosterone in the early nephropathy of SHR/NDmcr-cp (SHR/cp), a rat model of metabolic syndrome. In the present study, we investigated the effect of salt loading on renal damage in SHR/cps and explored the underlying mechanisms. SHR/cps fed a high-sodium diet for 4 weeks developed severe hypertension, massive proteinuria, and advanced renal lesions. High salt also worsened glomerular podocyte impairment. Surprisingly, selective mineralocorticoid receptor (MR) antagonist eplerenone dramatically ameliorated the salt-induced proteinuria and renal injury in SHR/cps. Although salt loading reduced circulating aldosterone, it increased nuclear MR and expression of aldosterone effector kinase Sgk1 in the kidney. Gene expressions of transforming growth factor-beta1 and plasminogen activator inhibitor-1 were also enhanced in the kidneys of salt-loaded SHR/cps, and eplerenone completely inhibited these injury markers. To clarify the discrepancy between decreased aldosterone and enhanced MR signaling by salt, we further investigated the role of oxidative stress, a putative key factor mediating salt-induced tissue damage. Interestingly, antioxidant Tempol attenuated the salt-evoked MR upregulation and Sgk1 induction and alleviated proteinuria and renal histological abnormalities, suggesting the involvement of oxidative stress in salt-induced MR activation. MR activation by salt was not attributed to increased serum corticosterone or reduced 11beta-hydroxysteroid dehydrogenase type 2 activity. In conclusion, sodium loading exacerbated proteinuria and renal injury in metabolic syndrome rats. Salt reduced circulating aldosterone but caused renal MR activation at least partially via induction of oxidative stress, and eplerenone effectively improved the nephropathy. PMID:17875821

  14. Therapeutic Efficacy of AAV1.SERCA2a in Monocrotaline-Induced Pulmonary Arterial Hypertension

    PubMed Central

    Hadri, Lahouaria; Kratlian, Razmig G.; Benard, Ludovic; Maron, Bradley A.; Dorfmüller, Peter; Ladage, Dennis; Guignabert, Christophe; Ishikawa, Kiyotake; Aguero, Jaume; Ibanez, Borja; Turnbull, Irene C.; Kohlbrenner, Erik; Liang, Lifan; Zsebo, Krisztina; Humbert, Marc; Hulot, Jean-Sébastien; Kawase, Yoshiaki; Hajjar, Roger J.; Leopold, Jane A.

    2014-01-01

    Background Pulmonary arterial hypertension (PAH) is characterized by dysregulated proliferation of pulmonary artery smooth muscle cells leading to (mal)adaptive vascular remodeling. In the systemic circulation, vascular injury is associated with downregulation of sarcoplasmic reticulum Ca2+-ATPase 2a (SERCA2a) and alterations in Ca2+ homeostasis in vascular smooth muscle cells that stimulate proliferation. We, therefore, hypothesized that downregulation of SERCA2a is permissive for pulmonary vascular remodeling and the development of PAH. Methods and Results SERCA2a expression was decreased significantly in remodeled pulmonary arteries from patients with PAH and the rat monocrotaline model of PAH in comparison with controls. In human pulmonary artery smooth muscle cells in vitro, SERCA2a overexpression by gene transfer decreased proliferation and migration significantly by inhibiting NFAT/STAT3. Overexpresion of SERCA2a in human pulmonary artery endothelial cells in vitro increased endothelial nitric oxide synthase expression and activation. In monocrotaline rats with established PAH, gene transfer of SERCA2a via intratracheal delivery of aerosolized adeno-associated virus serotype 1 (AAV1) carrying the human SERCA2a gene (AAV1.SERCA2a) decreased pulmonary artery pressure, vascular remodeling, right ventricular hypertrophy, and fibrosis in comparison with monocrotaline-PAH rats treated with a control AAV1 carrying ?-galactosidase or saline. In a prevention protocol, aerosolized AAV1.SERCA2a delivered at the time of monocrotaline administration limited adverse hemodynamic profiles and indices of pulmonary and cardiac remodeling in comparison with rats administered AAV1 carrying ?-galactosidase or saline. Conclusions Downregulation of SERCA2a plays a critical role in modulating the vascular and right ventricular pathophenotype associated with PAH. Selective pulmonary SERCA2a gene transfer may offer benefit as a therapeutic intervention in PAH. PMID:23804254

  15. Mechanisms in the PVN mediating local and central sodium-induced hypertension in Wistar rats.

    PubMed

    Gabor, Alexander; Leenen, Frans H H

    2009-03-01

    Sympathoexcitatory and hypertensive responses to central infusion of Na(+)-rich artificial cerebrospinal fluid (aCSF) are enhanced by aldosterone and mediated by mineralocorticoid receptors (MRs) and benzamil-blockable Na(+) influx, leading to "ouabain" release and ANG II type 1 (AT(1)) receptor stimulation. The present study evaluated the functional role of these mechanisms in the paraventricular nucleus (PVN). In conscious Wistar rats, Na(+)-rich aCSF was infused either directly into the PVN or intracerebroventricularly preceded by aldosterone and blockers. Infusion of Na(+)-rich aCSF in the PVN caused gradual increases in blood pressure (BP) and heart rate (HR). Aldosterone and a subpressor dose of ouabain in the PVN alone did not affect BP and HR but enhanced responses to Na(+). Eplerenone, benzamil, and "ouabain"-binding Fab fragments only blocked the enhancement by aldosterone, whereas losartan blocked all responses to Na(+)-rich aCSF in the PVN. Increases in BP and HR by intracerebroventricular infusion of Na(+)-rich aCSF were enhanced by aldosterone infused intracerebroventricularly, but not in the PVN. Telmisartan in the PVN again blocked all responses. In contrast, both eplerenone and benzamil in the PVN did not change the pressor responses to intracerebroventricular infusion of aldosterone and Na(+)-rich aCSF. These findings indicate that AT(1) receptors in the PVN mediate the responses to Na(+)-rich aCSF and their enhancement by aldosterone, both locally in the PVN or in the general CSF. MRs, benzamil-blockable Na(+) channels or transporters, and "ouabain" can be functionally active in the PVN, but in Wistar rats appear not to contribute to the pressor responses to short-term increases in CSF [Na(+)]. PMID:19109373

  16. The genetic deletion of Mas abolishes salt induced hypertension in mice.

    PubMed

    Heringer-Walther, Silvia; Gembardt, Florian; Perschel, Frank Holger; Katz, Norbert; Schultheiss, Heinz-Peter; Walther, Thomas

    2012-08-15

    The G protein-coupled receptor Mas is a physiological antagonist of the angiotensin II type 1 receptor and is associated with angiotensin-(1-7) signaling. We investigated the effect of Mas-deficiency on blood pressure regulation under physiological conditions and salt load using radiotelemetry. Mas-knockout mice and their wild-type controls received a telemetry implant in the carotid artery. One week after surgery, animals were monitored for 3 days receiving normal diet (0.6% NaCl) followed by one-week high-salt diet (8% NaCl). Under same high-salt diet, another set of mice was placed in individual metabolic cages for 4 days. Basal mean arterial pressure, heart rate and locomotor activity displayed normal day-night rhythm in Mas-deficient mice. Mas-knockout mice were normotensive. High dietary NaCl ingestion did not alter heart rate or locomotor activity in both groups, but significantly increased night time mean arterial pressure in control mice whereas this increase was blunted in Mas-deficient mice. Baseline food and water intake and urine osmolality were not different between both genotypes. Under high-salt diet, water consumption and food intake were equally increased in wild-type controls and Mas-knockout, but urinary electrolytes and osmolality were significantly higher in Mas-knockout. Taken together, basal hemodynamic parameters are unchanged in Mas-knockout mice. In contrast to wild-type controls, telemetric mean arterial pressure measurement revealed salt resistance in Mas-deficient animals, probably due to their higher urinary NaCl excretion. This is the first direct proof that Mas blockade might be a new option in the treatment of salt-sensitive hypertension. PMID:22652430

  17. Chronic N(G)-nitro-L-arginine methyl ester-induced hypertension : novel molecular adaptation to systolic load in absence of hypertrophy

    NASA Technical Reports Server (NTRS)

    Bartunek, J.; Weinberg, E. O.; Tajima, M.; Rohrbach, S.; Katz, S. E.; Douglas, P. S.; Lorell, B. H.; Schneider, M. (Principal Investigator)

    2000-01-01

    BACKGROUND: Chronic N(G)-nitro-L-arginine methyl ester (L-NAME), which inhibits nitric oxide synthesis, causes hypertension and would therefore be expected to induce robust cardiac hypertrophy. However, L-NAME has negative metabolic effects on protein synthesis that suppress the increase in left ventricular (LV) mass in response to sustained pressure overload. In the present study, we used L-NAME-induced hypertension to test the hypothesis that adaptation to pressure overload occurs even when hypertrophy is suppressed. METHODS AND RESULTS: Male rats received L-NAME (50 mg. kg(-1). d(-1)) or no drug for 6 weeks. Rats with L-NAME-induced hypertension had levels of systolic wall stress similar to those of rats with aortic stenosis (85+/-19 versus 92+/-16 kdyne/cm). Rats with aortic stenosis developed a nearly 2-fold increase in LV mass compared with controls. In contrast, in the L-NAME rats, no increase in LV mass (1. 00+/-0.03 versus 1.04+/-0.04 g) or hypertrophy of isolated myocytes occurred (3586+/-129 versus 3756+/-135 microm(2)) compared with controls. Nevertheless, chronic pressure overload was not accompanied by the development of heart failure. LV systolic performance was maintained by mechanisms of concentric remodeling (decrease of in vivo LV chamber dimension relative to wall thickness) and augmented myocardial calcium-dependent contractile reserve associated with preserved expression of alpha- and beta-myosin heavy chain isoforms and sarcoplasmic reticulum Ca(2+) ATPase (SERCA-2). CONCLUSIONS: When the expected compensatory hypertrophic response is suppressed during L-NAME-induced hypertension, severe chronic pressure overload is associated with a successful adaptation to maintain systolic performance; this adaptation depends on both LV remodeling and enhanced contractility in response to calcium.

  18. Candidate genes in quantitative trait loci associated with absolute and relative kidney weight in rats with Inherited Stress Induced Arterial Hypertension

    PubMed Central

    2015-01-01

    Background The kidney mass is significantly increased in hypertensive ISIAH rats with Inherited Stress Induced Arterial Hypertension as compared with normotensive WAG rats. The QTL/microarray approach was carried out to determine the positional candidate genes in the QTL for absolute and relative kidney weight. Results Several known and predicted genes differentially expressed in ISIAH and WAG kidney were mapped to genetic loci associated with the absolute and relative kidney weight in 6-month old F2 hybrid (ISIAHxWAG) males. The knowledge-driven filtering of the list of candidates helped to suggest several positional candidate genes, which may be related to the structural and mass changes in hypertensive ISIAH kidney. In the current study, we showed that all loci found for absolute and relative kidney weight didn't overlap with significant or suggestive loci for arterial blood pressure level. So, the genes differentially expressed in ISIAH and WAG kidneys and located in these QTL regions associated with absolute and relative kidney weight shouldn't substantially influence the BP level in the 6 month-old ISIAH rats. However, in some cases, small effects may be suggested. Conclusions The further experimental validation of causative genes and detection of polymorphisms will provide opportunities to advance our understanding of the underlying nature of structural and mass changes in hypertensive ISIAH kidney. PMID:25707311

  19. Thioredoxins 1 and 2 protect retinal ganglion cells from pharmacologically induced oxidative stress, optic nerve transection and ocular hypertension.

    PubMed

    Munemasa, Yasunari; Kwong, Jacky M K; Kim, Seok H; Ahn, Jae H; Caprioli, Joseph; Piri, Natik

    2010-01-01

    Oxidative damage has been implicated in retinal ganglion cell (RGC) death after optic nerve transection (ONT) and during glaucomatous neuropathy. Here, we analyzed the expression and cell protective role of thioredoxins (TRX), key regulators of the cellular redox state, in RGCs damaged by pharmacologically induced oxidative stress, ONT and elevated intraocular pressure (IOP). The endogenous level of thioredoxin-1 (TRX1) and thioredoxin-2 (TRX2) in RGCs after axotomy and in RGC-5 cells after glutamate/buthionine sulfoximine (BSO) treatment showed upregulation of TRX2, whereas no significant change was observed in TRX1 expression. The increased level TRX-interacting protein (TXNIP) in the retinas was observed 2 and 5 weeks after IOP elevation. TRX1 level was decreased at 2 weeks and more prominently at 5 weeks after IOP increase. No change in TRX2 levels in response to IOP change was observed. Overexpression of TRX1 and TRX2 in RGC-5 treated with glutamate/BSO increased the cell survival by 2- and 3-fold 24 and 48 h after treatment, respectively. Overexpression of these proteins in the retina increased the survival of RGCs by 35 and 135% 7 and 14 days after ONT, respectively. In hypertensive eyes, RGC loss was approximately 27% 5 weeks after IOP elevation compared to control. TRX1 and TRX2 overexpression preserved approximately 45 and 37% of RGCs, respectively, that were destined to die due to IOP increase. PMID:20238036

  20. 20-HETE and furosemide-induced natriuresis in salt-sensitive essential hypertension.

    PubMed

    Laffer, Cheryl L; Laniado-Schwartzman, Michal; Wang, Mong-Heng; Nasjletti, Alberto; Elijovich, Fernando

    2003-03-01

    Cyclooxygenase metabolites of arachidonic acid modulate the natriuretic effect of furosemide. It is not known whether 20-HETE, a monooxygenase metabolite of arachidonic acid that also inhibits sodium transport, participates in the action of furosemide. We measured urine sodium (UNaV) and 20-HETE during furosemide diuresis (40 mg three times over 12 hours) in 12 salt-sensitive (SS) and 11 salt-resistant (SR), salt-replete hypertensive subjects (126+/-24 mmol/24 hours positive sodium balance produced by 160-mmol-sodium diet and 2 L saline infusion). Individual systolic blood pressure decreases from the salt-replete to the salt-depleted state were the index of salt-sensitivity. SS had low plasma renin with blunted responses to changes in salt balance, inappropriate plasma aldosterone, and an increased aldosterone/renin ratio. UNaV by furosemide was less in SS (263+/-25 mmol/12 hours) than in SR (351+/-25 mmol/12 hours, P<0.02) patients. 20-HETE was not different between SS and SR patients before (1.92+/-0.38 versus 1.37+/-0.34 microg/h) or after furosemide (1.52+/-0.27 versus 2.01+/-0.40 microg/h), but furosemide changed 20-HETE excretion in opposite direction in SR (0.63+/-0.26) versus SS (-0.40+/-0.17, P<0.005) patients. In all patients together, %Delta20-HETE by furosemide correlated with %DeltaUNaV (r=0.56, P<0.01) and negatively with salt-sensitivity of blood pressure (r=-0.55, P<0.01). In SS, Delta20-HETE by furosemide correlated with Deltaaldosterone/renin ratio (r=0.60, P<0.05), whereas 20-HETE during furosemide had a negative correlation with body mass index (r=-0.73, P<0.01). Our data suggest that 20-HETE modulates the natriuretic response to furosemide, and impaired natriuresis of SS involves a mechanism that alters the 20-HETE response to furosemide and is linked to salt-sensitivity of blood pressure. PMID:12623983

  1. Mineralocorticoid hypertension

    PubMed Central

    Gupta, Vishal

    2011-01-01

    Hypertension affects about 10 – 25% of the population and is an important risk factor for cardiovascular and renal disease. The renin-angiotensin system is frequently implicated in the pathophysiology of hypertension, be it primary or secondary. The prevalence of primary aldosteronism increases with the severity of hypertension, from 2% in patients with grade 1 hypertension to 20% among resistant hypertensives. Mineralcorticoid hypertension includes a spectrum of disorders ranging from renin-producing pathologies (renin-secreting tumors, malignant hypertension, coarctation of aorta), aldosterone-producing pathologies (primary aldosteronism – Conns syndrome, familial hyperaldosteronism 1, 2, and 3), non-aldosterone mineralocorticoid producing pathologies (apparent mineralocorticoid excess syndrome, Liddle syndrome, deoxycorticosterone-secreting tumors, ectopic adrenocorticotropic hormones (ACTH) syndrome, congenitalvadrenal hyperplasia), and drugs with mineraocorticoid activity (locorice, carbenoxole therapy) to glucocorticoid receptor resistance syndromes. Clinical presentation includes hypertension with varying severity, hypokalemia, and alkalosis. Ratio of plasma aldosterone concentraion to plasma renin activity remains the best screening tool. Bilateral adrenal venous sampling is the best diagnostic test coupled with a CT scan. Treatment is either surgical (adrenelectomy) for unilateral adrenal disease versus medical therapy for idiopathic, ambiguous, or bilateral disease. Medical therapy focuses on blood pressure control and correction of hypokalemia using a combination of anti-hypertensives (calcium channel blockers, angiotensin converting enzyme inhibitors, or angiotensin receptor blockers) and potassium-raising therapies (mineralcorticoid receptor antagonist or potassium sparing diuretics). Direct aldosterone synthetase antagonists represent a promising future therapy. PMID:22145132

  2. SPONTANEOUSLY HYPERTENSIVE RATS ARE SUSCEPTIBLE TO AIRWAY DISEASE INDUCED BY SULFUR DIOXIDE

    EPA Science Inventory

    Rodent models of chronic pulmonary diseases induced by sulfur dioxide (SO2), elastase or tobacco smoke have limited utility because of their lack of chronicity of inflammation, and they demonstrate limited sensitivity to a given experimental manipulation. We hypothesized that dis...

  3. Rats with adenine-induced chronic renal failure develop low-renin, salt-sensitive hypertension and increased aortic stiffness.

    PubMed

    Nguy, Lisa; Johansson, Maria E; Grimberg, Elisabeth; Lundgren, Jaana; Teerlink, Tom; Carlström, Mattias; Lundberg, Jon O; Nilsson, Holger; Guron, Gregor

    2013-05-01

    Rats with adenine-induced chronic renal failure (A-CRF) develop metabolic and cardiovascular abnormalities resembling those in patients with chronic kidney disease. The aim of this study was to investigate the mechanisms of hypertension in this model and to assess aortic stiffness in vivo. Male Sprague-Dawley rats were equipped with radiotelemetry probes for arterial pressure recordings and received either chow containing adenine or normal control diet. At 7 to 11 wk after study start, blood pressure responses to high NaCl (4%) diet and different pharmacological interventions were analyzed. Aortic pulse wave velocity was measured under isoflurane anesthesia. Baseline 24-h mean arterial pressure (MAP) was 101 ± 10 and 119 ± 9 mmHg in controls and A-CRF animals, respectively (P < 0.01). After 5 days of a high-NaCl diet, MAP had increased by 24 ± 6 mmHg in A-CRF animals vs. 2 ± 1 mmHg in controls (P < 0.001). Candesartan (10 mg/kg by gavage) produced a more pronounced reduction of MAP in controls vs. A-CRF animals (-12 ± 3 vs. -5 ± 5 mmHg, P < 0.05). Aortic pulse wave velocity was elevated in A-CRF rats (5.10 ± 0.51 vs. 4.58 ± 0.17 m/s, P < 0.05). Plasma levels of creatinine were markedly elevated in A-CRF animals (259 ± 46 vs. 31 ± 2 ?M, P < 0.001), whereas plasma renin activity was suppressed (0.6 ± 0.5 vs. 12.3 ± 7.3 ?g·l(-1)·h(-1), P < 0.001). In conclusion, hypertension in A-CRF animals is characterized by low plasma renin activity and is aggravated by high-NaCl diet, suggesting a pathogenic role for sodium retention and hypervolemia probably secondary to renal insufficiency. Additionally, aortic stiffness was elevated in A-CRF animals as indicated by increased aortic pulse wave velocity. PMID:23515616

  4. An increase in adenosine-5’-triphosphate (ATP) content in rostral ventrolateral medulla is engaged in the high fructose diet-induced hypertension

    PubMed Central

    2014-01-01

    Background The increase in fructose ingestion has been linked to overdrive of sympathetic activity and hypertension associated with the metabolic syndrome. The premotor neurons for generation of sympathetic vasomotor activity reside in the rostral ventrolateral medulla (RVLM). Activation of RVLM results in sympathoexcitation and hypertension. Neurons in the central nervous system are able to utilize fructose as a carbon source of ATP production. We examined in this study whether fructose affects ATP content in RVLM and its significance in the increase in central sympathetic outflow and hypertension induced by the high fructose diet (HFD). Results In normotensive rats fed with high fructose diet (HFD) for 12 weeks, there was a significant increase in tissue ATP content in RVLM, accompanied by the increases in the sympathetic vasomotor activity and blood pressure. These changes were blunted by intracisternal infusion of an ATP synthase inhibitor, oligomycin, to the HFD-fed animals. In the catecholaminergic-containing N2a cells, fructose dose-dependently upregulated the expressions of glucose transporter 2 and 5 (GluT2, 5) and the rate-limiting enzyme of fructolysis, ketohexokinase (KHK), leading to the increases in pyruvate and ATP production, as well as the release of the neurotransmitter, dopamine. These cellular events were significantly prevented after the gene knocking down by lentiviral transfection of small hairpin RNA against KHK. Conclusion These results suggest that increases in ATP content in RVLM may be engaged in the augmented sympathetic vasomotor activity and hypertension associated with the metabolic syndrome induced by the HFD. At cellular level, the increase in pyruvate levels via fructolysis is involved in the fructose-induced ATP production and the release of neurotransmitter. PMID:24467657

  5. Vascular cytochrome P450 4A expression and 20-hydroxyeicosatetraenoic acid synthesis contribute to endothelial dysfunction in androgen-induced hypertension.

    PubMed

    Singh, Harpreet; Cheng, Jennifer; Deng, Huan; Kemp, Rowena; Ishizuka, Tsuneo; Nasjletti, Alberto; Schwartzman, Michal Laniado

    2007-07-01

    Epidemiological evidence suggests a role for sex-dependent mechanisms in the pathophysiology of hypertension. It has been shown that 5alpha-dihydrotestosterone (DHT) administration (56 mg/kg of body weight per day IP for 14 days) increases blood pressure, cytochrome P450 4A expression, and 20-hydroxyeicosatetraenoic acid synthesis in rats. We examined whether increased vascular 20-hydroxyeicosatetraenoic acid synthesis underlies endothelial dysfunction and hypertension in DHT-treated male Sprague-Dawley rats by using HET0016, a selective cytochrome P450 4A inhibitor. Coadministration of HET0016 (10 mg/kg per day IP for 14 days) to DHT-treated rats markedly reduced DHT-induced interlobar arterial production of 20-hydroxyeicosatetraenoic acid (14.3+/-1.5 versus 1.5+/-0.5 ng/mg of protein per hour; P<0.05), superoxide anion (246+/-47 versus 31+/-8 cpm/microg of protein), and the levels of gp91-phox, p47-phox, and 3-nitrosylated proteins. Moreover, the maximal relaxing response to acetylcholine in phenylephrine-preconstricted renal interlobar arteries from DHT-treated rats (42.8+/-4.8%) significantly (P<0.05) increased in the presence of HET0016 (81.5+/-10.8%). Importantly, the administration of HET0016 negated DHT-induced hypertension; systolic blood pressure was reduced from 146+/-2 mm Hg in DHT-treated rats to 130+/-1 mm Hg (P<0.05). The results strongly implicate vascular cytochrome P450 4A-derived 20-hydroxyeicosatetraenoic acid in the development of androgen-induced endothelial dysfunction and hypertension. PMID:17548721

  6. Common noncoding UMOD gene variants induce salt-sensitive hypertension and kidney damage by increasing uromodulin expression.

    PubMed

    Trudu, Matteo; Janas, Sylvie; Lanzani, Chiara; Debaix, Huguette; Schaeffer, Céline; Ikehata, Masami; Citterio, Lorena; Demaretz, Sylvie; Trevisani, Francesco; Ristagno, Giuseppe; Glaudemans, Bob; Laghmani, Kamel; Dell'Antonio, Giacomo; Loffing, Johannes; Rastaldi, Maria P; Manunta, Paolo; Devuyst, Olivier; Rampoldi, Luca

    2013-12-01

    Hypertension and chronic kidney disease (CKD) are complex traits representing major global health problems. Multiple genome-wide association studies have identified common variants in the promoter of the UMOD gene, which encodes uromodulin, the major protein secreted in normal urine, that cause independent susceptibility to CKD and hypertension. Despite compelling genetic evidence for the association between UMOD risk variants and disease susceptibility in the general population, the underlying biological mechanism is not understood. Here, we demonstrate that UMOD risk variants increased UMOD expression in vitro and in vivo. Uromodulin overexpression in transgenic mice led to salt-sensitive hypertension and to the presence of age-dependent renal lesions similar to those observed in elderly individuals homozygous for UMOD promoter risk variants. The link between uromodulin and hypertension is due to activation of the renal sodium cotransporter NKCC2. We demonstrated the relevance of this mechanism in humans by showing that pharmacological inhibition of NKCC2 was more effective in lowering blood pressure in hypertensive patients who are homozygous for UMOD promoter risk variants than in other hypertensive patients. Our findings link genetic susceptibility to hypertension and CKD to the level of uromodulin expression and uromodulin's effect on salt reabsorption in the kidney. These findings point to uromodulin as a therapeutic target for lowering blood pressure and preserving renal function. PMID:24185693

  7. Group B streptococcal phospholipid causes pulmonary hypertension

    NASA Astrophysics Data System (ADS)

    Curtis, Jerri; Kim, Geumsoo; Wehr, Nancy B.; Levine, Rodney L.

    2003-04-01

    Group B Streptococcus is the most common cause of bacterial infection in the newborn. Infection in many cases causes persistent pulmonary hypertension, which impairs gas exchange in the lung. We purified the bacterial components causing pulmonary hypertension and identified them as cardiolipin and phosphatidylglycerol. Synthetic cardiolipin or phosphatidylglycerol also induced pulmonary hypertension in lambs. The recognition that bacterial phospholipids may cause pulmonary hypertension in newborns with Group B streptococcal infection opens new avenues for therapeutic intervention.

  8. PARP-Inhibitor Treatment Prevents Hypertension Induced Cardiac Remodeling by Favorable Modulation of Heat Shock Proteins, Akt-1/GSK-3? and Several PKC Isoforms

    PubMed Central

    Deres, Laszlo; Bartha, Eva; Palfi, Anita; Eros, Krisztian; Riba, Adam; Lantos, Janos; Kalai, Tamas; Hideg, Kalman; Sumegi, Balazs; Gallyas, Ferenc; Toth, Kalman; Halmosi, Robert

    2014-01-01

    Spontaneously hypertensive rat (SHR) is a suitable model for studies of the complications of hypertension. It is known that activation of poly(ADP-ribose) polymerase enzyme (PARP) plays an important role in the development of postinfarction as well as long-term hypertension induced heart failure. In this study, we examined whether PARP-inhibitor (L-2286) treatment could prevent the development of hypertensive cardiopathy in SHRs. 6-week-old SHR animals were treated with L-2286 (SHR-L group) or placebo (SHR-C group) for 24 weeks. Wistar-Kyoto rats were used as aged-matched, normotensive controls (WKY group). Echocardiography was performed, brain-derived natriuretic peptide (BNP) activity and blood pressure were determined at the end of the study. We detected the extent of fibrotic areas. The amount of heat-shock proteins (Hsps) and the phosphorylation state of Akt-1Ser473, glycogen synthase kinase (GSK)-3?Ser9, forkhead transcription factor (FKHR)Ser256, mitogen activated protein kinases (MAPKs), and protein kinase C (PKC) isoenzymes were monitored. The elevated blood pressure in SHRs was not influenced by PARP-inhibitor treatment. Systolic left ventricular function and BNP activity did not differ among the three groups. L-2286 treatment decreased the marked left ventricular (LV) hypertrophy which was developed in SHRs. Interstitial collagen deposition was also decreased by L-2286 treatment. The phosphorylation of extracellular signal-regulated kinase (ERK)1/2Thr183-Tyr185, Akt-1Ser473, GSK-3?Ser9, FKHRSer256, and PKC ?Ser729 and the level of Hsp90 were increased, while the activity of PKC ?/?IIThr638/641, ?/?410/403 were mitigated by L-2286 administration. We could detect signs of LV hypertrophy without congestive heart failure in SHR groups. This alteration was prevented by PARP inhibition. Our results suggest that PARP-inhibitor treatment has protective effect already in the early stage of hypertensive myocardial remodeling. PMID:25014216

  9. Reactive Oxygen Species-Reducing Strategies Improve Pulmonary Arterial Responses to Nitric Oxide in Piglets with Chronic Hypoxia-Induced Pulmonary Hypertension

    PubMed Central

    Dikalova, Anna; Slaughter, James C.; Kaplowitz, M.R.; Zhang, Y.; Aschner, Judy L.

    2013-01-01

    Abstract Aims: There are no effective treatments for chronic pulmonary hypertension in infants with cardiopulmonary disorders associated with hypoxia, such as those with chronic lung disease. These patients often have poor or inconsistent pulmonary dilator responses to inhaled nitric oxide (iNO) therapy for unknown reasons. One possible explanation for poor responsiveness to iNO is reduced NO bioavailability caused by interactions between reactive oxygen species (ROS) and NO. Our major aim was to determine if strategies to reduce ROS improve dilator responses to the NO donor, S-nitroso-N-acetyl-penicillamine (SNAP), in resistance pulmonary arteries (PRAs) from a newborn piglet model of chronic pulmonary hypertension. Results: The dilation to SNAP was significantly impaired in PRAs from piglets with chronic hypoxia-induced pulmonary hypertension. ROS scavengers, including cell-permeable and impermeable agents to degrade hydrogen peroxide (H2O2), improved dilation to SNAP in PRAs from chronically hypoxic piglets. Treatment with agents to inhibit nitric oxide synthase and NADPH oxidase, potential enzymatic sources of ROS, also improved dilation to SNAP in PRAs from hypoxic piglets. Innovation: Our studies are the first to utilize a newborn model of chronic pulmonary hypertension to evaluate the impact of a number of potential therapeutic strategies for ROS removal on responses to exogenous NO in the vessels most relevant to the regulation of pulmonary vascular resistance (PRA). Conclusions: Strategies aimed at reducing ROS merit further evaluation and consideration as therapeutic approaches to improve responses to iNO in infants with chronic pulmonary hypertension. Antioxid. Redox Signal. 18, 1727–1738. PMID:23244497

  10. Chronic infusion of enalaprilat into hypothalamic paraventricular nucleus attenuates angiotensin II-induced hypertension and cardiac hypertrophy by restoring neurotransmitters and cytokines

    SciTech Connect

    Kang, Yu-Ming, E-mail: ykang@mail.xjtu.edu.cn [Department of Physiology and Pathophysiology, Xi'an Jiaotong University Cardiovascular Research Center, Xi'an Jiaotong University School of Medicine, Xi'an 710061 (China); Zhang, Dong-Mei [Department of Physiology, Dalian Medical University, Dalian 116044 (China); Yu, Xiao-Jing; Yang, Qing; Qi, Jie; Su, Qing [Department of Physiology and Pathophysiology, Xi'an Jiaotong University Cardiovascular Research Center, Xi'an Jiaotong University School of Medicine, Xi'an 710061 (China); Suo, Yu-Ping [Department of Obstetrics and Gynecology, Shanxi Provincial People's Hospital, Taiyuan 030012 (China); Yue, Li-Ying [Department of Physiology and Pathophysiology, Xi'an Jiaotong University Cardiovascular Research Center, Xi'an Jiaotong University School of Medicine, Xi'an 710061 (China); Zhu, Guo-Qing [Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029 (China); Qin, Da-Nian, E-mail: dnqin@stu.edu.cn [Department of Physiology, Shantou University Medical College, Shantou 515041 (China)

    2014-02-01

    The renin–angiotensin system (RAS) in the brain is involved in the pathogenesis of hypertension. We hypothesized that inhibition of angiotensin-converting enzyme (ACE) in the hypothalamic paraventricular nucleus (PVN) attenuates angiotensin II (ANG II)-induced hypertension via restoring neurotransmitters and cytokines. Rats underwent subcutaneous infusions of ANG II or saline and bilateral PVN infusions of ACE inhibitor enalaprilat (ENL, 2.5 ?g/h) or vehicle for 4 weeks. ANG II infusion resulted in higher mean arterial pressure and cardiac hypertrophy as indicated by increased whole heart weight/body weight ratio, whole heart weight/tibia length ratio, left ventricular weight/tibia length ratio, and mRNA expressions of cardiac atrial natriuretic peptide and beta-myosin heavy chain. These ANG II-infused rats had higher PVN levels of glutamate, norepinephrine, tyrosine hydroxylase, pro-inflammatory cytokines (PICs) and the chemokine monocyte chemoattractant protein-1, and lower PVN levels of gamma-aminobutyric acid, interleukin (IL)-10 and the 67-kDa isoform of glutamate decarboxylase (GAD67), and higher plasma levels of PICs, norepinephrine and aldosterone, and lower plasma IL-10, and higher renal sympathetic nerve activity. However, PVN treatment with ENL attenuated these changes. PVN microinjection of ANG II induced increases in IL-1? and IL-6, and a decrease in IL-10 in the PVN, and pretreatment with angiotensin II type 1 receptor (AT1-R) antagonist losartan attenuated these changes. These findings suggest that ANG II infusion induces an imbalance between excitatory and inhibitory neurotransmitters and an imbalance between pro- and anti-inflammatory cytokines in the PVN, and PVN inhibition of the RAS restores neurotransmitters and cytokines in the PVN, thereby attenuating ANG II-induced hypertension and cardiac hypertrophy. - Highlights: • Chronic ANG II infusion results in sympathetic hyperactivity and cardiac hypertrophy. • PVN inhibition of ACE attenuates ANG II-induced hypertension and cardiac hypertrophy. • PVN inhibition of ACE attenuates ANG II-induced imbalance of PVN neurotransmitters. • PVN inhibition of ACE attenuates ANG II-induced imbalance of cytokines in the PVN. • PVN blockade of AT1-R attenuates ANG II-induced imbalance of cytokines in the PVN.

  11. Vanadyl Sulfate Prevents Fructose-Induced Hyperinsulinemia and Hypertension in Rats

    Microsoft Academic Search

    Sanjay Bhanot; John H. McNeill; Michael Bryer-Ash

    To determine whether insulin resistance and hy- perinsulinemia are causally related to fructose-induced hyper- tension, we used vanadyl sulfate, a drug that improves insulin sensitivity in rats. Chronic oral vanadyl treatment was initiated in 6-week-old male Sprague-Dawley rats. One week after vanadyl was started, rats were fed either normal rat chow or a fructose-enriched diet. Plasma glucose and insulin levels

  12. Systemic inhibition of nitric oxide and prostaglandins in volume-induced natriuresis and hypertension.

    PubMed

    Krier, J D; Romero, J C

    1998-01-01

    Nitric oxide (NO) synthesis inhibition with NG-nitro-L-arginine methyl ester (L-NAME) (10 micrograms.kg-1.min-1 i.v.), cyclooxygenase inhibition with meclofenamate (Meclo; 5 mg/kg i.v. bolus), and combination of drugs (L-NAME + Meclo) were used to investigate the roles of NO and prostaglandins (PG) in the hemodynamic and natriuretic responses to isotonic saline volume expansion (VE; 5% body wt over 60 min) in anesthetized dogs. Before VE, L-NAME (n = 6), Meclo (n = 6), and L-NAME + Meclo (n = 6) produced significant increments in mean arterial pressure (MAP) of 12 +/- 2, 15 +/- 3, and 17 +/- 3 mmHg, respectively. VE did not change MAP in Meclo-treated dogs, but produced a significant elevation in the control dogs (14 +/- 6 mmHg), in L-NAME-treated dogs (17 +/- 6 mmHg), and in dogs pretreated with L-NAME + Meclo (12 +/- 5 mmHg). VE alone induced marked natriuretic responses in the control (38 +/- 9 to 562 +/- 86 mumol/min), L-NAME (31 +/- 9 to 664 +/- 65 mumol/min), and Meclo groups (41 +/- 10 to 699 +/- 51 mumol/min). However, this natriuretic response was attenuated in dogs pretreated with L-NAME + Meclo (12 +/- 4 to 185 +/- 52 mumol/ min). These results indicate that 1) blockade of both NO and PGs has significant diminishing effects on volume-induced natriuresis, 2) NO blockade alone impairs volume-induced natriuresis in a manner that requires further increases in MAP to restore the natriuresis, and 3) PG blockade alone does not curtail volume-induced natriuresis. PMID:9458915

  13. Blood Pressure Interventions Affect Acute and Four-Week Diesel Exhaust Induced Pulmonary Injury in Healthy and Hypertensive Rats

    EPA Science Inventory

    Rationale: We recently showed that inhalation exposure of normotensive Wistar Kyoto (WKY) rats to whole diesel exhaust (DE) elicits changes in cardiac gene expression that broadly mimics expression in spontaneously hypertensive (SH) rats without DE. We hypothesized that pharmacol...

  14. A pivotal role of the vascular endothelial growth factor signaling pathway in the formation of venous hypertension-induced dural arteriovenous fistulas

    PubMed Central

    LI, QIANG; ZHANG, QI; HUANG, QING-HAI; FANG, YI-BIN; ZHANG, ZHAO-LONG; XU, YI; LIU, JIAN-MIN

    2014-01-01

    Dural arteriovenous fistulas (DAVFs) are associated with venous hypertension. Numerous studies have revealed high expression levels of vascular endothelial growth factor (VEGF) in human DAVF specimens, as well as in animal models of experimental venous hypertension. The objective of the present study was to clarify whether the VEGF signaling pathway is important in the development of DAVFs. Rats (n=216) were randomly divided into six groups. In the rats from five groups (groups A and C-E, n=45 in each group; group B, n=12), experimental venous hypertension was induced by right common carotid artery (CCA)-external jugular vein (EJV) anastomosis, superior sinus occlusion and left transver sinus occlusion, while the remaining group (group F, n=24) underwent sham surgery. The rats in group A received a VEGF recombinant adenovirus injection into the distal section of the right EJV 30 min prior to anastomosis of the CCA and EJV. An equivalent control adenovirus was injected into the right EJV of group B rats prior to anastomosis. The rats in group C received no virus prior to anastomosis and no medicine subsequent to surgery. The group D rats were lavaged with Vatalanib, a VEGF receptor (VEGFR) inhibitor, and the group E rats were lavaged with an equal quantity of saline weekly following surgery. Six rats from groups A-E and one rat from group F were sacrificed in the first, second, fourth and twelfth weeks after surgery for immunohistochemical analysis of VEGF expression and analysis of microvessel density. Cerebral angiography was performed on the remaining rats in each group on the twelfth week after surgery. The results revealed that following transfection with VEGF recombinant adenovirus, angiogenesis in the dura mater of venous hypertensive rats was increased subsequent to the increase in the VEGF expression levels of the brain and dura mater. The rate of DAVF induction by venous hypertension was significantly reduced by the VEGFR antagonist due to reduced angiogenesis in the dura mater. In conclusion, VEGF and its receptor may be important in the formation of venous hypertension-induced DAVFs. PMID:24626343

  15. A pivotal role of the vascular endothelial growth factor signaling pathway in the formation of venous hypertension-induced dural arteriovenous fistulas.

    PubMed

    Li, Qiang; Zhang, Qi; Huang, Qing-Hai; Fang, Yi-Bin; Zhang, Zhao-Long; Xu, Yi; Liu, Jian-Min

    2014-05-01

    Dural arteriovenous fistulas (DAVFs) are associated with venous hypertension. Numerous studies have revealed high expression levels of vascular endothelial growth factor (VEGF) in human DAVF specimens, as well as in animal models of experimental venous hypertension. The objective of the present study was to clarify whether the VEGF signaling pathway is important in the development of DAVFs. Rats (n=216) were randomly divided into six groups. In the rats from five groups (groups A and C-E, n=45 in each group; group B, n=12), experimental venous hypertension was induced by right common carotid artery (CCA)?external jugular vein (EJV) anastomosis, superior sinus occlusion and left transver sinus occlusion, while the remaining group (group F, n=24) underwent sham surgery. The rats in group A received a VEGF recombinant adenovirus injection into the distal section of the right EJV 30 min prior to anastomosis of the CCA and EJV. An equivalent control adenovirus was injected into the right EJV of group B rats prior to anastomosis. The rats in group C received no virus prior to anastomosis and no medicine subsequent to surgery. The group D rats were lavaged with Vatalanib, a VEGF receptor (VEGFR) inhibitor, and the group E rats were lavaged with an equal quantity of saline weekly following surgery. Six rats from groups A-E and one rat from group F were sacrificed in the first, second, fourth and twelfth weeks after surgery for immunohistochemical analysis of VEGF expression and analysis of microvessel density. Cerebral angiography was performed on the remaining rats in each group on the twelfth week after surgery. The results revealed that following transfection with VEGF recombinant adenovirus, angiogenesis in the dura mater of venous hypertensive rats was increased subsequent to the increase in the VEGF expression levels of the brain and dura mater. The rate of DAVF induction by venous hypertension was significantly reduced by the VEGFR antagonist due to reduced angiogenesis in the dura mater. In conclusion, VEGF and its receptor may be important in the formation of venous hypertension-induced DAVFs. PMID:24626343

  16. Tyrosine Nitration of PA700 Activates the 26S Proteasome to Induce Endothelial Dysfunction in Mice With Angiotensin II–Induced Hypertension

    PubMed Central

    Xu, Jian; Wang, Shuangxi; Wu, Yong; Song, Ping; Zou, Ming-Hui

    2010-01-01

    The ubiquitin-proteasome system has been implicated in oxidative stress–induced endothelial dysfunction in cardiovascular diseases. However, the mechanism by which oxidative stress alters the ubiquitin-proteasome system is poorly defined. The present study was conducted to determine whether oxidative modifications of PA700, a 26S proteasome regulatory subunit, contributes to angiotensin II (Ang II)–induced endothelial dysfunction. Exposure of human umbilical vein endothelial cells to low concentrations of Ang II, but not vehicle, for 6 hours significantly decreased the levels of tetrahydro-L-biopterin (BH4), an essential cofactor of endothelial NO synthase, which was accompanied by a decrease in GTP cyclohydrolase I, the rate-limiting enzyme for de novo BH4 synthesis. In addition, Ang II increased both tyrosine nitration of PA700 and the 26S proteasome activity, which were paralleled by increased coimmunoprecipitation of PA700 and the 20S proteasome. Genetic inhibition of NAD(P)H oxidase or administration of uric acid (a peroxynitrite scavenger) or NG-nitro-L-arginine methyl ester (nonselective NO synthase inhibitor) significantly attenuated Ang II–induced PA700 nitration, 26S proteasome activation, and reduction of GTP cyclohydrolase I and BH4. Finally, Ang II infusion in mice decreased the levels of both BH4 and GTP cyclohydrolase I and impaired endothelial-dependent relaxation in isolated aortas, and all of these effects were prevented by the administration of MG132, a potent inhibitor for 26S proteasome. We conclude that Ang II increases tyrosine nitration of PA700 resulting in accelerated GTP cyclohydrolase I degradation, BH4 deficiency, and consequent endothelial dysfunction in hypertension. PMID:19597039

  17. Changes of Gene Expression after Bone Marrow Cell Transfusion in Rats with Monocrotaline-Induced Pulmonary Hypertension

    PubMed Central

    Kim, Kwan Chang; Lee, Hae Ryun; Kim, Sung Jin; Cho, Min-Sun

    2012-01-01

    Pulmonary artery hypertension (PAH) causes right ventricular failure and possibly even death by a progressive increase in pulmonary vascular resistance. Bone marrow-derived mesenchymal stem cell therapy has provided an alternative treatment for ailments of various organs by promoting cell regeneration at the site of pathology. The purpose of this study was to investigate changes of pulmonary haemodynamics, pathology and expressions of various genes, including ET (endothelin)-1, ET receptor A (ERA), endothelial nitric oxide synthase (NOS) 3, matrix metalloproteinase (MMP) 2, tissue inhibitor of matrix metalloproteinase (TIMP), interleukin (IL)-6 and tumor necrosis factor (TNF)-? in monocrotaline (MCT)-induced PAH rat models after bone marrow cell (BMC) transfusion. The rats were grouped as the control (C) group, monocrotaline (M) group, and BMC transfusion (B) group. M and B groups received subcutaneous (sc) injection of MCT (60 mg/kg). BMCs were transfused by intravenous injection at the tail 1 week after MCT injection in B group. Results showed that the average RV pressure significantly decreased in the B group compared with the M group. RV weight and the ratio of RH/LH+septum significantly decreased in the B group compared to the M group. Gene expressions of ET-1, ERA, NOS 3, MMP 2, TIMP, IL-6, and TNF-? significantly decreased in week 4 in the B group compared with the M group. In conclusion, BMC transfusion appears to improve survival rate, RVH, and mean RV pressure, and decreases gene expressions of ET-1, ERA, NOS 3, MMP 2, TIMP, IL-6, and TNF-?. PMID:22690090

  18. Difference in Susceptibility of Developing Renal Damage in Normotensive Fawn-Hooded (FHL) and August × Copenhagen Irish (ACI) Rats After N ?-Nitro- l-arginine Methyl Ester Induced Hypertension

    Microsoft Academic Search

    Richard P. E. van Dokkum; Howard J. Jacob; Abraham P. Provoost

    1997-01-01

    Previous studies using the fawn-hooded hypertensive (FHH) rat have indicated that genetic factors appear to be important in determining the susceptibility to develop renal damage. This was further investigated by comparing the effects of N?-nitro-l-arginine methyl ester (L-NAME) induced hypertension on functional and structural renal damage in two normotensive strains, the resistant August × Copenhagen Irish rat (ACI) and the

  19. The Anti-hypertensive Drug Prazosin Induces Apoptosis in the Medullary Thyroid Carcinoma Cell Line TT

    PubMed Central

    STRACKE, ANIKA; MEIER-ALLARD, NATHALIE; ABSENGER, MARKUS; INGOLIC, ELISABETH; HAAS, HELGA SUSANNE; PFRAGNER, ROSWITHA; SADJAK, ANTON

    2015-01-01

    Background/Aim Medullary thyroid carcinoma (MTC) is a tumor associated with poor prognosis since it exhibits high resistance against conventional cancer therapy. Recent studies have shown that quinazolines exhibit a pro-apoptotic effect on malignant cells. The aim of the present study was to elucidate whether MTC cells are affected by quinazolines, in particular prazosin. Materials and Methods Proliferation, apoptosis and cell morphology of the MTC cell line TT were analyzed by WST-1 assay, caspase 3/7 activation tests and microscopy. Fibroblasts were used as control for non-malignant cells. Results Prazosin potently inhibited the growth of TT cells, induced apoptosis and caused vacuolization, as well as needle-like filopodia. Fibroblasts were affected by prazosin in the same way as MTC cells. Conclusion MTC cells are responsive to prazosin treatment similar to other malignancies. The fact that fibroblasts also respond to prazosin further highlights the importance to identify the unknown pro-apoptotic target of quinazolines. PMID:25550532

  20. Impact of tannic acid on blood pressure, oxidative stress and urinary parameters in L-NNA-induced hypertensive rats.

    PubMed

    Turgut Co?an, Didem; Saydam, Faruk; Özbayer, Cansu; Do?aner, Fulya; Soyocak, Ahu; Güne?, Hasan Veysi; De?irmenci, ?rfan; Kurt, Hülyam; Üstüner, Mehmet Cengiz; Bal, Cengiz

    2015-01-01

    Hypertension is a major health problem with increasing prevalence around the world. Tannic acid is water-soluble polyphenol that is present in tea, green tea, coffee, red wine, nuts, fruits and many plant foods. It has been reported to serve as an antioxidant or a pro-oxidant depending on the type of cells and its concentration. The purpose of our study was to evaluate the effect of tannic acid on systolic blood pressure, oxidative stress and some urinary parameters in the rat model of essential hypertension. Blood pressures of all rats were measured using the tail-cuff method. The nitric oxide synthase inhibitor N (omega)-nitro-L-arginine was administered orally at a dose of 0.5 g/l/day for 15 days to rats in order to create an animal model of hypertension. Tannic acid was intraperitoneally injected at a dose of 50 mg/kg for 15 days. Superoxide dismutase, catalase activity and the concentration of malondialdehyde (MDA) were determined in blood plasma and homogenates of heart, liver and kidney. In order to evaluate renal functions, urine pH, urine volume, urine creatine, uric acid, and urea nitrogen values were measured. Compared with the hypertension group, a decrease in MDA concentrations of heart tissue (p < 0.01), urea nitrogen values (p < 0.01) and urine volumes (p < 0.001) were established in hypertension + tannic acid group. There was also a decrease in blood pressure values (20th and 30th days) of this group, but there was no a statistical difference according to hypertension group. The findings of our research show the effect of tannic acid in lowering blood pressure in hypertensive rats. PMID:24306272

  1. Effect of polyphenolic compounds on the renal Na(+),K(+)-ATPase during the restoration of normotension after experimentally induced hypertension in rats.

    PubMed

    Javorková, Veronika; Pechánová, Olga; Andriantsitohaina, Ramaroson; Vrbjar, Norbert

    2003-07-01

    It is commonly known that consumption of foods and beverages rich in polyphenols is associated with a lower incidence of cardiovascular disease. The purpose of this study was to assess whether the application of red wine polyphenols influences the kinetic properties of renal Na(+),K(+)-ATPase in rats in which hypertension has been experimentally induced by the nitric oxide synthase inhibitor L-NAME. Treatment with polyphenols during the recovery from hypertension to normotension resulted in the complete revival of the functional properties of the Na(+),K(+)-ATPase, as indicated by the total restoration of K(m), K(Na) (concentration of Na(+) necessary to achieve half-maximal reaction velocity) and V(max) for enzyme activation by ATP and/or Na(+) to pre-hypertension values. Two positive effects of polyphenols during the recovery period are indicated: a restoration of the affinity of the ATP and Na(+) binding sites to control values and a probable increase in the number of Na(+),K(+)-ATPase molecules to a level comparable to that in control conditions, as suggested by the complete renewal of V(max). PMID:12861334

  2. Common noncoding UMOD gene variants induce salt-sensitive hypertension and kidney damage by increasing uromodulin expression

    PubMed Central

    Trudu, Matteo; Janas, Sylvie; Lanzani, Chiara; Debaix, Huguette; Schaeffer, Céline; Ikehata, Masami; Citterio, Lorena; Demaretz, Sylvie; Trevisani, Francesco; Ristagno, Giuseppe; Glaudemans, Bob; Laghmani, Kamel; Dell’Antonio, Giacomo; Loffing, Johannes; Rastaldi, Maria P.; Manunta, Paolo

    2013-01-01

    Elevated blood pressure (BP) and chronic kidney disease (CKD) are complex traits representing major global health problems1,2. Multiple genome-wide association studies (GWAS) identified common variants giving independent susceptibility for CKD and hypertension in the promoter of the UMOD gene3-9, encoding uromodulin, the major protein secreted in the normal urine. Despite compelling genetic evidence, the underlying biological mechanism is not understood. Here, we demonstrate that UMOD risk variants directly increase UMOD expression in vitro and in vivo. We modeled this effect in transgenic mice and showed that uromodulin overexpression leads to salt-sensitive hypertension and to age-dependent renal lesions that are similarly observed in elderly subjects homozygous for UMOD risk variants. We demonstrate that the link between uromodulin and hypertension is caused by activation of the renal sodium co-transporter NKCC2. This very mechanism is relevant in humans, as pharmacological inhibition of NKCC2 is more effective in lowering BP in hypertensive patients homozygous for UMOD risk variants. Our findings establish a link between the genetic susceptibility to hypertension and CKD, the control of uromodulin expression and its role in a salt-reabsorbing tubular segment of the kidney. These data point to uromodulin as a novel therapeutic target to lower BP and preserve renal function. PMID:24185693

  3. Myocardial remodeling in hypertension.

    PubMed

    Nadruz, W

    2015-01-01

    Left ventricular (LV) hypertrophy and remodeling are frequently seen in hypertensive subjects and result from a complex interaction of several hemodynamic and non-hemodynamic variables. Although increased blood pressure is considered the major determinant of LV structural alterations, ethnicity, gender, environmental factors, such as salt intake, obesity and diabetes mellitus, as well as neurohumoral and genetic factors might influence LV mass and geometry. The conventional concept of hypertensive LV remodeling has been that hypertension leads to concentric hypertrophy, as an adaptive response to normalize wall stress, which is then followed by chamber dilation and heart failure. However, several lines of evidence have challenged this dogma. Concentric hypertrophy is not the most frequent geometric pattern and is less usually seen than eccentric hypertrophy in hypertensive subjects. In addition, data from recent studies suggested that transition from LV concentric hypertrophy to dilation and systolic dysfunction is not a common finding, especially in the absence of coronary heart disease. LV hypertrophy is also consistently associated with increased cardiovascular morbidity and mortality, raising doubts whether this phenotype is an adaptive response. Experimental evidence exists that a blunting of load-induced cardiomyocyte hypertrophy does not necessarily result in LV dysfunction or failure. Furthermore, the hypertrophic myocardium shows fibrosis, alterations in the coronary circulation and cardiomyocyte apoptosis, which may result in heart failure, myocardial ischemia and arrhythmias. Overall, this body of evidence suggests that LV hypertrophy is a complex phenotype that predicts adverse cardiovascular outcomes and may not be necessarily considered as an adaptive response to systemic hypertension. PMID:24804791

  4. Pulmonary Hypertension

    MedlinePLUS

    Pulmonary hypertension (PH) is high blood pressure in the arteries to your lungs. It is a serious condition. If you have ... and you can develop heart failure. Symptoms of PH include Shortness of breath during routine activity, such ...

  5. Increased neuronal activity in the OVLT of Cyp1a1-Ren2 transgenic rats with inducible Ang II-dependent malignant hypertension.

    PubMed

    Issa, Alexandra T; Miyata, Kayoko; Heng, Vibol; Mitchell, Kenneth D; Derbenev, Andrei V

    2012-06-21

    The contribution of angiotensin II (Ang II) to the pathophysiology of hypertension is established based on facts that high levels of circulating Ang II increase vasoconstriction of peripheral arteries causing a rise in blood pressure (BP). In addition, circulating Ang II has various effects on the central nervous system, including the osmosensitive neurons in the organum vasculosum of the lamina terminalis (OVLT). Osmosensitive neurons in the OVLT transduce hypertonicity via the activation of the nonselective cation channel known as transient receptor potential vanilloid 1 (TRPV1), causing membrane depolarization, followed by increased action potential discharge. This effect is absent in mice lacking expression of the TRPV1 gene. Most observations related to the importance of the OVLT in cardiovascular control are mainly based on models of lesion of the entire preoptic periventricular tissue. However, it remains unclear whether neuronal activity and TRPV1 protein expression levels alter in the OVLT of Cyp1a1-Ren2 transgenic rats with inducible Ang II-dependent malignant hypertension. C-fos was used as a marker of neuronal activity. Immunostaining was used to demonstrate distribution of c-fos positive neurons in the OVLT of Cyp1a1Ren2 transgenic rats. Western blot analysis showed increased c-fos and TRPV1 total protein expression levels in the OVLT of hypertensive rats. The present findings demonstrate increased c-fos and TRPV1 expression levels in the OVLT of Cyp1a1-Ren2 transgenic rats with Ang II-dependent malignant hypertension. PMID:22579820

  6. Over-Expression of Copper/Zinc Superoxide Dismutase in the Median Preoptic Nucleus Attenuates Chronic Angiotensin II-Induced Hypertension in the Rat

    PubMed Central

    Collister, John P.; Bellrichard, Mitch; Drebes, Donna; Nahey, David; Tian, Jun; Zimmerman, Matthew C.

    2014-01-01

    The brain senses circulating levels of angiotensin II (AngII) via circumventricular organs, such as the subfornical organ (SFO), and is thought to adjust sympathetic nervous system output accordingly via this neuro-hormonal communication. However, the cellular signaling mechanisms involved in these communications remain to be fully understood. Previous lesion studies of either the SFO, or the downstream median preoptic nucleus (MnPO) have shown a diminution of the hypertensive effects of chronic AngII, without providing a clear explanation as to the intracellular signaling pathway(s) involved. Additional studies have reported that over-expressing copper/zinc superoxide dismutase (CuZnSOD), an intracellular superoxide (O2·?) scavenging enzyme, in the SFO attenuates chronic AngII-induced hypertension. Herein, we tested the hypothesis that overproduction of O2·? in the MnPO is an underlying mechanism in the long-term hypertensive effects of chronic AngII. Adenoviral vectors encoding human CuZnSOD (AdCuZnSOD) or control vector (AdEmpty) were injected directly into the MnPO of rats implanted with aortic telemetric transmitters for recording of arterial pressure. After a 3 day control period of saline infusion, rats were intravenously infused with AngII (10 ng/kg/min) for ten days. Rats over-expressing CuZnSOD (n = 7) in the MnPO had a blood pressure increase of only 6 ± 2 mmHg after ten days of AngII infusion while blood pressure increased 21 ± 4 mmHg in AdEmpty-infected rats (n = 9). These results support the hypothesis that production of O2·? in the MnPO contributes to the development of chronic AngII-dependent hypertension. PMID:25474089

  7. Over-expression of copper/zinc superoxide dismutase in the median preoptic nucleus attenuates chronic angiotensin II-induced hypertension in the rat.

    PubMed

    Collister, John P; Bellrichard, Mitch; Drebes, Donna; Nahey, David; Tian, Jun; Zimmerman, Matthew C

    2014-01-01

    The brain senses circulating levels of angiotensin II (AngII) via circumventricular organs, such as the subfornical organ (SFO), and is thought to adjust sympathetic nervous system output accordingly via this neuro-hormonal communication. However, the cellular signaling mechanisms involved in these communications remain to be fully understood. Previous lesion studies of either the SFO, or the downstream median preoptic nucleus (MnPO) have shown a diminution of the hypertensive effects of chronic AngII, without providing a clear explanation as to the intracellular signaling pathway(s) involved. Additional studies have reported that over-expressing copper/zinc superoxide dismutase (CuZnSOD), an intracellular superoxide (O2·-) scavenging enzyme, in the SFO attenuates chronic AngII-induced hypertension. Herein, we tested the hypothesis that overproduction of O2·- in the MnPO is an underlying mechanism in the long-term hypertensive effects of chronic AngII. Adenoviral vectors encoding human CuZnSOD (AdCuZnSOD) or control vector (AdEmpty) were injected directly into the MnPO of rats implanted with aortic telemetric transmitters for recording of arterial pressure. After a 3 day control period of saline infusion, rats were intravenously infused with AngII (10 ng/kg/min) for ten days. Rats over-expressing CuZnSOD (n = 7) in the MnPO had a blood pressure increase of only 6 ± 2 mmHg after ten days of AngII infusion while blood pressure increased 21 ± 4 mmHg in AdEmpty-infected rats (n = 9). These results support the hypothesis that production of O2·- in the MnPO contributes to the development of chronic AngII-dependent hypertension. PMID:25474089

  8. Renoprotective effect of sitagliptin against hypertensive nephropathy induced by chronic administration of L-NAME in rats: role of GLP-1 and GLP-1 receptor.

    PubMed

    Abd El Motteleb, Dalia M; Elshazly, Shimaa M

    2013-11-15

    The present study was undertaken to assess the possible protective effects of sitagliptin, a dipeptidyl peptidase 4-inhibitor (DPP4), against N?-nitro-L-arginine methyl ester (L-NAME) induced hypertensive nephropathy in rats. Hypertension was induced in adult rats by administration of L-NAME for 6 weeks. Rats were treated with sitagliptin (10mg/kg/day or 30 mg/kg/day) for six weeks. Chronic L-NAME administration resulted in depletion of serum nitric oxide (NO) associated with elevation in the mean arterial pressure. When compared with the control group; serum urea, serum creatinine, albuminuria, urinary N-acetyl-ß-d-glucosaminidase (NAG) level and renal tissue malondialdhyde (MDA) content were significantly elevated, while creatinine clearance, serum level of glucagon like peptide-1 (GLP-1) as well as renal tissue superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were signifcantly decreased in L-NAME treated group. Renal expression of mRNA for eNOS and GLP-1 receptors were reduced in the L-NAME treated group as compared with the control group. Treatment with sitagliptin (10mg/kg or 30 mg/kg) successfully ameliorated the deleterious effects of L-NAME on the all tested parameters. Our study indicates a novel protective effect of sitagliptin against L-NAME induced hypertensive nephropathy. An effect which is mediated through, increasing serum level of GLP-1, upregulation of GLP-1 receptors, which in turn, lead to induction of expression eNOS, increased serum NO level, tandem with decreased lipid perodixation and restore the antioxidant defense mechanisms. It is worth mentioning that the effects produced by sitaglipin (30 mg/kg) were superior to the effects obtained by the lower dose. PMID:24238127

  9. N-ACETYL-SERYL-ASPARTYL-LYSYL-PROLINE REDUCES CARDIAC COLLAGEN CROSS-LINKING AND INFLAMMATION IN ANGIOTENSIN II INDUCED HYPERTENSIVE RATS

    PubMed Central

    GONZÁLEZ, Germán E.; RHALEB, Nour-Eddine; NAKAGAWA, Pablo; LIAO, Tang-Dong; LIU, Yunhe; LEUNG, Pablo; DAI, Xiangguo; YANG, Xiao-Ping; CARRETERO, Oscar A.

    2014-01-01

    We previously reported that N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) reduces fibrosis and inflammation (macrophages and mast cells). However, it is not known whether Ac-SDKP decreases collagen cross-linking and lymphocyte infiltration; lymphocytes modulate both collagen cross-linking and extracellular matrix formation in hypertension. Thus, we hypothesized that 1) in angiotensin (Ang) II-induced hypertension, Ac-SDKP prevents increases in cross-linked and total collagen by down-regulating lysyl oxidase (LOX), the enzyme responsible for cross-linking, and 2) these effects are associated with decreased a) pro-fibrotic cytokine TGF-? and b) the proinflammatory transcription factor nuclear factor ?B (NF?B), and c) CD4+/CD8+ lymphocyte infiltration. We induced hypertension in rats by infusing Ang II either alone or combined with Ac-SDKP for 3 weeks. While Ac-SDKP failed to lower blood pressure or left ventricular hypertrophy, it did prevent Ang II-induced increases in 1) cross-linked and total collagen, 2) LOX mRNA expression and LOXL1 protein, 3) TGF-? expression, 4) nuclear translocation of NF?B, 5) CD4+/CD8+ lymphocyte infiltration and 6) CD68+ macrophages infiltration. In addition, we found a positive correlation between CD4+ infiltration and LOXL1 expression. In conclusion, the effect of Ac-SDKP on collagen cross-linking and total collagen may be due to reduced TGF-?1, LOXL1 and lymphocyte and macrophages infiltration, and its effect on inflammation could be due to lower NF?B. PMID:23834332

  10. Neonatal Hypertension

    Microsoft Academic Search

    Joseph T. Flynn

    \\u000a Hypertension as a clinical problem in newborn infants was first recognized in the 1970s (1). However, recent advances in our ability to identify, evaluate, and care for prmature infants have lead to an increased awareness\\u000a of neonatal hypertension, not only in the neonatal intensive care unit (NICU) but also in the neonatal follow-up clinic. This\\u000a chapter will focus on the

  11. Arterial Hypertension

    Microsoft Academic Search

    Daniel A. Duprez

    \\u000a High blood pressure (BP) is a very important cardiovascular (CV) risk factor and is often labeled the “silent killer” because\\u000a arterial hypertension will lead to serious CV events such as ischemic heart disease, stroke, and heart failure. Moreover,\\u000a uncontrolled essential hypertension also leads to renal insufficiency, which accelerates the process of blood pressure elevation\\u000a (1, 2). There is a shift

  12. Is methylglyoxal a causative factor for hypertension development?

    PubMed

    Wu, Lingyun

    2006-01-01

    Hypertension is a life-threatening disease that is associated with increased cardiovascular risks. Causes and mechanisms for hypertension development remain poorly understood. Methylglyoxal (MG), a highly reactive molecule, is a metabolite of sugar. Increased circulation and tissue levels of MG have been documented not only in diabetes but also in hypertension. Many recent studies also link MG-induced vascular damage to the pathogenic process of hypertension. As such, an etiological role of MG in hypertension development is proposed. PMID:16845897

  13. Beneficial effects of a novel agonist of the adenosine A2A receptor on monocrotaline-induced pulmonary hypertension in rats

    PubMed Central

    Alencar, Allan K N; Pereira, Sharlene L; Montagnoli, Tadeu L; Maia, Rodolfo C; Kümmerle, Arthur E; Landgraf, Sharon S; Caruso-Neves, Celso; Ferraz, Emanuelle B; Tesch, Roberta; Nascimento, José H M; de Sant'Anna, Carlos M R; Fraga, Carlos A M; Barreiro, Eliezer J; Sudo, Roberto T; Zapata-Sudo, Gisele

    2013-01-01

    Background and Purpose Pulmonary arterial hypertension (PAH) is characterized by enhanced pulmonary vascular resistance, right ventricular hypertrophy and increased right ventricular systolic pressure. Here, we investigated the effects of a N-acylhydrazone derivative, 3,4-dimethoxyphenyl-N-methyl-benzoylhydrazide (LASSBio-1359), on monocrotaline (MCT)-induced pulmonary hypertension in rats. Experimental Approach PAH was induced in male Wistar rats by a single i.p. injection of MCT (60 mg·kg?1) and 2 weeks later, oral LASSBio-1359 (50 mg·kg?1) or vehicle was given once daily for 14 days. Echocardiography was used to measure cardiac function and pulmonary artery dimensions, with histological assay of vascular collagen. Studies of binding to human recombinant adenosine receptors (A1, A2A, A3) and of docking with A2A receptors were also performed. Key Results MCT administration induced changes in vascular and ventricular structure and function, characteristic of PAH. These changes were reversed by treatment with LASSBio-1359. MCT also induced endothelial dysfunction in pulmonary artery, as measured by diminished relaxation of pre-contracted arterial rings, and this dysfunction was reversed by LASSBio-1359. In pulmonary artery rings from normal Wistar rats, LASSBio-1359 induced relaxation, which was decreased by the adenosine A2A receptor antagonist, ZM 241385. In adenosine receptor binding studies, LASSBio-1359 showed most affinity for the A2A receptor and in the docking analyses, binding modes of LASSBio-1359 and the A2A receptor agonist, CGS21680, were very similar. Conclusion and Implications In rats with MCT-induced PAH, structural and functional changes in heart and pulmonary artery were reversed by treatment with oral LASSBio-1359, most probably through the activation of adenosine A2A receptors. PMID:23530610

  14. The Soluble Guanylate Cyclase Stimulator Riociguat Ameliorates Pulmonary Hypertension Induced by Hypoxia and SU5416 in Rats

    PubMed Central

    Tian, Xia; Kalymbetov, Anuar; Weissmann, Norbert; Grimminger, Friedrich; Kretschmer, Axel; Stasch, Johannes-Peter; Seeger, Werner; Ghofrani, Hossein Ardeschir; Schermuly, Ralph Theo

    2012-01-01

    Background The nitric oxide (NO)–soluble guanylate cyclase (sGC)–cyclic guanosine monophosphate (cGMP) signal-transduction pathway is impaired in many cardiovascular diseases, including pulmonary arterial hypertension (PAH). Riociguat (BAY 63–2521) is a stimulator of sGC that works both in synergy with and independently of NO to increase levels of cGMP. The aims of this study were to investigate the role of NO–sGC–cGMP signaling in a model of severe PAH and to evaluate the effects of sGC stimulation by riociguat and PDE5 inhibition by sildenafil on pulmonary hemodynamics and vascular remodeling in severe experimental PAH. Methods and Results Severe angioproliferative PAH was induced in rats by combined exposure to the vascular endothelial growth factor receptor antagonist SU5416 and hypoxia (SUHx). Twenty-one days thereafter rats were randomized to receive either riociguat (10 mg/kg/day), sildenafil (50 mg/kg/day) or vehicle by oral gavage, for 14 days until the day of the terminal hemodynamic measurements. Administration of riociguat or sildenafil significantly decreased right ventricular systolic pressure (RVSP). Riociguat significantly decreased RV hypertrophy (RVH) (0.55±0.02, p<0.05), increased cardiac output (60.8±.8 mL/minute, p<0.05) and decreased total pulmonary resistance (4.03±0.3 mmHg min?1 ml?1 100 g BW, p<0.05), compared with sildenafil and vehicle. Both compounds significantly decreased the RV collagen content and improved RV function, but the effects of riociguat on tricuspid annular plane systolic excursion and RV myocardial performance were significantly better than those of sildenafil (p<0.05). The proportion of occluded arteries was significantly lower in animals receiving riociguat than in those receiving vehicle (p<0.05); furthermore, the neointima/media ratio was significantly lower in those receiving riociguat than in those receiving sildenafil or vehicle (p<0.05). Conclusion Riociguat and sildenafil significantly reduced RVSP and RVH, and improved RV function compared with vehicle. Riociguat had a greater effect on hemodynamics and RVH than sildenafil. PMID:22912874

  15. Attenuation of monocrotaline-induced pulmonary hypertension by luminal adeno-associated virus serotype 9 gene transfer of prostacyclin synthase.

    PubMed

    Gubrij, Igor B; Martin, Sara Rebecca; Pangle, Amanda K; Kurten, Richard; Johnson, Larry G

    2014-06-01

    Idiopathic pulmonary arterial hypertension (iPAH) is associated with high morbidity and mortality. We evaluated whether luminal delivery of the human prostacyclin synthase (hPGIS) cDNA with adeno-associated virus (AAV) vectors could attenuate PAH. AAV serotype 5 (AAV5) and AAV9 vectors containing the hPGIS cDNA under the control of a cytomegalovirus-enhanced chicken ?-actin (CB) promoter or vehicle (saline) were instilled into lungs of rats. Two days later, rats were injected with monocrotaline (MCT, 60?mg/kg) or saline. Biochemical, hemodynamic, and morphologic assessments were performed when the rats developed symptoms (3-4 weeks) or at 6 weeks. Luminal (airway) administration of AAV5 and AAV9CBhPGIS vectors (MCT-AAV5 and MCT-AAV9 rats) significantly increased plasma levels of 6-keto-PGF1(?) as compared with MCT-controls, and closely resembled levels measured in rats not treated with MCT (saline-saline). Right ventricular (RV)/left ventricular (LV)+septum (S) ratios and RV systolic pressure (RVSP) were greater in MCT-control rats than in saline-saline rats, whereas the ratios and RVSP in MCT-AAV5CBhPGIS and MCT-AAV9CBhPGIS rats were similar to saline-saline rats. Thickening of the muscular media of small pulmonary arteries of MCT-control rats was detected in histological sections, whereas the thickness of the muscular media in MCT-AAV5CBhPGIS and MCT-AAV9CBhPGIS rats was similar to saline-saline controls. In experiments with different promoters, a trend toward increased levels of PGF1(?) expression was detected in lung homogenates, but not plasma, of MCT-treated rats transduced with an AAV9-hPGIS vector containing a CB promoter. This correlated with significant reductions in the RV/LV+S ratio and RVSP in MCT-AAV9CBhPGIS rats that resembled levels in saline-saline rats. No changes in levels of PGF1(?), RV/LV+S, or RVSP were detected in rats transduced with AAV9-hPGIS vectors containing a modified CB promoter (CB7) or a distal epithelial cell-specific promoter (CC10). Thus, AAV9CBhPGIS vectors prevented development of MCT-induced PAH and associated pulmonary vascular remodeling. PMID:24512101

  16. Plasma Potentiates the Priming Effects of Endotoxin on Platelet Activating Factor-Induced Pulmonary Hypertension in the Rabbit Lung

    Microsoft Academic Search

    Jason A. Goldsmith; Brian P. Kavanagh; Ronald G. Pearl

    1996-01-01

    During Gram-negative sepsis, endotoxin lipopolysac- charide (LPS) may activate host inflammatory re- sponses, resulting in the systemic inflammatory re- sponse syndrome and the adult respiratory distress syndrome. In cell culture systems, LPS activation of cel- lular responses may be potentiated by plasma proteins. In the isolated perfused rabbit lung, LPS administration markedly increases the pulmonary hypertensive re- sponse to subsequent

  17. Involvement of cytochrome P-450 1B1 in renal dysfunction, injury, and inflammation associated with angiotensin II-induced hypertension in rats

    PubMed Central

    Jennings, Brett L.; Anderson, Larry J.; Estes, Anne M.; Fang, Xiao R.; Song, Chi Young; Campbell, William B.

    2012-01-01

    We investigated the contribution of cytochrome P-450 1B1 (CYP1B1) to renal dysfunction and organ damage associated with ANG II-induced hypertension in rats. ANG II (300 ng·kg?1·min?1) or vehicle were infused for 2 wk, with daily injections of a selective CYP1B1 inhibitor, 2,4,3?,5?-tetramethoxystilbene (TMS; 300 ?g/kg ip), or its vehicle. ANG II increased blood pressure and renal CYP1B1 activity that were prevented by TMS. ANG II also increased water intake and urine output, decreased glomerular filtration rate, increased urinary Na+ and K+ excretion, and caused proteinuria, all of which were prevented by TMS. ANG II infusion caused hypertrophy, endothelial dysfunction, and increased reactivity of renal and interlobar arteries to vasoconstrictor agents and renal vascular resistance and interstitial fibrosis as indicated by accumulation of ?-smooth muscle actin, fibronectin, and collagen, and inflammation as indicated by increased infiltration of CD-3+ cells; these effects were inhibited by TMS. ANG II infusion also increased production of reactive oxygen species (ROS) and activities of NADPH oxidase, ERK1/2, p38 MAPK, and c-Src that were prevented by TMS. TMS alone had no effect on any of the above parameters. These data suggest that CYP1B1 contributes to the renal pathophysiological changes associated with ANG II-induced hypertension, most likely via increased ROS production and activation of ERK1/2, p38 MAPK, and c-Src and that CYP1B1 could serve as a novel target for treating renal disease associated with hypertension. PMID:22088434

  18. Pregnancy-Induced Hypertension

    MedlinePLUS

    ... is not a good idea if you have high blood pressure during pregnancy. Your body needs salt to keep up the flow of fluid in your body, so you need a normal intake of salt. Your doctor will tell you how ...

  19. [Portopulmonary hypertension].

    PubMed

    Halank, M; Miehlke, S; Kolditz, M; Hoeffken, G

    2005-07-01

    Patients with portal hypertension may develop pulmonary complications such as hepatopulmonary syndrome (HPS) or portopulmonary hypertension (PPHT). PPHT is defined as elevated pulmonary pressure, elevated pulmonary vascular resistance, a normal pulmonary capillary wedge pressure, and portal hypertension in the absence of other known causes pulmonary hypertension. Various factors such as hyperdynamic circulation, volume overload, and circulating vasoactive mediators are suspected to be involved in the pathogenesis of PPHT. The prognosis of patients with severe PPHT is significantly reduced due to the risk of right heart failure. In patients with moderate to severe PPHT liver transplantation is associated with a significantly increased mortality. The chief symptom of PPHT may be dyspnoe in the presence of typical histomorphological alterations comparable with idiopathic pulmonary hypertension. Continuous intravenous application of prostacyclin is currently regarded as the treatment of choice for patients with severe PPHT. Inhaled prostacyclin or its analogue iloprost or oral treatment with the endothelin-receptor antagonist bosentan may be promising alternatives which should be further investigated in randomized controlled trials. PMID:16001350

  20. Inflammation in pulmonary arterial hypertension

    Microsoft Academic Search

    P. Dorfmuller; F. Perros; K. Balabanian; M. Humbert

    2003-01-01

    ABSTRACT: Inflammatory,mechanisms,appear to play a significant role in some types of pulmonary hypertension (PH), including monocrotaline-induced PH in rats and pulmonary arterial hypertension of various origins in humans, such as connective tissue diseases (scleroderma, systemic lupus erythematosus, mixed connective disease), human immunodeficiency virus infection, or plasma cell dyscrasia with polyneuropathy, organomegaly, endocrinopathy, monoclonal (M) protein and skin changes (POEMS) syndrome.

  1. Functional and morphological effects of laser-induced ocular hypertension in retinas of adult albino Swiss mice

    PubMed Central

    Salinas-Navarro, Manuel; Alarcón-Martínez, Luis; Valiente-Soriano, Francisco Javier; Ortín-Martínez, Arturo; Jiménez-López, Manuel; Avilés-Trigueros, Marcelino; Villegas-Pérez, María Paz; de la Villa, Pedro

    2009-01-01

    Purpose To investigate the effects of laser photocoagulation (LP)-induced ocular hypertension (OHT) on the survival and retrograde axonal transport of retinal ganglion cells (RGC), as well as on the function of retinal layers. Methods Adult albino Swiss mice (35–45 g) received laser photocoagulation of limbal and episcleral veins in the left eye. Mice were sacrificed at 8, 17, 35, and 63 days. Intraocular pressure (IOP) in both eyes was measured with a Tono-Lab before LP and at various days after LP. Flash electroretinogram (ERG) scotopic threshold response (STR) and a- and b-wave amplitudes were recorded before LP and at various times after LP. RGCs were labeled with 10% hydroxystilbamidine methanesulfonate (OHSt) applied to both superior colliculi before sacrifice and in some mice, with dextran tetramethylrhodamine (DTMR) applied to the ocular stump of the intraorbitally transected optic nerve. Retinas were immunostained for RT97 or Brn3a. Retinas were prepared as whole-mounts and photographed under a fluorescence microscope. Labeled RGCs were counted using image analysis software, and an isodensity contour plot was generated for each retina. Results IOP increased to twice its basal values by 24 h and was maintained until day 5, after which IOP gradually declined to reach basal values by 1 wk. Similar IOP increases were observed in all groups. The mean total number of OHSt+ RGCs was 13,428±6,295 (n=12), 10,456±14,301 (n=13), 12,622±14,174 (n=21), and 10,451±13,949 (n=13) for groups I, II, III, and IV, respectively; these values represented 28%, 23%, 26%, and 22% of the values found in their contralateral fellow retinas. The mean total population of Brn3a+ RGCs was 24,343±5,739 (n=12) and 10,219±8,887 (n=9), respectively, for groups I and III; these values represented 49% and 20%, respectively, of the values found in their fellow eyes. OHT retinas showed an absence of OHSt+ and DTMR+ RGCs in both focal wedge-shaped and diffuse regions of the retina. By 1 wk, there was a discrepancy between the total number of surviving OHSt+ RGCs and Brn3a+ RGCs, suggesting that a large proportion of RGCs had impaired retrograde axonal transport. In the retinal areas lacking backlabeled RGCs, neurofibrillar staining revealed aberrant expression of RT97 within axons and RGC bodies characteristic of axotomy. Elevated IOP induced significant reductions in the registered ERG waves, including positive STR, a- and b-waves, that were observed by 24 h and remained throughout the period of study for the three groups analyzed. Conclusions LP of the perilimbal and episcleral veins resulted in OHT leading to a lack of retrograde axonal transport in approximately 75% of the original RGC population. This lack did not progress further between 8 and 63 days, and it was both focal (in sectors with the apex located in the optic disc) and diffuse within the retina. In addition, severe amplitude diminutions of the STR and a- and b-waves of the ERG appeared as early as 24 h after lasering and did not recover throughout the period of study, indicating that increased IOP results in severe damage to the innermost, inner nuclear, and outer nuclear layers of the retina. PMID:20011633

  2. Common Secondary Causes of Resistant Hypertension and Rational for Treatment

    PubMed Central

    Faselis, Charles; Doumas, Michael; Papademetriou, Vasilios

    2011-01-01

    Resistant hypertension is defined as uncontrolled blood pressure despite the use of three antihypertensive drugs, including a diuretic, in optimal doses. Treatment resistance can be attributed to poor adherence to antihypertensive drugs, excessive salt intake, physician inertia, inappropriate or inadequate medication, and secondary hypertension. Drug-induced hypertension, obstructive sleep apnoea, primary aldosteronism, and chronic kidney disease represent the most common secondary causes of resistant hypertension. Several drugs can induce or exacerbate pre-existing hypertension, with non-steroidal anti-inflammatory drugs being the most common due to their wide use. Obstructive sleep apnoea and primary aldosteronism are frequently encountered in patients with resistant hypertension and require expert management. Hypertension is commonly found in patients with chronic kidney disease and is frequently resistant to treatment, while the management of renovascular hypertension remains controversial. A step-by-step approach of patients with resistant hypertension is proposed at the end of this review paper. PMID:21423678

  3. Interleukin 13– and interleukin 17A–induced pulmonary hypertension phenotype due to inhalation of antigen and fine particles from air pollution

    PubMed Central

    Park, Sung-Hyun; Chen, Wen-Chi; Esmaeil, Nafiseh; Lucas, Benjamin; Marsh, Leigh M.; Reibman, Joan

    2014-01-01

    Abstract Pulmonary hypertension has a marked detrimental effect on quality of life and life expectancy. In a mouse model of antigen-induced pulmonary arterial remodeling, we have recently shown that coexposure to urban ambient particulate matter (PM) significantly increased the thickening of the pulmonary arteries and also resulted in significantly increased right ventricular systolic pressures. Here we interrogate the mechanism and show that combined neutralization of interleukin 13 (IL-13) and IL-17A significantly ameliorated the increase in right ventricular systolic pressure, the circumferential muscularization of pulmonary arteries, and the molecular change in the right ventricle. Surprisingly, our data revealed a protective role of IL-17A for the antigen- and PM-induced severe thickening of pulmonary arteries. This protection was due to the inhibition of the effects of IL-13, which drove this response, and the expression of metalloelastase and resistin-like molecule ?. However, the latter was redundant for the arterial thickening response. Anti-IL-13 exacerbated airway neutrophilia, which was due to a resulting excess effect of IL-17A, confirming concurrent cross inhibition of IL-13- and IL-17A-dependent responses in the lungs of animals exposed to antigen and PM. Our experiments also identified IL-13/IL-17A-independent molecular reprogramming in the lungs induced by exposure to antigen and PM, which indicates a risk for arterial remodeling and protection from arterial constriction. Our study points to IL-13- and IL-17A-coinduced inflammation as a new template for biomarkers and therapeutic targeting for the management of immune response–induced pulmonary hypertension. PMID:25610601

  4. The Effect of Amlodipine and Sildenafil on the NT-ProBNP Level of Patients with COPD-Induced Pulmonary Hypertension

    PubMed Central

    Sharif-kashani, Babak; Hamraghani, Ali; Salamzadeh, Jamshid; Abbasi Nazari, Mohammad; Malekmohammad, Majid; Behzadnia, Neda; Fahimi, Fanak

    2014-01-01

    Pulmonary hypertension (PH) is an important cause of heart failure in chronic obstructive pulmonary disease (COPD). The pro brain natriuretic peptide N-terminal (NT-proBNP) has been suggested as a noninvasive marker to evaluate ventricular function. However, there is no evidence to support the use of NT-proBNP in monitoring the benefits of vasodilators in COPD induced PH. Thus, we used NT-proBNP as a biomarker to evaluate the effect of oral vasodilators on cardiac function in COPD-induced PH. Forty clinically-stable PH patients were enrolled with history of COPD, normal left ventricular ejection-fraction (LVEF), right ventricular systolic pressure (RVSP) > 45 mmHg and baseline blood NT-proBNP levels >100 pg/mL. Patients were randomized into two groups, one group received sildenafil and second group were given amlodipine for two weeks. NT-proBNP and systolic pulmonary arterial pressure (systolic PA-pressure) were measured at the beginning and the end of study. Mean NT-proBNP level in the first group was 1297 ± 912 pg/mL before therapy and 554 ± 5 pg/mL after two weeks drug therapy, respectively. Similarly, in second group NT-proBNP level was 1657 ± 989 pg/mL and 646 ± 5 pg/mL before and after treatment. Amlodipine or sildenafil significantly reduced NT-proBNP levels in COPD-induced PH patients (p < 0.05). Our study shows that amlodipine and sildenafil have a similar effect on NT-proBNP levels. In both groups NT- proBNP levels were significantly reduced after treatment. Therefore, our findings support the potential benefits of treatment with vasodilators in COPD induced PH. Pulmonary hypertension, Chronic obstructive pulmonary disease, NT-proBNP, Amlodipine, Sildenafil PMID:24711842

  5. Interleukin 13- and interleukin 17A-induced pulmonary hypertension phenotype due to inhalation of antigen and fine particles from air pollution.

    PubMed

    Park, Sung-Hyun; Chen, Wen-Chi; Esmaeil, Nafiseh; Lucas, Benjamin; Marsh, Leigh M; Reibman, Joan; Grunig, Gabriele

    2014-12-01

    Pulmonary hypertension has a marked detrimental effect on quality of life and life expectancy. In a mouse model of antigen-induced pulmonary arterial remodeling, we have recently shown that coexposure to urban ambient particulate matter (PM) significantly increased the thickening of the pulmonary arteries and also resulted in significantly increased right ventricular systolic pressures. Here we interrogate the mechanism and show that combined neutralization of interleukin 13 (IL-13) and IL-17A significantly ameliorated the increase in right ventricular systolic pressure, the circumferential muscularization of pulmonary arteries, and the molecular change in the right ventricle. Surprisingly, our data revealed a protective role of IL-17A for the antigen- and PM-induced severe thickening of pulmonary arteries. This protection was due to the inhibition of the effects of IL-13, which drove this response, and the expression of metalloelastase and resistin-like molecule ?. However, the latter was redundant for the arterial thickening response. Anti-IL-13 exacerbated airway neutrophilia, which was due to a resulting excess effect of IL-17A, confirming concurrent cross inhibition of IL-13- and IL-17A-dependent responses in the lungs of animals exposed to antigen and PM. Our experiments also identified IL-13/IL-17A-independent molecular reprogramming in the lungs induced by exposure to antigen and PM, which indicates a risk for arterial remodeling and protection from arterial constriction. Our study points to IL-13- and IL-17A-coinduced inflammation as a new template for biomarkers and therapeutic targeting for the management of immune response-induced pulmonary hypertension. PMID:25610601

  6. Portal hypertension induced by congenital hepatic arterioportal fistula: Report of four clinical cases and review of the literature

    PubMed Central

    Zhang, Dan-Ying; Weng, Shu-Qiang; Dong, Ling; Shen, Xi-Zhong; Qu, Xu-Dong

    2015-01-01

    Intrahepatic arterioportal fistula (IAPF) can be caused by many secondary factors. We report four cases of portal hypertension that were eventually determined to be caused by congenital hepatic arterioportal fistula. The clinical manifestations included ascites, variceal hemorrhage and hepatic encephalopathy. Computed tomography scans from all of the patients revealed the early enhancement of the portal branches in the hepatic arterial phase. All patients were diagnosed using digital subtraction angiography (DSA). DSA before embolization revealed an arteriovenous fistula with immediate filling of the portal venous radicles. All four patients were treated with interventional embolization. The four patients remained in good condition throughout follow-up and at the time of publication. IAPF is frequently misdiagnosed due to its rarity; therefore, clinicians should consider IAPF as a potential cause of non-cirrhotic portal hypertension. PMID:25717263

  7. [Hypertension and sports activity].

    PubMed

    Mos, Lucio; Driussi, Caterina; Mihaleje, Martina

    2010-10-01

    The importance of physical activity in primary and secondary prevention of cardiovascular disease has been demonstrated in many studies. In particular, the effect of exercise, especially aerobioc exercise, is to reduce blood pressure and heart rate by reducing sympathetic tone, and to correct many factors of the metabolic syndrome. Exercise prescription should be based on knowledge of the changes induced by training, but also on risk assessment, both cardiovascular and non-cardiovascular, of hypertensive subjects. It is generally accepted that for prevention and treatment of hypertension is useful to perform 3-4 weekly sessions of aerobic exercise for 30-45 min, at 50-70% of maximum working capacity. The recommended activities are walking, running, cycling and programs of mixed aerobic exercise. People with hypertension may follow their own personal inclinations, by choosing a sport and doing it at a competitive level. In hypertensive athletes the eligibility for competitive sports activities implies a careful medical evaluation, according to the recently published Italian COCIS cardiac guidelines. PMID:21416836

  8. Third trimester maternal plasma total fibronectin levels in pregnancy-induced hypertension: results of a tertiary center.

    PubMed

    Aydin, Tahsin; Varol, Füsun G; Sayin, Niyazi Cenk

    2006-01-01

    The aim of this study was to evaluate maternal plasma total fibronectin values in pregnancy-associated hypertension in women in the third trimester of pregnancy. A total of 125 pregnant women at the 24th week of gestation participated in this study. Nonpregnant normotensive women were included as control group (n = 30). Plasma samples for fibronectin were obtained at the 24th, 28th, and 32nd weeks of gestation from all pregnant patients. From this cohort, 10 patients met the criteria for the diagnosis of gestational hypertension and 15 women met the stringent requirements of preeclampsia, whereas 100 patients were normotensive later in gestation. Plasma total fibronectin levels were determined by radial immunodiffusion technique. Data were analyzed using the SPSS program. The mean plasma fibronectin levels of the pregnant women in whom gestational hypertension and preeclampsia developed were significantly higher at the 24th, 28th, and 32nd weeks in comparison to normotensive pregnant women (p < 0.001). However, throughout the period from the 24th to 32nd weeks of pregnancy, plasma total fibronectin levels did not exhibit a significant change in normotensive pregnant patients or in patients with preeclampsia and gestational hypertension. There was also no correlation between plasma fibronectin levels and gestational age, mean arterial pressure, birth weight, and 5-minute Apgar scores in all groups (p < 0.05). The elevated maternal plasma fibronectin level over 40 mg/dL is capable of predicting preeclampsia with a sensitivity of 73% and a specificity of 92%. These results suggest that serial plasma fibronectin measurements before 24 weeks' of gestation may be helpful in the early detection of preeclampsia in normotensive gravid women who are destined to become clinically preeclamptic. PMID:16444432

  9. [Rare forms of hypertension : From pheochromocytoma to vasculitis].

    PubMed

    Haller, H; Limbourg, F; Schmidt, B M; Menne, J

    2015-03-01

    Secondary hypertension affects only 5-10?% of hypertensive patients. Screening is expensive and time-consuming and should be performed only in patients for whom there is a high clinical suspicion of secondary hypertension. Clinical signs of secondary forms of hypertension are new-onset hypertension in patients without other risk factors (i.e., family history, obesity, etc.), sudden increase of blood pressure (BP) in a previously stable patient, increased BP in prepubertal children, resistant hypertension, and severe hypertension or hypertensive emergencies. In adults, renal parenchymal and vascular diseases as well as obstructive sleep apnea are the most common causes of secondary hypertension. Medication-induced hypertension and non-adherence to medication have to be ruled out. Of the endocrine causes associated with hypertension, primary aldosteronism is the most common. Other endocrine causes of hypertension such as thyroid disease (hypo- or hyperthyroidism), hypercortisolism (Cushing's syndrome), hyperparathyroidism, and pheochromocytoma are rare. Monogenetic forms of hypertension are mostly of tubular origin and associated with alterations in mineralocorticoid handling or signaling. Rare causes of hypertension also include inflammatory vascular disease. Acute forms of vasculitis may present as "malignant" hypertension with associated thrombotic microangiopathy and organ damage/failure. It is important to diagnose these rare forms of hypertension in order to prevent acute organ damage in these patients or unnecessary invasive treatment strategies. PMID:25700646

  10. Analyses of Sequence Variants in the MYOC Gene and of Single Nucleotide Polymorphisms in the NR3C1 and FKBP5 Genes in Corticosteroid-induced Ocular Hypertension.

    PubMed

    Hogewind, Barend F; Micheal, Shazia; Schoenmaker-Koller, Frederieke E; Hoyng, Carel B; den Hollander, Anneke I

    2014-01-13

    Abstract Background: To perform an independent replication study to determine whether genetic variants in MYOC, NR3C1 and FKBP5 are involved in steroid-induced ocular hypertension. Materials and Methods: A retrospective case-control study was peformed on native Dutch patients who were treated with 4.0?mg intravitreal triamcinolone acetonide (IVTA). The patients were divided into an intraocular hypertension group (intraocular pressure >21?mmHg within a year after IVTA) and a non-intraocular hypertension group. The cohort was genotyped for 31 single-nucleotide polymorphisms (SNPs): 21 in NR3C1 and 10 in FKBP5. In addition, the open reading frame of MYOC was sequenced. Results: A total of 102 patients were included in this study: 58 steroid responders and 44 non-responders. No significant associations were found for the studied SNPs in NR3C1 and FKBP5. Heterozygous amino acid variants were detected in the MYOC gene in two patients of the non-intraocular hypertension group. Conclusions: This study does not confirm a role for genetic variants in the MYOC, NR3C1 and FKBP5 genes in the pathogenesis of corticosteroid-induced ocular hypertension. PMID:24417561

  11. Blood pressure and the susceptibility to renal damage after unilateral nephrectomy and L-NAME-induced hypertension in rats

    Microsoft Academic Search

    Dokkum van R. P. E; H. J. Jacob; A. P. Provoost

    2000-01-01

    BACKGROUND: Fawn-hooded hypertensive (FHH) rats carry several genes which\\u000a determine the susceptibility to develop renal damage, while renal damage\\u000a resistant August x Copenhagen Irish (ACI) rats do not. Kidneys from\\u000a heterozygous (FHH x ACI) F(1) rats, appear to be largely, but not\\u000a completely, protected after blood pressure elevation with\\u000a N(omega)-nitro-L-arginine methyl ester (L-NAME). We examined the role of\\u000a an increased

  12. Role of macrophage PPAR? in experimental hypertension.

    PubMed

    Kriska, Tamas; Cepura, Cody; Gauthier, Kathryn M; Campbell, William B

    2014-01-01

    Targeted disruption of the Alox15 gene makes mice resistant to angiotensin II-, DOCA/salt-, and N(?)-nitro-L-arginine methyl ester (L-NAME)-induced experimental hypertension. Macrophages, a primary source of Alox15, are facilitating this resistance, but the underlying mechanism is not known. Because Alox15 metabolites are peroxisome proliferator-activated receptor (PPAR)? agonists, we hypothesized that activation of macrophage PPAR? is the key step in Alox15 mediation of hypertension. Thioglycollate, used for macrophage elicitation, selectively upregulated PPAR? and its target gene CD36 in peritoneal macrophages of both wild-type (WT) and Alox15(-/-) mice. Moreover, thioglycollate-injected Alox15(-/-) mice became hypertensive upon L-NAME treatment. A similar hypertensive effect was observed with adoptive transfer of thioglycollate-elicited Alox15(-/-) macrophages into Alox15(-/-) recipient mice. The role of PPAR? was further specified by using the selective PPAR? antagonist GW9662. WT mice treated with 50 ?g/kg daily dose of GW9662 for 12 days became resistant to L-NAME-induced hypertension. The PPAR? antagonist treatment also prevented L-NAME-induced hypertension in thioglycollate-injected Alox15(-/-) mice, indicating a PPAR?-mediated effect in macrophage elicitation and the resultant hypertension. These results indicate a regulatory role for macrophage-localized PPAR? in L-NAME-induced experimental hypertension. PMID:24163073

  13. Role of macrophage PPAR? in experimental hypertension

    PubMed Central

    Cepura, Cody; Gauthier, Kathryn M.; Campbell, William B.

    2013-01-01

    Targeted disruption of the Alox15 gene makes mice resistant to angiotensin II-, DOCA/salt-, and N?-nitro-l-arginine methyl ester (l-NAME)-induced experimental hypertension. Macrophages, a primary source of Alox15, are facilitating this resistance, but the underlying mechanism is not known. Because Alox15 metabolites are peroxisome proliferator-activated receptor (PPAR)? agonists, we hypothesized that activation of macrophage PPAR? is the key step in Alox15 mediation of hypertension. Thioglycollate, used for macrophage elicitation, selectively upregulated PPAR? and its target gene CD36 in peritoneal macrophages of both wild-type (WT) and Alox15?/? mice. Moreover, thioglycollate-injected Alox15?/? mice became hypertensive upon l-NAME treatment. A similar hypertensive effect was observed with adoptive transfer of thioglycollate-elicited Alox15?/? macrophages into Alox15?/? recipient mice. The role of PPAR? was further specified by using the selective PPAR? antagonist GW9662. WT mice treated with 50 ?g/kg daily dose of GW9662 for 12 days became resistant to l-NAME-induced hypertension. The PPAR? antagonist treatment also prevented l-NAME-induced hypertension in thioglycollate-injected Alox15?/? mice, indicating a PPAR?-mediated effect in macrophage elicitation and the resultant hypertension. These results indicate a regulatory role for macrophage-localized PPAR? in l-NAME-induced experimental hypertension. PMID:24163073

  14. LIPID METABOLISM PARAMETERS AND RENAL FUNCTION IN HYPERTENSIVE ELDERLY PATIENTS

    Microsoft Academic Search

    Corina Vancea; Corina Serban; Ioana Mozos; Alina P?curari; I. Romosan

    Summary Hypertension is a major cause of morbidity and mortality worldwide. The kidney is an important target of hypertension-induced organ damage. High cholesterol and triglyceride plasma levels have been demonstrated to be independent risk factors for progression of renal disease in humans. The aim of this study was to compare lipid metabolism parameters and renal function of hypertensive patients and

  15. Hormones and Hypertension

    MedlinePLUS

    ... blood pressure increases with age. DiD you know? Primary hypertension (high blood pressure) most often can be controlled ... key role in the start and continuation of primary hypertension. Secondary hypertension is due to other diseases such ...

  16. Vascular Remodeling in Pulmonary Hypertension

    PubMed Central

    Shimoda, Larissa A; Laurie, Steven S.

    2013-01-01

    Pulmonary hypertension is a complex, progressive condition arising from a variety of genetic and pathogenic causes. Patients present with a spectrum of histologic and pathophysiological features, likely reflecting the diversity in underlying pathogenesis. It is widely recognized that structural alterations in the vascular wall contribute to all forms of pulmonary hypertension. Features characteristic of the remodeled vasculature in patients with pulmonary hypertension include increased stiffening of the elastic proximal pulmonary arteries, thickening of the intimal and/or medial layer of muscular arteries, development of vaso-occlusive lesions and the appearance of cells expressing smooth muscle specific markers in normally non-muscular small diameter vessels, resulting from proliferation and migration of pulmonary arterial smooth muscle cells and cellular trans-differentiation. The development of several animal models of pulmonary hypertension has provided the means to explore the mechanistic underpinnings of pulmonary vascular remodeling, although none of the experimental models currently used entirely replicates the pulmonary arterial hypertension observed in patients. Herein, we provide an overview of the histological abnormalities observed in humans with pulmonary hypertension and in preclinical models and discuss insights gained regarding several key signaling pathways contributing to the remodeling process. In particular, we will focus on the roles of ion homeostasis, endothelin-1, serotonin, bone morphogenetic proteins, Rho kinase and hypoxia-inducible factor 1 in pulmonary arterial smooth muscle and endothelial cells, highlighting areas of cross-talk between these pathways and potentials for therapeutic targeting. PMID:23334338

  17. Hypertension, cardiac hypertrophy, and impaired vascular relaxation induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin are associated with increased superoxide.

    PubMed

    Kopf, Phillip G; Huwe, Janice K; Walker, Mary K

    2008-12-01

    The mechanisms by which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases the incidence of human cardiovascular disease are not known. We investigated the degree to which cardiovascular disease develops in mice following subchronic TCDD exposure. Adult male C57BL/6 mice were dosed with vehicle or 300 ng TCDD/kg by oral gavage three times per week for 60 days. Blood pressure was recorded by radiotelemetry and aortic endothelial function was assessed by acetylcholine-induced vasorelaxation. Mean arterial pressure of TCDD-exposed mice was increased significantly by day 4 and between days 7-10, 25-35, and 45-60 with two periods of normalization on days 11-24 and days 36-39. Consistent with a prolonged period of systemic hypertension, heart weight was increased and was associated with concentric left ventricular hypertrophy. Significant increases in superoxide production also were observed in the kidney, heart, and aorta of TCDD-exposed mice. Furthermore, increased aortic superoxide resulted in endothelial dysfunction as demonstrated by significant impairment of acetylcholine-induced vasorelaxation in TCDD-exposed mice, which was restored by tempol, a superoxide dismutase (SOD) mimetic. Our model is the first to definitely demonstrate that sustained AhR activation by TCDD increases blood pressure and induces cardiac hypertrophy, which may be mediated, in part, by increased superoxide. PMID:18850075

  18. Adrenal causes of hypertension: Pheochromocytoma and primary aldosteronism

    Microsoft Academic Search

    William F. Young Jr

    2007-01-01

    The clinical presentations of the patient with pheochromocytoma—a rare endocrine neoplasm—include adrenal incidentaloma, hypertensive\\u000a paroxysms, sustained apparent polygenic hypertension, hypertension in pregnancy, and hypertensive crisis induced by anesthesia.\\u000a Although when undiagnosed a pheochromocytoma can be lethal, it can usually be cured with surgery. Biochemical documentation\\u000a with measurements of fractionated metanephrines and catecholamines should precede imaging studies. Abdomen and pelvis computed

  19. The Incidence of Antihypertensive Drug-induced Side Effects in Patients with Diabetes Mellitus Type 2 and Hypertension

    PubMed Central

    Loga-Zec, Svjetlana; Asceric, Mensura; Loga-Andrijic, Natasa; Kapetanovic, Berina; Zerem, Enver

    2014-01-01

    Objective: To determine types and frequency of side effects of antihypertensive drugs in patients with diabetes mellitus (DM) type 2 and hypertension. Subjects and Methods: We performed a prospective study of 79 patients with DM type 2 and hypertension, randomly selected by systematic sampling, who were followed over a period of six months. Patients were assessed at baseline and once a month measuring following parameters: types of used antihypertensive drugs and frequency of side effects, the values (mmHg) of systolic (SBP) and diastolic blood pressure (DBP). Results: Out of 79 patients, 48/79 (60.8%) were males and 31/79 (39.2%) were females. The median age in males was 53 years (IQR=48 to 55 years), in females was 53 years (IQR=49 to 56 years). There was no statistically significant difference in median age between males and females (P=0.368). There is a statistically significant difference in the values of SBP [?2(5)=312.296, P<0.001] and DBP [?2(5)=216.051, P<0.001] over a period of six months follow-up. The drug side effects were noted in 9/79 (11.4%) patients between 1-2 months, in 6/79 (7.6%) between 2-3 months, in 1/79 (1,3%) between 3-4 months. The most common side effect was cough (11/79 or 13.9%) associated with the combination of ACE inhibitor and thiazide diuretics. In 5/79 (6.3%) patients there were reports of: flushing, palpitations, headache, dizziness and leg edema associated with Ca blockers. Conclusion: The most common side effect of antihypertensive treatment was cough (13.9%) associated with the combination of ACE inhibitor and thiazide diuretic. PMID:25648509

  20. Losartan attenuates chronic cigarette smoke exposure-induced pulmonary arterial hypertension in rats: Possible involvement of angiotensin-converting enzyme-2

    SciTech Connect

    Han Suxia; He Guangming; Wang Tao; Chen Lei; Ning Yunye; Luo Feng; An Jin; Yang Ting; Dong Jiajia; Liao Zenglin; Xu Dan [Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, and Department of Respiratory Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan 610041 (China); Wen Fuqiang, E-mail: wenfuqiang.scu@gmail.co [Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, and Department of Respiratory Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan 610041 (China)

    2010-05-15

    Chronic cigarette smoking induces pulmonary arterial hypertension (PAH) by largely unknown mechanisms. Renin-angiotensin system (RAS) is known to function in the development of PAH. Losartan, a specific angiotensin II receptor antagonist, is a well-known antihypertensive drug with a potential role in regulating angiotensin-converting enzyme-2 (ACE2), a recently found regulator of RAS. To determine the effect of losartan on smoke-induced PAH and its possible mechanism, rats were daily exposed to cigarette smoke for 6 months in the absence and in the presence of losartan. Elevated right ventricular systolic pressure (RVSP), thickened wall of pulmonary arteries with apparent medial hypertrophy along with increased angiotensin II (Ang II) and decreased ACE2 levels were observed in smoke-exposed-only rats. Losartan administration ameliorated pulmonary vascular remodeling, inhibited the smoke-induced RVSP and Ang II elevation and partially reversed the ACE2 decrease in rat lungs. In cultured primary pulmonary artery smooth muscle cells (PASMCs) from 3- and 6-month smoke-exposed rats, ACE2 levels were significantly lower than in those from the control rats. Moreover, PASMCs from 6-month exposed rats proliferated more rapidly than those from 3-month exposed or control rats, and cells grew even more rapidly in the presence of DX600, an ACE2 inhibitor. Consistent with the in vivo study, in vitro losartan pretreatment also inhibited cigarette smoke extract (CSE)-induced cell proliferation and ACE2 reduction in rat PASMCs. The results suggest that losartan may be therapeutically useful in the chronic smoking-induced pulmonary vascular remodeling and PAH and ACE2 may be involved as part of its mechanism. Our study might provide insight into the development of new therapeutic interventions for PAH smokers.

  1. Angiotensin-(1-7) Blockade Attenuates Captopril- or Hydralazine-Induced Cardiovascular Protection in Spontaneously Hypertensive Rats-Treated with L-NAME

    PubMed Central

    Benter, Ibrahim F.; Yousif, Mariam H. M.; Al-Saleh, Fatemah M.; Chappell, Raj Raghupathy Mark C.; Diz, Debra I.

    2011-01-01

    We assessed the contribution of angiotensin-(1-7) [Ang-(1-7)] to captopril-induced cardiovascular protection in spontaneously hypertensive rats (SHR) chronically treated with the nitric oxide synthesis inhibitor L-NAME (SHR-L). L-NAME (80 mg/L) administration for three weeks increased mean arterial pressure (MAP) from 196 ± 6 mmHg to 229 ± 3 mmHg (p<0.05). Treatment of SHR-L with Ang-(1-7) antagonist, [D-Ala7]-Angiotensin-(1-7) (A779; 744 ?g/kg/day ip) further elevated MAP to 253 ± 6 mmHg (p<0.05 vs. SHR-L or SHR). Moreover, A779 treatment attenuated the reduction in MAP and proteinuria by either captopril (300 mg/L in drinking water) or hydralazine (1.5 mg/kg/day ip). In isolated perfused hearts, the recovery of left ventricular function from global ischemia was enhanced by captopril or hydralazine treatment, and was exacerbated with A779. The Ang-(1-7) antagonist attenuated the beneficial effects of captopril and hydralazine on cardiac function. Recovery from global ischemia was also improved in isolated SHR-L hearts acutely perfused with captopril during both the perfusion and reperfusion periods. The acute administration of A779 reduced the beneficial actions of captopril to improve recovery following ischemia. We conclude that during periods of reduced nitric oxide availability, endogenous Ang-(1-7) plays a protective role to effectively buffer the increase in blood pressure and renal injury, as well as the recovery from cardiac ischemia. Moreover, Ang-(1-7) contributes to the blood pressure lowering and tissue protective actions of captopril and hydralazine in a model of severe hypertension and end-organ damage. PMID:21326110

  2. Contribution of calcium-activated chloride channel to elevated pulmonary artery pressure in pulmonary arterial hypertension induced by high pulmonary blood flow

    PubMed Central

    Wang, Kai; Chen, Chuansi; Ma, Jianfa; Lao, Jinquan; Pang, Yusheng

    2015-01-01

    The correlation between calcium-activated chloride channel (CaCC) and pulmonary arterial hypertension (PAH) induced by high pulmonary blood flow remains uncertain. In this study, we investigated the possible role and effects of CaCC in this disease. Sixty rats were randomly assigned to normal, sham, and shunt groups. Rats in the shunt group underwent abdominal aorta and inferior vena cava shunt surgery. The pulmonary artery pressure was measured by catheterization. Pathological changes, right ventricle hypertrophy index (RVHI), arterial wall area/vessel area (W/V), and arterial wall thickness/vessel external diameter (T/D) were analyzed by optical microscopy. Electrophysiological characteristics of pulmonary arterial smooth muscle cells (PASMCs) were investigated using patch clamp technology. After 11 weeks of shunting, PAH and pulmonary vascular structural remodeling (PVSR) developed, accompanied by increased pulmonary pressure and pathological interstitial pulmonary changes. Compared with normal and sham groups, pulmonary artery pressure, RVHI, W/V, and T/D of the shunt group rats increased significantly. Electrophysiological results showed primary CaCC characteristics. Compared with normal and sham groups, membrane capacitance and current density of PASMCs in the shunt group increased significantly, which were subsequently attenuated following chloride channel blocker niflumic acid (NFA) treatment. To conclude, CaCC contributed to PAH induced by high pulmonary blood flow and may represent a potential target for treatment of PAH. PMID:25755701

  3. Rosiglitazone Attenuated Endothelin-1-Induced Vasoconstriction of Pulmonary Arteries in the Rat Model of Pulmonary Arterial Hypertension via Differential Regulation of ET-1 Receptors

    PubMed Central

    Huang, Yu; Wang, Nanping

    2014-01-01

    Pulmonary arterial hypertension (PAH) is a fatal disease characterized by a progressive increase in pulmonary arterial pressure leading to right ventricular failure and death. Activation of the endothelin (ET)-1 system has been demonstrated in plasma and lung tissue of PAH patients as well as in animal models of PAH. Recently, peroxisome proliferator-activated receptor ? (PPAR?) agonists have been shown to ameliorate PAH. The present study aimed to investigate the mechanism for the antivasoconstrictive effects of rosiglitazone in response to ET-1 in PAH. Sprague-Dawley rats were exposed to chronic hypoxia (10% oxygen) for 3 weeks. Pulmonary arteries from PAH rats showed an enhanced vasoconstriction in response to ET-1. Treatment with PPAR? agonist rosiglitazone (20?mg/kg per day) with oral gavage for 3 days attenuated the vasocontractive effect of ET-1. The effect of rosiglitazone was lost in the presence of L-NAME, indicating a nitric oxide-dependent mechanism. Western blotting revealed that rosiglitazone increased ETBR but decreased ETAR level in pulmonary arteries from PAH rats. ETBR antagonist A192621 diminished the effect of rosiglitazone on ET-1-induced contraction. These results demonstrated that rosiglitazone attenuated ET-1-induced pulmonary vasoconstriction in PAH through differential regulation of the subtypes of ET-1 receptors and, thus, provided a new mechanism for the therapeutic use of PPAR? agonists in PAH. PMID:24701204

  4. Aspirin-induced AMP-activated protein kinase activation regulates the proliferation of vascular smooth muscle cells from spontaneously hypertensive rats

    SciTech Connect

    Sung, Jin Young [Department of Pharmacology, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of)] [Department of Pharmacology, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of); Choi, Hyoung Chul, E-mail: hcchoi@med.yu.ac.kr [Department of Pharmacology, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of)

    2011-05-06

    Highlights: {yields} Aspirin-induced AMPK phosphorylation was greater in VSMC from SHR than WKY. {yields} Aspirin-induced AMPK phosphorylation inhibited proliferation of VSMC from SHR. {yields} Low basal AMPK phosphorylation in SHR elicits increased VSMC proliferation. {yields} Inhibition of AMPK restored decreased VSMC proliferation by aspirin in SHR. {yields} Aspirin exerts anti-proliferative effect through AMPK activation in VSMC from SHR. -- Abstract: Acetylsalicylic acid (aspirin), used to reduce risk of cardiovascular disease, plays an important role in the regulation of cellular proliferation. However, mechanisms responsible for aspirin-induced growth inhibition are not fully understood. Here, we investigated whether aspirin may exert therapeutic effects via AMP-activated protein kinase (AMPK) activation in vascular smooth muscle cells (VSMC) from wistar kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Aspirin increased AMPK and acetyl-CoA carboxylase phosphorylation in a time- and dose-dependent manner in VSMCs from WKY and SHR, but with greater efficacy in SHR. In SHR, a low basal phosphorylation status of AMPK resulted in increased VSMC proliferation and aspirin-induced AMPK phosphorylation inhibited proliferation of VSMCs. Compound C, an AMPK inhibitor, and AMPK siRNA reduced the aspirin-mediated inhibition of VSMC proliferation, this effect was more pronounced in SHR than in WKY. In VSMCs from SHR, aspirin increased p53 and p21 expression and inhibited the expression of cell cycle associated proteins, such as p-Rb, cyclin D, and cyclin E. These results indicate that in SHR VSMCs aspirin exerts anti-proliferative effects through the induction of AMPK phosphorylation.

  5. Correlation of bevacizumab-induced hypertension and outcome in the BOXER study, a phase II study of capecitabine, oxaliplatin (CAPOX) plus bevacizumab as peri-operative treatment in 45 patients with poor-risk colorectal liver-only metastases unsuitable for upfront resection

    PubMed Central

    Dewdney, A; Cunningham, D; Barbachano, Y; Chau, I

    2012-01-01

    Background: Bevacizumab is commonly used in combination with chemotherapy in the treatment of metastatic colorectal cancer, but to date, despite extensive research, no predictive or prognostic biomarkers for bevacizumab have been identified. The development of bevacizumab-induced arterial hypertension has recently been suggested as a potential predictive biomarker. Methods: Blood pressure was recorded during the BOXER study, a phase II study of capecitabine, oxaliplatin (CAPOX) plus bevacizumab as peri-operative treatment in 45 patients with poor-risk colorectal liver-only metastases unsuitable for upfront resection. In this analysis, the development of bevacizumab-induced hypertension was correlated with clinical outcomes. Results: Fifteen percent of patients developed ?grade 1 hypertension while receiving neoadjuvant chemotherapy, and 4% developed grade 3 hypertension. There was no correlation between the development of hypertension and radiological response rate (P=0.642), progression-free survival (P=0.644) or overall survival (P=0.480) in those who developed hypertension compared with those who did not. Conclusion: Bevacizumab-induced hypertension did not predict radiological response or survival in our study. The results highlight a number of important issues regarding the use of hypertension as a biomarker. PMID:22531628

  6. Microarray analysis after umbilical cord blood derived mesenchymal stem cells injection in monocrotaline-induced pulmonary artery hypertension rats

    PubMed Central

    Lee, Jae Chul; Kim, Kwan Chang; Yang, Yoon Sun; Oh, Wonil; Choi, Soo Jin

    2014-01-01

    Pulmonary arterial hypertension (PAH) is associated with structural alterations of lung vasculature. PAH is still a devastating disease needing an aggressive therapeutic approach. Despite the therapeutic potential of human umbilical cord mesenchymal stem cells (MSCs), the molecular parameters to define the stemness remain largely unknown. Using high-density oligonucleotide microarrays, the differential gene expression profiles between a fraction of mononuclear cells of human umbilical cord blood (UCB) and its MSC subpopulation were obtained. Of particular interest was a subset of 46 genes preferentially expressed at 7-fold or higher in the group treated with human UCB-MSCs. This subset contained numerous genes involved in the inflammatory response, immune response, lipid metabolism, cell adhesion, cell migration, cell differentiation, apoptosis, cell growth, transport, cell proliferation, transcription, and signal transduction. Our results provide a foundation for a more reproducible and reliable quality control using genotypic analysis for the definition of human UCB-MSCs. Therefore, our results will provide a basis for studies on molecular mechanisms controlling the core properties of human MSCs. PMID:25548719

  7. An Interaction of Renin-Angiotensin and Kallikrein-Kinin Systems Contributes to Vascular Hypertrophy in Angiotensin II-Induced Hypertension: In Vivo and In Vitro Studies

    PubMed Central

    Ceravolo, Graziela S.; Montezano, Augusto C.; Jordão, Maria T.; Akamine, Eliana H.; Costa, Tiago J.; Takano, Ana P.; Fernandes, Denise C.; Barreto-Chaves, Maria L.; Laurindo, Francisco R.; Tostes, Rita C.; Fortes, Zuleica B.; Chopard, Renato P.; Touyz, Rhian M.; Carvalho, Maria Helena C.

    2014-01-01

    The kallikrein-kinin and renin-angiotensin systems interact at multiple levels. In the present study, we tested the hypothesis that the B1 kinin receptor (B1R) contributes to vascular hypertrophy in angiotensin II (ANG II)–induced hypertension, through a mechanism involving reactive oxygen species (ROS) generation and extracellular signal-regulated kinase (ERK1/2) activation. Male Wistar rats were infused with vehicle (control rats), 400 ng/Kg/min ANG II (ANG II rats) or 400 ng/Kg/min ANG II plus B1 receptor antagonist, 350 ng/Kg/min des-Arg9-Leu8-bradykinin (ANGII+DAL rats), via osmotic mini-pumps (14 days) or received ANG II plus losartan (10 mg/Kg, 14 days, gavage - ANG II+LOS rats). After 14 days, ANG II rats exhibited increased systolic arterial pressure [(mmHg) 184±5.9 vs 115±2.3], aortic hypertrophy; increased ROS generation [2-hydroxyethidium/dihydroethidium (EOH/DHE): 21.8±2.7 vs 6.0±1.8] and ERK1/2 phosphorylation (% of control: 218.3±29.4 vs 100±0.25]. B1R expression was increased in aortas from ANG II and ANG II+DAL rats than in aortas from the ANG II+LOS and control groups. B1R antagonism reduced aorta hypertrophy, prevented ROS generation (EOH/DHE: 9.17±3.1) and ERK1/2 phosphorylation (137±20.7%) in ANG II rats. Cultured aortic vascular smooth muscle cells (VSMC) stimulated with low concentrations (0.1 nM) of ANG II plus B1R agonist exhibited increased ROS generation, ERK1/2 phosphorylation, proliferating-cell nuclear antigen expression and [H3]leucine incorporation. At this concentration, neither ANG II nor the B1R agonist produced any effects when tested individually. The ANG II/B1R agonist synergism was inhibited by losartan (AT1 blocker, 10 µM), B1R antagonist (10 µM) and Tiron (superoxide anion scavenger, 10 mM). These data suggest that B1R activation contributes to ANG II-induced aortic hypertrophy. This is associated with activation of redox-regulated ERK1/2 pathway that controls aortic smooth muscle cells growth. Our findings highlight an important cross-talk between the DABK and ANG II in the vascular system and contribute to a better understanding of the mechanisms involved in vascular remodeling in hypertension. PMID:25369284

  8. Apelin and pulmonary hypertension

    PubMed Central

    Andersen, Charlotte U.; Hilberg, Ole; Mellemkjær, Søren; Nielsen-Kudsk, Jens E.; Simonsen, U.

    2011-01-01

    Pulmonary arterial hypertension (PAH) is a devastating disease characterized by pulmonary vasoconstriction, pulmonary arterial remodeling, abnormal angiogenesis and impaired right ventricular function. Despite progress in pharmacological therapy, there is still no cure for PAH. The peptide apelin and the G-protein coupled apelin receptor (APLNR) are expressed in several tissues throughout the organism. Apelin is localized in vascular endothelial cells while the APLNR is localized in both endothelial and smooth muscle cells in vessels and in the heart. Apelin is regulated by hypoxia inducible factor -1? and bone morphogenetic protein receptor-2. Patients with PAH have lower levels of plasma-apelin, and decreased apelin expression in pulmonary endothelial cells. Apelin has therefore been proposed as a potential biomarker for PAH. Furthermore, apelin plays a role in angiogenesis and regulates endothelial and smooth muscle cell apoptosis and proliferation complementary and opposite to vascular endothelial growth factor. In the systemic circulation, apelin modulates endothelial nitric oxide synthase (eNOS) expression, induces eNOS-dependent vasodilatation, counteracts angiotensin-II mediated vasoconstriction, and has positive inotropic and cardioprotective effects. Apelin attenuates vasoconstriction in isolated rat pulmonary arteries, and chronic treatment with apelin attenuates the development of pulmonary hypertension in animal models. The existing literature thus renders APLNR an interesting potential new therapeutic target for PH. PMID:22140623

  9. Hyperreninemic hypertension secondary to radiation nephritis in a child

    Microsoft Academic Search

    William C. Hulbert Jr.; Lawrence J. Ettinger; Beverly E. Wood; Virginia M. Anderson; Thomas C. Putnam; Ronald Rabinowitz

    1985-01-01

    Radiation injury to the kidney, first reported almost eighty years ago, may vary from subclinical changes in renal blood flow or enzyme activity to clinically significant hypertension and\\/or renal failure. A child with radiation-induced hyperreninemic hypertension was cured by nephrectomy. The microscopic, subclinical, and clinical changes of irradiation injury are reviewed. The etiology of radiation-induced hypertension, methods of radioprotection, and

  10. Hyperreninemic hypertension secondary to radiation nephritis in a child

    SciTech Connect

    Hulbert, W.C. Jr.; Ettinger, L.J.; Wood, B.P.; Anderson, V.M.; Putnam, T.C.; Rabinowitz, R.

    1985-08-01

    Radiation injury to the kidney, first reported almost eighty years ago, may vary from subclinical changes in renal blood flow or enzyme activity to clinically significant hypertension and/or renal failure. A child with radiation-induced hyperreninemic hypertension was cured by nephrectomy. The microscopic, subclinical, and clinical changes of irradiation injury are reviewed. The etiology of radiation-induced hypertension, methods of radioprotection, and early detection of radiation renal damage are discussed.

  11. Abnormal thallium kinetics in postoperative coarctation of the aorta: evidence for diffuse hypertension-induced vascular pathology

    SciTech Connect

    Kimball, B.P.; Shurvell, B.L.; Mildenberger, R.R.; Houle, S.; McLaughlin, P.R.

    1986-03-01

    After operative correction of congenital coarctation of the aorta, patients continue to have excess cardiovascular mortality, including manifestations of ischemic heart disease. Previous morphologic studies support the concept of direct hypertensive vascular injury in these patients. To determine whether abnormalities of myocardial perfusion were present in an asymptomatic group of patients with coarctation repair, 18 men and 9 women with a mean age of 26 years (range 19 to 41) were studied between 2 and 25 years after operative correction. Stress electrocardiography and quantitative thallium imaging by a circumferential profile technique were used. These patients were compared with a normal group, statistically defined as having a less than 1% prevalence of significant obstructive coronary artery disease. The postoperative coarctation group demonstrated a reduction in global thallium redistribution in each view analyzed. As compared with findings in the control subjects, thallium washout in the anterior view (41.9 versus 48.6%, p = 0.02) and left anterior oblique projection (40.5 versus 48.2%, p = 0.007) was significantly diminished. Although the postoperative coarctation group had a lower thallium redistribution rate in the lateral view (41.4 versus 46.3%, p = 0.09) this difference did not reach statistical significance because of the intrinsic variability of this projection. Plots of the median percent thallium washout revealed independence from circumferential profile angle, indicating global abnormalities in perfusion. No correlation between clinical variables and thallium kinetics could be established, suggesting marked individual variability in the development of this vascular lesion. The observation of abnormal thallium kinetics in patients with coarctation repair may have consequences for long-term follow-up and therapy.

  12. Disease progression in iridocorneal angle tissues of BMP2-induced ocular hypertensive mice with optical coherence tomography

    PubMed Central

    Li, Guorong; Farsiu, Sina; Qiu, Jianming; Dixon, Angela; Song, Chunwei; McKinnon, Stuart J.; Yuan, Fan; Gonzalez, Pedro

    2014-01-01

    Purpose The goal of the present study was to test for the first time whether glaucomatous-like disease progression in a mouse can be assessed morphologically and functionally with spectral domain optical coherence tomography (SD-OCT). Methods We monitored progressive changes in conventional outflow tissues of living mice overexpressing human bone morphogenetic protein 2 (BMP2), a model for glaucoma. Intraocular pressure (IOP) and outflow tissue morphology/Young's modulus were followed in mice for 36 days with rebound tonometry and SD-OCT, respectively. Results were compared to standard histological methods. Outflow facility was calculated from flow measurements with direct cannulation of anterior chambers subjected to three sequential pressure steps. Results Overexpression of BMP2 significantly elevated IOP in a biphasic manner over time compared to mice that overexpressed green fluorescent protein in outflow cells and naïve controls. SD-OCT revealed changes in outflow tissues overexpressing BMP2 that corresponded with the timing of the IOP phases and decreased outflow facility. In the first phase, the angle was open, but the trabecular meshwork and the cornea were thickened. OCT detected increased trabecular meshwork stiffness after provocative IOP challenges of the BMP2 eyes, which corresponded to increased collagen deposition with transmission electron microscopy. In contrast, the angle was closed in the second phase. IOP elevation over 36 days due to BMP2 overexpression resulted in significant retinal ganglion cell and axon loss. Conclusions Although not a feasible open-angle glaucoma model, the BMP2 mice were useful for demonstrating the utility of SD-OCT in following disease progression and differentiating between two forms of ocular pathology over time that resulted in ocular hypertension. PMID:25558173

  13. Simvastatin decreased coenzyme Q in the left ventricle and skeletal muscle but not in the brain and liver in L-NAME-induced hypertension.

    PubMed

    Kucharská, J; Gvozdjáková, A; Simko, F

    2007-01-01

    Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (statins) have been proven to reduce effectively cholesterol level and morbidity and mortality in patients with coronary heart disease and/or dyslipoproteinemia. Statins inhibit synthesis of mevalonate, a precursor of both cholesterol and coenzyme Q (CoQ). Inhibited biosynthesis of CoQ may be involved in some undesirable actions of statins. We investigated the effect of simvastatin on tissue CoQ concentrations in the rat model of NO-deficient hypertension induced by chronic L-NAME administration. Male Wistar rats were treated daily for 6 weeks with L-NAME (40 mg/kg) or with simvastatin (10 mg/kg), another group received simultaneously L-NAME and simvastatin in the same doses. Coenzyme Q(9) and Q(10) concentrations were analyzed by high performance liquid chromatography. L-NAME and simvastatin alone had no effect on CoQ concentrations. However, simultaneous application of L-NAME and simvastatin significantly decreased concentrations of both CoQ homologues in the left ventricle and slightly decreased CoQ(9) concentration in the skeletal muscle. No effect was observed on CoQ level in the liver and brain. We conclude that the administration of simvastatin under the condition of NO-deficiency reduced the level of CoQ in the heart and skeletal muscle what may participate in adverse effect of statins under certain clinical conditions. PMID:17824807

  14. Reducing TRPC1 Expression through Liposome-Mediated siRNA Delivery Markedly Attenuates Hypoxia-Induced Pulmonary Arterial Hypertension in a Murine Model

    PubMed Central

    Zhen, Yen-Yi; Lu, Hung-I; Sung, Pei-Hsun; Chang, Li-Teh; Tsai, Tzu-Hsien; Sheu, Jiunn-Jye; Chen, Yung-Lung; Chua, Sarah; Chang, Hsueh-Wen; Lee, Fan-Yen; Yip, Hon-Kan

    2014-01-01

    We tested the hypothesis that Lipofectamine siRNA delivery to deplete transient receptor potential cation channel (TRPC) 1 protein expression can suppress hypoxia-induced pulmonary arterial hypertension (PAH) in mice. Adult male C57BL/6 mice were equally divided into group 1 (normal controls), group 2 (hypoxia), and group 3 (hypoxia + siRNA TRPC1). By day 28, right ventricular systolic pressure (RVSP), number of muscularized arteries, right ventricle (RV), and lung weights were increased in group 2 than in group 1 and reduced in group 3 compared with group 2. Pulmonary crowded score showed similar pattern, whereas number of alveolar sacs exhibited an opposite pattern compared to that of RVSP in all groups. Protein expressions of TRPCs, HIF-1?, Ku-70, apoptosis, and fibrosis and pulmonary mRNA expressions of inflammatory markers were similar pattern, whereas protein expressions of antifibrosis and VEGF were opposite to the pattern of RVSP. Cellular markers of pulmonary DNA damage, repair, and smooth muscle proliferation exhibited a pattern similar to that of RVSP. The mRNA expressions of proapoptotic and hypertrophy biomarkers displayed a similar pattern, whereas sarcomere length showed an opposite pattern compared to that of RVSP in all groups. Lipofectamine siRNA delivery effectively reduced TRPC1 expression, thereby attenuating PAH-associated RV and pulmonary arteriolar remodeling. PMID:25587286

  15. Renal cortex remodeling in streptozotocin-induced diabetic spontaneously hypertensive rats treated with olive oil, palm oil and fish oil from Menhaden.

    PubMed

    Medeiros, Fernanda J; Aguila, Marcia B; Mandarim-de-Lacerda, Carlos A

    2006-12-01

    We studied the effects of edible oils intake on the renal cortical structure of streptozotocin-induced diabetic (Db) and non-diabetic spontaneously hypertensive rats (SHR). Male SHR divided into 5 groups were studied during 6 weeks: one non-diabetic SHR group and four diabetic SHR groups (three groups received by gavage olive, palm or fish oil). Kidneys were analyzed by light microscopy and stereology. Oils intake did not change the plasma glucose levels. The blood pressure (BP) was lower in SHR-Db than in SHR, but SHR-Db-fish oil showed the lowest BP. Creatinine clearance was different between diabetic SHR and non-diabetic SHR, but not between treated SHR-Db and untreated SHR-Db. The renal cortex showed scars surrounding obsolete glomeruli with inflammatory infiltrate mainly in untreated SHR-Db. The olive oil, palm oil and mainly fish oil intake retard the usual loss of glomeruli and attenuate the renal cortex adverse remodeling of Db and non-Db SHR. PMID:16919431

  16. Low renin hypertension

    PubMed Central

    Sahay, Manisha; Sahay, Rakesh K.

    2012-01-01

    Low renin hypertension is an important and often underdiagnosed cause of hypertension. It may be associated with high aldosterone levels as in Conn's syndrome or low aldosterone levels as in Liddle syndrome, and syndrome of apparent mineralocorticoid excess, glucocorticoid remediable hypertension etc. Some forms of essential hypertension are also associated with low renin levels. Hypokalemia may be an important finding in low renin hypertension. The aldosterone to renin ratio helps in correct diagnosis. The treatment varies with etiology hence an accurate diagnosis is essential. Aldosterone antagonists play an important role in medical management of some varieties of low renin hypertension. PMID:23087856

  17. Refeeding hypertension in dietary obesity

    SciTech Connect

    Ernsberger, P.; Nelson, D.O. (Northwestern Univ. Medical School, Chicago, IL (USA))

    1988-01-01

    A novel model of nutritionally induced hypertension in the rat is described. Dietary obesity was produced by providing sweet milk in addition to regular chow, which elicited a 52% increase in caloric intake. Despite 54% greater body weight gain and 139% heavier retroperitoneal fat pads, 120 days of overfeeding failed to increase systolic pressure in the conscious state or mean arterial pressure under urethan anesthesia. In contrast, mild hypertension developed in intermittantly fasted obese animals. The first 4-day supplemented fast was initiated 4 wk after the introduction of sweet milk, when the animals were 47 g overweight relative to chow-fed controls. Thereafter, 4 days of starvation were alternated with 2 wk of refeeding for a total of 4 cycles. A rapid fall in systolic blood pressure accompanied the onset of supplemented fasting and was maintained thereafter. With refeeding, blood pressure rose precipitously, despite poststarvation anorexia. Blood pressure tended to rise slightly over the remainder of the realimentation period. After the 4th supplemented fast, hypertension was sustained during 30 days of refeeding. Cumulative caloric intake in starved-refed rats fell within 2% of that in chow-fed controls. Refeeding hypertension appeared to be due to increased sympathetic nervous activity, since (1) cardiac {beta}-adrenergic receptors were downregulated, as indicated by a 40% decrease in the maximum binding of ({sup 3}H)dihydroalpranolol; and (2) the decrease in heart rate as a result of {beta}-blockade was enhanced. Refeeding hypertension in the dietary obese rat may be a potential animal model for some forms of human obesity-related hypertension.

  18. Heart rate variability in hypertensive subjects

    Microsoft Academic Search

    Gianfranco Piccirillo; Maria Rita Munizzi; Filippo L. Fimognari; Vincenzo Marigliano

    1996-01-01

    Hypertension is often associated with findings of sympathetic hyperactivity. Evidence shows that adrenergic receptor stimulation can induce left ventricular hypertrophy. Using an autoregressive algorithm in a power spectrum analysis of heart-rate variability in 14 subjects with mild hypertension (mean age 41 ± 9.0 years) and 9 age-matched normotensives we compared autonomic nervous system function at baseline (rest) and during sympathetic

  19. What Is Pulmonary Hypertension?

    MedlinePLUS

    ... Dizziness Shortness of breath Symptoms and diagnosis of primary pulmonary hypertension (PPH) can be tricky. Early on, you may ... a definite health problem that needs treatment. Although primary pulmonary hypertension (PPH) is rare, diagnosing and treating PPH is ...

  20. Cardiovascular hypertensive emergencies.

    PubMed

    Papadopoulos, D P; Sanidas, E A; Viniou, N A; Gennimata, V; Chantziara, V; Barbetseas, I; Makris, T K

    2015-02-01

    Inevitably, a small proportion of patients with systematic hypertension will develop hypertensive crisis at some point. Hypertensive crises can be divided into hypertensive emergency or hypertensive urgency according to the presence or lack of acute target organ damage. In this review, we discuss cardiovascular hypertensive emergencies, including acute coronary syndrome, aortic dissection, congestive heart failure, and sympathomimetic hypertensive crises, including those caused by cocaine use. Each presents in a unique fashion, although some hypertensive emergency patients report nonspecific symptoms. Treatment includes several effective and rapid-acting medications to safely reduce the blood pressure, protect remaining end-organ function, relieve symptoms, minimize the risk of complications, and thereby improve patient outcomes. PMID:25620633

  1. Sex-specific immune modulation of primary hypertension.

    PubMed

    Sandberg, Kathryn; Ji, Hong; Hay, Meredith

    2015-04-01

    It is well known that the onset of essential hypertension occurs earlier in men than women. Numerous studies have shown sex differences in the vasculature, kidney and sympathetic nervous system contribute to this sex difference in the development of hypertension. The immune system also contributes to the development of hypertension; however, sex differences in immune system modulation of blood pressure (BP) and the development of hypertension has only recently begun to be explored. Here we review findings on the effect of one's sex on the immune system and specifically how these effects impact BP and the development of primary hypertension. We also propose a hypothesis for why mechanisms underlying inflammation-induced hypertension are sex-specific. These studies underscore the value of and need for studying both sexes in the basic science exploration of the pathophysiology of hypertension as well as other diseases. PMID:25498375

  2. Effects of diet on exaggerated natriuresis in hypertension.

    PubMed

    Chrysant, S G; Lindeman, R D

    1981-01-01

    The effects of high and low salt diet on exaggerated natriuresis after volume expansion were examined in two groups of hypertensive patients, 6 with labile and 6 with fixed uncomplicated essential hypertension. Fixed hypertensives eliminated the administered salt-load faster than the labile hypertensives, and diet had no effect on the exaggerated natriuresis of both groups. No association was observed between plasma renin activity and natriuresis in both groups of patients. We conclude that, 1) diet did not affect the saline-induced natriuresis in hypertensive patients, 2) there was no apparent association between plasma renin activity and exaggerated natriuresis in hypertension, 3) other factors such as the capacitance system and vasopressin may play an important role in volume expansion natriuresis, especially in fixed hypertensives. PMID:7472092

  3. Secondary Forms of Hypertension

    Microsoft Academic Search

    Kjell Tullus

    \\u000a In most studies, hypertension in children has been secondary to an identifiable cause in a large majority of those studied\\u000a (1,2). This has changed during the relatively recent epidemic of childhood obesity, where primary hypertension in many centers\\u000a now is the most common cause form of hypertension (3). In adults primary hypertension is the dominating diagnosis. This chapter will discuss

  4. Mechanism of garlic (Allium sativum) induced reduction of hypertension in 2K-1C rats: a possible mediation of Na\\/H exchanger isoform-1

    Microsoft Academic Search

    K. K. Al-Qattan; I. Khan; M. A. Alnaqeeb; M. Ali

    2003-01-01

    Garlic causes reduction in blood pressure (BP), however the role of Na\\/H exchanger (NHE) which mediates hypertension and related tissue-damage is poorly understood. In this study the effect of an established dose of raw garlic extract was investigated on the expression of NHE-1 and -3 and sodium pump activity in a 2K-1C model of hypertension in rats. 2K-1C animals showed

  5. Hypertension in developing countries.

    PubMed

    Tibazarwa, Kemi B; Damasceno, Albertino A

    2014-05-01

    The past 2 decades have seen a considerable global increase in cardiovascular disease, with hypertension remaining by far the most common. More than one-third of adults in Africa are hypertensive; as in the urban populations of most developing countries. Being a condition that occurs with relatively few symptoms, hypertension remains underdetected in many countries; especially in developing countries where routine screening at any point of health care is grossly underutilized. Because hypertension is directly related to cardiovascular disease, this has led to hypertension being the leading cause of adverse cardiovascular outcomes, as a result of patients living, often unknowingly, with uncontrolled hypertension for prolonged periods of time. In Africa, hypertension is the leading cause of heart failure; whereas at global levels, hypertension is responsible for more than half of deaths from stroke, just less than half of deaths from coronary artery disease, and for more than one-tenth of all global deaths. In this review, we discuss the escalating occurrence of hypertension in developing countries, before exploring the strengths and weaknesses of different measures to control hypertension, and the challenges of adopting these measures in developing countries. On a broad level, these include steps to curb the ripple effect of urbanization on the health and disease profile of developing societies, and suggestions to improve loopholes in various aspects of health care delivery that affect surveillance and management of hypertension. Furthermore, we consider how the industrial sectors' contributions toward the burden of hypertension can also be the source of the solution. PMID:24786443

  6. Primary Prevention of Hypertension

    E-print Network

    Bandettini, Peter A.

    Primary Prevention of Hypertension: Clinical and Public Health Advisory from the National High NIH PUBLICATION NO. 02-5076 NOVEMBER 2002 Primary Prevention of Hypertension: Clinical and Public LIFETIME BURDEN OF ELEVATED BLOOD PRESSURE 3 APPROACHES TO PRIMARY PREVENTION OF HYPERTENSION 4 Population

  7. Quantitative left ventricular contractility analysis under stress: a new practical approach in follow-up of hypertensive patients

    Microsoft Academic Search

    F Yalçin; H Yalçin; N Küçükler; T P Abraham

    2011-01-01

    Excessive sympathetic activity and stress-induced left ventricular (LV) hypercontractility have been described in hypertensive LV hypertrophy. Recent quantitative data have shown that hypertensive LV hypertrophy is associated with preserved global LV function. However, progression of uncontrolled hypertension have detrimental effects on both the ejection fraction (EF) and LV contractile response to stress. Hypertensive LV hypertrophy has some common characteristics, including

  8. Chronic central nervous system MC3/4R blockade attenuates hypertension induced by nitric oxide synthase inhibition but not by angiotensin II infusion.

    PubMed

    da Silva, Alexandre A; do Carmo, Jussara M; Dubinion, John H; Bassi, Mirian; Mokhtarpouriani, Kasra; Hamza, Shereen M; Hall, John E

    2015-01-01

    We examined whether central melanocortin 3 and 4 receptor (MC3/4R) blockade attenuates the blood pressure (BP) responses to chronic L-NAME or angiotensin II (Ang II) infusion in Sprague-Dawley rats implanted with telemetry transmitters, venous catheters, and intracerebroventricular cannula into the lateral ventricle. After 5 days of control measurements, L-NAME (10 ?g/kg/min IV, groups 1 and 2) or Ang II (10 ng/kg/min IV, groups 3 and 4) were infused for 24 days, and starting on day 7 of L-NAME or Ang II infusion, the MC3/4R antagonist SHU-9119 (24 nmol/d, n=6/group; groups 1 and 3) or vehicle (saline 0.5 ?L/h, n=6/group; groups 2 and 4) was infused intracerebroventricularly for 10 days. A control normotensive group also received SHU-9119 for 10 days (n=5). L-NAME and Ang II increased BP by 40±3 and 56±5 mm Hg, respectively, although heart rate was slightly reduced. MC3/4R blockade doubled food intake and reduced heart rate (?40 to ?50 bpm) in all groups. MC3/4R blockade caused only a small reduction in BP in normotensive group (4 mm Hg) and no change in rats receiving Ang II, although markedly reducing BP by 21±4 mm Hg in L-NAME-treated rats. After SHU-9119 infusion was stopped, food intake, heart rate, and BP gradually returned to values observed before SHU-9119 infusion was started. Ganglionic blockade at the end of L-NAME or Ang II infusion caused similar BP reduction in both groups. These results suggest that the brain MC3/4R contributes, at least in part, to the hypertension induced by chronic L-NAME infusion but not by Ang II. PMID:25287400

  9. Vascular relaxation and cyclic guanosine monophosphate in hypertension

    SciTech Connect

    Otsuka, Y.; DiPiero, A.; Lockette, W.

    1986-03-01

    Isolated aortae from hypertensive rats have a decreased relaxation response to acetylcholine (Ach), A23187, and nitroprusside (SNP). Since cyclic guanosine monophosphate (cGMP) has been shown to increase in response to these vasodilators, the authors measured cGMP in response to these agents in isolated aortae from normotensive rats and DOCA, 1K1C, and coarctation induced hypertension. cGMP was measured by radioimmunoassay in vessels after exposure to phenylephrine followed by either Ach, A23187, or SNP. The aortae from the hypertensive rats had decreased basal levels of cGMP and attenuated increases in cGMP in response to Ach and A23187. Rises in cGMP in response to SNP were also attenuated in aortae from the hypertensive rats, even at concentrations which induced similar relaxation in normotensive and hypertensive blood vessels. The data suggest that changes in cGMP do not necessarily reflect changes in endothelium independent vascular relaxation in hypertension.

  10. Altered skin flowmotion in hypertensive humans.

    PubMed

    Bruning, R S; Kenney, W L; Alexander, L M

    2015-01-01

    Essential hypertensive humans exhibit attenuated cutaneous nitric oxide (NO)-dependent vasodilation. Using spectral analysis (fast Fourier transformation) we aimed to characterize the skin flowmotion contained in the laser-Doppler flowmetry recordings during local heating-induced vasodilation before and after concurrent pharmacological inhibition of nitric oxide synthase (NOS) in hypertensive and age-matched normotensive men and women. We hypothesized that hypertensive subjects would have lower total power spectral densities (PSDs), specifically in the frequency intervals associated with intrinsic endothelial and neurogenic control of the microvasculature. Furthermore, we hypothesized that NOS inhibition would attenuate the endothelial frequency interval. Laser-Doppler flowmetry recordings during local heating experiments from 18 hypertensive (MAP: 108±2mmHg) and 18 normotensive (MAP: 88±2mmHg) men and women were analyzed. Within site NO-dependent vasodilation was assessed by perfusion of a non-specific NOS inhibitor (N(G)-nitro-l-arginine methyl ester; l-NAME) through intradermal microdialysis during the heating-induced plateau in skin blood flow. Local heating-induced vasodilation increased total PSD for all frequency intervals (all p<0.001). Hypertensives had a lower total PSD (p=0.03) and absolute neurogenic frequency intervals (p<0.01) compared to the normotensives. When normalized as a percentage of total PSD, hypertensives had reduced neurogenic (p<0.001) and augmented myogenic contributions (p=0.04) to the total spectrum. NOS inhibition decreased total PSD (p<0.001) for both groups, but hypertensives exhibited lower absolute endothelial (p<0.01), neurogenic (p<0.05), and total PSD (p<0.001) frequency intervals compared to normotensives. These data suggest that essential hypertension results in altered neurogenic and NOS-dependent control of skin flowmotion and support the use of spectral analysis as a non-invasive technique to study vasoreactivity. PMID:24418051

  11. The role of chemokines in hypertension.

    PubMed

    Martynowicz, Helena; Janus, Agnieszka; Nowacki, Dorian; Mazur, Grzegorz

    2014-01-01

    Hypertension is a major risk factor for cardiovascular disease, which is a serious health problem in the highly industrialized countries. In more than 95% of the cases, the etiology of hypertension remains unknown. A key role in the etiology of hypertension is played by endothelial dysfunction and the inflammatory reaction in the vascular wall, in which the low molecular weight proteins so called chemokines are involved. The chemokines involved in the pathogenesis of hypertension include monocyte chemoattractant protein-1, MCP-1, CCL2, interferon-inducible protein (IP-10; CXCL10), interleukin-8 (IL-8; CXCL8), RANTES (CCL5), fractalkine (CX3CL1) and their receptors CCR2, CCR5, CXCR1, CXCR2, CXCR3 and CX3CR1. The mechanisms involving chemokines and their receptors in the pathogenesis of hypertension are complex and not fully understood. They include the impact of the migration of macrophages and monocytes to the vascular wall, endothelial dysfunction, effects on nitric oxide and endothelin-1 and smooth muscle cell proliferation. Chemokines are also involved in the pathogenesis of complications of hypertension, such as atherosclerosis, myocardial and renal fibrosis. In Poland, only about 26% of patients are effectively treated with antihypertensive drugs. The use of new therapeutic methods based on the inhibition of the inflammatory process in the vascular wall, including the impact on the function of chemokines and their receptors, could improve the effectiveness of the treatment of hypertension. PMID:24979502

  12. Bone marrow mononuclear cells induce beneficial remodeling and reduce diastolic dysfunction in the left ventricle of hypertensive SS/MCWi rats

    PubMed Central

    Parker, Sarah J.; Didier, Daniela N.; Karcher, Jamie R.; Stodola, Timothy J.; Endres, Bradley

    2012-01-01

    Bone marrow mononuclear cells (BMMNCs) increase capillary density and reduce fibrosis in rodents after myocardial infarction, resulting in an overall improvement in left ventricular function. Little is known about the effectiveness of BMMNC therapy in hypertensive heart disease. In the current study, we show that delivery of BMMNCs from hypertension protected SS-13BN/MCWi donor rats, but not BMMNC from hypertension susceptible SS/MCWi donor rats, resulted in 57.2 and 83.4% reductions in perivascular and interstitial fibrosis, respectively, as well as a 60% increase in capillary-to-myocyte count in the left ventricles (LV) of hypertensive SS/MCWi recipients. These histological changes were associated with improvements in LV compliance and relaxation (103 and 46.4% improvements, respectively). Furthermore, improved diastolic function in hypertensive SS/MCWi rats receiving SS-13BN/MCWi derived BMMNCs was associated with lower clinical indicators of heart failure, including reductions in end diastolic pressure (65%) and serum brain natriuretic peptide levels (49.9%) with no improvements observed in rats receiving SS/MCWi BMMNCs. SS/MCWi rats had a lower percentage of endothelial progenitor cells in their bone marrow relative to SS-13BN/MCWi rats. These results suggest that administration of BMMNCs can prevent or reverse pathological remodeling in hypertensive heart disease, which contributes to ameliorating diastolic dysfunction and associated symptomology. Furthermore, the health and hypertension susceptibility of the BMMNC donor are important factors influencing therapeutic efficacy, possibly via differences in the cellular composition of bone marrow. PMID:22851760

  13. Exercise-induced arterial hypertension - an independent factor for hypertrophy and a ticking clock for cardiac fatigue or atrial fibrillation in athletes?

    PubMed Central

    Leischik, Roman; Spelsberg, Norman; Niggemann, Hiltrud; Dworrak, Birgit; Tiroch, Klaus

    2014-01-01

    Background : Exercise-induced arterial hypertension (EIAH) leads to myocardial hypertrophy and is associated with a poor prognosis. EIAH might be related to the “cardiac fatigue” caused by endurance training. The goal of this study was to examine whether there is any relationship between EIAH and left ventricular hypertrophy in Ironman-triathletes. Methods: We used echocardiography and spiroergometry to determine the left ventricular mass (LVM), the aerobic/anaerobic thresholds and the steady-state blood pressure of 51 healthy male triathletes. The main inclusion criterion was the participation in at least one middle or long distance triathlon. Results: When comparing triathletes with LVM <220g  and athletes with LVM >220g there was a significant difference between blood pressure values (BP) at the anaerobic threshold (185.2± 21.5 mmHg vs. 198.8 ±22.3 mmHg, p=0.037). The spiroergometric results were: maximum oxygen uptake (relative VO 2max) 57.3 ±7.5ml/min/kg vs. 59.8±9.5ml/min/kg (p=ns). Cut-point analysis for the relationship of BP >170 mmHg at the aerobic threshold and the probability of LVM >220g showed a sensitivity of 95.8%, a specificity of 33.3%, with a positive predictive value of 56.8 %, a good negative predictive value of 90%. The probability of LVM >220g increased with higher BP during exercise (OR: 1.027, 95% CI 1.002-1.052, p= 0.034) or with higher training volume (OR: 1.23, 95% CI 1.04 -1.47, p = 0.019). Echocardiography showed predominantly concentric remodelling, followed by concentric hypertrophy. Conclusion: Significant left ventricular hypertrophy with LVM >220g is associated with higher arterial blood pressure at the aerobic or anaerobic threshold. The endurance athletes with EIAH may require a therapeutic intervention to at least prevent extensive stiffening of the heart muscle and exercise-induced cardiac fatigue. PMID:25132960

  14. Corin in Natriuretic Peptide Processing and Hypertension

    PubMed Central

    Zhou, Yiqing; Wu, Qingyu

    2014-01-01

    Corin is a serine protease originally isolated from the heart. Functional studies show that corin is the long-sought enzyme responsible for activating cardiac natriuretic peptides. In mice, lack of corin prevents the natriuretic peptide processing, causing salt-sensitive hypertension. In humans, corin variants and mutations that reduce corin activity have been identified in patients with hypertension and heart failure. Decreased plasma levels of corin antigen and activity have been reported in patients with heart failure and coronary artery disease. Low levels of urinary corin also have been found in patients with chronic kidney disease. Most recent studies show that corin also acts in the uterus to promote spiral artery remodeling and prevent pregnancy-induced hypertension. Here we review the role of corin in natriuretic peptide processing and cardiovascular diseases such as hypertension, heart disease, pre-eclampsia, and chronic kidney disease. PMID:24407448

  15. Acute intravenous injection and short-term oral administration of N(G) -nitro-L-arginine methyl ester to the rat provoke increased pressor responses to agonists and hypertension, but not inhibition of acetylcholine-induced hypotensive responses.

    PubMed

    López, Ruth M; Pérez, Teresa; Castillo, Carlos; Castillo, María C; Castillo, Enrique F

    2011-06-01

    In experiments in vivo, we studied whether the endothelial dysfunction induced by nitric oxide (NO) synthesis inhibition is simultaneously or sequentially manifested as a reduced level of endothelium-dependent agonist-induced vasodilatation, an increased responsiveness to vasoconstrictors, and hypertension. Vascular responses to acetylcholine, phenylephrine, and angiotensin II were measured in pithed rats after acute intravenous injection (100 mg/kg) and short-term oral administration of N(G) -nitro-L-arginine methyl ester (L-NAME; 60 mg/kg per day) for 1 and 3 days (L-NAME(1d) and L-NAME(3d), respectively). Pithed rats were chosen because drug-induced cardiovascular responses reflect only peripheral effects. Parallel experiments examined mean arterial pressure (MAP) values in anesthetized rats. After short-term L-NAME(1d) and L-NAME(3d) treatments, the MAP was significantly elevated in anesthetized but not pithed rats. Acute intravenous administration of L-NAME elevated MAP in pithed rats. Intravenous infusion of phenylephrine was used to compensate for the pressor response induced by L-NAME in pithed animals. The maximum decrease and duration of the hypotensive responses to acetylcholine were unaltered by the acute and both short-term L-NAME treatments in pithed rats. These treatments, on the other hand, increased phenylephrine- and angiotensin II-induced pressor responses in pithed animals. In isolated aortic rings prepared from pithed rats treated acutely and short-term with L-NAME, acetylcholine-induced relaxations were inhibited. Thus, the inhibition of NO-dependent vasodilator tone after acute intravenous injection and short-term oral L-NAME administration may be associated with vascular smooth muscle hyper-responsiveness to pressor agonists and hypertension, whereas the hypotensive responses to acetylcholine could not be associated with the L-NAME-induced endothelial dysfunction in pithed rats. PMID:20608990

  16. Effects of acute hemodialysis-induced changes in sodium balance on the renin-angiotensin system in renovascular and spontaneously hypertensive rats.

    PubMed

    Röckel, A; Brand, A; Bechinger, W; Heidland, A

    1979-10-01

    In two-kidney Goldblatt hypertensive, spontaneously hypertensive, and normotensive control rats the activity of the renin-angiotensin system was tested during variation of sodium balance. Acute, exactly calculable and selective changes of total body sodium were achieved by hemodialyzing the conscious rats using dialysate with either high or low sodium content. The activity of the RAS was evaluated by blood pressure response to AT II blockade (saralasin bolus injection; 25 micrograms/kg b.w., i.v.) and the plasma-renin activity. During sodium depletion blood pressure maintenance became renin-dependent; sodium loading caused a decrease of renin-angiotensin activity in renovascular hypertension. A weak direct correlation between deprssor response to saralasin and the PRA could be established in the different sodium-depleted and -loaded states. PMID:523796

  17. Blood pressure, magnesium and other mineral balance in two rat models of salt-sensitive, induced hypertension: effects of a non-peptide angiotensin II receptor type 1 antagonist.

    PubMed

    Rondón, Lusliany Josefina; Marcano, Eunice; Rodríguez, Fátima; del Castillo, Jesús Rafael

    2014-01-01

    The renin-angiotensin system is critically involved in regulating arterial blood pressure (BP). Inappropriate angiotensin type-1 receptor activation by angiotensin-II (Ang-II) is related to increased arterial BP. Mg has a role in BP; it can affect cardiac electrical activity, myocardial contractility, and vascular tone. To evaluate the relationship between high BP induced by a high sodium (Na) diet and Mg, and other mineral balances, two experimental rat models of salt-sensitive, induced-hypertension were used: Ang-II infused and Dahl salt-sensitive (SS) rats. We found that: 1) Ang-II infusion progressively increased BP, which was accompanied by hypomagnesuria and signs of secondary hyperaldosteronism; 2) an additive effect between Ang-II and a high Na load may have an effect on strontium (Sr), zinc (Zn) and copper (Cu) balances; 3) Dahl SS rats fed a high Na diet had a slow pressor response, accompanied by altered Mg, Na, potassium (K), and phosphate (P) balances; and 4) losartan prevented BP increases induced by Ang II-NaCl, but did not modify mineral balances. In Dahl SS rats, losartan attenuated high BP and ameliorated magnesemia, Na and K balances. Mg metabolism maybe considered a possible defect in this strain of rat that may contribute to hypertension. PMID:25560239

  18. A pulmonary hypertension-producing plant from Tanzania

    Microsoft Academic Search

    D Heath; J Shaba; A Williams; P Smith; A Kombe

    1975-01-01

    An African youth who had died from primary pulmonary hypertension was suspected of having ingested a herbal remedy containing the seeds of the local plant Crotalaria laburnoides. Consequently powdered seeds of this plant were fed to 20 Wistar albino rats for 60 dyas to see if this would induce ventricular hypertrophy and associated hypertensive pulmonary vascular disease. At the end

  19. Effects of Mild Exercise on Insulin Sensitivity in Hypertensive Subjects

    Microsoft Academic Search

    Caroline Rhéaume; Paulo H. Waib; Yves Lacourcière; André Nadeau; Jean Cléroux

    Physical exercise increases insulin sensitivity in conditions associated with insulin resistance, such as obesity and diabetes, but little is known in this regard in hypertension. Whether postexercise changes in hemodynamics and\\/or changes in insulin-induced vasodilatation could contribute to a postexercise increase in insulin sensitivity in hypertensive subjects is unknown. We investigated the effects of acute physical exercise on insulin sensitivity

  20. [Theoretical considerations and comments on the physiopathology in renovascular hypertension].

    PubMed

    Burnei, Gh; Grigorean, V T; Gavriliu, St; Du?escu, S; Georgescu, I; Iacobini, M; Vlad, C; Stoian, A R; Burnei, A; Neac?u, C M

    2008-01-01

    The researches performed during the last four decades did not elucidate completely the pathogenic mechanism of the renovascular hypertension. The present knowledge considers that the origins of renovascular hypertension are the imbalance between the renal hypotensive system located in the medullar renal site (antihypertensive and hypotensive substances) and the renal hypertensive system (renin-angiotensin-aldosterone) located cortically. As an additional mechanism in producing hypertension is involved the disorder of hydro electrolytic metabolism, as a result of decreased excretory function, inducing an increase of plasmatic natrium level, of volemia and interstitial liquid. PMID:19274913

  1. Rod-Like Microglia Are Restricted to Eyes with Laser-Induced Ocular Hypertension but Absent from the Microglial Changes in the Contralateral Untreated Eye

    PubMed Central

    de Hoz, Rosa; Gallego, Beatriz I.; Ramírez, Ana I.; Rojas, Blanca; Salazar, Juan J.; Valiente-Soriano, Francisco J.; Avilés-Trigueros, Marcelino; Villegas-Perez, Maria P.; Vidal-Sanz, Manuel; Triviño, Alberto; Ramírez, José M.

    2013-01-01

    In the mouse model of unilateral laser-induced ocular hypertension (OHT) the microglia in both the treated and the normotensive untreated contralateral eye have morphological signs of activation and up-regulation of MHC-II expression in comparison with naïve. In the brain, rod-like microglia align to less-injured neurons in an effort to limit damage. We investigate whether: i) microglial activation is secondary to laser injury or to a higher IOP and; ii) the presence of rod-like microglia is related to OHT. Three groups of mice were used: age-matched control (naïve, n=15); and two lasered: limbal (OHT, n=15); and non-draining portion of the sclera (scleral, n=3). In the lasered animals, treated eyes as well as contralateral eyes were analysed. Retinal whole-mounts were immunostained with antibodies against, Iba-1, NF-200, MHC-II, CD86, CD68 and Ym1. In the scleral group (normal ocular pressure) no microglial signs of activation were found. Similarly to naïve eyes, OHT-eyes and their contralateral eyes had ramified microglia in the nerve-fibre layer related to the blood vessel. However, only eyes with OHT had rod-like microglia that aligned end-to-end, coupling to form trains of multiple cells running parallel to axons in the retinal surface. Rod-like microglia were CD68+ and were related to retinal ganglion cells (RGCs) showing signs of degeneration (NF-200+RGCs). Although MHC-II expression was up-regulated in the microglia of the NFL both in OHT-eyes and their contralateral eyes, no expression of CD86 and Ym1 was detected in ramified or in rod-like microglia. After 15 days of unilateral lasering of the limbal and the non-draining portion of the sclera, activated microglia was restricted to OHT-eyes and their contralateral eyes. However, rod-like microglia were restricted to eyes with OHT and degenerated NF-200+RGCs and were absent from their contralateral eyes. Thus, rod-like microglia seem be related to the neurodegeneration associated with HTO. PMID:24367610

  2. Riociguat for pulmonary hypertension.

    PubMed

    Cannon, John E; Pepke-Zaba, Joanna

    2014-05-01

    Pulmonary hypertension, an elevation of the mean pulmonary artery pressure ?25 mmHg, ultimately leads to premature death due to right ventricular dysfunction. Ten treatments from three classes of drugs are licensed for the management of pulmonary arterial hypertension. These treatments have improved exercise capacity but median survival is still poor. Additionally there are no licensed therapies for the other groups of pulmonary hypertension. Riociguat is a novel drug that stimulates soluble guanylate cyclase independently of nitric oxide and in synergy with nitric oxide. This review summarises the available evidence for riociguat in the treatment across all groups of pulmonary hypertension with a focus on pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension. PMID:24580082

  3. The baroreflex in hypertension.

    PubMed

    Fernandez, Genaro; Lee, Junsoo Alex; Liu, Lynn C; Gassler, John P

    2015-04-01

    Hypertension is a complex syndrome that increases the risk of developing other medical comorbidities and interacts with other medical conditions to increase the risk of target end-organ damage such as cardiovascular disease, stroke, and renal disease. Hypertension remains under-recognized and poorly controlled in the USA and worldwide. In some patients, hypertension is resistant to optimal medical therapy. Over the last few decades, there has been an increasing understanding of the role of the sympathetic nervous system in the development and maintenance of hypertension. This update reviews the physiology and role of the sympathetic nervous system in hypertension and pharmacological and interventional treatments directed at nervous system involvement in secondary hypertension. PMID:25754323

  4. High Prevalence of Myocardial Ischemia and Vasoconstrictive Hormonal Release in Hypertension during Chronic Renal Failure

    Microsoft Academic Search

    Claudio Napoli; Fernando Di Gregorio; Pompeo Sorice; Attilio Di Benedetto; Silvia Ciafre; Teresa Posca; Alessandro Ferrara; Erminio Di Paolo; Giuseppe Bruzzese; Francesco Paolo D’Armiento; Luigi Mansi; Antonio Liguori

    1997-01-01

    Objective: Indexes of myocardial ischemia and vasoconstrictive hormonal release were evaluated in order to investigate the difference between essential hypertension and hypertension during chronic renal failure. Background: Arterial hypertension induces several cardiovascular alterations that reflect themselves either on the heart and\\/or on the coronary blood flow enhancing the cardiovascular risk. Since chronic renal failure can influence the neuroendocrine response, various

  5. Nurse management for hypertension

    Microsoft Academic Search

    Peter Rudd; Nancy Houston Miller; Judy Kaufman; Helena C. Kraemer; Albert Bandura; George Greenwald; Robert F. Debusk

    2004-01-01

    Background: Standard office-based approaches to controlling hypertension show limited success. Such suboptimal hypertension control reflects in part the absence of both an infrastructure for patient education and frequent, regular blood pressure (BP) monitoring. We tested the efficacy of a physician-directed, nurse-managed, home-based system for hypertension management with standardized algorithms to modulate drug therapy, based on patients’ reports of home BP.Methods:

  6. Pulmonary Hypertension after Splenectomy?

    Microsoft Academic Search

    Marius M. Hoeper; Jost Niedermeyer; Frank Hoffmeyer; Peer Flemming; Helmut Fabel

    Results: The prevalence of asplenia in patients with pul- monary hypertension was 11.5% (95% CI, 4.7% to 22.2%) compared with 0% (CI, 0% to 3.2%) in those without pulmonary hypertension (P , 0.001). Histopathologic ex- amination of lung specimens from patients with postsple- nectomy pulmonary hypertension showed intimal fibrosis, plexiform lesions, and abundant thrombotic lesions. Conclusion: Patients who have had

  7. Homocysteine induced arteriosclerosis-like alterations of the aorta in normotensive and hypertensive rats following application of high doses of methionine

    Microsoft Academic Search

    D. Matthias; C.-H. Becker; R. Riezler; P. M. Kindling

    1996-01-01

    Following oral administration of methionine in high doses to normotensive (NR) and spontaneously hypertensive (SHR) rats, its degradation product, homocysteine (HC), which is markedly elevated in serum, exerts an angiotoxic action directed to the aorta. This is accompanied by considerable loss of endothelium and degeneration, partly with dissolution of the media cells with formation of characteristic processes of the degenerating

  8. Pathogenesis of Hypertension

    NSDL National Science Digital Library

    MD Suzanne Oparil (University of Alabama at Birmingham Department of Medicine)

    2003-11-04

    Physiology in Medicine review article A clearer understanding of the pathogenesis of hypertension will probably lead to more highly targeted therapies and to greater reduction in hypertension-related cardiovascular disease morbidity than can be achieved with current empirical treatment. Hypertension clusters in families and results from a complex interaction of genetic and environmental factors. Endothelial dysfunction, increased vascular reactivity, and vascular remodeling may be causes, rather than consequences, of blood pressure elevation; increased vascular stiffness contributes to isolated systolic hypertension in the elderly.

  9. Hypokalemia in thiazide-treated systemic hypertension.

    PubMed

    Maronde, R F; Chan, L S; Vlachakis, N

    1986-07-31

    Potassium supplementation in diuretic-induced hypokalemia (serum potassium less than 3.5 mmol/liter) in patients being treated for hypertension is a common event. In a previous study 40 mmol/day of orally administered potassium was not effective in preventing diuretic-induced hypokalemia in patients who had previously developed hypokalemia while being treated for hypertension with hydrochlorothiazide. In the study reported here dosages as high as 60 to 80 mmol/day of orally administered potassium failed to prevent hypokalemia in 7 of 19 hypertensive patients who were receiving hydrochlorothiazide. Potassium supplementation was compared with the potassium-sparing diuretic amiloride. The study design was open label and subject matched with crossover of therapeutic regimens. PMID:3524185

  10. Hypertension in renal failure

    Microsoft Academic Search

    Michael Cirigliano

    1998-01-01

    Hypertension is a common component of the morbidity associated with renal failure. The mechanisms that contribute to high blood pressure are reviewed in this section. Also covered are therapies to reduce hypertension, the treatment goals of those therapies, and the outcomes of antihypertensive therapy on kidney function in patients with renal failure. Various antihypertensive agents are specifically addressed, and a

  11. Noncirrhotic Portal Hypertension

    PubMed Central

    Rajekar, Harshal; Vasishta, Rakesh K; Chawla, Yogesh K; Dhiman, Radha K

    2011-01-01

    Portal hypertension is characterized by an increase in portal pressure (> 10 mmHg) and could be a result of cirrhosis of the liver or of noncirrhotic diseases. When portal hypertension occurs in the absence of liver cirrhosis, noncirrhotic portal hypertension (NCPH) must be considered. The prognosis of this disease is much better than that of cirrhosis. Noncirrhotic diseases are the common cause of portal hypertension in developing countries, especially in Asia. NCPH is a heterogeneous group of diseases that is due to intrahepatic or extrahepatic etiologies. In general, the lesions in NCPH are vascular in nature and can be classified based on the site of resistance to blood flow. In most cases, these disorders can be explained by endothelial cell lesions, intimal thickening, thrombotic obliterations, or scarring of the intrahepatic portal or hepatic venous circulation. Many different conditions can determine NCPH through the association of these various lesions in various degrees. Many clinical manifestations of NCPH result from the secondary effects of portal hypertension. Patients with NCPH present with upper gastrointestinal bleeding, splenomegaly, ascites after gastrointestinal bleeding, features of hypersplenism, growth retardation, and jaundice due to portal hypertensive biliopathy. Other sequelae include hyperdynamic circulation, pulmonary complications, and other effects of portosystemic collateral circulation like portosystemic encephalopathy. At present, pharmacologic and endoscopic treatments are the treatments of choice for portal hypertension. The therapy of all disorders causing NCPH involves the reduction of portal pressure by pharmacotherapy or portosystemic shunting, apart from prevention and treatment of complications of portal hypertension.

  12. Lifestyle and hypertension

    Microsoft Academic Search

    L. J. Beilin; I. B. Puddey; V. Burke

    1999-01-01

    Lifestyle factors are critical determinants of blood pressure levels operating against a background of genetic susceptibility. Excess body fat is a predominant cause of hypertension with additive effects of dietary salt, alcohol, and physical inactivity. Controlled trials in hypertensives show blood pressure lowering effects of supplemental potassium, fibre, n-3 fatty acids, and diets rich in fruit and vegetables and low

  13. Beneficial pleiotropic vascular effects of rosuvastatin in two hypertensive models

    Microsoft Academic Search

    Dinko Susic; Jasmina Varagic; Jwari Ahn; Michael Slama; Edward D Frohlich

    2003-01-01

    ObjectivesThe goal of this research was to study the effects of rosuvastatin on systemic and regional hemodynamics in two hypertensive rat models, one genetic, the other induced with inhibition of nitric oxide synthesis.

  14. Emerging concepts in hypertension.

    PubMed

    Francis, Joseph; Davisson, Robin L

    2014-01-01

    Cellular redox balance is vital in health and disease. In this Forum, we highlight the importance of reactive oxygen species (ROS) in the regulation of redox balance in different organ systems of the body and ROS contribution to the development of hypertension. The Forum examines interactions between oxidative and nitrosative stress in the brain, vasculature, and kidney, and redox effect on end-organ damage and hypertension. Furthermore, the Forum examines the role of immune cells in the modulation of hypertension. We also introduce a new role for endoplasmic reticulum stress in the induction of ROS and its possible contribution to the development of hypertension. Finally, we explore the clinical relevance of increased ROS in the setting of human hypertension. PMID:24392660

  15. RhoA GTPase-induced ocular hypertension in a rodent model is associated with increased fibrogenic activity in the trabecular meshwork.

    PubMed

    Pattabiraman, Padmanabhan P; Rinkoski, Tommy; Poeschla, Eric; Proia, Alan; Challa, Pratap; Rao, Ponugoti V

    2015-02-01

    Ocular hypertension arising from increased resistance to aqueous humor (AH) outflow through the trabecular meshwork is a primary risk factor for open-angle glaucoma, a leading cause of blindness. Ongoing efforts have found little about the molecular and cellular bases of increased resistance to AH outflow through the trabecular meshwork in ocular hypertension patients. To test the hypothesis that dysregulated Rho GTPase signaling and a resulting fibrotic activity within the trabecular meshwork may result in ocular hypertension, we investigated the effects of expressing a constitutively active RhoA GTPase (RhoAV14) in the AH outflow pathway in Sprague-Dawley rats by using lentiviral vector-based gene delivery. Rats expressing RhoAV14 in the iridocorneal angle exhibited a significantly elevated intraocular pressure. Elevated intraocular pressure in the RhoAV14-expressing rats was associated with fibrotic trabecular meshwork and increased levels of F-actin, phosphorylated myosin light chain, ?-smooth muscle actin, collagen-1A, and total collagen in the trabecular AH outflow pathway. Most of these changes were ameliorated by topical application of Rho kinase inhibitor. Human autopsy eyes from patients with glaucoma exhibited significant increases in levels of collagen-1A and total collagen in the trabecular AH outflow pathway. Collectively, these observations indicate that increased fibrogenic activity because of dysregulated RhoA GTPase activity in the trabecular AH outflow pathway increases intraocular pressure in a Rho kinase-dependent manner. PMID:25499974

  16. Valsartan regulates myocardial autophagy and mitochondrial turnover in experimental hypertension.

    PubMed

    Zhang, Xin; Li, Zi-Lun; Crane, John A; Jordan, Kyra L; Pawar, Aditya S; Textor, Stephen C; Lerman, Amir; Lerman, Lilach O

    2014-07-01

    Renovascular hypertension alters cardiac structure and function. Autophagy is activated during left ventricular hypertrophy and linked to adverse cardiac function. The angiotensin II receptor blocker, valsartan, lowers blood pressure and is cardioprotective, but whether it modulates autophagy in the myocardium is unclear. We hypothesized that valsartan would alleviate autophagy and improve left ventricular myocardial mitochondrial turnover in swine renovascular hypertension. Domestic pigs were randomized to control, unilateral renovascular hypertension, and renovascular hypertension treated with valsartan (320 mg/d) or conventional triple therapy (reserpine+hydralazine+hydrochlorothiazide) for 4 weeks after 6 weeks of renovascular hypertension (n=7 each group). Left ventricular remodeling, function, and myocardial oxygenation and microcirculation were assessed by multidetector computer tomography, blood oxygen level-dependent MRI, and microcomputer tomography. Myocardial autophagy, markers for mitochondrial degradation and biogenesis, and mitochondrial respiratory-chain proteins were examined ex vivo. Renovascular hypertension induced left ventricular hypertrophy and myocardial hypoxia, enhanced cellular autophagy and mitochondrial degradation, and suppressed mitochondrial biogenesis. Valsartan and triple therapy similarly decreased blood pressure, but valsartan solely alleviated left ventricular hypertrophy, ameliorated myocardial autophagy and mitophagy, and increased mitochondrial biogenesis. In contrast, triple therapy only slightly attenuated autophagy and preserved mitochondrial proteins, but elicited no improvement in mitophagy. These data suggest a novel potential role of valsartan in modulating myocardial autophagy and mitochondrial turnover in renovascular hypertension-induced hypertensive heart disease, which may possibly bolster cardiac repair via a blood pressure-independent manner. PMID:24752430

  17. Angiogenic growth factors and hypertension

    Microsoft Academic Search

    David C. Sane; Lauren Anton; K. Bridget Brosnihan

    2004-01-01

    Emerging evidence supports a novel view of hypertension as a disease of inadequate or aberrant responses to angiogenic growth factors (AGF). Patients with hypertension have reduced microvascular density, with some evidence supporting a primary role for rarefaction in causing hypertension. Two clinical models have demonstrated a link between inhibition of AGF activity and hypertension. A major side effect of bevacizumab,

  18. Cuminum cyminum, a dietary spice, attenuates hypertension via endothelial nitric oxide synthase and NO pathway in renovascular hypertensive rats.

    PubMed

    Kalaivani, Periyathambi; Saranya, Ramesh Babu; Ramakrishnan, Ganapathy; Ranju, Vijayan; Sathiya, Sekar; Gayathri, Veeraraghavan; Thiyagarajan, Lakshmi Kantham; Venkhatesh, Jayakothanda Ramaswamy; Babu, Chidambaram Saravana; Thanikachalam, Sadagopan

    2013-01-01

    Cuminum cyminum (CC) is a commonly used spice in South Indian foods. It has been traditionally used for the treatment and management of sleep disorders, indigestion, and hypertension. The present study was carried out to scientifically evaluate the anti-hypertensive potential of standardized aqueous extract of CC seeds and its role in arterial endothelial nitric oxide synthase expression, inflammation, and oxidative stress in renal hypertensive rats. Renal hypertension was induced by the two-kidney one-clip (2K/1C) method in rats. Systolic blood pressure (SBP), plasma nitrate/nitrite, carotid-eNOS, renal-TNF-?, IL-6, Bax, Bcl-2, thioredoxin 1 (TRX1), and thioredoxin reductase 1 (TRXR1) mRNA expressions were studied to demonstrate the anti-hypertensive action of CC. Cuminum cyminum was administered orally (200 mg/kg b.wt) for a period of 9 weeks; it improved plasma nitric oxide and decreased the systolic blood pressure in hypertensive rats. It also up-regulated the gene expression of eNOS, Bcl-2, TRX1, and TRXR1; and down-regulated Bax, TNF-?, and IL-6. These data reveal that CC seeds augment endothelial functions and ameliorate inflammatory and oxidative stress in hypertensive rats. The present report is the first of its kind to demonstrate the mechanism of anti-hypertensive action of CC seeds in an animal model of renovascular hypertension. PMID:23402543

  19. Pseudohyperaldosteronism, liquorice, and hypertension.

    PubMed

    Sontia, Bruno; Mooney, Jan; Gaudet, Lise; Touyz, Rhian M

    2008-02-01

    Consumption of large quantities of liquorice can cause hypokalemia and hypertension. These effects are associated with increased cortisol-mediated activation of renal mineralocorticoid receptors and hypoaldosteronism. The authors describe a patient with long-standing hypokalemia and uncontrolled hypertension related to excessive ingestion of liquorice. The case highlights the importance of obtaining a detailed dietary history, especially considering the increasing use of liquorice-containing foods, teas, and herbal products. The authors also discuss secondary causes of hypertension, focusing on pseudohyperaldosteronism. PMID:18256580

  20. Perioperative hypertension management

    PubMed Central

    Varon, Joseph; Marik, Paul E

    2008-01-01

    Perioperative hypertension is commonly encountered in patients that undergo surgery. While attempts have been made to standardize the method to characterize the intraoperative hemodynamics, these methods still vary widely. In addition, there is a lack of consensus concerning treatment thresholds and appropriate therapeutic targets, making absolute recommendations about treatment difficult. Nevertheless, perioperative hypertension requires careful management. When treatment is necessary, therapy should be individualized for the patient. This paper reviews the pharmacologic agents and strategies commonly used in the management of perioperative hypertension. PMID:18827911

  1. Management of Intracranial Hypertension

    PubMed Central

    Rangel-Castillo, Leonardo; Gopinath, Shankar; Robertson, Claudia S.

    2008-01-01

    Effective management of intracranial hypertension involves meticulous avoidance of factors that precipitate or aggravate increased intracranial pressure. When intracranial pressure becomes elevated, it is important to rule out new mass lesions that should be surgically evacuated. Medical management of increased intracranial pressure should include sedation, drainage of cerebrospinal fluid, and osmotherapy with either mannitol or hypertonic saline. For intracranial hypertension refractory to initial medical management, barbiturate coma, hypothermia, or decompressive craniectomy should be considered. Steroids are not indicated and may be harmful in the treatment of intracranial hypertension resulting from traumatic brain injury. PMID:18514825

  2. Smad7 inhibits AngII-mediated hypertensive nephropathy in a mouse model of hypertension.

    PubMed

    Liu, Guan-Xian; Li, You-Qi; Huang, Xiao R; Wei, Li Hua; Zhang, Yang; Feng, Min; Meng, Xiao-Ming; Chen, Hai-Yong; Shi, Yong-Jun; Lan, Hui Y

    2014-08-01

    The TGF? (transforming growth factor ?)/SMAD and NF-?B (nuclear factor ?B) signalling pathways play a key role in hypertensive nephropathy. The present study examined whether targeting these pathways by SMAD7, a downstream inhibitor of both pathways, blocks AngII (angiotensin II)-induced hypertensive kidney disease in mice. A doxycycline-inducible SMAD7-expressing plasmid was delivered into the kidney by a non-invasive ultrasound-microbubble technique before and after AngII infusion. Results showed that pre-treatment with SMAD7 prevented AngII-induced progressive renal injury by inhibiting an increase in proteinuria and serum creatinine while improving the glomerular filtration rate. Similarly, treatment with SMAD7 in the established hypertensive nephropathy at day 14 after AngII infusion halted the progressive renal injury. These preventive and therapeutic effects of SMAD7 on hypertensive kidney injury were associated with inhibition of AngII-induced up-regulation of SMURF2 (SMAD-specific E3 ubiquitin protein ligase 2) and Sp1 (specificity protein 1), blockade of TGF?/Smad3-mediated renal fibrosis and suppression of NF-?B-driven renal inflammation. Moreover, overexpression of SMAD7 also prevented AngII-induced loss of renal miR-29b, an miRNA with an inhibitory role in both TGF?/Smad3 and NF-?B pathways. In conclusion, SMAD7 may be a therapeutic agent for AngII-mediated hypertensive nephropathy. Inhibition of the Sp1/SMAD3/NF-?B/miR-29b regulatory network may be a mechanism by which SMAD7 inhibits hypertensive nephropathy. PMID:24511990

  3. Orexin, cardio-respiratory function, and hypertension

    PubMed Central

    Li, Aihua; Nattie, Eugene

    2014-01-01

    In this review we focus on the role of orexin in cardio-respiratory functions and its potential link to hypertension. (1) Orexin, cardiovascular function, and hypertension. In normal rats, central administration of orexin can induce significant increases in arterial blood pressure (ABP) and sympathetic nerve activity (SNA), which can be blocked by orexin receptor antagonists. In spontaneously hypertensive rats (SHRs), antagonizing orexin receptors can significantly lower blood pressure under anesthetized or conscious conditions. (2) Orexin, respiratory function, and central chemoreception. The prepro-orexin knockout mouse has a significantly attenuated ventilatory CO2 chemoreflex, and in normal rats, central application of orexin stimulates breathing while blocking orexin receptors decreases the ventilatory CO2 chemoreflex. Interestingly, SHRs have a significantly increased ventilatory CO2 chemoreflex relative to normotensive WKY rats and blocking both orexin receptors can normalize this exaggerated response. (3) Orexin, central chemoreception, and hypertension. SHRs have higher ABP and SNA along with an enhanced ventilatory CO2 chemoreflex. Treating SHRs by blocking both orexin receptors with oral administration of an antagonist, almorexant (Almxt), can normalize the CO2 chemoreflex and significantly lower ABP and SNA. We interpret these results to suggest that the orexin system participates in the pathogenesis and maintenance of high blood pressure in SHRs, and the central chemoreflex may be a causal link to the increased SNA and ABP in SHRs. Modulation of the orexin system could be a potential target in treating some forms of hypertension. PMID:24574958

  4. Hypertensive heart disease

    MedlinePLUS

    ... failure: pathophysiology and diagnosis. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 24th ed. Philadelphia, PA: ... Victor RG. Arterial hypertension. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 24th ed. Philadelphia, PA: ...

  5. High Blood Pressure (Hypertension)

    MedlinePLUS

    ... Text Size: A A A Listen High Blood Pressure (Hypertension) Nearly 1 in 3 American adults has ... your doctor prescribes it, medicine. What Is Blood Pressure? Blood pressure is the force of blood flow ...

  6. High Blood Pressure (Hypertension)

    MedlinePLUS

    ... Consumer Information by Audience For Women High Blood Pressure (Hypertension) Print and Share (PDF 109 KB) En ... Who is at risk? How is high blood pressure treated? Understanding your blood pressure: What do the ...

  7. Cervical spondylosis and hypertension: a clinical study of 2 cases.

    PubMed

    Peng, Baogan; Pang, Xiaodong; Li, Duanming; Yang, Hong

    2015-03-01

    Cervical spondylosis and hypertension are all common diseases, but the relationship between them has never been studied. Patients with cervical spondylosis are often accompanied with vertigo. Anterior cervical discectomy and fusion is an effective method of treatment for cervical spondylosis with cervical vertigo that is unresponsive to conservative therapy. We report 2 patients of cervical spondylosis with concomitant cervical vertigo and hypertension who were treated successfully with anterior cervical discectomy and fusion. Stimulation of sympathetic nerve fibers in pathologically degenerative disc could produce sympathetic excitation, and induce a sympathetic reflex to cause cervical vertigo and hypertension. In addition, chronic neck pain could contribute to hypertension development through sympathetic arousal and failure of normal homeostatic pain regulatory mechanisms.Cervical spondylosis may be one of the causes of secondary hypertension. Early treatment for resolution of symptoms of cervical spondylosis may have a beneficial impact on cardiovascular disease risk in patients with cervical spondylosis. PMID:25761188

  8. Management of hypertension emergencies

    Microsoft Academic Search

    William J. Elliott

    2003-01-01

    Although they have become less common, hypertensive emergencies occur with an incidence of approximately 1 to 2\\/100,000 people\\u000a per year. Our knowledge about this problem, its pathophysiology, risk factors, and appropriate treatment options has expanded\\u000a during the past decade. A hypertensive emergency can be declared when an elevated blood pressure is associated with acute\\u000a targetorgan damage. Rapid evaluation and treatment

  9. Pharmacotherapy of Pulmonary Hypertension

    PubMed Central

    Steinhorn, Robin H.

    2012-01-01

    Pulmonary arterial hypertension is a serious disease with significant morbidity and mortality. While it can occur idiopathically, it is more commonly associated with other cardiac or lung diseases. While most of the available therapies were tested in adult populations, and most therapies in children remain off-label, new reports and randomized trials are emerging that inform the treatment of pediatric populations. This review discusses currently available therapies for pediatric pulmonary hypertension, their biologic rationales, and evidence for their clinical effectiveness. PMID:23036248

  10. Chronic Thromboembolic Pulmonary Hypertension

    Microsoft Academic Search

    William R. Auger; Peter F. Fedullo

    Chronic thromboembolic pulmonary hypertension (CTEPH) is an important form of pulmonary hypertension to detect because prompt\\u000a treatment can lead to a surgical cure. The true incidence is unknown, but it is estimated to occur in 1% to 3% of patients\\u000a following acute thromboembolism. Detection may be difficult, because symptoms are nonspecific and other diagnoses are often\\u000a made before that of

  11. Dopaminergic defect in hypertension.

    PubMed

    Jose, P A; Eisner, G M; Felder, R A

    1993-12-01

    Reverse genetics and the candidate gene approach have been utilized to identify the genetic defect(s) in hypertension. We have proposed the dopamine receptor gene as one candidate in the pathogenesis of hypertension. Because some forms of hypertension are sodium dependent or aggravated by sodium loading and because dopamine is important in aiding the organism to eliminate "excess" sodium, an abnormality in the renal dopaminergic system may be responsible for the sodium retention in hypertension. Both human and animal models of hypertension are associated with renal dopamine production and/or post first messenger defects. The Dahl salt-sensitive rat, which has a decreased ability to generate renal dopamine, and the spontaneously hypertensive rat (SHR), which has no such limitation, have a defective coupling of a D1 receptor to a G protein/adenylyl cyclase complex. This coupling defect is: (1) genetic, since it precedes the onset of hypertension and co-segregates with the hypertensive phenotype, (2) receptor specific, since it is not shared by other humoral agents, and (3) organ and nephron segment selective, since it occurs in proximal tubules but not in cortical collecting ducts or the brain striatum. A consequence of the defective dopamine receptor/adenylyl cyclase coupling in the SHR is a decreased ability of D1 agonists to inhibit Na+/H+ exchange activity. A resistance to the natriuretic effect of dopamine and D1 agonists in the SHR is due mainly to decreased cyclic AMP production, although with maturation a post cyclic AMP defect is acquired. Radioligand binding studies suggest a "loss" of the high-affinity D1 binding site in the SHR.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8130121

  12. A hypertensive emergency with acute visual impairment due to excessive liquorice consumption.

    PubMed

    Schrà der, T; Hubold, C; Muck, P; Lehnert, H; Haas, C S

    2015-02-01

    Hypokalaemic hypertension is the classical presentation of primary hyperaldosteronism but may also result from other mineralocorticoid activity, such as liquorice ingestion. Onset of hypertension as well as serum renin and aldosterone levels are central for the diagnosis. Liquorice ingestion has been reported to induce hypertension, hypokalaemia and metabolic alkalosis due to inhibition of the enzyme 11-β-hydroxy steroiddehydrogenase 2. Here, we report the case of a hypertensive emergency with acute visual impairment due to hypertensive retinopathy in clear conjunction with a considerable consumption of liquorice. PMID:25753073

  13. Early co-expression of cyclooxygenase-2 and renin in the rat kidney cortex contributes to the development of N(G)-nitro-l-arginine methyl ester induced hypertension.

    PubMed

    Guzmán-Hernández, Elizabeth Alejandrina; Villalobos-Molina, Rafael; Sánchez-Mendoza, María Alicia; Del Valle-Mondragón, Leonardo; Pastelín-Hernández, Gustavo; Ibarra-Barajas, Maximiliano

    2015-04-01

    We investigated the involvement of cyclooxygenase-2 (COX-2) and the renin-angiotensin system in N(G)-nitro-l-arginine methyl ester (l-NAME)-induced hypertension. Male Wistar rats were treated with l-NAME (75.0 mg·(kg body mass)(-1)·day(-1), in their drinking water) for different durations (1-33 days). COX-2 and renin mRNA were measured using real-time PCR in the renal cortex, and prostanoids were assessed in the renal perfusate, whereas angiotensin II (Ang?II) and Ang?(1-7) were quantified in plasma. In some rats, nitric oxide synthase inhibition was carried out in conjunction with oral administration of captopril (30.0 mg·kg(-1)·day(-1)) or celecoxib (1.0 mg·kg(-1)·day(-1)) for 2 or 19 days. We found a parallel increase in renocortical COX-2 and renin mRNA starting at day 2 of treatment with l-NAME, and both peaked at 19-25 days. In addition, l-NAME increased renal 6-Keto-PGF1? (prostacyclin (PGI2) metabolite) and plasma Ang?II from day 2, but reduced plasma Ang?(1-7) at day 19. Captopril prevented the increase in blood pressure, which was associated with lower plasma Ang?II and increased COX-2-derived 6-Keto-PGF1? at day 2 and plasma Ang?(1-7) at day 19. Celecoxib partially prevented the increase in blood pressure; this effect was associated with a reduction in plasma Ang?II. These findings indicate that renal COX-2 expression increased in parallel with renin expression, renal PGI2 synthesis, and plasma Ang?II in l-NAME-induced hypertension. PMID:25761067

  14. Acute cardiovascular effects of the Wenchuan earthquake: ambulatory blood pressure monitoring of hypertensive patients

    Microsoft Academic Search

    Yucheng Chen; Jing Li; Hong Xian; JiangBo Li; Si Liu; GuanJian Liu; JianNan Lin; Jun Han; Zhi Zeng

    2009-01-01

    An increased incidence of cardiovascular events and sudden death occurs after an earthquake. However, the mechanism underlying this is not clear. Previous studies attributed this phenomenon to earthquake-induced elevation of sympathetic activity. This study investigated the acute cardiovascular effects of the Wenchuan earthquake on hypertensive or suspected hypertensive patients. We studied the role of earthquake-induced changes in blood pressure and

  15. Hypertension in pregnancy: changes in activin A maternal serum concentration.

    PubMed

    Petraglia, F; Aguzzoli, L; Gallinelli, A; Florio, P; Zonca, M; Benedetto, C; Woodruff, K

    1995-07-01

    Human placenta is the major source of activin A in maternal circulation. The aim of the present study was to evaluate maternal activin A serum concentration in pregnant women with chronic hypertension (n = 14), pregnancy-induced hypertension (n = 10) or pre-eclampsia (n = 16). In the group of pregnant women with chronic hypertension and of healthy pregnant women (n = 10) activin A was measured in samples collected longitudinally throughout gestation. Using a specific two-site enzyme-linked immunosorbent assay, it has been possible to measure maternal serum activin A concentration. In addition, the effect of recombinant human activin A administration on mean arterial pressure and heart rate in female rats have been also investigated. Mean +/- SEM of maternal serum activin A concentration in pre-eclamptic women (57.4 +/- 28.3 ng/ml), was significantly higher than in women with pregnancy-induced hypertension (14.8 +/- 10.5 ng/ml), chronic hypertension (10.3 +/- 5.4 ng/ml) or healthy control women (9.2 +/- 9.4 ng/ml) (P < 0.01). Serum activin A levels evaluated 2 weeks after anti-hypertensive treatment were not significantly different in pre-eclamptic women. Moreover, when exogenous recombinant human activin A was administered in female rats arterial pressure or frequency of heart rate did not change. The present study showed that maternal serum activin A concentration is abnormally high in patients with pre-eclampsia. Thus, since the patients with chronic hypertension or pregnancy-induced hypertension have activin A concentration in the normal range of values, activin A may be a prognostic marker of hypertension in pregnancy. PMID:7479615

  16. A pulmonary hypertension-producing plant from Tanzania.

    PubMed

    Heath, D; Shaba, J; Williams, A; Smith, P; Kombe, A

    1975-08-01

    An African youth who had died from primary pulmonary hypertension was suspected of having ingested a herbal remedy containing the seeds of the local plant Crotalaria laburnoides. Consequently powdered seeds of this plant were fed to 20 Wistar albino rats for 60 dyas to see if this would induce ventricular hypertrophy and associated hypertensive pulmonary vascular disease. At the end of the experimental period right ventricular hypertrophy, medial hypertrophy of the pulmonary trunk and 'muscular pulmonary arteries', and muscularization of the pulmonary arterioles had developed in a proportion of the test animals. These are the morbid anatomical features pathognomonic of a raised pulmonary arterial pressure and show that the seeds of Crotalaria laburnoides contain an agent capable of inducing pulmonary hypertension in rats. This study suggests the value of seeking a history of ingestion of herbal remedies and drugs in cases of unexplained pulmonary hypertension in man. PMID:126502

  17. A Blueberry-Enriched Diet Attenuates Nephropathy in a Rat Model of Hypertension via Reduction in Oxidative Stress

    Microsoft Academic Search

    Carrie M. Elks; Scott D. Reed; Nithya Mariappan; Barbara Shukitt-Hale; James A. Joseph; Donald K. Ingram; Joseph Francis; Carmine Zoccali

    2011-01-01

    Objective and BackgroundTo assess renoprotective effects of a blueberry-enriched diet in a rat model of hypertension. Oxidative stress (OS) appears to be involved in the development of hypertension and related renal injury. Pharmacological antioxidants can attenuate hypertension and hypertension-induced renal injury; however, attention has shifted recently to the therapeutic potential of natural products as antioxidants. Blueberries (BB) have among the

  18. Sequence of structural changes and elastin peptide release during vascular remodelling in sheep with chronic pulmonary hypertension induced by air embolization.

    PubMed Central

    Perkett, E. A.; Davidson, J. M.; Meyrick, B.

    1991-01-01

    The progression of structural changes in the pulmonary arterial bed were followed in a model of chronic pulmonary hypertension. Chronically instrumented awake sheep received continuous air embolization for 0 (controls), 1, 4, 8, or 12 days (n = 5-6/group). After the period of embolization, the lungs were removed, the pulmonary arteries were distended with barium-gelatin, and the lungs were fixed via the airways with formal-saline. Quantitative techniques were applied to sections from random blocks from the lungs of each animal. One day of embolization resulted in granulocyte sequestration in the lung interstitium and in small vessels; additionally, intraalveolar and perivascular edema was present. By 4 days, increased medial thickness, appearance of muscle in smaller arteries than normal (e.g., muscular arteries at alveolar duct level: control = 1.2 +/- 1.2%; day 4 = 22.7 +/- 7.7) and reduction in number of barium-filled intraacinar arteries was found. The arterial changes progressed in severity to day 8 and were similar at day 12. Since arterial remodelling involves increased elastin deposition, the concentration of elastin peptides was measured in lung lymph. Increased flux of elastin peptides was apparent from day 2 of embolization and continued to increase to a level 20 x baseline by day 12 (baseline 351 +/- 86 micrograms/15 min; day 12 = 6338 +/- 2999). Comparison of the onset of the structural changes with previous findings shows that the arterial remodelling parallels the onset of sustained pulmonary hypertension. The increase in lung-lymph elastin peptides by day 2 provides evidence that vascular remodelling is initiated before day 4 of embolization. The early sequestration of granulocytes and appearance of edema suggest that these may be part of the trigger to the development of the structural changes. Images Figure 1 Figure 3 Figure 3 Figure 4 PMID:1836307

  19. Pregnancy with portal hypertension.

    PubMed

    Aggarwal, Neelam; Negi, Neha; Aggarwal, Aakash; Bodh, Vijay; Dhiman, Radha K

    2014-06-01

    Even though pregnancy is rare with cirrhosis and advanced liver disease, but it may co-exist in the setting of non-cirrhotic portal hypertension as liver function is preserved but whenever encountered together is a complex clinical dilemma. Pregnancy in a patient with portal hypertension presents a special challenge to the obstetrician as so-called physiological hemodynamic changes associated with pregnancy, needed for meeting demands of the growing fetus, worsen the portal hypertension thereby putting mother at risk of potentially life-threatening complications like variceal hemorrhage. Risks of variceal bleed and hepatic decompensation increase many fold during pregnancy. Optimal management revolves round managing the portal hypertension and its complications. Thus management of such cases requires multi-speciality approach involving obstetricians experienced in dealing with high risk cases, hepatologists, anesthetists and neonatologists. With advancement in medical field, pregnancy is not contra-indicated in these women, as was previously believed. This article focuses on the different aspects of pregnancy with portal hypertension with special emphasis on specific cause wise treatment options to decrease the variceal bleed and hepatic decompensation. Based on extensive review of literature, management from pre-conceptional period to postpartum is outlined in order to have optimal maternal and perinatal outcomes. PMID:25755552

  20. Pregnancy with Portal Hypertension

    PubMed Central

    Aggarwal, Neelam; Negi, Neha; Aggarwal, Aakash; Bodh, Vijay; Dhiman, Radha K.

    2014-01-01

    Even though pregnancy is rare with cirrhosis and advanced liver disease, but it may co-exist in the setting of non-cirrhotic portal hypertension as liver function is preserved but whenever encountered together is a complex clinical dilemma. Pregnancy in a patient with portal hypertension presents a special challenge to the obstetrician as so-called physiological hemodynamic changes associated with pregnancy, needed for meeting demands of the growing fetus, worsen the portal hypertension thereby putting mother at risk of potentially life-threatening complications like variceal hemorrhage. Risks of variceal bleed and hepatic decompensation increase many fold during pregnancy. Optimal management revolves round managing the portal hypertension and its complications. Thus management of such cases requires multi-speciality approach involving obstetricians experienced in dealing with high risk cases, hepatologists, anesthetists and neonatologists. With advancement in medical field, pregnancy is not contra-indicated in these women, as was previously believed. This article focuses on the different aspects of pregnancy with portal hypertension with special emphasis on specific cause wise treatment options to decrease the variceal bleed and hepatic decompensation. Based on extensive review of literature, management from pre-conceptional period to postpartum is outlined in order to have optimal maternal and perinatal outcomes. PMID:25755552

  1. The immunological basis of hypertension.

    PubMed

    Rodríguez-Iturbe, Bernardo; Pons, Héctor; Quiroz, Yasmir; Johnson, Richard J

    2014-11-01

    A large number of investigations have demonstrated the participation of the immune system in the pathogenesis of hypertension. Studies focusing on macrophages and Toll-like receptors have documented involvement of the innate immunity. The requirements of antigen presentation and co-stimulation, the critical importance of T cell-driven inflammation, and the demonstration, in specific conditions, of agonistic antibodies directed to angiotensin II type 1 receptors and adrenergic receptors support the role of acquired immunity. Experimental findings support the concept that the balance between T cell-induced inflammation and T cell suppressor responses is critical for the regulation of blood pressure levels. Expression of neoantigens in response to inflammation, as well as surfacing of intracellular immunogenic proteins, such as heat shock proteins, could be responsible for autoimmune reactivity in the kidney, arteries, and central nervous system. Persisting, low-grade inflammation in these target organs may lead to impaired pressure natriuresis, an increase in sympathetic activity, and vascular endothelial dysfunction that may be the cause of chronic elevation of blood pressure in essential hypertension. PMID:25150828

  2. Renal Processing of Albumin in Diabetes and Hypertension in Rats

    Microsoft Academic Search

    Leileata M. Russo; Tanya M. Osicka; Gail C. Brammar; Riccardo Candido; George Jerums; Wayne D. Comper

    2003-01-01

    Background\\/Aims: Recent studies show that albuminuria may be the result of changes in post-glomerular cellular uptake and processing of albumin. This study aims to determine whether this processing is disrupted in diabetes and\\/or hypertension. Methods: Diabetes (d) was induced using streptozotocin in spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) and studied after 8, 16 and 24 weeks

  3. Evaluation of Hypertension as a Marker of Bevacizumab Efficacy

    Microsoft Academic Search

    Rebekah Ryanne Wu; Peter A. Lindenberg; Rebecca Slack; Anne-Michelle Noone; John L. Marshall; Aiwu R. He

    2009-01-01

    Background  Predictive factors for efficacy of vascular endothelial growth factor pathway-targeted therapies have not been identified\\u000a or confirmed. Hypertension has been observed as a side effect to anti-vascular endothelial growth factor therapy. The goal\\u000a of our study was to retrospectively assess if hypertension induced during treatment with bevacizumab was associated with clinical\\u000a outcome in metastatic colorectal cancer patients treated with bevacizumab.

  4. Hypertension promotes islet morphological changes with vascular injury on pre-diabetic status in SHRsp rats.

    PubMed

    Satoh, Minoru; Nagasu, Hajime; Haruna, Yoshisuke; Ihoriya, Chieko; Kadoya, Hiroyuki; Sasaki, Tamaki; Kashihara, Naoki

    2014-01-01

    Abstract Hypertensive patients have a higher incidence of new-onset diabetic mellitus than normotensive subjects, and we hypothesized that hypertension induces morphological changes in islets via vascular injury. To test our hypothesis, we administrated hydralazine or irbesartan to spontaneously hypertensive stroke-prone (SHRsp) rats. A greater islet fibrosis was observed in SHRsp rats compared with controls, and irbesartan significantly ameliorated the fibrosis. High fat diet induced glucose intorelance in SHRsp rats and irbesartan but not hydralazine improved glucose torelance. We demonstrate islet morphological changes in hypertensive rats, and our data suggest that angiotensin receptor blockers have the potential to prevent islet injury. PMID:23786428

  5. Functional sympatholysis in hypertension.

    PubMed

    Thomas, Gail D

    2015-03-01

    Sympathetic vasoconstriction is normally attenuated in exercising muscle by local changes in muscle metabolites and other substances that reduce vascular responsiveness to ?-adrenergic receptor activation. Termed functional sympatholysis, this protective mechanism is thought to optimize muscle blood flow distribution to match perfusion with metabolic demand. Emerging evidence from both animal and human studies indicate that functional sympatholysis is impaired in hypertension and may constitute an important underlying cause of skeletal muscle malperfusion during exercise in this common cardiovascular condition. Findings from studies of animal models of hypertension and patients with essential hypertension will be integrated in this review to provide insight into the underlying mechanisms responsible for inappropriate sympathetic vasoconstriction in exercising muscle and the treatment options that may restore functional sympatholysis and improve muscle perfusion during exercise. PMID:25458424

  6. Oxidative stress and hypertension.

    PubMed

    Harrison, David G; Gongora, Maria Carolina

    2009-05-01

    This review has summarized some of the data supporting a role of ROS and oxidant stress in the genesis of hypertension. There is evidence that hypertensive stimuli, such as high salt and angiotensin II, promote the production of ROS in the brain, the kidney, and the vasculature and that each of these sites contributes either to hypertension or to the untoward sequelae of this disease. Although the NADPH oxidase in these various organs is a predominant source, other enzymes likely contribute to ROS production and signaling in these tissues. A major clinical challenge is that the routinely used antioxidants are ineffective in preventing or treating cardiovascular disease and hypertension. This is likely because these drugs are either ineffective or act in a non-targeted fashion, such that they remove not only injurious ROS Fig. 5. Proposed role of T cells in the genesis of hypertension and the role of the NADPH oxidase in multiple cells/organs in modulating this effect. In this scenario, angiotensin II stimulates an NADPH oxidase in the CVOs of the brain, increasing sympathetic outflow. Sympathetic nerve terminals in lymph nodes activate T cells, and angiotensin II also directly activates T cells. These stimuli also activate expression of homing signals in the vessel and likely the kidney, which attract T cells to these organs. T cells release cytokines that stimulate the vessel and kidney NADPH oxidases, promoting vasoconstriction and sodium retention. SFO, subfornical organ. 630 Harrison & Gongora but also those involved in normal cell signaling. A potentially important and relatively new direction is the concept that inflammatory cells such as T cells contribute to hypertension. Future studies are needed to understand the interaction of T cells with the CNS, the kidney, and the vasculature and how this might be interrupted to provide therapeutic benefit. PMID:19427495

  7. Hypertension in terminal renal failure

    Microsoft Academic Search

    Peter Weidmann; Carlo Beretta-Piccoli; Fritz Steffen; Alfred Blumberg; François C Reubi

    1976-01-01

    Hypertension in terminal renal failure. Inverse interrelations between plasma renin activity and exchangeable sodium or blood volume were found in both normotensive (N = 23) and hypertensive (N = 29) hemodialysis patients (r = 0.47; P < 0.005); however, mean plasma renin for any given sodium\\/volume state was at least two-fold higher in hypertensive than in normotensive hemodialysis patients or

  8. Death-associated protein kinase 3 mediates vascular inflammation and development of hypertension in spontaneously hypertensive rats.

    PubMed

    Usui, Tatsuya; Okada, Muneyoshi; Hara, Yukio; Yamawaki, Hideyuki

    2012-10-01

    Death-associated protein kinase (DAPK) is a Ca2+/calmodulin-regulated serine/threonine kinase that mediates cell death. Our recent study demonstrated that DAPK3 protein increases in the mesenteric artery from spontaneously hypertensive rats compared with Wistar Kyoto rats. Pathogenesis of hypertension is modulated at least in part by vascular inflammation. We examined whether DAPK3 mediates vascular inflammatory responses and development of hypertension. In rat mesenteric arterial smooth muscle cells, small interfering RNA against DAPK3 inhibited vascular cell adhesion molecule 1 expression and monocyte adhesion induced by tumor necrosis factor-?. DAPK3 small interfering RNA inhibited phosphorylation of c-Jun amino-terminal kinase, p38, and Akt, as well as reactive oxygen species (ROS) production induced by tumor necrosis factor-?. In human umbilical vein endothelial cells, expressions of vascular cell adhesion molecule 1, endothelial selectin, and cyclooxygenase 2, as well as ROS production induced by tumor necrosis factor-?, were inhibited by DAPK inhibitor. In vivo, blood pressure, ROS production, inflammatory molecule expression (vascular cell adhesion molecule 1 and endothelial selectin), and hypertrophy in isolated mesenteric artery were elevated in spontaneously hypertensive rats (10 weeks old), which were prevented by long-term treatment with a DAPK inhibitor (500 µg/kg per day for 6 weeks). In isolated mesenteric artery, the increased angiotensin II-induced contraction and the impaired acetylcholine-induced endothelium-dependent relaxation in spontaneously hypertensive rats were reversed by a DAPK inhibitor. The present results for the first time demonstrated in cultured smooth muscle cells and endothelial cells that DAPK3 mediates tumor necrosis factor-induced inflammatory responses via ROS-dependent mechanisms. It is also suggested that DAPK3 mediates the development of hypertension in spontaneously hypertensive rats likely via ROS-dependent inflammation, hypertrophy, and hypercontractility. PMID:22868392

  9. Pregnancy Complications in PCOS

    Microsoft Academic Search

    Roy Homburg

    A higher prevalence of several complications of pregnancy in women with polycystic ovary syndrome (PCOS), compared with healthy\\u000a mothers with no PCOS, has been described. These include an increased prevalence of spontaneous miscarriage, gestational diabetes,\\u000a pre-eclamptic toxaemia and pregnancy-induced hypertension (PIH) and the birth of small-for-gestational-age (SGA) babies.

  10. Oxidative stress and hypertension: Possibility of hypertension therapy with antioxidants

    PubMed Central

    Baradaran, Azar; Nasri, Hamid; Rafieian-Kopaei, Mahmoud

    2014-01-01

    Hypertension is a major risk factor for myocardial infarction, heart failure, stroke, peripheral arterial disease, and aortic aneurysm, and is a cause of chronic kidney disease. Hypertension is often associated with metabolic abnormalities such as diabetes and dyslipidemia, and the rate of these diseases is increasing nowadays. Recently it has been hypothesized that oxidative stress is a key player in the pathogenesis of hypertension. A reduction in superoxide dismutase and glutathione peroxidase activity has been observed in newly diagnosed and untreated hypertensive subjects, which are inversely correlated with blood pressure. Hydrogen peroxide production is also higher in hypertensive subjects. Furthermore, hypertensive patients have higher lipid hydroperoxide production. Oxidative stress is also markedly increased in hypertensive patients with renovascular disease. If oxidative stress is indeed a cause of hypertension, then, antioxidants should have beneficial effects on hypertension control and reduction of oxidative damage should result in a reduction in blood pressure. Although dietary antioxidants may have beneficial effects on hypertension and cardiovascular risk factors, however, antioxidant supplementation has not been shown consistently to be effective and improvement is not usually seen in blood pressure after treatment with single or combination antioxidant therapy in subjects thought to be at high risk of cardiovascular disease. This matter is the main focus of this paper. A list of medicinal plants that have been reported to be effective in hypertension is also presented. PMID:25097610

  11. Increased Renal Iron Accumulation in Hypertensive Nephropathy of Salt-Loaded Hypertensive Rats

    PubMed Central

    Naito, Yoshiro; Sawada, Hisashi; Oboshi, Makiko; Fujii, Aya; Hirotani, Shinichi; Iwasaku, Toshihiro; Okuhara, Yoshitaka; Eguchi, Akiyo; Morisawa, Daisuke; Ohyanagi, Mitsumasa; Tsujino, Takeshi; Masuyama, Tohru

    2013-01-01

    Although iron is reported to be associated with the pathogenesis of chronic kidney disease, it is unknown whether iron participates in the pathophysiology of nephrosclerosis. Here, we investigate whether iron is involved in the development of hypertensive nephropathy and the effects of iron restriction on nephrosclerosis in salt- loaded stroke-prone spontaneously hypertensive rats (SHRSP). SHRSP were given either a normal or high-salt diet for 8 weeks. Another subset of SHRSP were fed a high-salt with iron-restricted diet. SHRSP given a high-salt diet developed severe hypertension and nephrosclerosis. As a result, survival rate was decreased after 8 weeks diet. Importantly, massive iron accumulation and increased iron content were observed in the kidneys of salt-loaded SHRSP, along with increased superoxide production, urinary 8-Hydroxy-2?-deoxyguanosine excretion, and urinary iron excretion; however, these changes were markedly attenuated by iron restriction. Of interest, expression of cellular iron transport proteins, transferrin receptor 1 and divalent metal transporter 1, was increased in the tubules of salt-loaded SHRSP. Notably, iron restriction attenuated the development of severe hypertension and nephrosclerosis, thereby improving survival rate in salt-loaded SHRSP. Taken together, these results suggest a novel mechanism by which iron plays a role in the development of hypertensive nephropathy and establish the effects of iron restriction on salt-induced nephrosclerosis. PMID:24116080

  12. Hypertension management in patients with renal cell cancer treated with anti-angiogenic agents.

    PubMed

    Larochelle, P; Kollmannsberger, C; Feldman, R D; Schiffrin, E L; Poirier, L; Patenaude, F; Ruether, D; Myers, M; Bjarnason, G

    2012-08-01

    Inhibitors of the vascular endothelial growth factor (vegf-is) signalling pathway have fundamentally changed the treatment of metastatic renal cell carcinoma (mrcc). Hypertension is one of the most common side effects of vegf-is and has been reported with almost every vegf-i used for treatment to date. The exact mechanism of vegf-i-induced hypertension appears complex and multifactorial, and it remains to be fully explained. No randomized clinical trials are available to guide the management of hypertension during vegf-i treatment in mrcc patients. The guiding principles suggested here summarize the consensus of opinions on the diagnosis and management of vegf-i-induced hypertension during treatment of mrcc obtained from an expert working group composed of 4 Canadian medical oncologists and 5 Canadian hypertension specialists. The Canadian Hypertension Education Program guidelines, available literature, and expert opinion were used to develop the guiding principles. PMID:22876146

  13. Hypertension management in patients with renal cell cancer treated with anti-angiogenic agents

    PubMed Central

    Larochelle, P.; Kollmannsberger, C.; Feldman, R.D.; Schiffrin, E.L.; Poirier, L.; Patenaude, F.; Ruether, D.; Myers, M.; Bjarnason, G.

    2012-01-01

    Inhibitors of the vascular endothelial growth factor (vegf-is) signalling pathway have fundamentally changed the treatment of metastatic renal cell carcinoma (mrcc). Hypertension is one of the most common side effects of vegf-is and has been reported with almost every vegf-i used for treatment to date. The exact mechanism of vegf-i–induced hypertension appears complex and multifactorial, and it remains to be fully explained. No randomized clinical trials are available to guide the management of hypertension during vegf-i treatment in mrcc patients. The guiding principles suggested here summarize the consensus of opinions on the diagnosis and management of vegf-i–induced hypertension during treatment of mrcc obtained from an expert working group composed of 4 Canadian medical oncologists and 5 Canadian hypertension specialists. The Canadian Hypertension Education Program guidelines, available literature, and expert opinion were used to develop the guiding principles. PMID:22876146

  14. Pulmonary hypertension caused by pulmonary venous hypertension

    PubMed Central

    2014-01-01

    Abstract The effect of pulmonary venous hypertension (PVH) on the pulmonary circulation is extraordinarily variable, ranging from no impact on pulmonary vascular resistance (PVR) to a marked increase. The reasons for this are unknown. Both acutely reversible pulmonary vasoconstriction and pathological remodeling (especially medial hypertrophy and intimal hyperplasia) account for increased PVR when present. The mechanisms involved in vasoconstriction and remodeling are not clearly defined, but increased wall stress, especially in small pulmonary arteries, presumably plays an important role. Myogenic contraction may account for increased vascular tone and also indirectly stimulate remodeling of the vessel wall. Increased wall stress may also directly cause smooth muscle growth, migration, and intimal hyperplasia. Even long-standing and severe pulmonary hypertension (PH) usually abates with elimination of PVH, but PVH-PH is an important clinical problem, especially because PVH due to left ventricular noncompliance lacks definitive therapy. The role of targeted PH therapy in patients with PVH-PH is unclear at this time. Most prospective studies indicate that these medications are not helpful or worse, but there is ample reason to think that a subset of patients with PVH-PH may benefit from phosphodiesterase inhibitors or other agents. A different approach to evaluating possible pharmacologic therapy for PVH-PH may be required to better define its possible utility. PMID:25610595

  15. Natural Antioxidants and Hypertension: Promise and Challenges

    PubMed Central

    Kizhakekuttu, Tinoy J.; Widlansky, Michael E.

    2010-01-01

    Hypertension reigns as a leading cause of cardiovascular morbidity and mortality worldwide. Excessive reactive oxygen species (ROS) has emerged as a central common pathway by which disparate influences may induce and exacerbate hypertension. Potential sources of excessive ROS in hypertension include NADPH oxidase, mitochondria, xanthine oxidase, endothelium-derived NO synthase (eNOS), cyclooxygenase 1 and 2, cytochrome P450 epoxygenase and transition metals. While a significant body of epidemiological and clinical data suggests that antioxidant rich diets reduce blood pressure and cardiovascular risk, randomized trials and population studies using natural antioxidants have yielded disappointing results. The reasons behind this lack of efficacy are not completely clear, but likely include a combination of 1) ineffective dosing regimens 2) the potential pro-oxidant capacity of some of these agents 3) selection of subjects less likely to benefit from antioxidant therapy (too healthy or too sick), 4) inefficiency of non-specific quenching of prevalent ROS versus prevention of excessive ROS production. Commonly used antioxidants include Vitamins A, C and E, L-arginine, flavanoids, and mitochondria targeted agents, Coenzyme Q10, acetyl-L-carnitine and alpha-lipoic acid. Various reasons, including incomplete knowledge of the mechanisms of action of these agents, lack of target specificity, and potential inter-individual differences in therapeutic efficacy preclude us from recommending any specific natural antioxidant for antihypertensive therapy at this time. This review focuses on recent literature regarding above mentioned issues evaluating naturally occurring antioxidants with respect to their impact on hypertension. PMID:20370791

  16. Mineralocorticoid actions in the brain and hypertension.

    PubMed

    Huang, Bing S; Leenen, Frans H H

    2011-06-01

    Mineralocorticoid receptors (MR) and epithelial sodium channels (ENaC) in the brain mediate central aldosterone-induced sympathetic hyperactivity and hypertension. Enzymes for biosynthesis of aldosterone are present in the brain, and aldosterone can be produced locally in the brain. Hypothalamic aldosterone levels increase in Dahl salt-sensitive rats on high-salt diet, and in Wistar rats with chronic central infusion of sodium-rich artificial cerebrospinal fluid (CSF) or with subcutaneous infusion of angiotensin II. Functional studies using antagonists of MR, ENaC, and ouabain-like compounds ("ouabain"), as well as specific aldosterone synthase inhibitors, suggest that an increase in local synthesis of aldosterone via MR and ENaC in the brain increases "ouabain" and thereby causes enhanced AT(1) receptor stimulation, leading to sympathoexcitation and hypertension. An increase in CSF sodium or an increase in angiotensinergic output from circumventricular organs such as the subfornical organ projecting to hypothalamic nuclei may increase local production of aldosterone and "ouabain" in magnocellular neurons in the supraoptic nucleus and paraventricular nucleus. This aldosterone-"ouabain" neuromodulatory mechanism appears to play a major role in salt-induced or angiotensin II-induced hypertension. PMID:21298576

  17. Hemoglobin-induced lung vascular oxidation, inflammation, and remodeling contribute to the progression of hypoxic pulmonary hypertension and is attenuated in rats with repeated-dose haptoglobin administration.

    PubMed

    Irwin, David C; Hyen Baek, Jin; Hassell, Kathryn; Nuss, Rachelle; Eigenberger, Paul; Lisk, Christina; Loomis, Zoe; Maltzahn, Joanne; Stenmark, Kurt R; Nozik-Grayck, Eva; Buehler, Paul W

    2015-05-01

    Haptoglobin (Hp) is an approved treatment in Japan for trauma, burns, and massive transfusion-related hemolysis. Additional case reports suggest uses in other acute hemolytic events that lead to acute kidney injury. However, Hp's protective effects on the pulmonary vasculature have not been evaluated within the context of mitigating the consequences of chronic hemoglobin (Hb) exposure in the progression of pulmonary hypertension (PH) secondary to hemolytic diseases. This study was performed to assess the utility of chronic Hp therapy in a preclinical model of Hb and hypoxia-mediated PH. Rats were simultaneously exposed to chronic Hb infusion (35mg per day) and hypobaric hypoxia for 5 weeks in the presence or absence of Hp treatment (90mg/kg twice a week). Hp inhibited the Hb plus hypoxia-mediated nonheme iron accumulation in lung and heart tissue, pulmonary vascular inflammation and resistance, and right-ventricular hypertrophy, which suggests a positive impact on impeding the progression of PH. In addition, Hp therapy was associated with a reduction in critical mediators of PH, including lung adventitial macrophage population and endothelial ICAM-1 expression. By preventing Hb-mediated pathology, Hp infusions: (1) demonstrate a critical role for Hb in vascular remodeling associated with hypoxia and (2) suggest a novel therapy for chronic hemolysis-associated PH. PMID:25656991

  18. Idiopathic pulmonary arterial hypertension.

    PubMed

    Souza, Rogerio; Jardim, Carlos; Humbert, Marc

    2013-10-01

    Idiopathic pulmonary arterial hypertension (IPAH), formerly called primary pulmonary hypertension, is a rare disease (incidence and prevalence rates of approximately one and six cases per million inhabitants, respectively) with different clinical phenotypes. A group of diverse conditions manifest pulmonary arterial hypertension (PAH) and share similar pathological and/or clinical findings with IPAH. By definition, IPAH is diagnosed only after alternative diagnoses have been ruled out. Extensive investigation is needed to determine if PAH is associated with thyroid diseases, infectious diseases, autoimmune conditions, exposure to certain drugs (particularly anorexigens), certain genetic mutations, and so on. The presence of genetic abnormalities and risk factors (such as specific drug exposures) reinforces the "multiple hit" concept for the development of pulmonary hypertension. Fortunately, within the past two decades, therapeutic options have become available for IPAH, resulting in improved survival and clinical outcomes. At least seven different compounds have been registered for PAH treatment. However, even with aggressive PAH-specific therapy, mortality rates remain high (?40% at 5 years). Given the high mortality rates, the use of combinations of agents that work by different pathways has been advocated (either as "add-on" therapy or initial "up front" therapy). Further, new therapeutic agents and treatment strategies are on the near horizon, aiming to further improve survival from the remarkable progress already seen. PMID:24037625

  19. Aldosterone and arterial hypertension

    Microsoft Academic Search

    Stefan Pilz; Eberhard Ritz; Barbara Obermayer-Pietsch; Thomas R. Pieber; Andreas Tomaschitz

    2009-01-01

    In the setting of primary aldosteronism, elevated aldosterone levels are associated with increased blood pressure. Aldosterone concentrations within the normal range, however, can also alter blood pressure. Furthermore, the aldosterone-to-renin ratio, an indicator of aldosterone excess, is associated with hypertension, even in patients without excessive absolute aldosterone levels. In this Review we assess the data on the role of aldosterone

  20. Sleep Apnea and Hypertension

    Microsoft Academic Search

    Alisa A. Acosta

    \\u000a Sleep disordered breathing (SDB) encompasses all forms of respiratory disorders specific to sleep (1). There is a spectrum of SDB ranging from mild to severe with the most severe form being obstructive sleep apnea (OSA) (2). In adults, OSA has been linked to cardiovascular disease, specifically hypertension (HTN) (3). The association between systemic HTN and OSA is well documented in

  1. Paranormal healing and hypertension

    Microsoft Academic Search

    Jaap J Beutler; Johannes T M Attevelt; Sybo A Schouten; Joop A J Faber; Evert J Dorhout Mees; Gijsbert G Geijskes

    1988-01-01

    A prospective randomised trial was carried out to see whether paranormal healing by laying on of hands might reduce blood pressure in essential hypertension and whether such an effect might be due to a paranormal, psychological, or placebo factor. Patients were randomised to three treatment groups: paranormal healing by laying on of hands (n=40), paranormal healing at a distance (n=37),

  2. Redox signaling in hypertension

    Microsoft Academic Search

    Tamara M. Paravicini; Rhian M. Touyz

    2006-01-01

    Diseases such as hypertension, atherosclerosis and diabetes are associated with vascular functional and structural changes including endothelial dysfunction, altered contractility and vascular remodeling. Cellular events underlying these processes involve changes in vascular smooth muscle cell (VSMC) growth, apoptosis\\/anoikis, cell migration, inflammation, and fibrosis. Many stimuli influence cellular changes, including mechanical forces, such as shear stress, and vasoactive agents, of which

  3. Early impairment of coronary flow reserve in young men with borderline hypertension

    Microsoft Academic Search

    Hanna Laine; Olli T Raitakari; Harri Niinikoski; Olli-Pekka Pitkänen; Hidehiro Iida; Jorma Viikari; Pirjo Nuutila; Juhani Knuuti

    1998-01-01

    Objectives. The purpose of this study was to investigate whether functional abnormalities in coronary vasomotion are present in young healthy asymptomatic men fulfilling the World Health Organization (WHO) criteria for borderline hypertension.Background. Previous studies have reported reduced coronary flow reserve in middle-aged subjects with sustained hypertension and hypertension-induced microvascular heart disease or left ventricular hypertrophy.Methods. Myocardial blood flow was measured

  4. Comparison of survival in patients with pulmonary hypertension associated with fenfluramine to patients with primary pulmonary hypertension

    Microsoft Academic Search

    Stuart Rich; Alicia Shillington; Vallerie McLaughlin

    2003-01-01

    To test whether the clinical presentation and prognosis of fenfluramine-induced pulmonary hypertension (PH) differs from primary PH (PPH), we compared the clinical profile and outcome of 10 patients with fenfluramine-induced PH with that of 70 patients with PPH referred to our center over the same time frame and treated identically. Patients with diet pill PH were similar to those with

  5. Cilnidipine induced ankle edema

    PubMed Central

    Annil, Vishal R.; Mahajan, Annil; Mahajan, Vivek; Khajuria, Vijay; Gillani, Zahid

    2014-01-01

    Cilnidipine is a 4th generation dihydropyridine calcium channel blocker approved recently for the treatment of essential hypertension. It is not known to present with ankle edema like amlodipine. Moreover, it has been proposed as an alternative anti-hypertensive for patients with amlodipine-induced edema. We report a case of cilnidipine induced ankle edema. PMID:24987189

  6. Cilnidipine induced ankle edema.

    PubMed

    Annil, Vishal R; Mahajan, Annil; Mahajan, Vivek; Khajuria, Vijay; Gillani, Zahid

    2014-01-01

    Cilnidipine is a 4(th) generation dihydropyridine calcium channel blocker approved recently for the treatment of essential hypertension. It is not known to present with ankle edema like amlodipine. Moreover, it has been proposed as an alternative anti-hypertensive for patients with amlodipine-induced edema. We report a case of cilnidipine induced ankle edema. PMID:24987189

  7. [When should secondary hypertension be suspected?].

    PubMed

    Koivuviita, Niina

    2009-01-01

    Secondary hypertension is diagnosed in 5 to 10% of hypertensive patients. The probability of secondary hypertension increases, if the screening is focused on patients in which even a combination of three medicaments fails to attain the therapeutic objective, i.e. the so-called treatment-resistant hypertensives. Exclusion of secondary hypertension is part of the analysis of treatment-resistant hypertension. The most common causes of secondary hypertension are renal diseases, renal artery stenosis and primary hyperaldosteronism. PMID:19585906

  8. A single exposure to particulate or gaseous air pollution increases the risk of aconitine-induced cardiac arrythmia in hypertensive rats

    EPA Science Inventory

    Epidemiological studies demonstrate a significant association between arrhythmias and air pollution exposure. Sensitivity to aconitine-induced arrhythmia has been used repeatedly to examine the factors that increase the risk of such cardiac electrical dysfunction. In this study, ...

  9. Airways Hyperresponsiveness Following a Single Inhalation Exposure to Doxorubicin-Induced Heart Failure Prevents Airways Transition Metal-Rich Particulate Matter in Hypertensive Rats

    EPA Science Inventory

    Exposure to particulate matter (PM) air pollution results in airways hyperresponsiveness (AHR), however it also results in adverse cardiovascular effects, particularly in individuals with underlying cardiovascular disease. The impact of pre-existing cardiac deficit on PM-induced ...

  10. Effects of Hypertension and Exercise on Cardiac Proteome Remodelling

    PubMed Central

    Petriz, Bernardo A.; Franco, Octavio L.

    2014-01-01

    Left ventricle hypertrophy is a common outcome of pressure overload stimulus closely associated with hypertension. This process is triggered by adverse molecular signalling, gene expression, and proteome alteration. Proteomic research has revealed that several molecular targets are associated with pathologic cardiac hypertrophy, including angiotensin II, endothelin-1 and isoproterenol. Several metabolic, contractile, and stress-related proteins are shown to be altered in cardiac hypertrophy derived by hypertension. On the other hand, exercise is a nonpharmacologic agent used for hypertension treatment, where cardiac hypertrophy induced by exercise training is characterized by improvement in cardiac function and resistance against ischemic insult. Despite the scarcity of proteomic research performed with exercise, healthy and pathologic heart proteomes are shown to be modulated in a completely different way. Hence, the altered proteome induced by exercise is mostly associated with cardioprotective aspects such as contractile and metabolic improvement and physiologic cardiac hypertrophy. The present review, therefore, describes relevant studies involving the molecular characteristics and alterations from hypertensive-induced and exercise-induced hypertrophy, as well as the main proteomic research performed in this field. Furthermore, proteomic research into the effect of hypertension on other target-demerged organs is examined. PMID:24877123

  11. Mechanisms and consequences of arterial hypertension after renal transplantation.

    PubMed

    Koomans, H A; Ligtenberg, G

    2001-09-27

    The high incidence of hypertension after renal transplantation contributes to the risk of cardiovascular morbidity and mortality in renal transplant recipients. Although cyclosporine has been influential in the improvement of transplant outcome, it has emerged as a major cause of hypertension after organ transplantation. The underlying pathophysiological mechanisms of cyclosporine-induced hypertension include enhanced sympathetic nervous system activity, renal vasoconstriction, and sodium/water retention. Hypertension is also significantly associated with reduced graft survival and thereby requires aggressive treatment intervention. Calcium channel blockers may offer some advantages over angiotensin-converting enzyme inhibitors for the treatment of hypertension in stable renal transplant recipients. Nevertheless, selection of the most appropriate antihypertensive agent should take into account the possibility of pharmacokinetic interactions with immunosuppressive agents. There is evidence to suggest that the use of tacrolimus-based immunosuppression induces less hypertension compared with cyclosporine. Not only do patients receiving tacrolimus tend to require less antihypertensive therapy, but converting patients from cyclosporine to tacrolimus has been shown to result in significant reductions in blood pressure. Thus, tacrolimus may be associated with an improved cardiovascular risk profile in renal transplant recipients. PMID:11585243

  12. Connecting tubule glomerular feedback in hypertension.

    PubMed

    Wang, Hong; D'Ambrosio, Martin A; Garvin, Jeffrey L; Ren, Yilin; Carretero, Oscar A

    2013-10-01

    In Dahl salt-sensitive rats (Dahl SS), glomerular capillary pressure increases in response to high salt intake and this is accompanied by significant glomerular injury compared with spontaneously hypertensive rats with similar blood pressure. Glomerular capillary pressure is controlled mainly by afferent arteriolar resistance, which is regulated by the vasoconstrictor tubule glomerular feedback (TGF) and the vasodilator connecting TGF (CTGF). We hypothesized that Dahl SS have a decreased TGF response and enhanced TGF resetting compared with spontaneously hypertensive rats, and that these differences are attributable in part to an increase in CTGF. In vivo, using micropuncture we measured stop-flow pressure (a surrogate of glomerular capillary pressure). TGF was calculated as the maximal decrease in stop-flow pressure caused by increasing nephron perfusion, TGF resetting as the attenuation in TGF induced by high salt diet, and CTGF as the difference in TGF response before and during CTGF inhibition with benzamil. Compared with spontaneously hypertensive rats, Dahl SS had (1) lower TGF responses in normal (6.6±0.1 versus 11.0±0.2 mm Hg; P<0.001) and high-salt diets (3.3±0.1 versus 10.1±0.3 mm Hg; P<0.001), (2) greater TGF resetting (3.3±0.1 versus 1.0±0.3 mm Hg; P<0.001), and (3) greater CTGF (3.4±0.4 versus 1.2±0.1 mm Hg; P<0.001). We conclude that Dahl SS have lower TGF and greater CTGF than spontaneously hypertensive rats, and that CTGF antagonizes TGF. Furthermore, CTGF is enhanced by a high-salt diet and contributes significantly to TGF resetting. Our findings may explain in part the increase in vasodilatation, glomerular capillary pressure, and glomerular damage in SS hypertension during high salt intake. PMID:23959547

  13. An update on hypertensive emergencies and urgencies.

    PubMed

    Muiesan, Maria Lorenza; Salvetti, Massimo; Amadoro, Valentina; di Somma, Salvatore; Perlini, Stefano; Semplicini, Andrea; Borghi, Claudio; Volpe, Massimo; Saba, Pier Sergio; Cameli, Matteo; Ciccone, Marco Matteo; Maiello, Maria; Modesti, Pietro Amedeo; Novo, Salvatore; Palmiero, Pasquale; Scicchitano, Pietro; Rosei, Enrico Agabiti; Pedrinelli, Roberto

    2015-05-01

    Severe acute arterial hypertension is usually defined as 'hypertensive crisis', although 'hypertensive emergencies' or 'hypertensive urgencies', as suggested by the Joint National Committee and the European Society of Hypertension, have completely different diagnostic and therapeutic approaches.The prevalence and demographics of hypertensive emergencies and urgencies have changed over the last four decades, but hypertensive emergencies and urgencies are still associated with significant morbidity and mortality.Different scientific societies have repeatedly produced up-to-date guidelines; however, the treatment of hypertensive emergencies and urgencies is still inappropriate, with potential clinical implications.This review focuses on hypertensive emergencies and urgencies management and treatment, as suggested by recent data. PMID:25575271

  14. Bone lead, hypertension, and lead nephropathy

    SciTech Connect

    Wedeen, R.P.

    1988-06-01

    There is considerable clinical evidence that excessive lead absorption causes renal failure with hypertension and predisposes individuals to hypertension even in the absence of detectable renal failure. Recent analyses of transiliac bone biopsies indicate that unsuspected elevated bone leads may reflect the cause (or contributing cause) of end-stage renal disease in 5% of the European dialysis population. In these patients, bone lead levels were four times higher than in unexposed cadavers (6 micrograms/g wet weight) and approximated levels found in lead workers (30 micrograms/g). At present, the most reliable index of the body lead burden is the CaNa2 EDTA lead mobilization test. In vivo tibial X-ray-induced X-ray fluorescence (XRF) is a more practical noninvasive technique for assessing bone lead, which should find widespread application as a diagnostic tool and for epidemiologic studies.

  15. Depressed endothelium-dependent relaxation in hypertension: relation to increased blood pressure and reversibility

    Microsoft Academic Search

    J. Van de Voorde; B. Vanheel; I. Leusen

    1988-01-01

    Endothelium-dependent relaxation effects have been reported to be impaired in thoracic aorta from genetic and experimentally induced hypertensive rats. This study extends these observations to carotid artery and abdominal aorta from renovascular hypertensive rats. It was also found that rats with coarctation of aorta show depressed endothelium-dependent relaxation responses in thoracic aorta above the stenosis (high pressure region) while no

  16. Riociguat for pulmonary hypertension.

    PubMed

    Ghofrani, Hossein-Ardeschir; Voswinckel, Robert; Gall, Henning; Schermuly, Ralph; Weissmann, Norbert; Seeger, Werner; Grimminger, Friedrich

    2010-03-01

    Pulmonary hypertension (PH) encompasses a group of diseases associated with progressively increasing pulmonary vascular resistance, right heart failure and premature death. Riociguat is a novel, first-in-class oral drug that directly stimulates soluble guanylate cyclase, both independently of the endogenous vasodilator nitric oxide (NO) and in synergy with NO. Single oral doses of riociguat were well tolerated in a Phase I study of healthy volunteers. They had a favorable safety profile, and improved pulmonary hemodynamics and cardiac index to a greater extent than inhaled NO in a proof-of-concept study in patients with moderate-to-severe PH. In a 12-week Phase II trial in patients with chronic thromboembolic PH or pulmonary arterial hypertension, pulmonary hemodynamics and exercise capacity improved following individual dose titration with oral riociguat, which was generally well tolerated. Further trials in PH have been initiated. PMID:20230258

  17. [Diabetes and hypertension].

    PubMed

    Sayk, F; Iwen, K A; Lehnert, H

    2009-11-01

    Diabetes mellitus and arterial hypertension are major cardiovascular risk factors with high co-morbidity. Microalbuminuria is an independent risk marker, and routine monitoring of urinary albumin is mandatory in patients with diabetes and hypertension. The therapeutic goal of antihypertensive treatment is < 130/80 mm Hg, however in the presence of nephropathy < 125/75 mm Hg should be achieved. Therapy is based on lifestyle-interventions including 1) weight reduction, 2) regular moderate physical activity, 3) modification of diet with restriction of salt- and alcohol consumption as well as 4) cessation of smoking. Renin- and ACE-inhibitors as well as AT1-receptor antagonists are drugs of first choice, delaying the progression of diabetic nephropathy most effectively. PMID:19876807

  18. Hypertension and insulin disorders

    Microsoft Academic Search

    Michinori Imazu

    2002-01-01

    Insulin resistance and\\/or compensatory hyperinsulinemia are associated with hypertension, obesity, dyslipidemia, and glucose\\u000a intolerance. Insulin resistance and hyperinsulinemia are considered to increase blood pressure through sympathetic nervous\\u000a system activation, renin-angiotensin system stimulation, and vascular smooth muscle cell proliferation. Leptin, magnesium\\u000a ions, nitric oxide, endothelin, peroxisome proliferator-activated receptor ?, and tumor necrosis factor-? also modulate blood\\u000a pressure. Decreasing insulin resistance by

  19. Hyponatremic hypertensive syndrome.

    PubMed

    Peco-Anti?, A; Dimitrijevi?, N; Jovanovi?, O; Marseni?, O; Kosti?, M

    2000-12-01

    We report on a 4-year-old girl with hyponatremic-hypertensive syndrome (HHS), a rare entity in childhood. The girl was referred to us from a local hospital with a history of recurrent fever, vomiting, and seizures. On admission she was markedly dehydrated. Initial investigations revealed severe hyponatremia (serum Na 120 mmol/l), hypochloremia (serum Cl 68 mmol/l), and mild hypokalemia (serum K 3.3 mmol/l), while serum calcium and magnesium were normal. Serum urea was 5 mmol/l and serum creatinine was 62 mumol/l. Despite hyponatremic dehydration, her urine output was high (2050 ml/24 h), as was her urinary sodium (168 mmol/24 h). She had massive transient proteinuria (maximal 1642 mg/24 h) while being severely hypertensive (blood pressure 210/160 mmHg). Further investigations revealed right kidney scarring, hyper-reflexive bladder dysfunction, massive brain infarcts, and myocardial left ventricular hypertrophy. Renal arteries were normal on arteriography. Blood pressure control resulted in normalization of serum and urinary electrolytes and decrease of proteinuria. Hyponatremia and transient massive proteinuria in this patient seem to be caused by high-pressure-forced diuresis due to malignant renoparenchymal hypertension. PMID:11149128

  20. Hypertension in developing countries.

    PubMed

    Ibrahim, M Mohsen; Damasceno, Albertino

    2012-08-11

    Data from different national and regional surveys show that hypertension is common in developing countries, particularly in urban areas, and that rates of awareness, treatment, and control are low. Several hypertension risk factors seem to be more common in developing countries than in developed regions. Findings from serial surveys show an increasing prevalence of hypertension in developing countries, possibly caused by urbanisation, ageing of population, changes to dietary habits, and social stress. High illiteracy rates, poor access to health facilities, bad dietary habits, poverty, and high costs of drugs contribute to poor blood pressure control. The health system in many developing countries is inadequate because of low funds, poor infrastructure, and inexperience. Priority is given to acute disorders, child and maternal health care, and control of communicable diseases. Governments, together with medical societies and non-governmental organisations, should support and promote preventive programmes aiming to increase public awareness, educate physicians, and reduce salt intake. Regulations for the food industry and the production and availability of generic drugs should be reinforced. PMID:22883510

  1. Roles of hypertension in the rupture of intracranial aneurysms

    PubMed Central

    Tada, Yoshiteru; Wada, Kosuke; Shimada, Kenji; Makino, Hiroshi; Liang, Elena I.; Murakami, Shoko; Kudo, Mari; Kitazato, Keiko T.; Nagahiro, Shinji; Hashimoto, Tomoki

    2014-01-01

    Background and Purpose Systemic hypertension has long been considered as a risk factor of aneurysmal rupture. However, a causal link between systemic hypertension and the development of aneurysmal rupture has not been established. In this study, using a mouse model of intracranial aneurysm rupture, we examined the roles of systemic hypertension in the development of aneurysmal rupture. Methods Aneurysms were induced by a combination of deoxycorticosterone acetate (DOCA)-salt induced hypertension and a single injection of elastase into the cerebrospinal fluid in mice. Anti-hypertensive treatment was started six days after aneurysm induction. Aneurysmal rupture was detected by neurological symptoms and confirmed by the presence of intracranial aneurysm with subarachnoid hemorrhage. Hydralazine (direct vasodilator) or the discontinuation of the DOCA-salt treatment was used to assess the roles of systemic hypertension. Captopril (angiotensin converting enzyme inhibitor) or losartan (angiotensin II type 1 receptor antagonist) was used to assess the roles of the local renin-angiotensin system in the vascular wall. Results Normalization of blood pressure by hydralazine significantly reduced the incidence of ruptured aneurysms and the rupture rate. There was a dose dependent relationship between the reduction of blood pressure and the prevention of aneurysmal rupture. Captopril and losartan were able to reduce the rupture rates without affecting systemic hypertension induced by DOCA-salt treatment. Conclusions Normalization of blood pressure after aneurysm formation prevented aneurysmal rupture in mice. In addition, we found that the inhibition of the local renin-angiotensin system independent from the reduction of blood pressure can prevent aneurysmal rupture. PMID:24370755

  2. Imaging in hypertensive heart disease

    PubMed Central

    Janardhanan, Rajesh; Kramer, Christopher M

    2014-01-01

    Hypertensive heart disease is the target organ response to arterial hypertension. Left ventricular hypertrophy represents an important predictor for cardiovascular events. Myocardial fibrosis, a common end point in hypertensive heart disease, has been linked to the development of left ventricular hypertrophy and diastolic dysfunction. Echocardiography is clinically useful in the detection of left ventricular hypertrophy and the assessment of diastolic function. Although echocardiography is more widely available, cardiac magnetic resonance has been demonstrated to be more reproducible for the estimation of left ventricular mass. Future developments in cardiac magnetic resonance techniques may facilitate the quantification of diffuse fibrosis that occurs in hypertensive heart disease. Thus, advances in cardiac imaging provide comprehensive, noninvasive tools for imaging left ventricular hypertrophy, diastolic dysfunction, myocardial fibrosis and ischemia observed in hypertensive heart disease. The objective of this article is to summarize the state-of-the-art and the future of multimodality imaging of hypertensive heart disease. PMID:21453216

  3. Autonomic reactivity to cold pressor test in prehypertensive and hypertensive medical students.

    PubMed

    Farah, Khaliq; Keshav, Gupta; Pawan, Singh

    2011-01-01

    Autonomic reactivity to stress has been hypothesized to be a marker for subsequent neurogenic hypertension. Medical training is highly stressful particularly for those who are beginning their medical education. The present study was undertaken to study the autonomic reactivity to cold pressor test in prehypertensive and hypertensive undergraduate medical students. One hundred and seventeen undergraduate medical students between 17-21 years of age got examined for blood pressure and stress level. Twelve Hypertensives and eight prehypertensives selected from the above subjects and twenty normotensives underwent cold pressure test (CPT) to assess autonomic reactivity to laboratory induced stress. 10.25% of the subjects were found to be hypertensive and 6.83% pre hypertensive. On the stress scale 53% had mild stress, 7% showed moderate stress while none had stress as a major problem. There was no correlation between BP and stress score. On CPT, BP increased significantly in all the three groups (hypertensive, prehypertensive and normotensive) but came back to basal levels within 5 minutes indicating normal autonomic response. Rise of BP was higher in hypertensive group as compared to normotensive group. The rise of diastolic and mean BP during CPT was significantly higher in subjects having family history of hypertension. Forty percent of normotensive subjects had more than 20 mm Hg rise in systolic BP on CPT. Adolescents must be routinely screened to detect asymptomatic hypertension. The CPT may identify individuals with an occult physiological abnormality that predisposes them to hypertension in their later life. PMID:22471232

  4. Pulmonary Hypertension in Cardiac Surgery

    PubMed Central

    Denault, André; Deschamps, Alain; Tardif, Jean-Claude; Lambert, Jean; Perrault, Louis

    2010-01-01

    Pulmonary hypertension is an important prognostic factor in cardiac surgery associated with increased morbidity and mortality. With the aging population and the associated increase severity of illness, the prevalence of pulmonary hypertension in cardiac surgical patients will increase. In this review, the definition of pulmonary hypertension, the mechanisms and its relationship to right ventricular dysfunction will be presented. Finally, pharmacological and non-pharmacological therapeutic and preventive approaches will be presented. PMID:21286273

  5. Pulmonary Hypertension: Evaluation and Management

    Microsoft Academic Search

    Gustavo A. Heresi; Raed A. Dweik

    2007-01-01

    Pulmonary hypertension (PH) is a hemodynamic state characterized by elevation in the mean pulmonary arterial pressure and\\u000a pulmonary vascular resistance leading to right ventricular failure and premature death. PH can be the result of a variety\\u000a of diseases of different etiologies. Pulmonary arterial hypertension (PAH) should be distinctly differentiated from pulmonary\\u000a venous hypertension (PVH) as a result of left heart

  6. Chapter 7. Atherosclerosis and hypertension

    PubMed Central

    Matova, E. E.; Vihert, A. M.

    1976-01-01

    Autopsy studies of atherosclerosis of the aorta and the coronary arteries were carried out in 3134 subjects with essential hypertension. A comparison was made with low, average, and high atherosclerosis groups. Essential hypertension was found to accelerate the development of all types of aortic lesion, except fatty streak, as compared with the standardized average atherosclerosis group, and to accelerate the development of fibrous plaque but not complicated and calcified lesions as compared with the high atherosclerosis group. The extent of fibrous plaque in the coronary arteries was greater in the essential hypertension group than in the low and standardized average atherosclerosis groups but did not differ from that in the high atherosclerosis group. The extent of complicated and calcified lesions and the prevalence of coronary stenosis were higher in the high atherosclerosis group than in cases of hypertension. Geographical differences in atherosclerosis among hypertensives in different towns reflected the findings for the whole material. Symptomatic hypertension was found to accelerate aortic atherosclerosis at least to the same extent as essential hypertension. It was conductive to coronary atherosclerosis but not to the same extent as essential hypertension. Coronary stenosis and various manifestations of coronary heart disease were rare in symptomatic hypertension. PMID:1087193

  7. Haemodynamic evaluation of pulmonary hypertension

    Microsoft Academic Search

    D. Chemla; V. Castelain; P. Herve; Y. Lecarpentier; S. Brimioulle

    2002-01-01

    ABSTRACT: Pulmonary,hypertension,is characterised by the chronic elevation of pulmonary,artery pressure (PAP) and pulmonary,vascular resistance (PVR) leading to right ventricular enlargement,and,hypertrophy. Pulmonary,hypertension,may,result from respiratory and cardiac diseases, the most severe forms occurring in thrombo- embolic and primary,pulmonary,hypertension. Pulmonary,hypertension is most often defined as a mean,PAP w25 mmHg,at rest or w30 mmHg during exercise, the pressure being measured invasively with a pulmonary

  8. Oxidative stress in the brain causes hypertension via sympathoexcitation

    PubMed Central

    Kishi, Takuya; Hirooka, Yoshitaka

    2012-01-01

    Activation of the sympathetic nervous system (SNS) has an important role in the pathogenesis of hypertension, and is determined by the brain. Previous many studies have demonstrated that oxidative stress, mainly produced by angiotensin II type 1 (AT1) receptor and nicotinamide adenine dinucleotide phosphate (NAD (P) H) oxidase, in the autonomic brain regions was involved in the activation of the SNS of hypertension. In this concept, we have investigated the role of oxidative stress in the rostral ventrolateral medulla (RVLM), which is known as the cardiovascular center in the brainstem, in the activation of the SNS, and demonstrated that AT1 receptor and NAD (P) H oxidase-induced oxidative stress in the RVLM causes sympathoexcitation in hypertensive rats. The mechanisms in which brain oxidative stress causes sympathoexcitation have been investigated, such as the interactions with nitric oxide (NO), effects on the signal transduction, or inflammations. Interestingly, the environmental factors of high salt intake and high calorie diet may also increase the oxidative stress in the brain, particularly in the RVLM, thereby activating the central sympathetic outflow and increasing the risk of hypertension. Furthermore, several orally administered AT1 receptor blockers have been found to cause sympathoinhibition via reduction of oxidative stress through the inhibition of central AT1 receptor. In conclusion, we must consider that AT1 receptor and the related oxidative stress production in the brain cause the activation of SNS in hypertension, and that AT1 receptor in the brain could be novel therapeutic target of the treatments for hypertension. PMID:22934082

  9. Dopamine blockade abolishes the exaggerated natriuresis of essential hypertension.

    PubMed

    Coruzzi, P; Musiari, L; Biggi, A; Ravanetti, C; Novarini, A

    1987-10-01

    We studied natriuresis during central hypervolaemia by immersing eight normal subjects and eight patients with uncomplicated essential hypertension up to the neck in water, either in the absence (study 1) or presence (study 2) of dopamine blockade by metoclopramide. Water immersion without metoclopramide induced an exaggerated natriuresis in hypertensives compared with normotensives (P less than 0.001). This occurred in the presence of identical hormonal (plasma renin activity, plasma aldosterone and prolactin), renal (creatinine clearance) and pressor responses in both groups (study 1). The marked natriuresis seen during water immersion alone in normotensives was significantly blunted (P less than 0.02) but not abolished during water immersion with addition of metoclopramide. On the other hand, the exaggerated natriuresis found in hypertensives during water immersion alone was completely abolished during water immersion plus dopamine blockade by metoclopramide (study 2). Similar hormonal, renal and pressor changes were detected in both normotensive and hypertensive subjects during water immersion plus metoclopramide administration. Our data demonstrate that metoclopramide abolishes the exaggerated natriuretic response seen in hypertensives during volume expansion produced by water immersion, and suggest that dopamine may play a critical role in mediating the hypernatriuresis of essential hypertension. PMID:3323313

  10. Neuroendocrine Mechanisms of Acupuncture in the Treatment of Hypertension

    PubMed Central

    Zhou, Wei; Longhurst, John C.

    2012-01-01

    Hypertension affects approximately 1 billion individuals worldwide. Pharmacological therapy has not been perfected and often is associated with adverse side effects. Acupuncture is used as an adjunctive treatment for a number of cardiovascular diseases like hypertension. It has long been established that the two major contributors to systemic hypertension are the intrarenal renin-angiotensin system and chronic activation of the sympathetic nervous system. Recent evidence indicates that in some models of cardiovascular disease, blockade of AT1 receptors in the rostral ventrolateral medulla (rVLM) reduces sympathetic nerve activity and blood pressure, suggesting that overactivity of the angiotensin system in this nucleus may play a role in the maintenance of hypertension. Our experimental studies have shown that electroacupuncture stimulation activates neurons in the arcuate nucleus, ventrolateral gray, and nucleus raphe to inhibit the neural activity in the rVLM in a model of visceral reflex stimulation-induced hypertension. This paper will discuss current knowledge of the effects of acupuncture on central nervous system and how they contribute to regulation of acupuncture on the endocrine system to provide a perspective on the future of treatment of hypertension with this ancient technique. PMID:22216059

  11. [Long-term follow-up of pulmonary hypertension of unknown etiology].

    PubMed

    Lang, I; Kneussl, M; Frank, H; Mlczoch, J

    1990-07-01

    Since 1967, 166 patients with primary pulmonary hypertension of unknown etiology have been followed-up at the Department of Cardiology at the University of Vienna. Although an exact etiopathogenetic differentiation was not possible, three groups of patients were identified clinically: patients with so-called primary pulmonary hypertension (PPH)--group 1; patients with pulmonary hypertension induced by anorexipens (aminorex fumarate)--group 2; and patients with pulmonary hypertension due to emboli in the large pulmonary vessels--group 3. In addition to non-invasive echocardiographic assessment of pulmonary pressures, regular cardiac catheterizations were carried out, which revealed right atrial mean pressure, cardiac output, and mixed venous saturation to be prognostic predictive factors. Patients with anorexigen-induced pulmonary hypertension have a clearly better life expectancy than those with PPH. Owing to the temporally limited effect of the pulmonary hypertension-inducing agent, aminorex fumarate (Menocil), patients with anorexigen-induced pulmonary hypertension may be considered a model group for drug-induced vascular pathology. PMID:2399244

  12. Carotid body potentiation during chronic intermittent hypoxia: implication for hypertension

    PubMed Central

    Del Rio, Rodrigo; Moya, Esteban A.; Iturriaga, Rodrigo

    2014-01-01

    Autonomic dysfunction is involved in the development of hypertension in humans with obstructive sleep apnea, and animals exposed to chronic intermittent hypoxia (CIH). It has been proposed that a crucial step in the development of the hypertension is the potentiation of the carotid body (CB) chemosensory responses to hypoxia, but the temporal progression of the CB chemosensory, autonomic and hypertensive changes induced by CIH are not known. We tested the hypothesis that CB potentiation precedes the autonomic imbalance and the hypertension in rats exposed to CIH. Thus, we studied the changes in CB chemosensory and ventilatory responsiveness to hypoxia, the spontaneous baroreflex sensitivity (BRS), heart rate variability (HRV) and arterial blood pressure in pentobarbital anesthetized rats exposed to CIH for 7, 14, and 21 days. After 7 days of CIH, CB chemosensory and ventilatory responses to hypoxia were enhanced, while BRS was significantly reduced by 2-fold in CIH-rats compared to sham-rats. These alterations persisted until 21 days of CIH. After 14 days, CIH shifted the HRV power spectra suggesting a predominance of sympathetic over parasympathetic tone. In contrast, hypertension was found after 21 days of CIH. Concomitant changes between the gain of spectral HRV, BRS, and ventilatory hypoxic chemoreflex showed that the CIH-induced BRS attenuation preceded the HRV changes. CIH induced a simultaneous decrease of the BRS gain along with an increase of the hypoxic ventilatory gain. Present results show that CIH-induced persistent hypertension was preceded by early changes in CB chemosensory control of cardiorespiratory and autonomic function. PMID:25429271

  13. Splanchnic-aortic inflammatory axis in experimental portal hypertension

    PubMed Central

    Aller, Maria-Angeles; de las Heras, Natalia; Nava, Maria-Paz; Regadera, Javier; Arias, Jaime; Lahera, Vicente

    2013-01-01

    Splanchnic and systemic low-grade inflammation has been proposed to be a consequence of long-term prehepatic portal hypertension. This experimental model causes minimal alternations in the liver, thus making a more selective study possible for the pathological changes characteristic of prehepatic portal hypertension. Low-grade splanchnic inflammation after long-term triple partial portal vein ligation could be associated with liver steatosis and portal hypertensive intestinal vasculopathy. In fact, we have previously shown that prehepatic portal hypertension in the rat induces liver steatosis and changes in lipid and carbohydrate metabolism similar to those produced in chronic inflammatory conditions described in metabolic syndrome in humans. Dysbiosis and bacterial translocation in this experimental model suggest the existence of a portal hypertensive intestinal microbiome implicated in both the splanchnic and systemic alterations related to prehepatic portal hypertension. Among the systemic impairments, aortopathy characterized by oxidative stress, increased levels of proinflammatory cytokines and profibrogenic mediators stand out. In this experimental model of long-term triple portal vein ligated-rats, the abdominal aortic proinflammatory response could be attributed to oxidative stress. Thus, the increased aortic reduced-nicotinamide-adenine dinucleotide phosphate [NAD(P)H] oxidase activity could be associated with reactive oxygen species production and promote aortic inflammation. Also, oxidative stress mediated by NAD(P)H oxidase has been associated with risk factors for inflammation and atherosclerosis. The splanchnic and systemic pathology that is produced in the long term after triple partial portal vein ligation in the rat reinforces the validity of this experimental model to study the chronic low-grade inflammatory response induced by prehepatic portal hypertension. PMID:24307792

  14. Mechanisms of hypertension in renal radiation

    SciTech Connect

    Juncos, L.; Cornejo, J.C.; Cejas, H.; Broglia, C. (Instituto Privado de Especialidades Medicas, Cordoba (Argentina))

    1990-02-01

    This study was undertaken to investigate the role played by renal functional and structural changes in the development of radiation-induced hypertension. Four groups of rats were studied: (1) left kidney radiated, (2) sham procedure, (3) uninephrectomy followed 3 weeks later by radiation of the contralateral kidney, and (4) uninephrectomy followed by sham procedure 3 weeks later. All radiated rats became hypertensive at 12 weeks (p less than 0.05) and had higher protein excretion (p less than 0.05). In the presence of an intact contralateral kidney, radiation causes mild-to-moderate histological abnormalities, and therefore, creatinine clearance and water and sodium handling do not change. Plasma renin activity increased in this group (p less than 0.05). Radiated uninephrectomized rats showed decreased creatinine clearance (p less than 0.05), but renin activity remained unchanged. These rats developed severe histological abnormalities in glomeruli, interstitia, tubuli, and vessels resulting in increased sodium and water output. The average of individual tubular and interstitial scores correlated significantly with both water intake and output but not with sodium excretion. These studies suggest that in the presence of an intact kidney, renin is an important determinant in the development or maintenance of radiation hypertension, whereas in the absence of the contralateral kidney, severe histological changes and renal failure are prominent despite increased water intake and output. The more severe glomerular sclerosis and proteinuria in the latter model could be related to diminished renal mass.

  15. Vitamin D, arterial hypertension & cerebrovascular disease

    PubMed Central

    Kienreich, Katharina; Grübler, Martin; Tomaschitz, Andreas; Schmid, Johannes; Verheyen, Nicolas; Rutters, Femke; Dekker, Jacqueline M.; Pilz, Stefan

    2013-01-01

    Vitamin D is mainly derived from endogenous ultraviolet-B induced vitamin D synthesis in the skin, and the current high prevalence of vitamin D deficiency can, therefore, largely be attributed to lifestyle related low sunlight exposure. Regulation of bone and mineral metabolism is a classic vitamin D effect, but the identification of the vitamin D receptor (VDR) in almost all human cells suggests a role for vitamin D also in extra-skeletal diseases. Experimental studies demonstrated several antihypertensive and vascular protective effects of vitamin D, such as suppression of the renin angiotensin aldosterone system, beneficial modulation of classic cardiovascular risk factors, and anti-atherosclerotic properties including improvements of endothelial function. Additional neuroprotective actions of vitamin D have also been reported. In line with this, epidemiological studies have largely shown that vitamin D deficiency is an independent risk factor for arterial hypertension and strokes. Data from randomized controlled trials (RCTs) are, however, limited and less promising, with currently no confirmation that vitamin D reduces stroke incidence. Whereas some RCTs suggest that vitamin D supplementation might modestly reduce blood pressure, this has not been consistently observed in all studies. It is, therefore, premature to recommend vitamin D supplementation for the prevention and treatment of arterial hypertension and stroke. Nevertheless, the fact that patients with arterial hypertension and cerebrovascular disease are at a relatively high risk of vitamin D deficiency, and therewith associated musculoskeletal diseases can serve as a rationale for the evaluation, prevention and treatment of vitamin D deficiency in these patients. PMID:23703334

  16. Vitamin D, arterial hypertension & cerebrovascular disease.

    PubMed

    Kienreich, Katharina; Grubler, Martin; Tomaschitz, Andreas; Schmid, Johannes; Verheyen, Nicolas; Rutters, Femke; Dekker, Jacqueline M; Pilz, Stefan

    2013-04-01

    Vitamin D is mainly derived from endogenous ultraviolet-B induced vitamin D synthesis in the skin, and the current high prevalence of vitamin D deficiency can, therefore, largely be attributed to lifestyle related low sunlight exposure. Regulation of bone and mineral metabolism is a classic vitamin D effect, but the identification of the vitamin D receptor (VDR) in almost all human cells suggests a role for vitamin D also in extra-skeletal diseases. Experimental studies demonstrated several antihypertensive and vascular protective effects of vitamin D, such as suppression of the renin angiotensin aldosterone system, beneficial modulation of classic cardiovascular risk factors, and anti-atherosclerotic properties including improvements of endothelial function. Additional neuroprotective actions of vitamin D have also been reported. In line with this, epidemiological studies have largely shown that vitamin D deficiency is an independent risk factor for arterial hypertension and strokes. Data from randomized controlled trials (RCTs) are, however, limited and less promising, with currently no confirmation that vitamin D reduces stroke incidence. Whereas some RCTs suggest that vitamin D supplementation might modestly reduce blood pressure, this has not been consistently observed in all studies. It is, therefore, premature to recommend vitamin D supplementation for the prevention and treatment of arterial hypertension and stroke. Nevertheless, the fact that patients with arterial hypertension and cerebrovascular disease are at a relatively high risk of vitamin D deficiency, and therewith associated musculoskeletal diseases can serve as a rationale for the evaluation, prevention and treatment of vitamin D deficiency in these patients. PMID:23703334

  17. Management of Hypertension in Intrapericardial Paraganglioma

    PubMed Central

    Imperatori, Andrea; Bacuzzi, Alessandro; Conti, Valentina

    2014-01-01

    Functioning paraganglioma is extra-adrenal catecholamine-secreting tumours that may cause secondary hypertension. Primary intrapericardial paragangliomas are very rare and are located adjacent to the great vessels or heart, typically near the left atrium. These tumours are an exceptionally uncommon finding during the investigation of refractory hypertension. However, in recent years, intrapericardial paragangliomas have been diagnosed incidentally with increased frequency, due to the extensive use of radiologic chest imaging. The mainstay of treatment of functioning intrapericardial paraganglioma is surgical removal, which usually achieves blood pressure normalization. Due to the locations of these tumours, the surgical approach is through a median sternotomy or posterolateral thoracotomy, and manipulation-induced catecholamine release may cause paroxysmal hypertension. Typically in these patients, blood pressure fluctuates dramatically intra- and post-operatively, increasing the risk of cardiovascular complications. We review here the current modalities of perioperative fluid and hypotensive drug administration in the setting of surgery for functioning intrapericardial paraganglioma and discuss the recently proposed paradigm shift that omits preoperative preparation. PMID:24688789

  18. Pulmonary hypertension: pathology.

    PubMed

    Dorfmüller, Peter

    2013-01-01

    Pulmonary hypertension (PH) is a life-threatening and often fatal disease, characterized by elevated pulmonary vascular resistance and secondary right ventricular failure. Since etiologies of PH are multiple and its pathogenesis is complex, histology from lungs of patients with PH may help us to determine different etiological factors of the disease. The degree of involvement of various cell types and structures within the lung tissue represents an important indicator of the pathophysiologal process. So even if the role for pathologists in routine management of PH is limited, lessons can be learned from morphology. The present chapter outlines the current understanding of this disease from the pathologist's point of view. PMID:24092336

  19. Primary pulmonary hypertension

    Microsoft Academic Search

    LEWISJ. RUBIN; BERTRON M. GROVES; MICHAEL FROSOLONO; FRANKLIN HANDEL

    1993-01-01

    SUMMARY Toevaluate theeffects ofprostacyclin (prostaglandin 12) on pulmonary vascular tonein primary pulmonary hypertension (PPH), we performed right-heart catheterization on sevenpatients with PPHandmadehemodynamic measurements before andafter infusing incremental doses ofprostacyclin. In maximaldoses of2-12ng\\/kg\\/min (mean5.7± 3.1ng\\/kg\\/min), prostacyclin reduced mean pulmonary arterial pressurefrom62± 15to55± 16mm Hg(p< 0.05) andtotal pulmonary resistance from17.1 8.7to9.7+ 5.9units (p< 0.005), andincreased cardiac output from4.22 ± 1.64to6.57 ± 2.041\\/min

  20. Management of portal hypertension

    PubMed Central

    Samonakis, D; Triantos, C; Thalheimer, U; Patch, D; Burroughs, A

    2004-01-01

    Treatment of portal hypertension is evolving based on randomised controlled trials. In acute variceal bleeding, prophylactic antibiotics are mandatory, reducing mortality as well as preventing infections. Terlipressin or somatostatin combined with endoscopic ligation or sclerotherapy is the best strategy for control of bleeding but there is no added effect of vasoactive drugs on mortality. Non-selective ß-blockers are the first choice therapy for both secondary and primary prevention; if contraindications or intolerance to ß-blockers are present then band ligation should be used. Novel therapies target the increased intrahepatic resistance caused by microcirculatory intrahepatic deficiency of nitric oxide and contraction of activated intrahepatic stellate cells. PMID:15537846

  1. The absence of intrarenal ACE protects against hypertension.

    PubMed

    Gonzalez-Villalobos, Romer A; Janjoulia, Tea; Fletcher, Nicholas K; Giani, Jorge F; Nguyen, Mien T X; Riquier-Brison, Anne D; Seth, Dale M; Fuchs, Sebastien; Eladari, Dominique; Picard, Nicolas; Bachmann, Sebastian; Delpire, Eric; Peti-Peterdi, Janos; Navar, L Gabriel; Bernstein, Kenneth E; McDonough, Alicia A

    2013-05-01

    Activation of the intrarenal renin-angiotensin system (RAS) can elicit hypertension independently from the systemic RAS. However, the precise mechanisms by which intrarenal Ang II increases blood pressure have never been identified. To this end, we studied the responses of mice specifically lacking kidney angiotensin-converting enzyme (ACE) to experimental hypertension. Here, we show that the absence of kidney ACE substantially blunts the hypertension induced by Ang II infusion (a model of high serum Ang II) or by nitric oxide synthesis inhibition (a model of low serum Ang II). Moreover, the renal responses to high serum Ang II observed in wild-type mice, including intrarenal Ang II accumulation, sodium and water retention, and activation of ion transporters in the loop of Henle (NKCC2) and distal nephron (NCC, ENaC, and pendrin) as well as the transporter activating kinases SPAK and OSR1, were effectively prevented in mice that lack kidney ACE. These findings demonstrate that ACE metabolism plays a fundamental role in the responses of the kidney to hypertensive stimuli. In particular, renal ACE activity is required to increase local Ang II, to stimulate sodium transport in loop of Henle and the distal nephron, and to induce hypertension. PMID:23619363

  2. Garlic, hypertension and patient education

    Microsoft Academic Search

    Mustafa Capraz; Melda Dilek; Tekin Akpolat

    2007-01-01

    The aims of this study are to investigate the frequency of garlic usage in hypertensive population and to evaluate acute effect of garlic and garlic tablets on blood pressure in patients with hypertension. 4102 of the 7703 patients (53.3%) reported that they were using garlic. No significant effect on blood pressure was observed in any of the three groups (placebo,

  3. Wine, Diet, and Arterial Hypertension

    Microsoft Academic Search

    Caterina Carollo; Rosalia Lo Presti; Gregorio Caimi

    2007-01-01

    Hypertension is one of the leading causes of death in developed countries, and the number of prehypertensive patients is increasing. The beneficial effects of moderate wine consumption on cardiovascular diseases have been demonstrated, along with the healthy influence of a Mediterranean dietary pattern. The association of these 2 factors on hypertension and its complications is considered here. As wine polyphenols

  4. Hypertension in children and adolescents

    Microsoft Academic Search

    Bonita Falkner; Robert H. Sadowski

    1995-01-01

    The absolute levels of blood pressure (BP) that define hypertension differ in children and adults. Extensive epidemiological data on growth and blood pressure in children and adolescents now provide values for normal ranges of blood pressure throughout childhood. Hypertension in the young is defined as systolic or diastolic blood pressure that is repeatedly above the 95th percentile for age and

  5. The Immune System in Hypertension

    ERIC Educational Resources Information Center

    Trott, Daniel W.; Harrison, David G.

    2014-01-01

    While hypertension has predominantly been attributed to perturbations of the vasculature, kidney, and central nervous system, research for almost 50 yr has shown that the immune system also contributes to this disease. Inflammatory cells accumulate in the kidneys and vasculature of humans and experimental animals with hypertension and likely…

  6. Hypertension in the Transplanted Patient

    Microsoft Academic Search

    M. Zeier; A. Mandelbaum; E. Ritz

    1998-01-01

    Hypertension is a common finding after renal transplantation, and it has a variety of underlying mechanisms. One reason is the type of immunosuppressive therapy, with a higher prevalence of hypertension in cyclosporine-treated patients. Cyclosporine interferes with several humoral and neural systems which are involved in blood pressure regulation such as the renin-angiotensin system, endothelins, nitric oxide, prostaglandins and the sympathetic

  7. Mathematical model of vasorenal hypertension

    Microsoft Academic Search

    N. I. Tankovich; M. A. Pal'tsev; V. V. Serov

    1985-01-01

    The use of mathematical models is a most promising method of analysis of diseases with a complex pathogenesis [2, 3, 5]. Attempts have been made to use mathematical methods to predict the results of surgical treatment of patients with vasorena! hypertension [i]. The authors have analyzed the character of development of vasorenal hypertension by establishing equations and a mathematical model

  8. Hypertension, Anti-Hypertensive Medication Use, and Risk of Psoriasis

    PubMed Central

    Wu, Shaowei; Han, Jiali; Li, Wen-Qing; Qureshi, Abrar A.

    2014-01-01

    Importance Individuals with psoriasis are shown to have an elevated risk of hypertension, and anti-hypertensive medications, especially beta-blockers, have been linked to psoriasis development. However, the association of prior existing hypertension and anti-hypertensive medications with risk of incident psoriasis has not been accessed using prospective data. Objective To evaluate the association of hypertension and anti-hypertensive medications with risk of psoriasis based on data from the Nurses’ Health Study (NHS). Design Prospective cohort study (1996–2008). Setting Nurses’ Health Study. Participants A total of 77,728 U.S. women who provided biennially updated data on hypertension and anti-hypertensive medications. Main Outcome and Measure Physician-diagnosed psoriasis. Results We documented a total of 843 incident psoriasis cases during 1,066,339 person-years of follow-up. Compared to normotensive women, women with hypertension duration more than 6 years were at a higher risk of developing psoriasis [HR=1.27, 95% confidence interval (CI), 1.03–1.57]. In stratified analysis, the risk of psoriasis was higher among hypertensive women without medication [HR=1.49, 95% CI, 1.15–1.92] and among hypertensive women with current medication [HR=1.31, 95% CI, 1.10–1.55] when compared to normotensive participants without medication. Compared to women who never used beta-blockers, the multivariate HRs for psoriasis were 1.11 (95% CI, 0.82–1.51) for women who regularly used 1–2 years, 1.06 (95% CI, 0.79–1.40) for 3–5 years, and 1.39 (95% CI, 1.11–1.73) for 6 or more years (P for trend=0.009). There was no association between other individual anti-hypertensive drugs and risk of psoriasis. Conclusions Long-term hypertensive status is associated with an increased risk of psoriasis. Long-term regular use of beta-blockers may also increase the risk of psoriasis. PMID:24990147

  9. Dietary Approaches to Prevent Hypertension

    PubMed Central

    Bazzano, Lydia A.; Green, Torrance; Harrison, Teresa N.

    2015-01-01

    Elevated blood pressure arises from a combination of environmental and genetic factors and the interactions of these factors. A substantial body of evidence from animal studies, epidemiologic studies, meta-analyses, and randomized controlled trials has demonstrated that certain dietary patterns and individual dietary elements play a prominent role in the development of hypertension. Changes in diet can lower blood pressure, prevent the development of hypertension, and reduce the risk of hypertension-related complications. Dietary strategies for the prevention of hypertension include reducing sodium intake, limiting alcohol consumption, increasing potassium intake, and adopting an overall dietary pattern such as the DASH (Dietary Approaches to Stop Hypertension) diet or a Mediterranean diet. In order to reduce the burden of blood pressure-related complications, efforts that focus on environmental and individual behavioral changes that encourage and promote healthier food choices are warranted. PMID:24091874

  10. Hypertension and obstructive sleep apnea

    PubMed Central

    Phillips, Craig L; O’Driscoll, Denise M

    2013-01-01

    Obstructive sleep apnea (OSA) is increasingly being recognized as a major health burden with strong focus on the associated cardiovascular risk. Studies from the last two decades have provided strong evidence for a causal role of OSA in the development of systemic hypertension. The acute physiological changes that occur during apnea promote nocturnal hypertension and may lead to the development of sustained daytime hypertension via the pathways of sympathetic activation, inflammation, oxidative stress, and endothelial dysfunction. This review will focus on the acute hemodynamic disturbances and associated intermittent hypoxia that characterize OSA and the potential pathophysiological mechanisms responsible for the development of hypertension in OSA. In addition the epidemiology of OSA and hypertension, as well as the role of treatment of OSA, in improving blood pressure control will be examined. PMID:23750107

  11. Blood Pressure Variability and Stress Management Training for Essential Hypertension

    ERIC Educational Resources Information Center

    Garcia-Vera, Maria Paz; Sanz, Jesus; Labrador, Francisco J.

    2004-01-01

    The purpose of this study was to determine whether stress management training reduces blood pressure (BP) variability in hypertensive patients. Previous literature suggests that cardiovascular risk is not only a function of BP levels, but also of BP variability, and this partially depends on changes induced by the stress of everyday life. The…

  12. Brainstem Hypoxia Contributes to the Development of Hypertension in the Spontaneously Hypertensive Rat

    PubMed Central

    Ang, Richard; Machhada, Asif; Kasymov, Vitaliy; Karagiannis, Anastassios; Hosford, Patrick S.; Mosienko, Valentina; Teschemacher, Anja G.; Vihko, Pirkko; Paton, Julian F. R.; Kasparov, Sergey

    2015-01-01

    Systemic arterial hypertension has been previously suggested to develop as a compensatory condition when central nervous perfusion/oxygenation is compromised. Principal sympathoexcitatory C1 neurons of the rostral ventrolateral medulla oblongata (whose activation increases sympathetic drive and the arterial blood pressure) are highly sensitive to hypoxia, but the mechanisms of this O2 sensitivity remain unknown. Here, we investigated potential mechanisms linking brainstem hypoxia and high systemic arterial blood pressure in the spontaneously hypertensive rat. Brainstem parenchymal PO2 in the spontaneously hypertensive rat was found to be ?15 mm?Hg lower than in the normotensive Wistar rat at the same level of arterial oxygenation and systemic arterial blood pressure. Hypoxia-induced activation of rostral ventrolateral medulla oblongata neurons was suppressed in the presence of either an ATP receptor antagonist MRS2179 or a glycogenolysis inhibitor 1,4-dideoxy-1,4-imino-d-arabinitol, suggesting that sensitivity of these neurons to low PO2 is mediated by actions of extracellular ATP and lactate. Brainstem hypoxia triggers release of lactate and ATP which produce excitation of C1 neurons in vitro and increases sympathetic nerve activity and arterial blood pressure in vivo. Facilitated breakdown of extracellular ATP in the rostral ventrolateral medulla oblongata by virally-driven overexpression of a potent ectonucleotidase transmembrane prostatic acid phosphatase results in a significant reduction in the arterial blood pressure in the spontaneously hypertensive rats (but not in normotensive animals). These results suggest that in the spontaneously hypertensive rat, lower PO2 of brainstem parenchyma may be associated with higher levels of ambient ATP and l-lactate within the presympathetic circuits, leading to increased central sympathetic drive and concomitant sustained increases in systemic arterial blood pressure. PMID:25712724

  13. Brainstem hypoxia contributes to the development of hypertension in the spontaneously hypertensive rat.

    PubMed

    Marina, Nephtali; Ang, Richard; Machhada, Asif; Kasymov, Vitaliy; Karagiannis, Anastassios; Hosford, Patrick S; Mosienko, Valentina; Teschemacher, Anja G; Vihko, Pirkko; Paton, Julian F R; Kasparov, Sergey; Gourine, Alexander V

    2015-04-01

    Systemic arterial hypertension has been previously suggested to develop as a compensatory condition when central nervous perfusion/oxygenation is compromised. Principal sympathoexcitatory C1 neurons of the rostral ventrolateral medulla oblongata (whose activation increases sympathetic drive and the arterial blood pressure) are highly sensitive to hypoxia, but the mechanisms of this O2 sensitivity remain unknown. Here, we investigated potential mechanisms linking brainstem hypoxia and high systemic arterial blood pressure in the spontaneously hypertensive rat. Brainstem parenchymal PO2 in the spontaneously hypertensive rat was found to be ?15 mm?Hg lower than in the normotensive Wistar rat at the same level of arterial oxygenation and systemic arterial blood pressure. Hypoxia-induced activation of rostral ventrolateral medulla oblongata neurons was suppressed in the presence of either an ATP receptor antagonist MRS2179 or a glycogenolysis inhibitor 1,4-dideoxy-1,4-imino-d-arabinitol, suggesting that sensitivity of these neurons to low PO2 is mediated by actions of extracellular ATP and lactate. Brainstem hypoxia triggers release of lactate and ATP which produce excitation of C1 neurons in vitro and increases sympathetic nerve activity and arterial blood pressure in vivo. Facilitated breakdown of extracellular ATP in the rostral