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Sample records for alters cardiovascular responses

  1. Age alters the cardiovascular response to direct passive heating

    NASA Technical Reports Server (NTRS)

    Minson, C. T.; Wladkowski, S. L.; Cardell, A. F.; Pawelczyk, J. A.; Kenney, W. L.

    1998-01-01

    During direct passive heating in young men, a dramatic increase in skin blood flow is achieved by a rise in cardiac output (Qc) and redistribution of flow from the splanchnic and renal vascular beds. To examine the effect of age on these responses, seven young (Y; 23 +/- 1 yr) and seven older (O; 70 +/- 3 yr) men were passively heated with water-perfused suits to their individual limit of thermal tolerance. Measurements included heart rate (HR), Qc (by acetylene rebreathing), central venous pressure (via peripherally inserted central catheter), blood pressures (by brachial auscultation), skin blood flow (from increases in forearm blood flow by venous occlusion plethysmography), splanchnic blood flow (by indocyanine green clearance), renal blood flow (by p-aminohippurate clearance), and esophageal and mean skin temperatures. Qc was significantly lower in the older than in the young men (11.1 +/- 0.7 and 7.4 +/- 0.2 l/min in Y and O, respectively, at the limit of thermal tolerance; P < 0. 05), despite similar increases in esophageal and mean skin temperatures and time to reach the limit of thermal tolerance. A lower stroke volume (99 +/- 7 and 68 +/- 4 ml/beat in Y and O, respectively, P < 0.05), most likely due to an attenuated increase in inotropic function during heating, was the primary factor for the lower Qc observed in the older men. Increases in HR were similar in the young and older men; however, when expressed as a percentage of maximal HR, the older men relied on a greater proportion of their chronotropic reserve to obtain the same HR response (62 +/- 3 and 75 +/- 4% maximal HR in Y and O, respectively, P < 0.05). Furthermore, the older men redistributed less blood flow from the combined splanchnic and renal circulations at the limit of thermal tolerance (960 +/- 80 and 720 +/- 100 ml/min in Y and O, respectively, P < 0. 05). As a result of these combined attenuated responses, the older men had a significantly lower increase in total blood flow directed to

  2. Leptin in nucleus of the solitary tract alters the cardiovascular responses to aortic baroreceptor activation.

    PubMed

    Ciriello, John

    2013-06-01

    Recent data suggests that neurons expressing the long form of the leptin receptor form at least two distinct groups within the caudal nucleus of the solitary tract (NTS): a group within the lateral NTS (Slt) and one within the medial (Sm) and gelantinosa (Sg) NTS. Discrete injections of leptin into Sm and Sg, a region that receives chemoreceptor input, elicit increases in arterial pressure (AP) and renal sympathetic nerve activity (RSNA). However, the effect of microinjections of leptin into Slt, a region that receives baroreceptor input is unknown. Experiments were done in the urethane-chloralose anesthetized, paralyzed and artificially ventilated Wistar or Zucker obese rat to determine leptin's effect in Slt on heart rate (HR), AP and RSNA during electrical stimulation of the aortic depressor nerve (ADN). Depressor sites within Slt were first identified by the microinjection of l-glutamate (Glu; 0.25M; 10nl) followed by leptin microinjections. In the Wistar rat leptin microinjection (50ng; 20nl) into depressor sites within the lateral Slt elicited increases in HR and RSNA, but no changes in AP. Additionally, leptin injections into Slt prior to Glu injections at the same site or to stimulation of the ADN were found to attenuate the decreases in HR, AP and RSNA to both the Glu injection and ADN stimulation. In Zucker obese rats, leptin injections into NTS depressor sites did not elicit cardiovascular responses, nor altered the cardiovascular responses elicited by stimulation of ADN. Those data suggest that leptin acts at the level of NTS to alter the activity of neurons that mediate the cardiovascular responses to activation of the aortic baroreceptor reflex. PMID:23535030

  3. Leptin in nucleus of the solitary tract alters the cardiovascular responses to aortic baroreceptor activation.

    PubMed

    Ciriello, John

    2013-06-01

    Recent data suggests that neurons expressing the long form of the leptin receptor form at least two distinct groups within the caudal nucleus of the solitary tract (NTS): a group within the lateral NTS (Slt) and one within the medial (Sm) and gelantinosa (Sg) NTS. Discrete injections of leptin into Sm and Sg, a region that receives chemoreceptor input, elicit increases in arterial pressure (AP) and renal sympathetic nerve activity (RSNA). However, the effect of microinjections of leptin into Slt, a region that receives baroreceptor input is unknown. Experiments were done in the urethane-chloralose anesthetized, paralyzed and artificially ventilated Wistar or Zucker obese rat to determine leptin's effect in Slt on heart rate (HR), AP and RSNA during electrical stimulation of the aortic depressor nerve (ADN). Depressor sites within Slt were first identified by the microinjection of l-glutamate (Glu; 0.25M; 10nl) followed by leptin microinjections. In the Wistar rat leptin microinjection (50ng; 20nl) into depressor sites within the lateral Slt elicited increases in HR and RSNA, but no changes in AP. Additionally, leptin injections into Slt prior to Glu injections at the same site or to stimulation of the ADN were found to attenuate the decreases in HR, AP and RSNA to both the Glu injection and ADN stimulation. In Zucker obese rats, leptin injections into NTS depressor sites did not elicit cardiovascular responses, nor altered the cardiovascular responses elicited by stimulation of ADN. Those data suggest that leptin acts at the level of NTS to alter the activity of neurons that mediate the cardiovascular responses to activation of the aortic baroreceptor reflex.

  4. Aging alters muscle reflex control of autonomic cardiovascular responses to rhythmic contractions in humans.

    PubMed

    Sidhu, Simranjit K; Weavil, Joshua C; Venturelli, Massimo; Rossman, Matthew J; Gmelch, Benjamin S; Bledsoe, Amber D; Richardson, Russell S; Amann, Markus

    2015-11-01

    We investigated the influence of aging on the group III/IV muscle afferents in the exercise pressor reflex-mediated cardiovascular response to rhythmic exercise. Nine old (OLD; 68 ± 2 yr) and nine young (YNG; 24 ± 2 yr) males performed single-leg knee extensor exercise (15 W, 30 W, 80% max) under control conditions and with lumbar intrathecal fentanyl impairing feedback from group III/IV leg muscle afferents. Mean arterial pressure (MAP), cardiac output, leg blood flow (QL), systemic (SVC) and leg vascular conductance (LVC) were continuously determined. With no hemodynamic effect at rest, fentanyl blockade during exercise attenuated both cardiac output and QL ∼17% in YNG, while the decrease in cardiac output in OLD (∼5%) was significantly smaller with no impact on QL (P = 0.8). Therefore, in the face of similar significant ∼7% reduction in MAP during exercise with fentanyl blockade in both groups, LVC significantly increased ∼11% in OLD, but decreased ∼8% in YNG. The opposing direction of change was reflected in SVC with a significant ∼5% increase in OLD and a ∼12% decrease in YNG. Thus while cardiac output seems to account for the majority of group III/IV-mediated MAP responses in YNG, the impact of neural feedback on the heart may decrease with age and alterations in SVC become more prominent in mediating the similar exercise pressor reflex in OLD. Interestingly, in terms of peripheral hemodynamics, while group III/IV-mediated feedback plays a clear role in increasing LVC during exercise in the YNG, these afferents seem to actually reduce LVC in OLD. These peripheral findings may help explain the limited exercise-induced peripheral vasodilation often associated with aging.

  5. Aging alters muscle reflex control of autonomic cardiovascular responses to rhythmic contractions in humans.

    PubMed

    Sidhu, Simranjit K; Weavil, Joshua C; Venturelli, Massimo; Rossman, Matthew J; Gmelch, Benjamin S; Bledsoe, Amber D; Richardson, Russell S; Amann, Markus

    2015-11-01

    We investigated the influence of aging on the group III/IV muscle afferents in the exercise pressor reflex-mediated cardiovascular response to rhythmic exercise. Nine old (OLD; 68 ± 2 yr) and nine young (YNG; 24 ± 2 yr) males performed single-leg knee extensor exercise (15 W, 30 W, 80% max) under control conditions and with lumbar intrathecal fentanyl impairing feedback from group III/IV leg muscle afferents. Mean arterial pressure (MAP), cardiac output, leg blood flow (QL), systemic (SVC) and leg vascular conductance (LVC) were continuously determined. With no hemodynamic effect at rest, fentanyl blockade during exercise attenuated both cardiac output and QL ∼17% in YNG, while the decrease in cardiac output in OLD (∼5%) was significantly smaller with no impact on QL (P = 0.8). Therefore, in the face of similar significant ∼7% reduction in MAP during exercise with fentanyl blockade in both groups, LVC significantly increased ∼11% in OLD, but decreased ∼8% in YNG. The opposing direction of change was reflected in SVC with a significant ∼5% increase in OLD and a ∼12% decrease in YNG. Thus while cardiac output seems to account for the majority of group III/IV-mediated MAP responses in YNG, the impact of neural feedback on the heart may decrease with age and alterations in SVC become more prominent in mediating the similar exercise pressor reflex in OLD. Interestingly, in terms of peripheral hemodynamics, while group III/IV-mediated feedback plays a clear role in increasing LVC during exercise in the YNG, these afferents seem to actually reduce LVC in OLD. These peripheral findings may help explain the limited exercise-induced peripheral vasodilation often associated with aging. PMID:26386110

  6. Leptin signaling in the nucleus of the solitary tract alters the cardiovascular responses to activation of the chemoreceptor reflex.

    PubMed

    Ciriello, John; Moreau, Jason M

    2012-10-01

    Circulating levels of leptin are elevated in individuals suffering from chronic intermittent hypoxia (CIH). Systemic and central administration of leptin elicits increases in sympathetic nervous activity (SNA), arterial pressure (AP), and heart rate (HR), and it attenuates the baroreceptor reflex, cardiovascular responses that are similar to those observed during CIH as a result of activation of chemoreceptors by the systemic hypoxia. Therefore, experiments were done in anesthetized Wistar rats to investigate the effects of leptin in nucleus of the solitary tract (NTS) on AP and HR responses, and renal SNA (RSNA) responses during activation of NTS neurons and the chemoreceptor reflex. Microinjection of leptin (5-100 ng; 20 nl) into caudal NTS pressor sites (l-glutamate; l-Glu; 0.25 M; 10 nl) elicited dose-related increases in AP, HR, and RSNA. Leptin microinjections (5 ng; 20 nl) into these sites potentiated the increase in AP and HR elicited by l-Glu. Additionally, bilateral injections of leptin (5 ng; 100 nl) into NTS potentiated the increase in AP and attenuated the bradycardia to systemic activation of the chemoreflex. In the Zucker obese rat, leptin injections into NTS neither elicited cardiovascular responses nor altered the cardiovascular responses to activation of the chemoreflex. Taken together, these data indicate that leptin exerts a modulatory effect on neuronal circuits within NTS that control cardiovascular responses elicited during the reflex activation of arterial chemoreceptors and suggest that increased AP and SNA observed in individuals with CIH may be due, in part, by leptin's effects on the chemoreflex at the level of NTS.

  7. Malnutrition alters the cardiovascular responses induced by central injection of tityustoxin in Fischer rats.

    PubMed

    Silva, Fernanda Cacilda Santos; Guidine, Patrícia Alves; Ribeiro, Mara Fernandes; Fernandes, Luciano Gonçalves; Xavier, Carlos Henrique; de Menezes, Rodrigo Cunha; Silva, Marcelo Eustáquio; Moraes-Santos, Tasso; Moraes, Márcio Flávio; Chianca, Deoclécio Alves

    2013-12-15

    Scorpion envenoming and malnutrition are considered two important public health problems in Brazil, involving mainly children. Both these conditions are more common among the economically stratified lower income portion of the population, thus suggesting that these factors should be analyzed concomitantly. It is known that cardiorespiratory manifestations, as cardiac arrhythmias, arterial hypertension and hypotension, pulmonary edema and circulatory failure are the main "causa mortis" of scorpion envenomation. Additionally, there are evidences in the literature that deficiencies in dietary intake endanger the CNS and modify the cardiovascular homeostasis. Then, the objective of this work is to evaluate the protein malnourished effect on cardiovascular responses induced by tityustoxin (TsTX, an α-type toxin extracted from the Tityus serrulatus scorpion venom). Fischer rats (n = 20) were injected i.c.v. with TsTX and divided in control and malnorished groups, which were, respectively, submitted to a control and a low-protein diet. Arterial pressure recordings were done until death of the animals. Although both groups presented an increased mean arterial pressure after TsTX injection, this increase was smaller and delayed in malnourished rats, when compared to control rats. In addition, heart rate increased only in rats from the control group. Finally, malnourished rats had an increase in survival time (9:9/13.5 vs. 15.5:10.5/18 min; p = 0.0009). In summary, our results suggest that the protein restriction attenuates the cardiovascular manifestations resulting from TsTX action on CNS. PMID:24060375

  8. Acrolein Inhalation Alters Arterial Blood Gases and Triggers Carotid Body Mediated Cardiovascular Responses in Hypertensive Rats

    EPA Science Inventory

    Exposure to air pollution increases risk of cardiovascular morbidity and mortality, especially in individuals with underlying cardiopulmonary disease. While the mechanisms accounting for these effects are unclear, several epidemiological studies have reported decreases in oxygen ...

  9. Acrolein inhalation alters arterial blood gases and triggers carotid body-mediated cardiovascular responses in hypertensive rats

    PubMed Central

    Perez, Christina M.; Hazari, Mehdi S.; Ledbetter, Allen D.; Haykal-Coates, Najwa; Carll, Alex P.; Cascio, Wayne E.; Winsett, Darrell W.; Costa, Daniel L.; Farraj, Aimen K.

    2016-01-01

    Context Air pollution exposure affects autonomic function, heart rate, blood pressure and left ventricular function. While the mechanism for these effects is uncertain, several studies have reported that air pollution exposure modifies activity of the carotid body, the major organ that senses changes in arterial oxygen and carbon dioxide levels, and elicits downstream changes in autonomic control and cardiac function. Objective We hypothesized that exposure to acrolein, an unsaturated aldehyde and mucosal irritant found in cigarette smoke and diesel exhaust, would activate the carotid body chemoreceptor response and lead to secondary cardiovascular responses in rats. Materials and methods Spontaneously hypertensive (SH) rats were exposed once for 3 h to 3 ppm acrolein gas or filtered air in whole body plethysmograph chambers. To determine if the carotid body mediated acrolein-induced cardiovascular responses, rats were pretreated with an inhibitor of cystathionine γ-lyase (CSE), an enzyme essential for carotid body signal transduction. Results Acrolein exposure induced several cardiovascular effects. Systolic, diastolic and mean arterial blood pressure increased during exposure, while cardiac contractility decreased 1 day after exposure. The cardiovascular effects were associated with decreases in pO2, breathing frequency and expiratory time, and increases in sympathetic tone during exposure followed by parasympathetic dominance after exposure. The CSE inhibitor prevented the cardiovascular effects of acrolein exposure. Discussion and conclusion Pretreatment with the CSE inhibitor prevented the cardiovascular effects of acrolein, suggesting that the cardiovascular responses with acrolein may be mediated by carotid body-triggered changes in autonomic tone. (This abstract does not reflect EPA policy.) PMID:25600140

  10. [Cardiovascular alterations associated with doping].

    PubMed

    Thieme, D; Büttner, A

    2015-05-01

    Doping -the abuse of anabolic-androgenic steroids in particular- is widespread in amateur and recreational sports and does not solely represent a problem of professional sports. Excessive overdose of anabolic steroids is well documented in bodybuilding or powerlifting leading to significant side effects. Cardiovascular damages are most relevant next to adverse endocrine effects.Clinical cases as well as forensic investigations of fatalities or steroid consumption in connection with trafficking of doping agents provide only anecdotal evidence of correlations between side effects and substance abuse. Analytical verification and self-declarations of steroid users have repeatedly confirmed the presumption of weekly dosages between 300 and 2000 mg, extra to the fact that co-administration of therapeutics to treat side-effects represent a routine procedure. Beside the most frequent use of medications used to treat erectile dysfunction or estrogenic side-effects, a substantial number of antihypertensive drugs of various classes, i.e. beta-blockers, diuretics, angiotensin II receptor antagonists, calcium channel blockers, as well as ACE inhibitors were recently confiscated in relevant doping cases. The presumptive correlation between misuse of anabolic steroids and self-treatment of cardiovascular side effects was explicitly confirmed by detailed user statements.Two representative fatalities of bodybuilders were introduced to outline characteristic, often lethal side effects of excessive steroid abuse. Moreover, illustrative autopsy findings of steroid acne, thrombotic occlusion of Ramus interventricularis anterior and signs of cardiac infarctions are presented.A potential steroid abuse should be carefully considered in cases of medical consultations of patients exhibiting apparent constitutional modifications and corresponding adverse effects. Moreover, common self-medications -as frequently applied by steroid consumers- should be taken into therapeutic considerations.

  11. Altered cardiovascular control in preterm infants with bronchopulmonary dysplasia.

    PubMed

    Viskari, Suvi; Andersson, Sture; Hytinantti, Timo; Kirjavainen, Turkka

    2007-05-01

    Vestibulo-mediated cardiovascular control in hazardous situations is important. Our hypothesis is that the prerequisite for sudden infant death syndrome (SIDS) is impaired vestibulo-mediated cardiovascular control. Prematurity is a risk factor for SIDS, and postnatal intermittent hypoxia may contribute to this risk. We studied heart rate (HR) and blood pressure (BP) responses in 10 infants with bronchopulmonary dysplasia (BPD) who were born at 27 +/- 2.4 (23-30) wk of gestation. Twenty healthy term infants served as controls. Cardiovascular tests were performed under polysomnographic control during slow-wave sleep (SWS) at a corrected age of 12 +/- 3.5 (7-19) wk. Control infants showed biphasic HR and BP responses to side motion with an immediate increase followed by a modest decrease and return to baseline. Compared with the controls, half of the BPD infants had altered BP responses (p < 0.005) without an early increase, followed by a more prominent decrease in BP. BPD infants also presented with a greater variability in BP responses to head-up tilts than did the controls (p < 0.001). In conclusion, these findings suggest that some BPD infants have impaired vestibular sympathoreflex-mediated cardiovascular control. This dysfunction may become critical in life-threatening situations. PMID:17413872

  12. Cardiovascular responses to spaceflight

    NASA Technical Reports Server (NTRS)

    Nicogossian, A.; Pool, S. L.; Rambaut, P. C.

    1983-01-01

    The cardiovascular system's adaptive changes during and after spaceflight are discussed. Cephalic fluid shifts are demonstrated by photographs along with calf girth and leg volume changes. Inflight measurements show an increase in average resting heart rate and systolic blood pressure, and a sympathetic-parasympathetic neural imbalance. Postflight findings include a small but reversible decrease in the left ventricular muscle mass. Since 1980, NASA's research has emphasized cardiovascular deconditioning and countermeasures: hemodynamic changes, endocrine and neurohumoral aspects, etiologic factors, and lower body negative pressure devices. Though human beings acclimate to the space environment, questions concerning the immediate and long-term aspects of spaceflight need to be answered for adequate planning of extended space missions.

  13. Cardiovascular Deconditioning in Humans: Alteration in Cardiovascular Regulation and Function During Simulated Microgravity

    NASA Technical Reports Server (NTRS)

    Cohen, Richard

    1999-01-01

    Alterations in cardiovascular regulation and function that occur during and after space flight have been reported. These alterations are manifested, for example, by reduced orthostatic tolerance upon reentry to the earth's gravity from space. However, the precise physiologic mechanisms responsible for these alterations remain to be fully elucidated. Perhaps, as a result, effective countermeasures have yet to be developed. In this project we apply a powerful, new method - cardiovascular system identification (CSI) - for the study of the effects of space flight on the cardiovascular system so that effective countermeasures can be developed. CSI involves the mathematical analysis of second-to-second fluctuations in non-invasively measured heart rate, arterial blood pressure (ABP), and instantaneous lung volume (ILV - respiratory activity) in order to characterize quantitatively the physiologic mechanisms responsible for the couplings between these signals. Through the characterization of all the physiologic mechanisms coupling these signals, CSI provides a model of the closed-loop cardiovascular regulatory state in an individual subject. The model includes quantitative descriptions of the heart rate baroreflex, autonomic function, as well as other important physiologic mechanisms. We are in the process of incorporating beat-to-beat fluctuations of stroke volume into the CSI technique in order to quantify additional physiologic mechanisms such as those involved in control of peripheral vascular resistance and alterations in cardiac contractility. We apply CSI in conjunction with the two general protocols of the Human Studies Core project. The first protocol involves ground-based, human head down tilt bed rest to simulate microgravity and acute stressors - upright tilt, standing and bicycle exercise - to provide orthostatic and exercise challenges. The second protocol is intended to be the same as the first but with the addition of sleep deprivation to determine whether

  14. Cardiovascular response to thermoregulatory challenges.

    PubMed

    Liu, Cuiqing; Yavar, Zubin; Sun, Qinghua

    2015-12-01

    A growing number of extreme climate events are occurring in the setting of ongoing climate change, with an increase in both the intensity and frequency. It has been shown that ambient temperature challenges have a direct and highly varied impact on cardiovascular health. With a rapidly growing amount of literature on this issue, we aim to review the recent publications regarding the impact of cold and heat on human populations with regard to cardiovascular disease (CVD) mortality/morbidity while also examining lag effects, vulnerable subgroups, and relevant mechanisms. Although the relative risk of morbidity/mortality associated with extreme temperature varied greatly across different studies, both cold and hot temperatures were associated with a positive mean excess of cardiovascular deaths or hospital admissions. Cause-specific study of CVD morbidity/mortality indicated that the sensitivity to temperature was disease-specific, with different patterns for acute and chronic ischemic heart disease. Vulnerability to temperature-related mortality was associated with some characteristics of the populations, including sex, age, location, socioeconomic condition, and comorbidities such as cardiac diseases, kidney diseases, diabetes, and hypertension. Temperature-induced damage is thought to be related to enhanced sympathetic reactivity followed by activation of the sympathetic nervous system, renin-angiotensin system, as well as dehydration and a systemic inflammatory response. Future research should focus on multidisciplinary adaptation strategies that incorporate epidemiology, climatology, indoor/building environments, energy usage, labor legislative perfection, and human thermal comfort models. Studies on the underlying mechanism by which temperature challenge induces pathophysiological response and CVD await profound and lasting investigation.

  15. Metabolic Alterations and Cardiovascular Outcomes of Cortisol Excess.

    PubMed

    Pivonello, Rosario; De Martino, Maria Cristina; Iacuaniello, Davide; Simeoli, Chiara; Muscogiuri, Giovanna; Carlomagno, Francesco; De Leo, Monica; Cozzolino, Alessia; Colao, Annamaria

    2016-01-01

    Cushing's syndrome (CS) is a severe chronic and systemic condition caused by endogenous or exogenous excess of glucocorticoids, associated with increased morbidity and mortality. Patients with active CS suffer from many metabolic alterations, including visceral obesity, systemic arterial hypertension, impairment of glucose metabolism and dyslipidemia. Additionally, in these patients several cardiovascular abnormalities, i.e. atherosclerosis, clotting disorders, left ventricular hypertrophy, concentric remodeling and diastolic dysfunction have been documented. These alterations, which persist even long after hypercortisolism remission, account for the increased cardiovascular risk and greatly contribute to the increased mortality observed in patients with CS. The current review aims to discuss the main adverse effects of CS on metabolism and cardiovascular risk, focusing on the active and remission phases of disease, and underlining the importance of long-term monitoring and treatment of these complications during active disease, as well as in the long-term follow-up after CS remission. PMID:27212264

  16. Central autonomic network mediates cardiovascular responses to acute inflammation: Relevance to increased cardiovascular risk in depression?

    PubMed Central

    Harrison, Neil A.; Cooper, Ella; Voon, Valerie; Miles, Ken; Critchley, Hugo D.

    2013-01-01

    Inflammation is a risk factor for both depression and cardiovascular disease. Depressed mood is also a cardiovascular risk factor. To date, research into mechanisms through which inflammation impacts cardiovascular health rarely takes into account central effects on autonomic cardiovascular control, instead emphasizing direct effects of peripheral inflammatory responses on endothelial reactivity and myocardial function. However, brain responses to inflammation engage neural systems for motivational and homeostatic control and are expressed through depressed mood state and changes in autonomic cardiovascular regulation. Here we combined an inflammatory challenge, known to evoke an acute reduction in mood, with neuroimaging to identify the functional brain substrates underlying potentially detrimental changes in autonomic cardiovascular control. We first demonstrated that alterations in the balance of low to high frequency (LF/HF) changes in heart rate variability (a measure of baroreflex sensitivity) could account for some of the inflammation-evoked changes in diastolic blood pressure, indicating a central (rather than solely local endothelial) origin. Accompanying alterations in regional brain metabolism (measured using 18FDG-PET) were analysed to localise central mechanisms of inflammation-induced changes in cardiovascular state: three discrete regions previously implicated in stressor-evoked blood pressure reactivity, the dorsal anterior and posterior cingulate and pons, strongly mediated the relationship between inflammation and blood pressure. Moreover, activity changes within each region predicted the inflammation-induced shift in LF/HF balance. These data are consistent with a centrally-driven component originating within brain areas supporting stressor evoked blood pressure reactivity. Together our findings highlight mechanisms binding psychological and physiological well-being and their perturbation by peripheral inflammation. PMID:23416033

  17. Characteristics of Vibration that Alter Cardiovascular Parameters in Mice.

    PubMed

    Li, Yao; Rabey, Karyne N; Schmitt, Daniel; Norton, John N; Reynolds, Randall P

    2015-07-01

    We hypothesized that short-term exposure of mice to vibration within a frequency range thought to be near the resonant frequency range of mouse tissue and at an acceleration of 0 to 1 m/s(2) would alter heart rate (HR) and mean arterial pressure (MAP). We used radiotelemetry to evaluate the cardiovascular response to vibration in C57BL/6 and CD1 male mice exposed to vertical vibration of various frequencies and accelerations. MAP was consistently increased above baseline values at an acceleration near 1 m/s(2) and a frequency of 90 Hz in both strains, and HR was increased also in C57BL/6 mice. In addition, MAP increased at 80 Hz in individual mice of both strains. When both strains were analyzed together, mean MAP and HR were increased at 90 Hz at 1 m/s(2), and HR was increased at 80 Hz at 1 m/s(2). No consistent change in MAP or HR occurred when mice were exposed to frequencies below 80 Hz or above 90 Hz. The increase in MAP and HR occurred only when the mice had conscious awareness of the vibration, given that these changes did not occur when anesthetized mice were exposed to vibration. Tested vibration acceleration levels lower than 0.75 m/s(2) did not increase MAP or HR at 80 or 90 Hz, suggesting that a relatively high level of vibration is necessary to increase these parameters. These data are important to establish the harmful frequencies and accelerations of environmental vibration that should be minimized or avoided in mouse facilities.

  18. Alterations in Cardiovascular Regulation and Function During Long-Term Simulated Microgravity

    NASA Technical Reports Server (NTRS)

    Cohen, Richard J.

    1999-01-01

    The Cardiovascular Alterations Team is conducting studies of hemodynamic regulation and susceptibility to arrhythmias resulting from sixteen days of simulated microgravity exposure. In these studies very intensive measurements are made during a short duration of bed rest. In this collaborative effort are making many of the same measurements, however much less frequently, on subjects who are exposed to a much longer duration of simulated microgravity. Alterations in cardiovascular regulation and function that occur during and after space flight have been reported. These alterations are manifested, for example, by reduced orthostatic tolerance upon reentry to the earth's gravity from space. However, the precise physiologic mechanisms responsible for these alterations remain to be fully elucidated. Perhaps, as a result, effective countermeasures have yet to be developed. In addition, numerous reports from the past 30 years suggest that the incidence of ventricular arrhythmias among astronauts is increased during space flight. However, the effects of space flight and the associated physiologic stresses on cardiac conduction processes are not known, and an increase in cardiac susceptibility to arrhythmias has never been quantified. In this project we are applying the most powerful technologies available to determine, in a ground-based study of long duration space flight, the mechanisms by which space flight affects cardiovascular function, and then on the basis of an understanding of these mechanisms to develop rational and specific countermeasures. To this end we are conducting a collaborative project with the Bone Demineralization/Calcium Metabolism Team of the National Space Biomedical Research Institute (NSBRI). The Bone Team is conducting bed rest studies in human subjects lasting 17 weeks, which provides a unique opportunity to study the effects of long duration microgravity exposure on the human cardiovascular system. We are applying a number of powerful new

  19. Cardiovascular responses to hypogravic environments

    NASA Technical Reports Server (NTRS)

    Sandler, H.

    1983-01-01

    The cardiovascular deconditioning observed during and after space flight is characterized in a review of human space and simulation studies and animal simulations. The various simulation techniques (horizontal bed rest, head-down tilt, and water immersion in man, and immobilization of animals) are examined, and sample results are presented in graphs. Countermeasures such as exercise regimens, fluid replacement, drugs, venous pooling, G-suits, oscillating beds, electrostimulation of muscles, lower-body negative pressure, body-surface cooling, and hypoxia are reviewed and found to be generally ineffective or unreliable. The need for future space experimentation in both humans and animals is indicated.

  20. Endocannabinoids and the cardiovascular response to stress.

    PubMed

    O'Sullivan, Saoirse E; Kendall, Patrick J; Kendall, David A

    2012-01-01

    Stress activates the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS), resulting in cardiovascular responses. The endocannabinoid system (ECS), a ubiquitously expressed lipid signalling system, modulates both HPA and SNS activity. The purpose of this review is to explore the possible involvement/role of the ECS in the cardiovascular response to stress. The ECS has numerous cardiovascular effects including modulation of blood pressure, heart rate, the baroreflex, and direct vascular actions. It is also involved in a protective manner in response to stressors in cardiac preconditioning, and various stressors (for example, pain, orthostasis and social stress) increase plasma levels of endocannabinoids. Given the multitude of vascular effects of endocannabinoids, this is bound to have consequences. Beneficial effects of ECS upregulation could include cardioprotection, vasodilatation, CB(2)-mediated anti-inflammatory effects and activation of peroxisome proliferator-activated receptors. Negative effects of endocannabinoids could include mediation of the effects of glucocorticoids, CB(1)-mediated metabolic changes, and metabolism to vasoconstrictor products. It is also likely that there is a central role for the ECS in modulating cardiovascular activity via the HPA and SNS. However, much more work is required to fully integrate the role of the ECS in mediating many of the physiological responses to stress, including cardiovascular responses.

  1. Oxytocin in the cardiovascular responses to stress.

    PubMed

    Wsol, A; Cudnoch-Jedrzejewska, A; Szczepanska-Sadowska, E; Kowalewski, S; Puchalska, L

    2008-12-01

    The present study was designed to determine the role of central oxytocin (OXY) in regulation of the cardiovascular responses to the alarming stress. Three groups of male, normotensive Sprague Dawley rats, received intracerebroventricular (i.c.v.) infusion of one of the following: 1) vehicle, 2) OXY or 3) OXY antagonist (OXANT). Mean arterial blood pressure (MABP) and heart rate (HR) were recorded at rest, during and after application of the alarming stressor (air jet). Under resting conditions the i.c.v. infusions of vehicle, OXY or OXYANT did not influence the cardiovascular parameters. The alarming stressor evoked significant increases in MABP and HR that were significantly greater in the rats receiving i.c.v. infusion of oxytocin antagonist than in those receiving vehicle or OXY. The study provides evidence that stimulation of the brain oxytocin receptors by endogenous oxytocin plays significant role in inhibition of cardiovascular responses to stress.

  2. Cardiovascular responses to static exercise in distance runners and weight lifters

    NASA Technical Reports Server (NTRS)

    Longhurst, J. C.; Kelly, A. R.; Gonyea, W. J.; Mitchell, J. H.

    1980-01-01

    Three groups of athletes including long-distance runners, competitive and amateur weight lifters, and age- and sex-matched control subjects have been studied by hemodynamic and echocardiographic methods in order to determine the effect of the training programs on the cardiovascular response to static exercise. Blood pressure, heart rate, and double product data at rest and at fatigue suggest that competitive endurance (dynamic exercise) training alters the cardiovascular response to static exercise. In contrast to endurance exercise, weight lifting (static exercise) training does not alter the cardiovascular response to static exercise: weight lifters responded to static exercise in a manner very similar to that of the control subjects.

  3. The cardiovascular response to the AGS

    NASA Technical Reports Server (NTRS)

    Cardus, David; Mctaggart, Wesley G.

    1993-01-01

    This paper reports the preliminary results of experiments on human subjects conducted to study the cardiovascular response to various g-levels and exposure times using an artificial gravity simulator (AGS). The AGS is a short arm centrifuge consisting of a turntable, a traction system, a platform and four beds. Data collection hardware is part of the communication system. The AGS provides a steep acceleration gradient in subjects in the supine position.

  4. Human cardiovascular responses to passive heat stress.

    PubMed

    Crandall, Craig G; Wilson, Thad E

    2015-01-01

    Heat stress increases human morbidity and mortality compared to normothermic conditions. Many occupations, disease states, as well as stages of life are especially vulnerable to the stress imposed on the cardiovascular system during exposure to hot ambient conditions. This review focuses on the cardiovascular responses to heat stress that are necessary for heat dissipation. To accomplish this regulatory feat requires complex autonomic nervous system control of the heart and various vascular beds. For example, during heat stress cardiac output increases up to twofold, by increases in heart rate and an active maintenance of stroke volume via increases in inotropy in the presence of decreases in cardiac preload. Baroreflexes retain the ability to regulate blood pressure in many, but not all, heat stress conditions. Central hypovolemia is another cardiovascular challenge brought about by heat stress, which if added to a subsequent central volumetric stress, such as hemorrhage, can be problematic and potentially dangerous, as syncope and cardiovascular collapse may ensue. These combined stresses can compromise blood flow and oxygenation to important tissues such as the brain. It is notable that this compromised condition can occur at cardiac outputs that are adequate during normothermic conditions but are inadequate in heat because of the increased systemic vascular conductance associated with cutaneous vasodilation. Understanding the mechanisms within this complex regulatory system will allow for the development of treatment recommendations and countermeasures to reduce risks during the ever-increasing frequency of severe heat events that are predicted to occur.

  5. Human Cardiovascular Responses to Passive Heat Stress

    PubMed Central

    Crandall, Craig G.; Wilson, Thad E.

    2016-01-01

    Heat stress increases human morbidity and mortality compared to normothermic conditions. Many occupations, disease states, as well as stages of life are especially vulnerable to the stress imposed on the cardiovascular system during exposure to hot ambient conditions. This review focuses on the cardiovascular responses to heat stress that are necessary for heat dissipation. To accomplish this regulatory feat requires complex autonomic nervous system control of the heart and various vascular beds. For example, during heat stress cardiac output increases up to twofold, by increases in heart rate and an active maintenance of stroke volume via increases in inotropy in the presence of decreases in cardiac preload. Baroreflexes retain the ability to regulate blood pressure in many, but not all, heat stress conditions. Central hypovolemia is another cardiovascular challenge brought about by heat stress, which if added to a subsequent central volumetric stress, such as hemorrhage, can be problematic and potentially dangerous, as syncope and cardiovascular collapse may ensue. These combined stresses can compromise blood flow and oxygenation to important tissues such as the brain. It is notable that this compromised condition can occur at cardiac outputs that are adequate during normothermic conditions but are inadequate in heat because of the increased systemic vascular conductance associated with cutaneous vasodilation. Understanding the mechanisms within this complex regulatory system will allow for the development of treatment recommendations and countermeasures to reduce risks during the ever-increasing frequency of severe heat events that are predicted to occur. PMID:25589263

  6. Implications of fundamental signalling alterations in diabetes mellitus-associated cardiovascular disease .

    PubMed

    Balakumar, Pitchai

    2014-12-01

    The chronic diabetes mellitus (DM) is a major risk factor for cardiovascular disease. The incidence of cardiovascular disease might be a foremost cause of morbidity and mortality in patients afflicted with DM. In fact, DM is associated with multi-factorial cardiovascular signalling alterations via significant modulation of expression pattern, activation or release of PI3K, PKB, eNOS, EDRF, NADPH oxidase, EDHF, CGRP, adenosine, iNOS, ROCK, PKC-β2, CaMKII, microRNA (miR)-126 and miR-130a, which could result in inadequate maintenance of cardiovascular physiology and subsequent development of cardiovascular pathology. This review highlights the possible adverse implications of fundamental cardiovascular signalling alteration in DM-associated cardiovascular disease pathology.

  7. Physical fitness and cardiovascular response to lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Raven, P. B.; Rohm-Young, D.; Blomqvist, C. G.

    1984-01-01

    Klein et al. (1977) have questioned the concept of endurance training as an appropriate means of preparing for prolonged space flights. Their opinion was mainly based on reports of endurance athletes who had a decreased tolerance to orthostatic or gravitational stress induced by lower body negative pressure (LBNP), upright tilt, or whole body water immersion. The present investigation had the objective to determine if the hemodynamic response to LBNP is different between a high and average fit group of subjects. In addition, the discrete aspect of cardiovascular function which had been altered by chronic training was to be identified. On the basis of the results of experiments conducted with 14 young male volunteers, it is concluded that the reflex response to central hypovolemia is altered by endurance exercise training.

  8. Cardiovascular responses of snakes to hypergravity

    NASA Technical Reports Server (NTRS)

    Lillywhite, H. B.; Ballard, R. E.; Hargens, A. R.; Rosenberg, H. I.

    1997-01-01

    Snakes have provided useful vertebrate models for understanding circulatory adaptation to gravity, attributable to their elongate body shape and evolutionary diversificaton in terms of ecology and behavior. Recently we have studied cardiovascular responses of snakes to hypergravic acceleration forces produced acutely in the head-to-tail direction (+Gz) on a short-arm centrifuge. Snakes were held in a nearly straight position within a horizontal plastic tube and subjected to a linear force gradient during acceleration. Carotid blood flow provided an integrated measure of cardiovascular performance. Thus, cardiovascular tolerance of snakes to stepwise increments of Gz was measured as the caudal Gz force at which carotid blood flow ceased. Tolerance to increasing Gz varies according to adaptive evolutionary history inferred from the ecology and behavior of species. With respect to data for six species we investigated, multiple regression analysis demonstrates that Gz tolerance correlates with gravitational habitat, independently of body length. Relative to aquatic and non-climbing species, carotid blood flow is better maintained in arboreal or scansorial species, which tolerate hypergravic forces of +2 to +3.5 Gz. Additionally, semi-arboreal rat snakes (Elaphe obsoleta) exhibit plasticity of responses to long-term, intermittent +1.5 Gz stress. Compared to non-acclimated controls, acclimated snakes show greater increases of heart rate during head-up tilt or acceleration, greater sensitivity of arterial pressure to circulating catecholamines, higher blood levels of prostaglandin ratios favorable to maintenance of arterial blood pressure, and medial hypertrophy in major arteries and veins. As in other vertebrates, Gz tolerance of snakes is enhanced by acclimation, high arterial pressure, comparatively large blood volume, and body movements. Vascular studies of snakes suggest the importance to acclimation of local responses involving vascular tissue, in addition to

  9. Airway reflexes, autonomic function, and cardiovascular responses.

    PubMed Central

    Widdicombe, J; Lee, L Y

    2001-01-01

    In this article, we review the cardiovascular responses to the inhalation of irritants and pollutants. Many sensory receptors in the respiratory system, from nose to alveoli, respond to these irritants and set up powerful reflex changes, including those in the cardiovascular system. Systemic hypotension or hypertension, pulmonary hypertension, bradycardia, tachycardia, and dysrhythmias have all been described previously. Most of the experiments have been acute and have been performed on anesthetized experimental animals. Experiments on humans suggest we have similar sensory systems and reflex responses. However, we must use caution when applying the animal results to humans. Most animal experiments, unlike those with humans, have been performed using general anesthesia, with irritants administered in high concentrations, and often to a restricted part of the respiratory tract. Species differences in the response to irritants are well established. We must be even more careful when applying the results of acute experiments in animals to the pathophysiologic changes observed in prolonged exposure to environmental pollution in humans. PMID:11544167

  10. Alterations in cardiovascular autonomic function tests in idiopathic hyperhidrosis.

    PubMed

    De Marinis, Milena; Colaizzo, Elisa; Petrelli, Rosa Anna Nives; Santilli, Valter

    2012-04-01

    We performed cardiovascular autonomic function tests to assess sympathetic and parasympathetic functions in patients with idiopathic hyperhidrosis. We studied 35 patients with idiopathic hyperhidrosis and 35 age- and sex-matched controls. A thermoregulatory sweat test (TST) was performed in all subjects. Sweating was qualitatively (Minor's test at 22°C) and quantitatively (skin conductance) evaluated. Orthostatism, tilt to 65°, cold pressor test, deep breathing, Valsalva maneuver and hyperventilation were performed in patients and controls. A greater fall in blood pressure values was observed in patients than in controls in the upright tests (p<0.05). In particular, postural hypotension was present in a subgroup of patients (34%), in whom changes in lying-to-standing blood pressure and heart rate were greater (p<0.001) than those of the remaining patients. The TST revealed that the total body sweat rate (ml/cm(2)/min) was more pronounced in patients with postural hypotension (p<0.001) than in the other patients and controls. The skin conductance values of patients with postural hypotension were higher (p<0.001) than those of the remaining patients. A positive correlation was found between skin conductance values and postural hypotension. Dehydration and poor water intake may play a role in postural hypotension in patients with severe hyperhidrosis and pronounced thermoregulatory sweating. A significantly marked increase in parasympathetic function was observed in patients. Responses to deep breathing, Valsalva maneuver and hyperventilation were significantly greater in patients (p<0.001) than in controls. Idiopathic hyperhidrosis seems to be a complex dysfunction that involves autonomic pathways other than those related to sweating.

  11. Modeling of Cardiovascular Response to Weightlessness

    NASA Technical Reports Server (NTRS)

    Sharp, M. Keith

    1999-01-01

    It was the hypothesis of this Project that the Simple lack of hydrostatic pressure in microgravity generates several purely physical reactions that underlie and may explain, in part, the cardiovascular response to weightlessness. For instance, hydrostatic pressure within the ventricles of the heart may improve cardiac performance by promoting expansion of ventricular volume during diastole. The lack of hydrostatic pressure in microgravity might, therefore, reduce diastolic filling and cardiac performance. The change in transmural pressure is possible due to the difference in hydrostatic pressure gradients between the blood inside the ventricle and the lung tissue surrounding the ventricle due to their different densities. On the other hand, hydrostatic pressure within the vasculature may reduce cardiac inlet pressures because of the typical location of the heart above the hydrostatic indifference level (the level at which pressure remains constant throughout changes in gravity). Additional physical responses of the body to changing gravitational conditions may influence cardiovascular performance. For instance, fluid shifts from the lower body to the thorax in microgravity may serve to increase central venous pressure (CVP) and boost cardiac output (CO). The concurrent release of gravitational force on the rib cage may tend to increase chest girth and decrease pedcardial pressure, augmenting ventricular filling. The lack of gravity on pulmonary tissue may allow an upward shifting of lung mass, causing a further decrease in pericardial pressure and increased CO. Additional effects include diuresis early in the flight, interstitial fluid shifts, gradual spinal extension and movement of abdominal mass, and redistribution of circulatory impedance because of venous distention in the upper body and the collapse of veins in the lower body. In this project, the cardiovascular responses to changes in intraventricular hydrostatic pressure, in intravascular hydrostatic

  12. Cardiovascular adaptations during long-term altered gravity

    NASA Technical Reports Server (NTRS)

    Popovic, V. P.

    1982-01-01

    Cardiovascular studies were performed on unrestrained, unanesthetized rats and on the same animals in head-down hypokinetic conditions as well as during readaptation of the same animals to free activity. Possible circulatory mechanisms that evolved in mammals during long-lasting gravity exposure are considered. These mechanisms are likely to be affected during exposure to 0-g forces.

  13. Role of mitochondrial dysfunction and altered autophagy in cardiovascular aging and disease: from mechanisms to therapeutics

    PubMed Central

    Marzetti, Emanuele; Csiszar, Anna; Dutta, Debapriya; Balagopal, Gauthami; Calvani, Riccardo

    2013-01-01

    Advanced age is associated with a disproportionate prevalence of cardiovascular disease (CVD). Intrinsic alterations in the heart and the vasculature occurring over the life course render the cardiovascular system more vulnerable to various stressors in late life, ultimately favoring the development of CVD. Several lines of evidence indicate mitochondrial dysfunction as a major contributor to cardiovascular senescence. Besides being less bioenergetically efficient, damaged mitochondria also produce increased amounts of reactive oxygen species, with detrimental structural and functional consequences for the cardiovascular system. The age-related accumulation of dysfunctional mitochondrial likely results from the combination of impaired clearance of damaged organelles by autophagy and inadequate replenishment of the cellular mitochondrial pool by mitochondriogenesis. In this review, we summarize the current knowledge about relevant mechanisms and consequences of age-related mitochondrial decay and alterations in mitochondrial quality control in the cardiovascular system. The involvement of mitochondrial dysfunction in the pathogenesis of cardiovascular conditions especially prevalent in late life and the emerging connections with neurodegeneration are also illustrated. Special emphasis is placed on recent discoveries on the role played by alterations in mitochondrial dynamics (fusion and fission), mitophagy, and their interconnections in the context of age-related CVD and endothelial dysfunction. Finally, we discuss pharmacological interventions targeting mitochondrial dysfunction to delay cardiovascular aging and manage CVD. PMID:23748424

  14. Role of mitochondrial dysfunction and altered autophagy in cardiovascular aging and disease: from mechanisms to therapeutics.

    PubMed

    Marzetti, Emanuele; Csiszar, Anna; Dutta, Debapriya; Balagopal, Gauthami; Calvani, Riccardo; Leeuwenburgh, Christiaan

    2013-08-15

    Advanced age is associated with a disproportionate prevalence of cardiovascular disease (CVD). Intrinsic alterations in the heart and the vasculature occurring over the life course render the cardiovascular system more vulnerable to various stressors in late life, ultimately favoring the development of CVD. Several lines of evidence indicate mitochondrial dysfunction as a major contributor to cardiovascular senescence. Besides being less bioenergetically efficient, damaged mitochondria also produce increased amounts of reactive oxygen species, with detrimental structural and functional consequences for the cardiovascular system. The age-related accumulation of dysfunctional mitochondrial likely results from the combination of impaired clearance of damaged organelles by autophagy and inadequate replenishment of the cellular mitochondrial pool by mitochondriogenesis. In this review, we summarize the current knowledge about relevant mechanisms and consequences of age-related mitochondrial decay and alterations in mitochondrial quality control in the cardiovascular system. The involvement of mitochondrial dysfunction in the pathogenesis of cardiovascular conditions especially prevalent in late life and the emerging connections with neurodegeneration are also illustrated. Special emphasis is placed on recent discoveries on the role played by alterations in mitochondrial dynamics (fusion and fission), mitophagy, and their interconnections in the context of age-related CVD and endothelial dysfunction. Finally, we discuss pharmacological interventions targeting mitochondrial dysfunction to delay cardiovascular aging and manage CVD.

  15. FINE AMBIENT AIR PARTICULAR MATTER EXPOSURE INDUCES MOLECULAR ALTERATIONS INDICATIVE OF CARDIOVASCULAR DISEASE PROGRESSION IN ATHEROSCLEROTIC SUSCEPTIBLE MICE

    EPA Science Inventory

    Epidemiological, clinical, and toxicological studies have demonstrated that exposure to ambient air particulate matter (PM) can alter cardiovascular function and may influence cardiovascular disease (CVD). It has been shown that exposure to concentrated ambient air particles (CA...

  16. Long-term moderate exercise accelerates the recovery of stress-evoked cardiovascular responses.

    PubMed

    Hsu, Yuan-Chang; Tsai, Sheng-Feng; Yu, Lung; Chuang, Jih-Ing; Wu, Fong-Sen; Jen, Chauying J; Kuo, Yu-Min

    2016-01-01

    Psychological stress is an important global health problem. It is well documented that stress increases the incidences of various cardiovascular disorders. Regular exercise is known to reduce resting blood pressure (BP) and heart rate (HR). This study was designed to clarify the effects of long-term exercise on stress-evoked cardiovascular responses and to emphasize post-stress recovery effects. Male Wistar rats underwent 8 weeks of moderate treadmill training, with cardiovascular responses, autonomic nervous system activities and local Fos reactivity changes in the cardiovascular regulation center were monitored before, during and after immobilization stress. A spectral analysis of cardiovascular parameters was used to examine autonomic nervous activities. We found that long-term exercise (i) lowered resting BP, HR and sympathetic activity, but increased resting parasympathetic activity and baroreflex sensitivity (BRS); (ii) accelerated post-stress recovery of stress-evoked cardiovascular and sympathetic responses along with increased BRS and (iii) accelerated post-stress recovery of stress-evoked neuron activations in the paraventricular nucleus, but delayed it in the nucleus of the tractus solitarius. We conclude that, in rats, long-term exercise accelerated recovery of stress-evoked cardiovascular responses differentially altering hypothalamic and medullar neuron activities.

  17. Endothelium and Its Alterations in Cardiovascular Diseases: Life Style Intervention

    PubMed Central

    Paganelli, Corrado; Buffoli, Barbara; Rodella, Luigi Fabrizio; Rezzani, Rita

    2014-01-01

    The endothelium, which forms the inner cellular lining of blood vessels and lymphatics, is a highly metabolically active organ that is involved in many physiopathological processes, including the control of vasomotor tone, barrier function, leukocyte adhesion, and trafficking and inflammation. In this review, we summarized and described the following: (i) endothelial cell function in physiological conditions and (ii) endothelial cell activation and dysfunction in the main cardiovascular diseases (such as atherosclerosis, and hypertension) and to diabetes, cigarette smoking, and aging physiological process. Finally, we presented the currently available evidence that supports the beneficial effects of physical activity and various dietary compounds on endothelial functions. PMID:24719887

  18. Melatonin modulates the fetal cardiovascular defense response to acute hypoxia.

    PubMed

    Thakor, Avnesh S; Allison, Beth J; Niu, Youguo; Botting, Kimberley J; Serón-Ferré, Maria; Herrera, Emilio A; Giussani, Dino A

    2015-08-01

    Experimental studies in animal models supporting protective effects on the fetus of melatonin in adverse pregnancy have prompted clinical trials in human pregnancy complicated by fetal growth restriction. However, the effects of melatonin on the fetal defense to acute hypoxia, such as that which may occur during labor, remain unknown. This translational study tested the hypothesis, in vivo, that melatonin modulates the fetal cardiometabolic defense responses to acute hypoxia in chronically instrumented late gestation fetal sheep via alterations in fetal nitric oxide (NO) bioavailability. Under anesthesia, 6 fetal sheep at 0.85 gestation were instrumented with vascular catheters and a Transonic flow probe around a femoral artery. Five days later, fetuses were exposed to acute hypoxia with or without melatonin treatment. Fetal blood was taken to determine blood gas and metabolic status and plasma catecholamine concentrations. Hypoxia during melatonin treatment was repeated during in vivo NO blockade with the NO clamp. This technique permits blockade of de novo synthesis of NO while compensating for the tonic production of the gas, thereby maintaining basal cardiovascular function. Melatonin suppressed the redistribution of blood flow away from peripheral circulations and the glycemic and plasma catecholamine responses to acute hypoxia. These are important components of the fetal brain sparing response to acute hypoxia. The effects of melatonin involved NO-dependent mechanisms as the responses were reverted by fetal treatment with the NO clamp. Melatonin modulates the in vivo fetal cardiometabolic responses to acute hypoxia by increasing NO bioavailability.

  19. Metabolic and Cardiovascular Responses of Children during Prolonged Physical Activity.

    ERIC Educational Resources Information Center

    Chausow, Sharon A.; And Others

    1984-01-01

    Metabolic and cardiovascular responses during 45 minutes of continuous moderate intensity exercise were investigated in 11 children, 8-11 years of age. Results indicate that children exhibit metabolic and cardiovascular adjustments similar to those noted in adults during prolonged exercise. (Author/JMK)

  20. Simultaneous cerebrovascular and cardiovascular responses during presyncope

    NASA Technical Reports Server (NTRS)

    Bondar, R. L.; Kassam, M. S.; Stein, F.; Dunphy, P. T.; Fortney, S.; Riedesel, M. L.

    1995-01-01

    BACKGROUND AND PURPOSE: Presyncope, characterized by symptoms and signs indicative of imminent syncope, can be aborted in many situations before loss of consciousness occurs. The plasticity of cerebral autoregulation in healthy humans and its behavior during this syncopal prodrome are unclear, although systemic hemodynamic instability has been suggested as a key factor in the precipitation of syncope. Using lower body negative pressure (LBNP) to simulate central hypovolemia, we previously observed falling mean flow velocities (MFVs) with maintained mean arterial blood pressure (MABP). These findings, and recent reports suggesting increased vascular tone within the cerebral vasculature at presyncope, cannot be explained by the classic static cerebral autoregulation curve; neither can they be totally explained by a recent suggestion of a rightward shift in this curve. METHODS: Four male and five female healthy volunteers were exposed to presyncopal LBNP to evaluate their cerebrovascular and cardiovascular responses by use of continuous acquisition of MFV from the right middle cerebral artery with transcranial Doppler sonography, MABP (Finapres), and heart rate (ECG). RESULTS: At presyncope, MFV dropped on average by 27.3 +/- 14% of its baseline value (P < .05), while MABP remained at 2.0 +/- 27% above its baseline level. Estimated cerebrovascular resistance increased during LBNP. The percentage change from baseline to presyncope in MFV and MABP revealed consistent decreases in MFV before MABP. CONCLUSIONS: Increased estimated cerebrovascular resistance, falling MFV, and constant MABP are evidence of an increase in cerebral vascular tone with falling flow, suggesting a downward shift in the cerebral autoregulation curve. Cerebral vessels may have a differential sensitivity to sympathetic drive or more than one type of sympathetic innervation. Future work to induce dynamic changes in MABP during LBNP may help in assessing the plasticity of the cerebral autoregulation

  1. ALTERATIONS OF FE HOMEOSTASIS IN RAT CARDIOVASCULAR DISEASE MODELS AND ITS CONTRIBUTION TO CARDIOPULMONARY TOXICITY

    EPA Science Inventory

    Introduction: Fe homeostasis can be disrupted in human cardiovascular diseases (CVD). We addressed how dysregulation of Fe homeostasis affected the pulmonary inflammation/oxidative stress response and disease progression after exposure to Libby amphibole (LA), an asbestifonn mine...

  2. BIOAVAILABLE AIR PARTICULATE POLLUTION CONSTITUENTS DIRECTLY ALTER CARDIOVASCULAR FUNCTION EX VIVO

    EPA Science Inventory

    Epidemiological studies have reported associations between particulate air pollution exposure and cardiovascular (CV) effects within susceptible individuals. Particle characteristics and biological mechanisms responsible for these observations are not known. We examined whether s...

  3. Diabetes mellitus associated cardiovascular signalling alteration: a need for the revisit.

    PubMed

    Sharma, Arun Kumar; Khanna, Deepa

    2013-05-01

    Diabetes mellitus, a chronic metabolic disorder, is recognized as a root cause of cardiovascular disorders. A long-term and uncontrolled diabetes mellitus coincides with the cardiovascular signalling alteration, resulting in inadequacy of maintaining the cardiovascular physiology. Nitric oxide (NO) is an imperative mediator of cardiovascular physiology as its signalling is known to mediate vasodilatory, anti-platelet, anti-proliferative, and anti-inflammatory actions in vessels. In 1998, Robert Furchgott, Louis Ignarro and Ferid Murad received the Nobel Prize in Medicine or Physiology for their great discoveries concerning the role of NO (originally identified as endothelium-derived relaxing factor, EDRF) as a key signalling molecule in regulating cardiovascular physiology. The activation of phosphatidylinositol 3-kinase (PI3-K) further activates protein kinase B (PKB/Akt), which subsequently enhances eNOS activation and vascular NO generation. However, in recent studies a marked impairment in PI3-K/Akt-eNOS-NO signalling has been demonstrated in the condition of diabetes mellitus. Therefore, the defective PI3-K-Akt-eNOS-NO signalling pathways could make diabetic patients more vulnerable to cardiovascular disease pathology concerning the key functions of NO. Adenosine produced by cardiac cells has abilities to attenuate the proliferation of cardiac fibroblasts, inhibit collagen synthesis, and defend the myocardium against ischemia-reperfusion injury. However, diabetes mellitus is associated with enhanced unidirectional uptake of interstitial adenosine and reduced ability to release adenosine by cardiac cells during ATP deprivation. The reduced myocardial extracellular availability and increased uptake of adenosine could make diabetic subjects more susceptible to myocardial abnormalities. This review throws lights on diabetes mellitus-associated cardiovascular signalling alterations and their possible contribution to cardiovascular disease pathology.

  4. Gender-based differences in the cardiovascular response to standing

    NASA Technical Reports Server (NTRS)

    Gotshall, Robert W.; Tsai, Pai-Feng; Frey, Mary A. B.

    1991-01-01

    The cardiovascular responses of men and women to the stand test were compared by measuring respective values for heart rate, blood pressure, stroke volume, cardiac output, and total peripheral resistance during a 5-min supine and a 5-min standing test in ten subjects of each gender. It was found that, while the male and female subjects had similar heart rate values, all other responses exhibited greater changes in men than in women. While differences in the height of the subjects did not account for differences in cardiovascular responses, no mechanism responsible for these differences could be identified.

  5. Altered Nitric Oxide System in Cardiovascular and Renal Diseases

    PubMed Central

    Bae, Eun Hui; Ma, Seong Kwon; Kim, Soo Wan

    2016-01-01

    Nitric oxide (NO) is synthesized by a family of NO synthases (NOS), including neuronal, inducible, and endothelial NOS (n/i/eNOS). NO-mediated effects can be beneficial or harmful depending on the specific risk factors affecting the disease. In hypertension, the vascular relaxation response to acetylcholine is blunted, and that to direct NO donors is maintained. A reduction in the activity of eNOS is mainly responsible for the elevation of blood pressure, and an abnormal expression of iNOS is likely to be related to the progression of vascular dysfunction. While eNOS/nNOS-derived NO is protective against the development of atherosclerosis, iNOS-derived NO may be proatherogenic. eNOS-derived NO may prevent the progression of myocardial infarction. Myocardial ischemia/reperfusion injury is significantly enhanced in eNOS-deficient animals. An important component of heart failure is the loss of coronary vascular eNOS activity. A pressure-overload may cause severer left ventricular hypertrophy and dysfunction in eNOS null mice than in wild-type mice. iNOS-derived NO has detrimental effects on the myocardium. NO plays an important role in regulating the angiogenesis and slowing the interstitial fibrosis of the obstructed kidney. In unilateral ureteral obstruction, the expression of eNOS was decreased in the affected kidney. In triply n/i/eNOS null mice, nephrogenic diabetes insipidus developed along with reduced aquaporin-2 abundance. In chronic kidney disease model of subtotal-nephrectomized rats, treatment with NOS inhibitors decreased systemic NO production and induced left ventricular systolic dysfunction (renocardiac syndrome). PMID:27231671

  6. Computer model of cardiovascular control system responses to exercise

    NASA Technical Reports Server (NTRS)

    Croston, R. C.; Rummel, J. A.; Kay, F. J.

    1973-01-01

    Approaches of systems analysis and mathematical modeling together with computer simulation techniques are applied to the cardiovascular system in order to simulate dynamic responses of the system to a range of exercise work loads. A block diagram of the circulatory model is presented, taking into account arterial segments, venous segments, arterio-venous circulation branches, and the heart. A cardiovascular control system model is also discussed together with model test results.

  7. Enhanced carotid body chemosensory activity and the cardiovascular alterations induced by intermittent hypoxia

    PubMed Central

    Iturriaga, Rodrigo; Andrade, David C.; Del Rio, Rodrigo

    2014-01-01

    The carotid body (CB) plays a main role in the maintenance of the oxygen homeostasis. The hypoxic stimulation of the CB increases the chemosensory discharge, which in turn elicits reflex sympathetic, cardiovascular, and ventilatory adjustments. An exacerbate carotid chemosensory activity has been associated with human sympathetic-mediated diseases such as hypertension, insulin resistance, heart failure, and obstructive sleep apnea (OSA). Indeed, the CB chemosensory discharge becomes tonically hypereactive in experimental models of OSA and heart failure. Chronic intermittent hypoxia (CIH), a main feature of OSA, enhances CB chemosensory baseline discharges in normoxia and in response to hypoxia, inducing sympathetic overactivity and hypertension. Oxidative stress, increased levels of ET-1, Angiotensin II and pro-inflammatory cytokines, along with a reduced production of NO in the CB, have been associated with the enhanced carotid chemosensory activity. In this review, we will discuss new evidence supporting a main role for the CB chemoreceptor in the autonomic and cardiorespiratory alterations induced by intermittent hypoxia, as well as the molecular mechanisms involved in the CB chemosensory potentiation. PMID:25520668

  8. High Molecular Weight Barley β-Glucan Alters Gut Microbiota Toward Reduced Cardiovascular Disease Risk

    PubMed Central

    Wang, Yanan; Ames, Nancy P.; Tun, Hein M.; Tosh, Susan M.; Jones, Peter J.; Khafipour, Ehsan

    2016-01-01

    The physiological cholesterol-lowering benefits of β-glucan have been well documented, however, whether modulation of gut microbiota by β-glucan is associated with these physiological effects remains unknown. The objectives of this study were therefore to determine the impact of β-glucan on the composition of gut microbiota in mildly hypercholesterolemic individuals and to identify if the altered microbiota are associated with bioactivity of β-glucan in improving risk factors of cardiovascular disease (CVD). Using a randomized, controlled crossover study design, individuals received for 5-week either a treatment breakfast containing 3 g high molecular weight (HMW), 3 g low molecular weight (LMW), 5 g LMW barley β-glucan, or wheat and rice. The American Heart Association (AHA) diet served as the background diet for all treatment groups. Phases were separated by 4-week washout periods. Fecal samples were collected at the end of each intervention phase and subjected to Illumina sequencing of 16S rRNA genes. Results revealed that at the phylum level, supplementation of 3 g/d HMW β-glucan increased Bacteroidetes and decreased Firmicutes abundances compared to control (P < 0.001). At the genus level, consumption of 3 g/d HMW β-glucan increased Bacteroides (P < 0.003), tended to increase Prevotella (P < 0.1) but decreased Dorea (P < 0.1), whereas diets containing 5 g LMW β-glucan and 3 g LMW β-glucan failed to alter the gut microbiota composition. Bacteroides, Prevotella, and Dorea composition correlated (P < 0.05) with shifts of CVD risk factors, including body mass index, waist circumference, blood pressure, as well as triglyceride levels. Our data suggest that consumption of HMW β-glucan favorably alters the composition of gut microbiota and this altered microbiota profile associates with a reduction of CVD risk markers. Together, our study suggests that β-glucan induced shifts in gut microbiota in a MW-dependent manner and that might be one of the

  9. Early growth response-1 in the pathogenesis of cardiovascular disease.

    PubMed

    Khachigian, Levon M

    2016-07-01

    This article reviews the regulatory roles of the immediate-early gene product and prototypic zinc finger transcription factor, early growth response-1 in models of cardiovascular pathobiology, focusing on insights using microRNA, DNAzymes, small hairpin RNA, small interfering RNA, oligonucleotide decoy strategies and mice deficient in early growth response-1. PMID:27251707

  10. Gender-Related Differences in Cardiovascular Responses to Orthostatic Stress

    NASA Technical Reports Server (NTRS)

    Fritsch-Yelle, Janice M.; DAunno, Dominick S.; Waters, Wendy W.; Freeman-Perez, Sondra

    1999-01-01

    There is evidence that men and women have different cardiovascular responses to standing, and that women are more susceptible to orthostatic hypotension than men. The present study seeks to determine if decreased orthostatic tolerance in women is caused by diminished vasoconstrictive responses.

  11. Human cardiovascular response to sympathomimetic agents during head-down bed rest: the effect of dietary sodium

    NASA Technical Reports Server (NTRS)

    Williams, W. J.; Stuart, C. A.; Fortney, S. M.; Pietrzyk, R. A.; Chen, Y. M.; Whitson, P. A.

    1994-01-01

    Changes in sympathoadrenal function and cardiovascular deconditioning have long been recognized as a feature of the physiological adaptation to microgravity. The deconditioning process, coupled with altered hydration status, is thought to significantly contribute to orthostatic intolerance upon return to Earth gravity. The cardiovascular response to stimulation by sympathomimetic agents before, during, and after exposure to simulated microgravity was determined in healthy volunteers equilibrated on normal or high sodium diets in order to further the understanding of the deconditioning process.

  12. Cardiovascular response to histamine during normoxaemia and hypoxaemia in piglets.

    PubMed

    Taylor, B J

    1989-02-01

    The cardiovascular effects of exogenously administered histamine were investigated in conscious newborn piglets aged 10-11 days during normoxia (21% (v/v) O2) and during isocapneic alveolar hypoxia (10% O2, 3% CO2, 87% N2) to determine its influence on preexisting vascular tone. In the first set of experiments (n = 6), four histamine doses (1,10,50,100 micrograms/kg) were tested in sequence during normoxia. Histamine was injected intravenously and cardiovascular variables were recorded. Heart rate increased at all doses studied. Pulmonary and systemic arterial pressures, cardiac output and stroke volume were unchanged at the low histamine doses (1 and 10 micrograms), but all decreased at the high doses (50 and 100 micrograms). Pulmonary and systemic vascular resistances were unchanged at each dose. In the second set of experiments (n = 7), two histamine doses (1 and 5 micrograms/kg) were administered during alveolar hypoxia. Hypoxia caused increases in heart rate and pulmonary arterial pressure and resistance. After injection of each dose of histamine, pulmonary pressure and resistance decreased but remained higher than baseline. No other measured cardiovascular variables were altered. Thus, during normoxia histamine did not alter vascular tone, but high doses did adversely affect myocardial function. During alveolar hypoxia histamine caused weak pulmonary vasodilation at doses that did not alter systemic vascular tone. Histamine is not a potent modifier of the circulation in the newborn piglet during conditions of normoxaemia or hypoxaemia.

  13. Cardiovascular responses to weightlessness and ground-based simulations

    NASA Technical Reports Server (NTRS)

    Sandler, H.

    1982-01-01

    Mission experience, from NASA and Soviet programs, on human cardiovascular responses to weightlessness, and the ability of bed rest studies to simulate these are discussed. In-flight effects include fluid shift to the upper body, decreased heart size, bone demineralization, orthostatic intolerance, and loss of exercise tolerance. All the cardiovascular changes that occur with weightlessness also occur with prolonged bed rest. They are most manifest when subjects stand suddenly, or undergo tilting or lower body negative pressure. The mechanisms which control these responses, e.g., the role of the central nervous system, are unclear.

  14. Cardiovascular responses of women to lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Frey, M. A. B.; Mathes, K. L.; Hoffler, G. W.

    1986-01-01

    The effects of lower body negative pressure (LBNP) on the cardiovascular response of 20 women between 23-43 years are evaluated. Calf circumference and cardiovascular data were recorded for women in the follicular and luteal phases of the menstrual cycle at -30, -40, and -50 mm Hg LBNP. The data reveal that the two menstrual phases did not cause differences in the way women respond to LBNP. It is observed that during LBNP calf circumference is enlarged; transthoracic impedance, and heart rate are increased; stroke volume, left ventricular ejection time, the Heather Index of contractility and systolic pressure, and cardiac output are reduced; and total peripheral resistance is elevated. The experimental data are compared to Montgomery et al. (1979). It is noted that the response of women to -50 mm Hg LBNP is similar to that of men; however, women adapt to stresses on the cardiovascular system with greater heart rate adjustments.

  15. Cardiovascular and thermal responses to SCUBA diving.

    PubMed

    Doubt, T J

    1996-05-01

    Recreational SCUBA diving exposes individuals to environmental stresses not often encountered in other types of activity. These stresses include increased ambient pressure, raised partial pressure of O(2), increased resistance to movement, added weight and drag of diving equipment, cold stress, and a higher breathing resistance. One means to understand how such stresses affect a diver is to employ the stress-strain-adaptive response model. Physiologic adaptations, like an increase in VO(2) in response to cold stress, will minimize the strain placed on thermal balance. Nonphysiologic adaptive responses include those behavioral and equipment interventions that isolate the diver from a particular stress. Self-contained underwater breathing apparatus (SCUBA) isolates the diver from the inability to extract O(2) from the water; dive garments minimize the stress of cold water immersion. This review will focus on cardiorespiratory and thermal responses to SCUBA diving, using the stress-strain-adaptive response model to illustrate the interaction between diver and environment. Some responses like hyperventilation, cardiac arrhythmias, or cold injury due to vasoconstriction are not considered adaptive but are realistic possibilities in diving environments.

  16. CARDIOVASCULAR RESPONSES TO ULTRAFINE CARBON PARTICLE EXPOSURES IN RATS

    EPA Science Inventory

    TD-02-042 (U. KODAVANTI) GPRA # 10108

    Cardiovascular Responses to Ultrafine Carbon Particle Exposures in Rats.
    V. Harder1, B. Lentner1, A. Ziesenis1, E. Karg1, L. Ruprecht1, U. Kodavanti2, A. Stampfl3, J. Heyder1, H. Schulz1
    GSF- Institute for Inhalation Biology1, I...

  17. CARDIOVASCULAR RESPONSES TO WALKING IN PATIENTS WITH PERIPHERAL ARTERY DISEASE

    PubMed Central

    Ritti-Dias, Raphael Mendes; Meneses, Annelise Lins; Parker, Donald E.; Montgomery, Polly S.; Khurana, Aman; Gardner, Andrew W.

    2013-01-01

    Purposes To assess the cardiovascular responses during constant load walking and to identify predictors of this response in peripheral artery disease (PAD) patients. Methods Seventy-nine patients with PAD performed a constant load treadmill test (2 mph, 0% grade). During the test, systolic blood pressure (BP), diastolic BP, and heart rate (HR) were obtained at the fourth minute to the last minute of exercise. Patients were also characterized on demographic measures, cardiovascular risk factors, baseline exercise performance and vascular measures. Results During constant load walking, there was a significant increase (p<0.01) in systolic BP (+12 ± 10 mmHg), diastolic BP (+6 ± 9 mmHg), and HR (+5 ± 5 bpm). The HR responses was negatively correlated with ischemic window (r= −0.23; p<0.05), expressed as an area under the curve of the resting ankle systolic BP and its recovery from maximal graded treadmill test, and positively correlated with the HR during the first minute of recovery from maximal graded treadmill test (r= 0.27; p<0.05). The increase in cardiovascular variables during constant load walking was greater in subjects with higher body mass index and in men (p<0.05). Conclusion Patients with PAD had an increased cardiovascular response during constant load walking, and these responses were greater in obese patients and in men. The clinical implication is that PAD patients engaged in walking training programs, particularly men and those with obesity, require frequent assessment of cardiovascular parameters to avoid exaggerated increases in BP and HR during constant load walking. PMID:21502888

  18. Xenobiotic pulmonary exposure and systemic cardiovascular response via neurological links.

    PubMed

    Stapleton, Phoebe A; Abukabda, Alaeddin B; Hardy, Steven L; Nurkiewicz, Timothy R

    2015-11-15

    The cardiovascular response to xenobiotic particle exposure has been increasingly studied over the last two decades, producing an extraordinary scope and depth of research findings. With the flourishing of nanotechnology, the term "xenobiotic particles" has expanded to encompass not only air pollution particulate matter (PM) but also anthropogenic particles, such as engineered nanomaterials (ENMs). Historically, the majority of research in these fields has focused on pulmonary exposure and the adverse physiological effects associated with a host inflammatory response or direct particle-tissue interactions. Because these hypotheses can neither account entirely for the deleterious cardiovascular effects of xenobiotic particle exposure nor their time course, the case for substantial neurological involvement is apparent. Indeed, considerable evidence suggests that not only is neural involvement a significant contributor but also a reality that needs to be investigated more thoroughly when assessing xenobiotic particle toxicities. Therefore, the scope of this review is several-fold. First, we provide a brief overview of the major anatomical components of the central and peripheral nervous systems, giving consideration to the potential biologic targets affected by inhaled particles. Second, the autonomic arcs and mechanisms that may be involved are reviewed. Third, the cardiovascular outcomes following neurological responses are discussed. Lastly, unique problems, future risks, and hurdles associated with xenobiotic particle exposure are discussed. A better understanding of these neural issues may facilitate research that in conjunction with existing research, will ultimately prevent the untoward cardiovascular outcomes associated with PM exposures and/or identify safe ENMs for the advancement of human health. PMID:26386111

  19. Can bread processing conditions alter glycaemic response?

    PubMed

    Lau, Evelyn; Soong, Yean Yean; Zhou, Weibiao; Henry, Jeyakumar

    2015-04-15

    Bread is a staple food that is traditionally made from wheat flour. This study aimed to compare the starch digestibility of western baked bread and oriental steamed bread. Four types of bread were prepared: western baked bread (WBB) and oriental steamed bread (OSB), modified baked bread (MBB) made with the OSB recipe and WBB processing, and modified steamed bread (MSB) made with the WBB recipe and OSB processing. MBB showed the highest starch digestibility in vitro, followed by WBB, OSB and MSB. A similar trend was observed for glycaemic response in vivo. MBB, WBB, OSB and MSB had a glycaemic index of 75±4, 71±5, 68±5 and 65±4, respectively. Processing differences had a more pronounced effect on starch digestibility in bread, and steamed bread was healthier in terms of glycaemic response. The manipulation of processing conditions could be an innovative route to alter the glycaemic response of carbohydrate-rich foods.

  20. Cardiovascular Response Patterns to Sympathetic Stimulation by Central Hypovolemia.

    PubMed

    Bronzwaer, Anne-Sophie G T; Verbree, Jasper; Stok, Wim J; van Buchem, Mark A; Daemen, Mat J A P; van Osch, Matthias J P; van Lieshout, Johannes J

    2016-01-01

    In healthy subjects, variation in cardiovascular responses to sympathetic stimulation evoked by submaximal lower body negative pressure (LBNP) is considerable. This study addressed the question whether inter-subject variation in cardiovascular responses coincides with consistent and reproducible responses in an individual subject. In 10 healthy subjects (5 female, median age 22 years), continuous hemodynamic parameters (finger plethysmography; Nexfin, Edwards Lifesciences), and time-domain baroreflex sensitivity (BRS) were quantified during three consecutive 5-min runs of LBNP at -50 mmHg. The protocol was repeated after 1 week to establish intra-subject reproducibility. In response to LBNP, 5 subjects (3 females) showed a prominent increase in heart rate (HR; 54 ± 14%, p = 0.001) with no change in total peripheral resistance (TPR; p = 0.25) whereas the other 5 subjects (2 females) demonstrated a significant rise in TPR (7 ± 3%, p = 0.017) with a moderate increase in HR (21 ± 9%, p = 0.004). These different reflex responses coincided with differences in resting BRS (22 ± 8 vs. 11 ± 3 ms/mmHg, p = 0.049) and resting HR (57 ± 8 vs. 71 ± 12 bpm, p = 0.047) and were highly reproducible over time. In conclusion, we found distinct cardiovascular response patterns to sympathetic stimulation by LBNP in young healthy individuals. These patterns of preferential autonomic blood pressure control appeared related to resting cardiac BRS and HR and were consistent over time. PMID:27378944

  1. Cardiovascular Response Patterns to Sympathetic Stimulation by Central Hypovolemia

    PubMed Central

    Bronzwaer, Anne-Sophie G. T.; Verbree, Jasper; Stok, Wim J.; van Buchem, Mark A.; Daemen, Mat J. A. P.; van Osch, Matthias J. P.; van Lieshout, Johannes. J.

    2016-01-01

    In healthy subjects, variation in cardiovascular responses to sympathetic stimulation evoked by submaximal lower body negative pressure (LBNP) is considerable. This study addressed the question whether inter-subject variation in cardiovascular responses coincides with consistent and reproducible responses in an individual subject. In 10 healthy subjects (5 female, median age 22 years), continuous hemodynamic parameters (finger plethysmography; Nexfin, Edwards Lifesciences), and time-domain baroreflex sensitivity (BRS) were quantified during three consecutive 5-min runs of LBNP at −50 mmHg. The protocol was repeated after 1 week to establish intra-subject reproducibility. In response to LBNP, 5 subjects (3 females) showed a prominent increase in heart rate (HR; 54 ± 14%, p = 0.001) with no change in total peripheral resistance (TPR; p = 0.25) whereas the other 5 subjects (2 females) demonstrated a significant rise in TPR (7 ± 3%, p = 0.017) with a moderate increase in HR (21 ± 9%, p = 0.004). These different reflex responses coincided with differences in resting BRS (22 ± 8 vs. 11 ± 3 ms/mmHg, p = 0.049) and resting HR (57 ± 8 vs. 71 ± 12 bpm, p = 0.047) and were highly reproducible over time. In conclusion, we found distinct cardiovascular response patterns to sympathetic stimulation by LBNP in young healthy individuals. These patterns of preferential autonomic blood pressure control appeared related to resting cardiac BRS and HR and were consistent over time. PMID:27378944

  2. Radiation response of the canine cardiovascular system

    SciTech Connect

    Gavin, P.R.; Gillette, E.L.

    1982-06-01

    The hearts of dogs were irradiated with /sup 60/Co ..gamma.. rays. The dose required to produce pericardial effusion in 50% of the dogs by 180 days (PED/sub 50///sub 180/) was 1220 rad. For cardiac tamponade, the CTD /sub 50///sub 180/ was 1500 rad. Morphometric analyses of the hearts showed decreased capillary volume and increased fibrosis as radiation dose increased. The pericardial thickness increased with increased radiation dose. The slopes of the dose response for these parameters were similar as determined by linear regression of the parameter versus radiation dose.

  3. Cardiovascular disease management through restrained inflammatory responses.

    PubMed

    Jabir, Nasimudeen R; Tabrez, Shams

    2016-01-01

    Cardio vascular disease (CVD) is the end result of the accumulation of atheromatous plaques within the walls of the coronary arteries and remains the leading cause of death worldwide. Vascular inflammation and associated ongoing inflammatory responses have been considered as the critical culprits in the pathogenesis of CVD. Moreover, the activation of inflammatory pathways is not confined to coronary lesions only but involves the activation of neutrophils, monocytes and lymphocytes in peripheral blood. In view of high mortality rate associated with this devastated disease, it is essential that CVD and related complications should be taken care off at its earliest. To achieve that goal, some inflammatory mediators could be potentially targeted. In the current article, we will highlight targeting some inflammatory mediators viz. IL-1, IL-6, TNF-α etc for CVD management. As far as our knowledge goes, we are for the first time reporting the targeting inflammatory mediators especially IL-1, IL-6 and TNF-α together in a single article. Based on our review, we believe that scientific community will come up with certain anti-inflammatory agents against atherosclerosis in near future and hopefully that will be used for the successful management of CVD patients.

  4. Cardiovascular response to dynamic aerobic exercise: a mathematical model.

    PubMed

    Magosso, E; Ursino, M

    2002-11-01

    An original mathematical model of the cardiovascular response to dynamic exercise is presented. It includes the pulsating heart, the pulmonary and systemic circulation, a separate description of the vascular bed in active tissues, the local metabolic vasodilation in these tissues and the mechanical effects of muscular contractions on venous return. Moreover, the model provides a description of the ventilatory response to exercise and various neural regulatory mechanisms working on cardiovascular parameters. These mechanisms embrace the so-called central command, the arterial baroreflex and the lung inflation reflex. All parameters in the model have been given in accordance with physiological data from the literature. In this work, the model has been used to simulate the steady-state value of the main cardiorespiratory quantities at different levels of aerobic exercise and the temporal pattern in the transient phase from rest to moderate exercise. Results suggest that, with suitable parameter values the model is able accurately to simulate the cardiorespiratory response in the overall range of aerobic exercise. This response is characterised by a moderate hypertension (10-30%) and by a conspicuous increase in systemic conductance (80-130%), heart rate (64-150%) and cardiac output (100-200%). The transient pattern exhibits three distinct phases (lasting approximately 5s, 15s and 2 min), that reflect the temporal heterogeneity of the mechanisms involved. The model may be useful to improve understanding of exercise physiology and as an educational tool to analyse the complexity of cardiovascular and respiratory regulation.

  5. Cardiovascular response to dynamic aerobic exercise: a mathematical model.

    PubMed

    Magosso, E; Ursino, M

    2002-11-01

    An original mathematical model of the cardiovascular response to dynamic exercise is presented. It includes the pulsating heart, the pulmonary and systemic circulation, a separate description of the vascular bed in active tissues, the local metabolic vasodilation in these tissues and the mechanical effects of muscular contractions on venous return. Moreover, the model provides a description of the ventilatory response to exercise and various neural regulatory mechanisms working on cardiovascular parameters. These mechanisms embrace the so-called central command, the arterial baroreflex and the lung inflation reflex. All parameters in the model have been given in accordance with physiological data from the literature. In this work, the model has been used to simulate the steady-state value of the main cardiorespiratory quantities at different levels of aerobic exercise and the temporal pattern in the transient phase from rest to moderate exercise. Results suggest that, with suitable parameter values the model is able accurately to simulate the cardiorespiratory response in the overall range of aerobic exercise. This response is characterised by a moderate hypertension (10-30%) and by a conspicuous increase in systemic conductance (80-130%), heart rate (64-150%) and cardiac output (100-200%). The transient pattern exhibits three distinct phases (lasting approximately 5s, 15s and 2 min), that reflect the temporal heterogeneity of the mechanisms involved. The model may be useful to improve understanding of exercise physiology and as an educational tool to analyse the complexity of cardiovascular and respiratory regulation. PMID:12507317

  6. Cardiovascular responses to hypoxia and anaemia in the toad Bufo marinus.

    PubMed

    Andersen, Johnnie B; Hedrick, Michael S; Wang, Tobias

    2003-03-01

    Amphibians exhibit cardiorespiratory responses to hypoxia and, although several oxygen-sensitive chemoreceptor sites have been identified, the specific oxygen stimulus that triggers these responses remains controversial. This study investigates whether the cardiovascular response to oxygen shortage correlates with decreased oxygen partial pressure of arterial blood (Pa(O(2))) or reduced oxygen concentration ([O(2)]) in toads. Toads, equipped with blood flow probes and an arterial catheter, were exposed to graded hypoxia [fraction of oxygen in the inspired air (FI(O(2)))=0.21, 0.15, 0.10, 0.07 and 0.05] before and after reductions in arterial [O(2)] by isovolemic anaemia that reduced haematocrit by approximately 50%. Toads responded to hypoxia by increasing heart rate (fH) and pulmocutaneous blood flow (Q(pc)) and reducing the net cardiac right-to-left-shunt. When arterial [O(2)] was reduced by anaemia, the toads exhibited a similar cardiovascular response to that observed in hypoxia. While arterial CO(2) partial pressure (Pa(CO(2))) decreased significantly during hypoxia, indicative of increased alveolar ventilation, anaemia did not alter Pa(CO(2))). This suggests that reductions in [O(2)] mediate cardiovascular adjustments, while ventilatory responses are caused by reduced Pa(O(2)).

  7. Role of arterial baroreceptors in mediating cardiovascular response to exercise

    NASA Technical Reports Server (NTRS)

    Mcritchie, R. J.; Vatner, S. F.; Patrick, T. A.; Braunwald, E.; Boettcher, D.; Heyndrickx, G. R.

    1976-01-01

    Experiments were conducted to define the role of the major arterial baroreceptors during moderately severe exercise by comparing the responses of untethered conscious dogs instrumented for the measurement of aortic pressure and cardiac output with those of dogs with total arterial baroreceptor denervation. The reflex heart rate responses to intravenous bolus doses of methoxamine were also examined in intact animals, both at rest and during exercise. Methoxamine is found to cause striking bradycardia at rest, but little bradycardia during exercise. Experimental findings suggest that the arterial baroreceptor reflex is normally inhibited during severe exercise and therefore plays little role in modulating the cardiovascular response to exercise.

  8. Cardiovascular

    NASA Video Gallery

    Overview of Cardiovascular research which addresses risks of space flight, including adaptive changes to the cephalad fluid shift (such as reduced circulating blood volume), potential for heart rhy...

  9. High density lipoproteins and endothelial functions: mechanistic insights and alterations in cardiovascular disease.

    PubMed

    Riwanto, Meliana; Landmesser, Ulf

    2013-12-01

    Prospective population studies in the primary prevention setting have shown that reduced plasma levels of HDL cholesterol are associated with an increased risk of coronary disease and myocardial infarction. Experimental and translational studies have further revealed several potential anti-atherogenic effects of HDL, including protective effects on endothelial cell functions. HDL has been suggested to protect endothelial cell functions by prevention of oxidation of LDL and its adverse endothelial effects. Moreover, HDL from healthy subjects can directly stimulate endothelial cell production of nitric oxide and anti-inflammatory, anti-apoptotic, and anti-thrombotic effects as well as endothelial repair processes. However, several recent clinical trials using HDL cholesterol-raising agents, such as torcetrapib, dalcetrapib, and niacin, did not demonstrate a significant reduction of cardiovascular events in patients with coronary disease. Of note, growing evidence suggests that the vascular effects of HDL can be highly heterogeneous and vasoprotective properties of HDL are altered in patients with coronary disease. Characterization of underlying mechanisms and understanding of the clinical relevance of this "HDL dysfunction" is currently an active field of cardiovascular research. Notably, in some recent studies no clear association of higher HDL cholesterol levels with a reduced risk of cardiovascular events was observed in patients with already established coronary disease. A greater understanding of mechanisms of action of HDL and its altered vascular effects is therefore critical within the context of HDL-targeted therapies. In this review, we will address different effects of HDL on endothelial cell functions potentially relevant to atherosclerotic vascular disease and explore molecular mechanisms leading to "dysfunctional HDL".

  10. Task difficulty, cardiovascular response, and the magnitude of goal valence.

    PubMed

    Wright, R A; Contrada, R J; Patane, M J

    1986-10-01

    Sixty-four young women expected to perform an easy, moderately difficult, or extremely difficult memory task with the opportunity to earn a small incentive for good performance. Cardiovascular (heart rate, systolic and diastolic blood pressure) and subjective measures were taken immediately prior to task performance. Both systolic blood pressure (SBP) responses and ratings of goal attractiveness were nonmonotonically related to expected task difficulty, with the most pronounced SBP elevations and highest goal attractiveness in the moderately difficult task condition. Product-moment correlations among cardiovascular response measures revealed a strong positive association between systolic and diastolic pressure (but not heart rate) change in the easy condition, positive relationships among all measures in the moderately difficult condition, and no significant correlations in the extremely difficult condition. Subjective measures of arousal were not affected by the task difficulty manipulation. Principal findings are discussed in terms of a theoretical model proposed by Brehm (1979) that states that motivation varies as a nonmonotonic function of the difficulty of goal attainment. Intercorrelations among cardiovascular response variables are considered in terms of their possible indication of the mechanisms underlying blood pressure changes associated with variations in motivation. PMID:3783427

  11. Cardiovascular responses to water drinking: does osmolality play a role?

    PubMed

    Brown, Clive M; Barberini, Luc; Dulloo, Abdul G; Montani, Jean-Pierre

    2005-12-01

    Water drinking activates the autonomic nervous system and induces acute hemodynamic changes. The actual stimulus for these effects is undetermined but might be related to either gastric distension or to osmotic factors. In the present study, we tested whether the cardiovascular responses to water drinking are related to water's relative hypoosmolality. Therefore, we compared the cardiovascular effects of a water drink (7.5 ml/kg body wt) with an identical volume of a physiological (0.9%) saline solution in nine healthy subjects (6 male, 3 female, aged 26 +/- 2 years), while continuously monitoring beat-to-beat blood pressure (finger plethysmography), cardiac intervals (electrocardiography), and cardiac output (thoracic impedance). Total peripheral resistance was calculated as mean blood pressure/cardiac output. Cardiac interval variability (high-frequency power) was assessed by spectral analysis as an index of cardiac vagal tone. Baroreceptor sensitivity was evaluated using the sequence technique. Drinking water, but not saline, decreased heart rate (P = 0.01) and increased total peripheral resistance (P < 0.01), high-frequency cardiac interval variability (P = 0.03), and baroreceptor sensitivity (P = 0.01). Neither water nor saline substantially increased blood pressure. These responses suggest that water drinking simultaneously increases sympathetic vasoconstrictor activity and cardiac vagal tone. That these effects were absent after drinking physiological saline indicate that the cardiovascular responses to water drinking are influenced by its hypoosmotic properties.

  12. Race and blood pressure status influences cardiovascular responses to challenge.

    PubMed

    Saab, P G; Tischenkel, N; Spitzer, S B; Gellman, M D; Pasin, R D; Schneiderman, N

    1991-03-01

    The influence of race and blood pressure status on cardiovascular responses to three challenges (interview, video game and cold pressor) was investigated in 50 healthy normotensive and 30 unmedicated mild-to-moderate hypertensive black and white men, aged 25-44 years old. Group differences were obtained for two tasks. The interview evoked race and blood pressure status differences: higher heart rate responses were elicited from normotensives compared with hypertensives and larger diastolic blood pressure (DBP) responses were elicited from whites compared with blacks. For the video game, black hypertensives displayed larger DBP responses than white hypertensives and greater systolic blood pressure and DBP responses than black normotensives. The video game heart rate response of white normotensives exceeded that of black normotensives and white hypertensives. These findings suggest that cardiovascular responses to challenge are affected by race and blood pressure status. The blood pressure hyperresponsiveness of black hypertensives compared with black normotensives to a psychological challenge (video game) provides generality to previous research conducted only on whites. PMID:1851788

  13. Differential cardiovascular responses to stressors in hypertensive and normotensive rats.

    PubMed

    McDougall, Stuart J; Lawrence, Andrew J; Widdop, Robert E

    2005-01-01

    The aim of this study was to determine to what extent stress-induced cardiovascular responses depend upon rat strain and/or stressor. Spontaneously hypertensive rats (SHRs), Wistar-Kyoto rats (WKYs) and Sprague-Dawley (SD) rats were implanted with telemetry probes in order to measure heart rate and blood pressure changes when exposed to a stressor. The stress protocols employed included handling, air-jet and restraint, where each stressor was repeated over 10 consecutive days. In addition, a heterologous protocol was established whereby the experimental groups having experienced 10 days of air-jet stress were then immediately exposed to 10 consecutive days of restraint. Each stressor caused graded tachycardic and pressor responses in all strains. For all strains, the magnitude and duration of heart rate and blood pressure increases were greatest in the restraint-based protocols while handling and air-jet caused submaximal changes. A comparison between strains indicated that SHRs exhibited prolonged pressor responses to each of the stressor types tested as compared to the normotensive strains. In addition, repeated exposure over 10 days to handling and air-jet in SHRs caused tachycardic and/or pressor responses to adapt to 'normotensive-like' levels. Heterologous restraint stress caused sensitization of cardiovascular responses upon first exposure, predominantly in normotensive strains. Collectively these data show that the magnitude and duration of the tachycardia and pressor responses evoked by the stressors were different within the strains and were also modified by prior experience. In addition, the cardiovascular profiles presented in this study demonstrate that, within each strain, the heart rate response during stress is graded according to the type of stressor encountered.

  14. Fungal symbionts alter plant drought response.

    PubMed

    Worchel, Elise R; Giauque, Hannah E; Kivlin, Stephanie N

    2013-04-01

    Grassland productivity is often primarily limited by water availability, and therefore, grasslands may be especially sensitive to climate change. Fungal symbionts can mediate plant drought response by enhancing drought tolerance and avoidance, but these effects have not been quantified across grass species. We performed a factorial meta-analysis of previously published studies to determine how arbuscular mycorrhizal (AM) fungi and endophytic fungal symbionts affect growth of grasses under drought. We then examined how the effect of fungal symbionts on plant growth was influenced by biotic (plant photosynthetic pathway) and abiotic (level of drought) factors. We also measured the phylogenetic signal of fungal symbionts on grass growth under control and drought conditions. Under drought conditions, grasses colonized by AM fungi grew larger than those without mycorrhizal symbionts. The increased growth of grasses conferred from fungal symbionts was greatest at the lowest soil moisture levels. Furthermore, under both drought and control conditions, C3 grasses colonized by AM fungi grew larger than C3 grasses without symbionts, but the biomass of C4 grasses was not affected by AM fungi. Endophytes did not increase plant biomass overall under any treatment. However, there was a phylogenetically conserved increase in plant biomass in grasses colonized by endophytes. Grasses and their fungal symbionts seem to interact within a context-dependent symbiosis, varying with biotic and abiotic conditions. Because plant-fungal symbioses significantly alter plant drought response, including these responses could improve our ability to predict grassland functioning under global change.

  15. Sleep duration and cardiovascular responses to stress in undergraduate men.

    PubMed

    Mezick, Elizabeth J; Matthews, Karen A; Hall, Martica H; Richard Jennings, J; Kamarck, Thomas W

    2014-01-01

    Short sleep has been related to incident cardiovascular disease, but physiological mechanisms accounting for this relationship are largely unknown. This study examines sleep duration and cardiovascular stress responses in 79 healthy, young men. Sleep duration was assessed by wrist actigraphy for seven nights. Participants then completed a series of laboratory stress tasks while heart rate and blood pressure were monitored. Shorter total sleep time was related to a greater reduction in high-frequency heart rate variability during stress tasks, and to prolonged elevations in heart rate and diastolic pressure following tasks. Associations were independent of age, race, body mass index, caffeine intake, and smoking status. In sum, healthy young men with shorter actigraphy-assessed sleep exhibit less cardiac vagal activity, and poorer heart rate and diastolic blood pressure recovery, upon encountering stressful stimuli, than those with longer sleep. PMID:24016263

  16. Renal Function and Cardiovascular Response to Mental Stress

    PubMed Central

    Seliger, Stephen L.; Katzel, Leslie I.; Fink, Jeffrey C.; Weir, Matthew R.; Waldstein, Shari R.

    2008-01-01

    Background/Aims Cardiovascular reactivity (CVR), defined as an exaggerated hemodynamic response to mental stress, is a putative vascular risk factor and may reflect sympathetic hyperactivity. Chronic kidney disease (CKD) is also associated with sympathetic hyperactivity and vascular risk, but its relationship with CVR is unknown. Methods CVR was assessed in 107 individuals without overt cardiovascular disease or diabetes. Blood pressure and heart rate responses were elicited by three experimental tasks designed to evoke mental stress. Glomerular filtration rate (eGFR) was estimated using the MDRD formula. General linear models estimated the association between renal function and CVR, adjusting for potential confounders. Results Mean age was 66 years and 11% had eGFR of <60 ml/min/1.73 m2. After multivariate adjustment, a low eGFR was associated with a greater stress response of systolic blood pressure, heart rate, and pulse pressure. Associations were only partially attenuated after adjustment for lipids and glucose tolerance. When considered as a continuous variable, lower eGFR was associated with a greater blood pressure response after adjustment for glycemia. Conclusion Although there were relatively few participants with CKD, these results suggest a relationship between CKD and greater CVR. Further investigation is warranted into factors that mediate this relationship and potential clinical consequences of this exaggerated response to stress in CKD. PMID:18025779

  17. Success importance and urge magnitude as determinants of cardiovascular response to a behavioral restraint challenge.

    PubMed

    Agtarap, Stephanie D; Wright, Rex A; Mlynski, Christopher; Hammad, Rawan; Blackledge, Sabrina

    2016-04-01

    Decades of research have investigated a conceptual analysis concerned with determinants and cardiovascular correlates of effort in people confronted with performance challenges, that is, opportunities to alter some course of events by acting. One suggestion is that effort and associated cardiovascular responses should be determined jointly by the difficulty of meeting a challenge and the importance of doing so. The present experiment tested this in a context involving behavioral restraint, that is, effortful resistance against a behavioral impulse or urge. Participants were presented a mildly evocative violent film clip (restraint difficulty low) or a strongly evocative violent film clip (restraint difficulty high) with instructions to refrain from showing any facial response. Success was made more or less important through coordinated manipulations of outcome expectancy, ego-involvement and social evaluation. As expected, SBP responses assessed during the work period were proportional to clip evocativeness - i.e., the difficulty of the restraint challenge - when importance was high, but low regardless of clip evocativeness when importance was low. Findings conceptually replicate previous cardiovascular results and support extension of the guiding analysis to the behavioral restraint realm. PMID:26968495

  18. Here we go again: bullying history and cardiovascular responses to social exclusion.

    PubMed

    Newman, Matthew L

    2014-06-22

    Previous research suggests that social exclusion-both acute and chronic-may be associated with a pattern of blunted cardiovascular responding. But it is unknown to what extent acute and chronic exclusion interact. That is, what happens when victims of long-term social rejection encounter an instance of exclusion later in life? The goal of the present study was to test whether prior experience being bullied would alter cardiovascular responses to an acute experience of social exclusion. Participants took part in a short online chat, during which they were either included or excluded from the conversation. Consistent with hypotheses, all participants showed an increase in sympathetic activity in the exclusion condition, but this response was significantly blunted among those with more chronic history of bullying victimization. No differences were observed for parasympathetic activity. This pattern suggests that a history of chronic victimization magnifies the cardiovascular "blunting" shown previously among victims of ostracism. This line of work suggests that bullying victims may develop regulatory mechanisms in response to social threats, and this may ultimately provide valuable information for helping victims become more resilient.

  19. Gravitational effects on human cardiovascular responses to isometric muscle contractions

    NASA Astrophysics Data System (ADS)

    Bonde-Petersen, Flemmig; Suzuki, Yoji; Sadamoto, Tomoko

    Isometric exercise induces profound cardiovascular adaptations increasing mean arterial pressure and heart rate. We investigated effects of simulated +Gz and -Gz respectively on the central and peripheral cardiovascular system. Sustained handgrip exercise was performed at 40% of maximum for 2 minutes in five subjects. This maneuver increased mean arterial pressure by 40-45 mm Hg both during head out water immersion which simulates weightlessness, as well as bedrest during -25, 0, and +25 degrees tilt from the horizontal. Lower body negative pressure (-60 mm Hg for 10 min) attenuated the response to handgrip exercise to 30 mm Hg. It also increased the heart rate minimally by about 20 beats per minute while the water immersion, as well as head up, head down and horizontal bedrest showed increments of about 50 beats per min. It was concluded that the response to isometric contraction is mediated through the high pressure baroreceptors, because similar responses were seen during stresses producing a wide variation in central venous pressure. During lower body negative pressure the increased sympathetic nervous activity itself increased resting heart rate and mean arterial pressure. The responses to static exercise were, therefore, weaker.

  20. Endocrine alterations and cardiovascular risk in CKD: is there a link?

    PubMed

    Ros, Silvia; Carrero, Juan J

    2013-01-01

    The kidney plays an important role in synthesis, metabolism and elimination of a plethora of hormones. Thus, chronic kidney disease (CKD) naturally progresses with hormonal disorders. This review will focus in emerging evidence regarding the association between CKD-associated disturbances in the hypothalamic-pituitary-gonadal axis and cardiovascular risk factors. Hormonal derangements discussed are prolactin retention, testosterone deficiency and the low trioodothyronine syndrome, all of which have traditionally been interpreted as innocent bystanders of uremia and received relatively scarce attention by the Nephrology community. We here show that these disorders share intriguing links with inflammation, endothelial dysfunction, arterial stiffness, protein-energy wasting and other cardiometabolic alterations inherent to CKD-related excess mortality. We argue that these disorders may be novel uremic risk factors with possibility to serve as therapeutic targets.

  1. Cardiovascular alterations in Macaca monkeys exposed to stationary magnetic fields: experimental observations and theoretical analysis

    SciTech Connect

    Tenforde, T.S.; Gaffey, C.T.; Moyer, B.R.; Budinger, T.F.

    1983-01-01

    Simultaneous measurements were made of the electrocardiogram (ECG) and the intraarterial blood pressure of adult male Macaca monkeys during acute exposure to homogeneous stationary magnetic fields ranging in strength up to 1.5 tesla. An instantaneous, field strength-dependent increase in the ECG signal amplitude at the locus of the T wave was observed in fields greater than 0.1 tesla. The temporal sequence of this signal in the ECG record and its reversibility following termination of the magnetic field exposure are consistent with an earlier suggestion that it arises from a magnetically induced aortic blood flow potential superimposed on the native T-wave signal. No measurable alterations in blood pressure resulted from exposure to fields up to 1.5 tesla. This experimental finding is in agreement with theoretical calculations of the magnetohydrodynamic effect on blood flow in the major arteries of the cardiovascular system. 27 references, 1 figure, 1 table.

  2. Increased Klk9 Urinary Excretion Is Associated to Hypertension-Induced Cardiovascular Damage and Renal Alterations

    PubMed Central

    Blázquez-Medela, Ana M.; García-Sánchez, Omar; Quirós, Yaremi; Blanco-Gozalo, Victor; Prieto-García, Laura; Sancho-Martínez, Sandra M.; Romero, Miguel; Duarte, Juan M.; López-Hernández, Francisco J.; López-Novoa, José M.; Martínez-Salgado, Carlos

    2015-01-01

    Abstract Early detection of hypertensive end-organ damage and secondary diseases are key determinants of cardiovascular prognosis in patients suffering from arterial hypertension. Presently, there are no biomarkers for the detection of hypertensive target organ damage, most outstandingly including blood vessels, the heart, and the kidneys. We aimed to validate the usefulness of the urinary excretion of the serine protease kallikrein-related peptidase 9 (KLK9) as a biomarker of hypertension-induced target organ damage. Urinary, plasma, and renal tissue levels of KLK9 were measured by the Western blot in different rat models of hypertension, including angiotensin-II infusion, DOCA-salt, L-NAME administration, and spontaneous hypertension. Urinary levels were associated to cardiovascular and renal injury, assessed by histopathology. The origin of urinary KLK9 was investigated through in situ renal perfusion experiments. The urinary excretion of KLK9 is increased in different experimental models of hypertension in rats. The ACE inhibitor trandolapril significantly reduced arterial pressure and the urinary level of KLK9. Hypertension did not increase kidney, heart, liver, lung, or plasma KLK9 levels. Hypertension-induced increased urinary excretion of KLK9 results from specific alterations in its tubular reabsorption, even in the absence of overt nephropathy. KLK9 urinary excretion strongly correlates with cardiac hypertrophy and aortic wall thickening. KLK9 appears in the urine in the presence of hypertension as a result of subtle renal handling alterations. Urinary KLK9 might be potentially used as an indicator of hypertensive cardiac and vascular damage. PMID:26469898

  3. Cardiovascular responses to glucagon - Physiologic measurement by external recordings.

    NASA Technical Reports Server (NTRS)

    Byrne, M. J.; Pigott, V.; Spodick, D. H.

    1972-01-01

    Assessment by noninvasive polygraphic techniques of the cardiovascular responses of normal subjects to intravenous injections of glucagon and glucagon diluent. A blinding procedure which eliminated observer bias was used during the reading of tracings. Analysis of group results showed that glucagon provoked uniformly significant changes, including increase in heart rate, blood pressure, pressure-rate product, and ejection time index, and decrease in prejection period, mechanical and electromechanical systole, left ventricular ejection time, and the ratio PEP/LVET. The principal results correlated well with those of previous studies of the hemodynamic effects of glucagon.

  4. Exposure to Maternal Gestational Diabetes Is Associated With Higher Cardiovascular Responses to Stress in Adolescent Indians

    PubMed Central

    Veena, Sargoor R.; Jones, Alexander; Srinivasan, Krishnamachari; Osmond, Clive; Karat, Samuel C.; Kurpad, Anura V.; Fall, Caroline H. D.

    2015-01-01

    Context: Altered endocrinal and autonomic nervous system responses to stress may link impaired intra-uterine growth with later cardiovascular disease. Objective: To test the hypothesis that offspring of gestational diabetic mothers (OGDM) have high cortisol and cardiosympathetic responses during the Trier Social Stress Test for Children (TSST-C). Design: Adolescents from a birth cohort in India (n = 213; mean age, 13.5 y), including 26 OGDM, 22 offspring of diabetic fathers (ODF), and 165 offspring of nondiabetic parents (controls) completed 5 minutes each of public speaking and mental arithmetic tasks in front of two unfamiliar “evaluators” (TSST-C). Salivary cortisol concentrations were measured at baseline and at regular intervals after the TSST-C. Heart rate, blood pressure (BP), stroke volume, cardiac output, and total peripheral resistance were measured continuously at baseline, during the TSST-C, and for 10 minutes after the test using a finger cuff; the beat-to-beat values were averaged for these periods. Results: Cortisol and cardiosympathetic parameters increased from baseline during stress (P < .001). OGDM had greater systolic BP (mean difference, 5.6 mm Hg), cardiac output (0.5 L/min), and stroke volume (4.0 mL) increases and a lower total peripheral resistance rise (125 dyn · s/cm5) than controls during stress. ODF had greater systolic BP responses than controls (difference, 4.1 mm Hg); there was no difference in other cardiosympathetic parameters. Cortisol responses were similar in all three groups. Conclusions: Maternal diabetes during pregnancy is associated with higher cardiosympathetic stress responses in the offspring, which may contribute to their higher cardiovascular disease risk. Further research may confirm stress-response programming as a predictor of cardiovascular risk in OGDM. PMID:25478935

  5. Role of autonomic reflex arcs in cardiovascular responses to air pollution exposure.

    PubMed

    Perez, Christina M; Hazari, Mehdi S; Farraj, Aimen K

    2015-01-01

    The body responds to environmental stressors by triggering autonomic reflexes in the pulmonary receptors, baroreceptors, and chemoreceptors to maintain homeostasis. Numerous studies have shown that exposure to various gases and airborne particles can alter the functional outcome of these reflexes, particularly with respect to the cardiovascular system. Modulation of autonomic neural input to the heart and vasculature following direct activation of sensory nerves in the respiratory system, elicitation of oxidative stress and inflammation, or through other mechanisms is one of the primary ways that exposure to air pollution affects normal cardiovascular function. Any homeostatic process that utilizes the autonomic nervous system to regulate organ function might be affected. Thus, air pollution and other inhaled environmental irritants have the potential to alter both local airway function and baro- and chemoreflex responses, which modulate autonomic control of blood pressure and detect concentrations of key gases in the body. While each of these reflex pathways causes distinct responses, the systems are heavily integrated and communicate through overlapping regions of the brainstem to cause global effects. This short review summarizes the function of major pulmonary sensory receptors, baroreceptors, and carotid body chemoreceptors and discusses the impacts of air pollution exposure on these systems.

  6. The cardiovascular response to passive movement is joint dependent.

    PubMed

    Burns, Keith J; Pollock, Brandon S; McDaniel, John

    2016-03-01

    The cardiovascular responses to passive limb movement (PLM) at the knee are well established, however, responses to PLM at other joints involving smaller muscle volume are unknown. To compare the cardiovascular responses to passive movement at other joints, 10 participants underwent a PLM protocol in which the wrist, elbow, ankle, and knee joints were passively extended and flexed at 1 Hz for 1 min. Heart rate (HR), mean arterial blood pressure (MAP), and arterial blood flow to that limb segment (BF) were measured and vascular conductance (VC) was calculated for a 30-sec baseline period and for 3-sec intervals throughout PLM protocols. PLM of the knee and elbow resulted in significant increases in BF and VC from baseline values with peak values 180% (P < 0.001) greater than baseline. PLM of the elbow resulted in significant increases in BF and VC from baseline values with peak values 109% and 115% (P < 0.001) greater than baseline, respectively. No changes in BF and VC were observed in the ankle and wrist. Furthermore, the greater increase in blood flow per limb segment volume in the thigh and upper arm (62.8 ± 36.5 and 55.5 ± 30.3 mL min(-1) L(-1), respectively) compared to the forearm and lower leg (23.6 ± 16.7 and 19.1 ± 10.3 mL min(-1) L(-1), respectively) indicates the limb volume is not solely responsible for the differences in the hyperemic responses. These data indicate that the use of PLM to assess vascular function or as a rehabilitation modality to maintain vascular health may be most appropriate for the muscles that span the elbow and knee.

  7. Increased cardiovascular response to static contraction of larger muscle groups.

    PubMed

    Seals, D R; Washburn, R A; Hanson, P G; Painter, P L; Nagle, F J

    1983-02-01

    The purpose of this study was to investigate the influence of the size of the active muscle mass on the cardiovascular response to static contraction. Twelve male subjects performed one-arm handgrip (HG), two-leg extension (LE), and a "dead-lift" maneuver (DL) in a randomly assigned order for 3 min at 30% of maximal voluntary contraction. O2 uptake (VO2), heart rate (HR), and mean intra-arterial blood pressure (MABP) were measured at rest and, in addition to absolute tension exerted, throughout contraction. There was a direct relationship between the size of the active muscle mass and the magnitude of the increases in VO2, HR, and MABP, even though all contractions were performed at the same relative intensity. Tension, VO2, HR, and MABP increased progressively from HG to LE to DL. It was concluded that at the same percentage of maximal voluntary contraction, the magnitude of the cardiovascular response to isometric exercise is directly influenced by the size of the contracting muscle mass.

  8. Cardiovascular response to static contraction in borderline hypertension.

    PubMed

    Seals, D R; Hanson, P G; Washburn, R A; Painter, P L; Ward, A; Nagle, F J

    1985-06-01

    Nine young males with borderline hypertension (BH) (mean age +/- SD, 25 +/- 5 yr) and 13 young male normotensive controls (NT) (24 +/- 3 yr) were studied to determine their cardiovascular responses to small and large muscle static contractions. The subjects performed one-arm handgrip and two-leg extension in a randomly assigned order for 3 min at 30% of maximal voluntary contraction. Mean intra-arterial blood pressure (MABP), heart rate (HR), and tension were measured throughout the contractions. Borderline hypertensive patients had a higher MABP at rest (p less than 0.005) and at the end of both types of static contractions (p less than 0.05). The average increases in MABP from rest to the end of exercise (delta MABP) were slightly greater for the BH patients (6 mmHg), but these differences were not significant (p greater than 0.1). However, a greater percentage of BH patients were hyperreactive to handgrip (delta BP greater than 35 mmHg) and leg extension (delta BP greater than 40 mmHg) when compared to controls. These data indicate that, in general, young men with borderline hypertension demonstrate normal cardiovascular regulation in response to static contraction, but that a portion of this population may be hyperreactive to this type of circulatory stress.

  9. Test anxiety and cardiovascular responses to daily academic stressors.

    PubMed

    Conley, Kristen M; Lehman, Barbara J

    2012-02-01

    Routine academic events may cause stress and produce temporary elevations in blood pressure. Students who experience test anxiety may be especially prone to cardiovascular activation in response to academic stress. This study drew on self-reported stress and ambulatory blood pressure measurements provided by 99 undergraduate participants (30% men, mean age=21 years) who participated over 4 days. Posture, activity level, recent consumption and the previous same-day reading were considered as covariates in a series of hierarchical linear models. Results indicate elevations in systolic blood pressure at times of acute academic stressors; neither diastolic blood pressure nor heart rate was linked with academic stress. In addition, those participants higher in test anxiety exhibited especially pronounced elevations in systolic blood pressure during times of acute academic stress. This research suggests that everyday academic stressors are linked with temporary increases in blood pressure and that test anxiety may contribute to these elevations. Test anxiety has implications for future academic and job success, and cardiovascular responses to everyday stress may contribute to health problems later in life.

  10. Type A behavior, personality hardiness, and cardiovascular responses to stress.

    PubMed

    Contrada, R J

    1989-11-01

    Type A behavior and hardiness were examined as predictors of cardiovascular responses to stress in 68 male undergraduates. Systolic and diastolic blood pressure (SBP and DBP) and heart rate were monitored while subjects performed a difficult mirror-tracing task. Type A assessments based on the Structured Interview, but not those based on the Jenkins Activity Survey, were associated with significantly enhanced SBP and DBP elevations. Hardiness was associated with significantly reduced DBP responsiveness. In addition, a significant interaction indicated that the Type B-high hardiness group showed the least DBP reactivity. A near-significant interaction (p = .06) suggested that Type B-high hardiness subjects also reported the least anger. Further exploration of the data indicated that the challenge component of hardiness accounted for its relationship to DBP reactivity. These results have implications both for the psychophysiologic study of Type A behavior and for understanding the health-promoting effects of hardiness.

  11. Oral Cannabidiol does not Alter the Subjective, Reinforcing or Cardiovascular Effects of Smoked Cannabis.

    PubMed

    Haney, Margaret; Malcolm, Robert J; Babalonis, Shanna; Nuzzo, Paul A; Cooper, Ziva D; Bedi, Gillinder; Gray, Kevin M; McRae-Clark, Aimee; Lofwall, Michelle R; Sparenborg, Steven; Walsh, Sharon L

    2016-07-01

    Cannabidiol (CBD), a constituent of cannabis with few psychoactive effects, has been reported in some studies to attenuate certain aspects of Δ(9)-tetrahydrocannabinol (THC) intoxication. However, most studies have tested only one dose of CBD in combination with one dose of oral THC, making it difficult to assess the nature of this interaction. Further, the effect of oral CBD on smoked cannabis administration is unknown. The objective of this multi-site, randomized, double-blind, within-subject laboratory study was to assess the influence of CBD (0, 200, 400, 800 mg, p.o.) pretreatment on the reinforcing, subjective, cognitive, and physiological effects of smoked cannabis (0.01 (inactive), 5.30-5.80% THC). Non-treatment-seeking, healthy cannabis smokers (n=31; 17M, 14 F) completed eight outpatient sessions. CBD was administered 90 min prior to cannabis administration. The behavioral and cardiovascular effects of cannabis were measured at baseline and repeatedly throughout the session. A subset of participants (n=8) completed an additional session to measure plasma CBD concentrations after administration of the highest CBD dose (800 mg). Under placebo CBD conditions, active cannabis (1) was self-administered by significantly more participants than placebo cannabis and (2) produced significant, time-dependent increases in ratings of 'High', 'Good Effect', ratings of the cannabis cigarette (eg, strength, liking), and heart rate relative to inactive cannabis. CBD, which alone produced no significant psychoactive or cardiovascular effects, did not significantly alter any of these outcomes. Cannabis self-administration, subjective effects, and cannabis ratings did not vary as a function of CBD dose relative to placebo capsules. These findings suggest that oral CBD does not reduce the reinforcing, physiological, or positive subjective effects of smoked cannabis. PMID:26708108

  12. Altered cardiovascular autonomic regulation in overweight children engaged in regular physical activity.

    PubMed

    Lucini, Daniela; de Giacomi, Gaia; Tosi, Fabio; Malacarne, Mara; Respizzi, Stefano; Pagani, Massimo

    2013-03-01

    Overweight (OW) and obesity in children are important forerunners of cardiovascular risk, possibly through autonomic nervous system (ANS) dysregulation, while physical exercise exerts a beneficial influence. In this observational study we hypothesise that OW might influence ANS profile even in a population performing high volume of supervised exercise. We study 103 young soccer players, homogeneous in terms of gender (all male), cultural background, school, age (11.2 ± 1 years) and exercise routine, since they all belong to the same soccer club, thus guaranteeing equality of supervised training and similar levels of competitiveness. ANS is evaluated by autoregressive spectral analysis of heart rate and systolic arterial pressure (SAP) variabilities. We estimate also the accumulated weekly Metabolic Equivalents and time spent in sedentary activities. We subdivide the entire population in two subgroups (normal weight and OW) based on the International Obesity Task Force criteria. In OW soccer players (10.7% of total group) we observe an altered profile of autonomic cardiovascular regulation, characterised by higher values of SAP (113 ± 4 vs 100 ± 1 mm Hg, 39.7 ± 3 vs 66.2 ± 10%), higher Low Frequency variability power of SAP (an index of vasomotor sympathetic regulation) (12 ± 3 vs 4.5 mm Hg(2)) and smaller spontaneous baroreflex gain (an index of cardiac vagal regulation) (19 ± 3 vs 33 ± 3 ms/mm Hg) (all (p < 0.02)). Moreover Correlation analysis on the entire study population shows a significant link between anthropometric and autonomic indices. These data show that OW is associated to a clear autonomic impairment even in children subjected to an intense aerobic training. PMID:23086975

  13. Hybridization among divergent stocks of largemouth bass (Micropterus salmoides) results in altered cardiovascular performance: the influence of genetic and geographic distance.

    PubMed

    Cooke, S J; Philipp, D P

    2006-01-01

    Animal populations exhibit wide ranges of divergence associated with both geographic and genetic distances. Here, we examined the role of crossing distance on the cardiovascular response to exhaustive exercise among differentiated stocks of largemouth bass Micropterus salmoides at 10 degrees C and 20 degrees C. Stocks of 2+ fish were produced using adults from three regions in the midwestern United States (southeastern Wisconsin, northwestern Wisconsin, and west central Minnesota) and were crossed with fish from central Illinois. Doppler flow probes were used to quantify cardiac output, heart rate, and stroke volume. Cardiac variables (both resting and maximal) were consistently lowest in pure Illinois fish relative to the F(1) interstock hybrids. Additionally, when exposed to exercise, cardiac variables for F(1) interstock hybrids required approximately 40% longer to return to resting levels compared with the pure Illinois stock. However, the time required to exhaust fish was similar across stocks. Interestingly, all of the stocks (including the interstock hybrids and pure Illinois) maintained cardiac scope. In general, the patterns observed in cardiovascular performance were consistent for both water temperatures. Multiple regression analysis was used to determine which of the divergence metrics contributed to variation in cardiovascular performance in interstock hybrids. Mitochondrial DNA data (genetic distance) were infrequently identified as a significant source of variation in cardiovascular performance. However, genetic distance data for the neutral allozyme markers revealed that these stocks have experienced significant divergence. Latitude (geographic distance) accounted for between 31% and 45% of variation observed in the recovery parameters. This study suggests that the magnitude of stock divergence is an important determinant in the degree to which cardiovascular performance of bass is altered from interstock hybridization and associated breakdown of

  14. Plasticity of cardiovascular function in snapping turtle embryos (Chelydra serpentina): chronic hypoxia alters autonomic regulation and gene expression.

    PubMed

    Eme, John; Rhen, Turk; Tate, Kevin B; Gruchalla, Kathryn; Kohl, Zachary F; Slay, Christopher E; Crossley, Dane A

    2013-06-01

    Reptile embryos tolerate large decreases in the concentration of ambient oxygen. However, we do not fully understand the mechanisms that underlie embryonic cardiovascular short- or long-term responses to hypoxia in most species. We therefore measured cardiac growth and function in snapping turtle embryos incubated under normoxic (N21; 21% O₂) or chronic hypoxic conditions (H10; 10% O₂). We determined heart rate (fH) and mean arterial pressure (Pm) in acute normoxic (21% O₂) and acute hypoxic (10% O₂) conditions, as well as embryonic responses to cholinergic, adrenergic, and ganglionic pharmacological blockade. Compared with N21 embryos, chronic H10 embryos had smaller bodies and relatively larger hearts and were hypotensive, tachycardic, and following autonomic neural blockade showed reduced intrinsic fH at 90% of incubation. Unlike other reptile embryos, cholinergic and ganglionic receptor blockade both increased fH. β-Adrenergic receptor blockade with propranolol decreased fH, and α-adrenergic blockade with phentolamine decreased Pm. We also measured cardiac mRNA expression. Cholinergic tone was reduced in H10 embryos, but cholinergic receptor (Chrm2) mRNA levels were unchanged. However, expression of adrenergic receptor mRNA (Adrb1, Adra1a, Adra2c) and growth factor mRNA (Igf1, Igf2, Igf2r, Pdgfb) was lowered in H10 embryos. Hypoxia altered the balance between cholinergic receptors, α-adrenoreceptor and β-adrenoreceptor function, which was reflected in altered intrinsic fH and adrenergic receptor mRNA levels. This is the first study to link gene expression with morphological and cardioregulatory plasticity in a developing reptile embryo. PMID:23552497

  15. Captive European starlings (Sturnus vulgaris) in breeding condition show an increased cardiovascular stress response to intruders.

    PubMed

    Dickens, Molly J; Nephew, Benjamin C; Romero, L Michael

    2006-01-01

    European starlings (Sturnus vulgaris) alter their physiology and behavior between seasons, becoming territorial during the spring/summer and flocking during the fall/winter. We used captive male starlings in breeding (photostimulated to 18L : 6D) and nonbreeding (11L : 13D) conditions to determine whether changing physiology and behavior alters their reaction to crowding. One or five intruders entered a resident's cage without human disturbance. A subcutaneous heart rate transmitter recorded cardiovascular output in residents. Corticosterone and testosterone were measured in plasma samples taken before and after the intrusion. While corticosterone concentrations did not change, heart rate changed significantly, indicating that these responses can be regulated independently. Long-day birds showed a significantly elevated heart rate response to the single-bird intrusion compared to short-day birds. Whereas five intruders elicited an identical peak response in both groups, long-day birds also demonstrated an equivalent response to one intruder. In addition, one intruder induced longer elevation in heart rate for long-day birds. Male starlings in breeding condition, therefore, demonstrate an increased sensitivity to additional conspecifics. This seasonal shift in response suggests that a higher tolerance for intrusion (i.e., considering a nearby starling as less stressful) may facilitate flocking behavior, while a lower tolerance may aid in territoriality. PMID:16927240

  16. Kalpaamruthaa ameliorates mitochondrial and metabolic alterations in diabetes mellitus induced cardiovascular damage.

    PubMed

    Latha, Raja; Shanthi, Palanivelu; Sachdanandam, Panchanadham

    2014-12-01

    Efficacy of Kalpaamruthaa on the activities of lipid and carbohydrate metabolic enzymes, electron transport chain complexes and mitochondrial ATPases were studied in heart and liver of experimental rats. Cardiovascular damage (CVD) was developed in 8 weeks after type 2 diabetes mellitus induction with high fat diet (2 weeks) and low dose of streptozotocin (2 × 35 mg/kg b.w. i.p. in 24 hr interval). In CVD-induced rats, the activities of total lipase, cholesterol ester hydrolase and cholesterol ester synthetase were increased, while lipoprotein lipase and lecithin-cholesterol acyltransferase activities were decreased. The activities of lipid-metabolizing enzymes were altered by Kalpaamruthaa in CVD-induced rats towards normal. Kalpaamruthaa modulated the activities of glycolytic enzymes (hexokinase, phosphogluco-isomerase, aldolase and glucose-6-phosphate dehydrogenase), gluconeogenic enzymes (glucose-6-phosphatase and fructose-1, 6-bisphosphatase) and glycogenolytic enzyme (glycogen phosphorylase) along with increased glycogen content in the liver of CVD-induced rats. The activities of isocitrate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, α-ketoglutarate dehydrogenase, Complexes and ATPases (Na(+)/K(+)-ATPase, Ca(2+)-ATPase and Mg(2+)-ATPase) were decreased in CVD-induced rats, which were ameliorated by the treatment with Kalpaamruthaa. This study ascertained the efficacy of Kalpaamruthaa for the treatment of CVD in diabetes through the modulation of metabolizing enzymes and mitochondrial dysfunction. PMID:24552274

  17. Cardiovascular alterations after injection of 2% lidocaine with norepinephrine 1:50,000 (xylestesin) in rats.

    PubMed

    Faraco, Fatima Neves; Armonia, Paschoal Laercio; Malamed, Stanley F

    2007-01-01

    The purpose of the present study is to determine the cardiovascular effects produced by intravascular injection of 2% lidocaine with 20 microg/mL of norepinephrine on systolic, diastolic, and mean arterial pressures and heart rate of rats at the following times: control period, during the injection (first 15 seconds), during the first minute, and at the end of 1, 2, 3, 4, 5, 10, 15, 20, 25, and 30 minutes after drug administration. The study was performed on 13 male Wistar rats with weights between 200 grams and 220 grams that were awake during the recording of these parameters. The dose administered was proportional to 1 cartridge of local anesthetic (1.8 mL) in an average-size human, which is equivalent to 0.51 mg/kg of lidocaine hydrochloride and 0.51 microg/kg of norepinephrine hydrochloride. The average time of injection was 15.7 seconds. The results of this study showed significant increases in systolic, diastolic, and mean arterial pressure and a noticeable decrease in heart rate. The greatest variation occurred in the systolic blood pressure. The greatest alterations occurred during injection and within the first minute following administration of the anesthetic solution. We would anticipate these changes in the parameters analyzed to be clinically significant. Thus, dentists using 2% lidocaine with norepinephrine 20 mug/mL should be very careful to avoid intravascular injection.

  18. Cardiovascular Alterations After Injection of 2% Lidocaine With Norepinephrine 1:50,000 (Xylestesin) in Rats

    PubMed Central

    Faraco, Fatima Neves; Armonia, Paschoal Laercio; Malamed, Stanley F

    2007-01-01

    The purpose of the present study is to determine the cardiovascular effects produced by intravascular injection of 2% lidocaine with 20 μg/mL of norepinephrine on systolic, diastolic, and mean arterial pressures and heart rate of rats at the following times: control period, during the injection (first 15 seconds), during the first minute, and at the end of 1, 2, 3, 4, 5, 10, 15, 20, 25, and 30 minutes after drug administration. The study was performed on 13 male Wistar rats with weights between 200 grams and 220 grams that were awake during the recording of these parameters. The dose administered was proportional to 1 cartridge of local anesthetic (1.8 mL) in an average-size human, which is equivalent to 0.51 mg/kg of lidocaine hydrochloride and 0.51 μg/kg of norepinephrine hydrochloride. The average time of injection was 15.7 seconds. The results of this study showed significant increases in systolic, diastolic, and mean arterial pressure and a noticeable decrease in heart rate. The greatest variation occurred in the systolic blood pressure. The greatest alterations occurred during injection and within the first minute following administration of the anesthetic solution. We would anticipate these changes in the parameters analyzed to be clinically significant. Thus, dentists using 2% lidocaine with norepinephrine 20 μg/mL should be very careful to avoid intravascular injection. PMID:17579502

  19. Kalpaamruthaa ameliorates mitochondrial and metabolic alterations in diabetes mellitus induced cardiovascular damage.

    PubMed

    Latha, Raja; Shanthi, Palanivelu; Sachdanandam, Panchanadham

    2014-12-01

    Efficacy of Kalpaamruthaa on the activities of lipid and carbohydrate metabolic enzymes, electron transport chain complexes and mitochondrial ATPases were studied in heart and liver of experimental rats. Cardiovascular damage (CVD) was developed in 8 weeks after type 2 diabetes mellitus induction with high fat diet (2 weeks) and low dose of streptozotocin (2 × 35 mg/kg b.w. i.p. in 24 hr interval). In CVD-induced rats, the activities of total lipase, cholesterol ester hydrolase and cholesterol ester synthetase were increased, while lipoprotein lipase and lecithin-cholesterol acyltransferase activities were decreased. The activities of lipid-metabolizing enzymes were altered by Kalpaamruthaa in CVD-induced rats towards normal. Kalpaamruthaa modulated the activities of glycolytic enzymes (hexokinase, phosphogluco-isomerase, aldolase and glucose-6-phosphate dehydrogenase), gluconeogenic enzymes (glucose-6-phosphatase and fructose-1, 6-bisphosphatase) and glycogenolytic enzyme (glycogen phosphorylase) along with increased glycogen content in the liver of CVD-induced rats. The activities of isocitrate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, α-ketoglutarate dehydrogenase, Complexes and ATPases (Na(+)/K(+)-ATPase, Ca(2+)-ATPase and Mg(2+)-ATPase) were decreased in CVD-induced rats, which were ameliorated by the treatment with Kalpaamruthaa. This study ascertained the efficacy of Kalpaamruthaa for the treatment of CVD in diabetes through the modulation of metabolizing enzymes and mitochondrial dysfunction.

  20. Effect of hindlimb suspension on cardiovascular responses to sympathomimetics and lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Overton, J. Michael; Tipton, Charles M.

    1990-01-01

    To determine whether hindlimb suspension is associated with the development of cardiovascular deconditioning, male rats were studied before and after undergoing one of three treatment conditions for 9 days: (1) cage control (n = 15, CON), (2) horizontal suspension (n = 15, HOZ), and (3) head-down suspension (n = 18, HDS). Testing included lower body negative pressure administered during chloralose-urethan anesthesia and graded doses of sympathomimetic agents (norepinephrine, phenylephrine, and tyramine) administered to conscious unrestrained animals. Both HDS and HOZ were associated with a small decrease in the hypotensive response to lower body negative pressure. The HOZ group, but not the HDS group, exhibited augmented reflex tachycardia. Furthermore, both HDS and HOZ groups manifested reduced pressor responses to phenylephrine after treatment. These reductions were associated with significantly attenuated increases in mesenteric vascular resistance. However, baroreflex control of heart rate was not altered by the treatment conditions. Collectively, these results indicate that 9 days of HDS in rats does not elicit hemodynamic response patterns generally associated with cardiovascular deconditioning induced by hypogravic conditions.

  1. Essential Hypertension: Cardiovascular Response to Breath Hold Combined with Exercise.

    PubMed

    Hoffmann, U; Urban, P; Koschate, J; Drescher, U; Pfister, R; Michels, G

    2015-07-01

    Essential hypertension (EH) is a widespread disease and might be prevalent in apnea divers and master athletes. Little is known about the influence of EH and the antihypertensive drugs (AHD) on cardiovascular reactions to combined breath hold (BH) and exercise. In this pilot study, healthy divers (HCON) were compared with treated hypertensive divers with regard to heart rate (HR) and mean blood-pressure (MAP) responses to BH, exercise and the combination of both. Ten subjects with EH and ten healthy divers were tested. 3 different 20 s stimuli were applied: BH combined with 30 W or 150 W and 150 W without BH. The time-charts during the stress intervals and during recovery were compared. Subjects treated with an angiotensin-converting enzyme (ACE) inhibitor showed higher changes for MAP values if breath hold was performed. HR responses were obviously changed if a β-blocker was part of the medication. One subject showed extreme MAP responses to all stimuli and conspicuous HR if BH was involved. The modulation of HR-/MAP-response in EH subjects depends on the mechanisms of antihypertensive agents. The combination of an ACE inhibitor and a β-blocker may give the best protection. It is recommended to include short apnea tests in the fitness-to-dive examination to individually predict potential endangerment. PMID:25875316

  2. Autonomic cardiovascular responses to smoke exposure in conscious rats

    SciTech Connect

    Nakamura, T.; Hayashida, Y. )

    1992-05-01

    Autonomic cardiovascular responses and the change in renal sympathetic nerve activity (RSNA) in response to smoke exposure were investigated in unrestrained conscious rats. Smoke exposure caused a prominent increase in RSNA (to 557.3 +/- 221.9% of the control level) and plasma norepinephrine (from 0.18 +/- 0.08 (control) to 0.66 +/- 0.22 ng/ml (at peak response of smoke exposure)), a slight increase in arterial blood pressure (from 89.6 +/- 3.3 to 103.6 +/- 3.8 mmHg), and marked bradycardia (from 386.6 +/- 12.8 to 231.3 +/- 20.6 beats/min). Respiratory rate in conscious rats was initially increased (from 1.6 +/- 0.1 to 6.1 +/- 0.3 breaths/s) but was decreased (to 0.9 +/- 0.1 breaths/s) at the peak phase of the cardiovascular responses to smoke inhalation. Blood gases and pH reflected these changes in respiratory rate to some extent. Sinoaortic denervation did not attenuate the bradycardia (from 402 +/- 17.5 to 255.8 +/- 16.2 beats/min) or increase in RSNA (to 413.4 +/- 74.9%) that occurred during smoke inhalation. Atropine sulfate abolished the bradycardic response (from 440.4 +/- 13.8 to 485.4 +/- 8.6 beats/min). Initial tachypnea was also observed in both sinoaortic denervated rats and atropine-treated rats. Anesthesia, induced by pentobarbital sodium (30 mg/kg iv) or alpha-chloralose (65 mg/kg iv), abolished the bradycardia, the increase in RSNA, and the change in respiratory rate caused by smoke exposure. Ablation of the olfactory lobes also greatly attenuated the smoke-induced increase in RSNA (to 150.9 +/- 22.9%), bradycardia (from 372.9 +/- 19.6 to 376.3 +/- 24.1 beats/min), and the respiratory change.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Divergent Associations of Antecedent- and Response-Focused Emotion Regulation Strategies with Midlife Cardiovascular Disease Risk

    PubMed Central

    Loucks, Eric B.; Buka, Stephen L.; Kubzansky, Laura D.

    2014-01-01

    Background It is not known whether various forms of emotion regulation are differentially related to cardiovascular disease risk. Purpose The purpose of this study is to assess whether antecedent and response-focused emotion regulation would have divergent associations with likelihood of developing cardiovascular disease. Methods Two emotion regulation strategies were examined: reappraisal (antecedent-focused) and suppression (response-focused). Cardiovascular disease risk was assessed with a validated Framingham algorithm that estimates the likelihood of developing CVD in 10 years. Associations were assessed among 373 adults via multiple linear regression. Pathways and gender-specific associations were also considered. Results One standard deviation increases in reappraisal and suppression were associated with 5.9 % lower and 10.0 % higher 10-year cardiovascular disease risk, respectively, in adjusted analyses. Conclusions Divergent associations of antecedent and response-focused emotion regulation with cardiovascular disease risk were observed. Effective emotion regulation may promote cardiovascular health. PMID:24570218

  4. Effects of thyroid hormone on. beta. -adrenergic responsiveness of aging cardiovascular systems

    SciTech Connect

    Tsujimoto, G.; Hashimoto, K.; Hoffman, B.B.

    1987-03-01

    The authors have compared the effects of ..beta..-adrenergic stimulation on the heart and peripheral vasculature of young (2-mo-old) and older (12-mo-old) rats both in the presence and absence of triiodothyronine (T/sub 3/)-induced hyperthyroidism. The hemodynamic consequences of T/sub 3/ treatment were less prominent in the aged hyperthyroid rats compared with young hyperthyroid rats (both in intact and pithed rats). There was a decrease in sensitivity of chronotropic responsiveness to isoproterenol in older pithed rats, which was apparently reversed by T/sub 3/ treatment. The number and affinity of myocardial ..beta..-adrenergic receptor sites measured by (/sup 125/I)cyanopindolol were not significantly different in young and older control rats; also, ..beta..-receptor density increased to a similar extent in both young and older T/sub 3/-treated rats. The ability of isoproterenol to relax mesenteric arterial rings, markedly blunted in older rats, was partially restored by T/sub 3/ treatment without their being any change in isoproterenol-mediated relaxation in the arterial preparation from young rats. The number and affinity of the ..beta..-adrenergic receptors measured in the mesenteric arteries was unaffected by either aging or T/sub 3/ treatment. The data suggest that effects of thyroid hormone and age-related alterations of cardiovascular responsiveness to ..beta..-adrenergic stimulation are interrelated in a complex fashion with a net result that the hyperkinetic cardiovascular manifestations in hyperthyroidism are attenuated in the older animals.

  5. Metabolic and Cardiovascular Response to Shallow Water Exercise in Young and Older Women.

    ERIC Educational Resources Information Center

    Campbell, Jennifer A.; D'Acquisto, Leo J.; D'Acquisto, Debra M.; Cline, Michael G.

    2003-01-01

    Compared the metabolic and cardiovascular responses of young and older women while performing shallow water exercise (SWE). Overall, SWE elicited metabolic and cardiovascular responses that met American College of Sports Medicine's guidelines for establishing health benefits. Older females self-selected a greater relative exercise intensity during…

  6. Epigenetic transgenerational inheritance of altered stress responses.

    PubMed

    Crews, David; Gillette, Ross; Scarpino, Samuel V; Manikkam, Mohan; Savenkova, Marina I; Skinner, Michael K

    2012-06-01

    Ancestral environmental exposures have previously been shown to promote epigenetic transgenerational inheritance and influence all aspects of an individual's life history. In addition, proximate life events such as chronic stress have documented effects on the development of physiological, neural, and behavioral phenotypes in adulthood. We used a systems biology approach to investigate in male rats the interaction of the ancestral modifications carried transgenerationally in the germ line and the proximate modifications involving chronic restraint stress during adolescence. We find that a single exposure to a common-use fungicide (vinclozolin) three generations removed alters the physiology, behavior, metabolic activity, and transcriptome in discrete brain nuclei in descendant males, causing them to respond differently to chronic restraint stress. This alteration of baseline brain development promotes a change in neural genomic activity that correlates with changes in physiology and behavior, revealing the interaction of genetics, environment, and epigenetic transgenerational inheritance in the shaping of the adult phenotype. This is an important demonstration in an animal that ancestral exposure to an environmental compound modifies how descendants of these progenitor individuals perceive and respond to a stress challenge experienced during their own life history.

  7. Computational modeling of cardiovascular response to orthostatic stress

    NASA Technical Reports Server (NTRS)

    Heldt, Thomas; Shim, Eun B.; Kamm, Roger D.; Mark, Roger G.

    2002-01-01

    The objective of this study is to develop a model of the cardiovascular system capable of simulating the short-term (< or = 5 min) transient and steady-state hemodynamic responses to head-up tilt and lower body negative pressure. The model consists of a closed-loop lumped-parameter representation of the circulation connected to set-point models of the arterial and cardiopulmonary baroreflexes. Model parameters are largely based on literature values. Model verification was performed by comparing the simulation output under baseline conditions and at different levels of orthostatic stress to sets of population-averaged hemodynamic data reported in the literature. On the basis of experimental evidence, we adjusted some model parameters to simulate experimental data. Orthostatic stress simulations are not statistically different from experimental data (two-sided test of significance with Bonferroni adjustment for multiple comparisons). Transient response characteristics of heart rate to tilt also compare well with reported data. A case study is presented on how the model is intended to be used in the future to investigate the effects of post-spaceflight orthostatic intolerance.

  8. Computational modeling of cardiovascular response to orthostatic stress.

    PubMed

    Heldt, Thomas; Shim, Eun B; Kamm, Roger D; Mark, Roger G

    2002-03-01

    The objective of this study is to develop a model of the cardiovascular system capable of simulating the short-term (< or = 5 min) transient and steady-state hemodynamic responses to head-up tilt and lower body negative pressure. The model consists of a closed-loop lumped-parameter representation of the circulation connected to set-point models of the arterial and cardiopulmonary baroreflexes. Model parameters are largely based on literature values. Model verification was performed by comparing the simulation output under baseline conditions and at different levels of orthostatic stress to sets of population-averaged hemodynamic data reported in the literature. On the basis of experimental evidence, we adjusted some model parameters to simulate experimental data. Orthostatic stress simulations are not statistically different from experimental data (two-sided test of significance with Bonferroni adjustment for multiple comparisons). Transient response characteristics of heart rate to tilt also compare well with reported data. A case study is presented on how the model is intended to be used in the future to investigate the effects of post-spaceflight orthostatic intolerance. PMID:11842064

  9. Ultrastructural alterations in allylamine cardiovascular toxicity. Late myocardial and vascular lesions.

    PubMed Central

    Boor, P. J.; Ferrans, V. J.

    1985-01-01

    The late myocardial and vascular ultrastructural changes in rat hearts following consumption of the cardiovascular toxin allylamine were studied. Rats were given 0.1% allylamine HCl in drinking water for 10-104 days. From 10 to 21 days, there was organization of acute myocardial necrosis by macrophages and scattered polymorphonuclear leukocytes with prominent interstitial-cell proliferation. Alterations at 21-104 days included extensive scarring with formation of dense mature collagen with scattered fibroblasts present, grossly evident left-ventricular aneurysm, and gross and microscopic changes similar to those observed in the secondary form of endocardial fibroelastosis. Areas of scar contained highly cellular foci of smooth-muscle cells, myofibroblasts, and abundant extracellular elastin. Cardiac myocytes frequently showed markedly disorganized myofilaments, bizarrely distorted mitochondria with condensed cristae, and other severe degenerative changes. Small vessels within and adjacent to scar showed proliferation of intimal smooth-muscle cells. Endothelial lesions or recent or organized thrombi were not seen. Focal endocardial metaplasia, consisting of both chondroid and osseous tissue, was found in areas of transmural scarring, or ventricular aneurysm. Chondrocytes had the overall nuclear and cellular morphology, abundant rough endoplasmic reticulum, and surrounding lacunae typical of mature fibrocartilage. In some areas, the collagen matrix was undergoing calcification with the typical cross-banded pattern of calcifying connective tissue. Osteocytes were located in a densely calcified bone matrix and displayed characteristic cellular extensions into surrounding canaliculi. These findings indicate a severe myocardial, small-vessel, and endocardial injury during the course of chronic allylamine intoxication. Images Figure 13 Figure 14 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 15 Figure

  10. Microemboli alter the acute stress response and cause prolonged expression of MCP-1 in the hippocampus.

    PubMed

    Nemeth, Christina L; Neigh, Gretchen N

    2015-04-01

    Microvascular ischemia is linked to cardiovascular disease pathology, as well as alterations in mood and cognition. Ischemia activates the hypothalamic-pituitary-adrenal (HPA) axis and through chronic activation, alters HPA axis function. Dysregulation of the HPA axis can lead to the chronic release of glucocorticoids, a hyper-inflammatory cerebral response, cell damage, and changes in behavior. Although the interactions between injury and HPA axis activity have been established in global ischemia, HPA-related repercussions of diffuse ischemic damage and subsequent inflammation have not been assessed. The current study used a rat model of microsphere embolism (ME) ischemia to test the hypothesis that microvascular ischemia would lead to long term alterations in HPA axis function and inflammatory activity. Furthermore, given the pro-inflammatory nature of chronic stress, we assessed the implications of chronic stress for gene expression of inflammatory factors and key components of the glucocorticoid receptor response, following microvascular ischemia. Results indicated that ME altered the response to an acute stress fourteen days following ME injury and increased hippocampal expression of monocyte chemoattractant protein 1 (Mcp-1) as long as 4 weeks following ME injury, without concomitant effects on gene expression of the glucocorticoid receptor or its co-chaperones. Furthermore, no exacerbative effects of chronic stress exposure were observed following ME injury beyond the effects of ME injury alone. Together, these results indicate that ME injury is sufficient to alter both HPA axis activity and cerebral inflammation for a prolonged period of time following injury.

  11. Endothelial cell injury in cardiovascular surgery: the procoagulant response.

    PubMed

    Boyle, E M; Verrier, E D; Spiess, B D

    1996-11-01

    The vascular endothelium plays a critical role in the regulation of coagulation through the constitutive expression and release of anticoagulants and the inducible expression of procoagulant substances. Cardiopulmonary bypass dysregulates this process by activating endothelial cells, initially promoting bleeding and then thrombosis. Endothelial cell activation in response to circulating inflammatory mediators leads to the initiation of coagulation when tissue factor is expressed throughout the intravascular space. This results in the widespread consumption of coagulation factors. Additionally, there is a cardiopulmonary bypass-related qualitative platelet defect that is exacerbated by thrombocytopenia as platelets are consumed from the circulation by clot and adherence to the cardiopulmonary bypass circuit. Finally, cardiopulmonary bypass results in the endothelial release of plasminogen activators, which lead to an increase in systemic fibrinolysis. The diffuse generation of thrombin, driven by the inducible intravascular expression of tissue factor, plays a major role in all of these processes. Efforts to understand the critical role of the endothelium in coagulation may lead to novel therapies to prevent bleeding or thrombosis in cardiovascular surgery patients.

  12. Cardiovascular responses to microgravity - Adaptation, maladjustment, and countermeasures

    NASA Technical Reports Server (NTRS)

    Gaffney, F. Andrew

    1989-01-01

    Humans have worked in space for up to 237 days without significant inflight limitations, although major cardiovascular disability is seen following space flight of even a few days duration. Most of the cardiovascular research on microgravity deconditioning has been observational in character. Detailed studies of mechanisms and causes of postflight exercise intolerance, low blood pressure and fainting in astronauts and cosmonauts have not been done, despite almost 30 years of manned space flight. A review of possible mechanisms of postflight cardiovascular deconditioning and directions for study is provided.

  13. Dietary methionine restriction in mice elicits an adaptive cardiovascular response to hyperhomocysteinemia.

    PubMed

    Ables, Gene P; Ouattara, Amadou; Hampton, Thomas G; Cooke, Diana; Perodin, Frantz; Augie, Ines; Orentreich, David S

    2015-03-06

    Dietary methionine restriction (MR) in rodents increased lifespan despite higher heart-to-body weight ratio (w/w) and hyperhomocysteinemia, which are symptoms associated with increased risk for cardiovascular disease. We investigated this paradoxical effect of MR on cardiac function using young, old, and apolipoprotein E-deficient (ApoE-KO) mice. Indeed, MR animals exhibited higher heart-to-body weight ratio (w/w) and hyperhomocysteinemia with a molecular pattern consistent with cardiac stress while maintaining the integrity of cardiac structure. Baseline cardiac function, which was measured by non-invasive electrocardiography (ECG), showed that young MR mice had prolonged QRS intervals compared with control-fed (CF) mice, whereas old and ApoE-KO mice showed similar results for both groups. Following β-adrenergic challenge, responses of MR mice were either similar or attenuated compared with CF mice. Cardiac contractility, which was measured by isolated heart retrograde perfusion, was similar in both groups of old mice. Finally, the MR diet induced secretion of cardioprotective hormones, adiponectin and fibroblast growth factor 21 (FGF21), in MR mice with concomitant alterations in cardiac metabolic molecular signatures. Our findings demonstrate that MR diet does not alter cardiac function in mice despite the presence of hyperhomocysteinemia because of the adaptive responses of increased adiponectin and FGF21 levels.

  14. Anxious women do not show the expected decrease in cardiovascular stress responsiveness as pregnancy advances.

    PubMed

    Braeken, M A K A; Jones, A; Otte, R A; Widjaja, D; Van Huffel, S; Monsieur, G J Y J; van Oirschot, C M; Van den Bergh, B R H

    2015-10-01

    Altered stress responsiveness is a risk factor for mental and physical illness. In non-pregnant populations, it is well-known that anxiety can alter the physiological regulation of stress reactivity. Characterization of corresponding risks for pregnant women and their offspring requires greater understanding of how stress reactivity and recovery are influenced by pregnancy and women's anxiety feelings. In the current study, women were presented repeatedly with mental arithmetic stress tasks in the first and third pregnancy trimester and reported their trait anxiety using the state trait anxiety inventory. Cardiovascular stress reactivity in late pregnancy was lower than reactivity in the first pregnancy trimester (heart rate (HR): t(197)=4.98, p<.001; high frequency heart rate variability (HF HRV): t(196)=-2.09, p=.04). Less attenuation of stress reactivity occurred in more anxious women (HR: b=0.15, SE=0.06, p=.008; HF HRV: b=-10.97, SE=4.79, p=.02). The study design did not allow the influence of habituation to repeated stress task exposure to be assessed separately from the influence of pregnancy progression. Although this is a limitation, the clear differences between anxious and non-anxious pregnant women are important, regardless of the extent to which differing habituation between the groups is responsible. Less dampened stress reactivity through pregnancy may pose long-term risks for anxious women and their offspring. Follow-up studies are required to determine these risks.

  15. Dietary methionine restriction in mice elicits an adaptive cardiovascular response to hyperhomocysteinemia.

    PubMed

    Ables, Gene P; Ouattara, Amadou; Hampton, Thomas G; Cooke, Diana; Perodin, Frantz; Augie, Ines; Orentreich, David S

    2015-01-01

    Dietary methionine restriction (MR) in rodents increased lifespan despite higher heart-to-body weight ratio (w/w) and hyperhomocysteinemia, which are symptoms associated with increased risk for cardiovascular disease. We investigated this paradoxical effect of MR on cardiac function using young, old, and apolipoprotein E-deficient (ApoE-KO) mice. Indeed, MR animals exhibited higher heart-to-body weight ratio (w/w) and hyperhomocysteinemia with a molecular pattern consistent with cardiac stress while maintaining the integrity of cardiac structure. Baseline cardiac function, which was measured by non-invasive electrocardiography (ECG), showed that young MR mice had prolonged QRS intervals compared with control-fed (CF) mice, whereas old and ApoE-KO mice showed similar results for both groups. Following β-adrenergic challenge, responses of MR mice were either similar or attenuated compared with CF mice. Cardiac contractility, which was measured by isolated heart retrograde perfusion, was similar in both groups of old mice. Finally, the MR diet induced secretion of cardioprotective hormones, adiponectin and fibroblast growth factor 21 (FGF21), in MR mice with concomitant alterations in cardiac metabolic molecular signatures. Our findings demonstrate that MR diet does not alter cardiac function in mice despite the presence of hyperhomocysteinemia because of the adaptive responses of increased adiponectin and FGF21 levels. PMID:25744495

  16. Predictors of cardiovascular response to methamphetamine administration in methamphetamine-dependent individuals.

    PubMed

    Fleury, Gilles; De La Garza, Richard; Mahoney, James J; Evans, Sarah E; Newton, Thomas F

    2008-01-01

    The goal of the present investigation was to determine predictors of cardiovascular response to methamphetamine administrated in the laboratory. Heart rate (HR) and blood pressure (BP) were measured at baseline and at several time points following the administration of methamphetamine or saline placebo. One-way ANOVA was used to determine the differences between female and male subjects in their cardiovascular response. In male subjects, linear regression and one-way ANOVA were used to determine the influence of potential predictors on cardiovascular response, including age, weight, drug use indicators, concurrent use of other substances, route of administration, and race. Methamphetamine administration provoked significant increases in HR and BP, as compared to placebo. Female gender was associated with larger peak change in diastolic BP following administration. Baseline HR and BP were found to be strong predictors of cardiovascular response to methamphetamine administration in male subjects. Lifetime use and recent use of methamphetamine and nicotine did not predict cardiovascular response to methamphetamine. Recent alcohol use was associated with increased peak change in diastolic BP. Also, current use of cannabis was negatively correlated with peak HR change. Male cannabis users show lower peak change in HR as compared to non-cannabis users. As compared to methamphetamine smokers, intravenous users demonstrated higher peak change in diastolic BP following drug administration. Race did not have a significant effect on cardiovascular response. Taken together, these findings may help in the prevention and treatment of cardiovascular events in a population at high risk of premature morbidity and mortality.

  17. Predictors of cardiovascular response to methamphetamine administration in methamphetamine-dependent individuals.

    PubMed

    Fleury, Gilles; De La Garza, Richard; Mahoney, James J; Evans, Sarah E; Newton, Thomas F

    2008-01-01

    The goal of the present investigation was to determine predictors of cardiovascular response to methamphetamine administrated in the laboratory. Heart rate (HR) and blood pressure (BP) were measured at baseline and at several time points following the administration of methamphetamine or saline placebo. One-way ANOVA was used to determine the differences between female and male subjects in their cardiovascular response. In male subjects, linear regression and one-way ANOVA were used to determine the influence of potential predictors on cardiovascular response, including age, weight, drug use indicators, concurrent use of other substances, route of administration, and race. Methamphetamine administration provoked significant increases in HR and BP, as compared to placebo. Female gender was associated with larger peak change in diastolic BP following administration. Baseline HR and BP were found to be strong predictors of cardiovascular response to methamphetamine administration in male subjects. Lifetime use and recent use of methamphetamine and nicotine did not predict cardiovascular response to methamphetamine. Recent alcohol use was associated with increased peak change in diastolic BP. Also, current use of cannabis was negatively correlated with peak HR change. Male cannabis users show lower peak change in HR as compared to non-cannabis users. As compared to methamphetamine smokers, intravenous users demonstrated higher peak change in diastolic BP following drug administration. Race did not have a significant effect on cardiovascular response. Taken together, these findings may help in the prevention and treatment of cardiovascular events in a population at high risk of premature morbidity and mortality. PMID:18393052

  18. Autonomic and cardiovascular responses to chemoreflex stress in apnoea divers.

    PubMed

    Steinback, Craig D; Breskovic, Toni; Banic, Ivana; Dujic, Zeljko; Shoemaker, J Kevin

    2010-08-25

    Sleep apnoea, with repeated periods of hypoxia, results in cardiovascular morbidity and concomitant autonomic dysregulation. Trained apnoea divers also perform prolonged apnoeas accompanied by large lung volumes, large reductions in cardiac output and severe hypoxia and hypercapnia. We tested the hypothesis that apnoea training would be associated with decreased cardiovagal and sympathetic baroreflex gains and reduced respiratory modulation of muscle sympathetic nerve activity (MSNA; microneurography). Six trained divers and six controls were studied at rest and during asphyxic rebreathing. Despite an elevated resting heart rate (70+/-14 vs. 56+/-10 bpm; p=0.038), divers had a similar cardiovagal baroreflex gain (-1.22+/-0.47 beats/mmHg) as controls (-1.29+/-0.61; NS). Similarly, though MSNA burst frequency was slightly higher in divers at rest (16+/-4 bursts/min vs. 10+/-5 bursts/min, p=0.03) there was no difference in baseline burst incidence, sympathetic baroreflex gain (-3.8+/-2.1%/mmHg vs. -4.7+/-1.7%/mmHg) or respiratory modulation of MSNA between groups. Resting total peripheral resistance (11.9+/-2.6 vs. 12.3+/-2.2 mmHg/L/min) and pulse wave velocity (5.82+/-0.55 vs. 6.10+/-0.51 m/s) also were similar between divers and controls, respectively. Further, the sympathetic response to asphyxic rebreathing was not different between controls and divers (-1.70+/-1.07 vs. -1.74+/-0.84 a.u./% desaturation). Thus, these data suggest that, unlike patients with sleep apnoea, apnoea training in otherwise healthy individuals does not produce detectable autonomic dysregulation or maladaption.

  19. Predicting in vivo cardiovascular properties of β-blockers from cellular assays: a quantitative comparison of cellular and cardiovascular pharmacological responses

    PubMed Central

    Baker, Jillian G.; Kemp, Philip; March, Julie; Fretwell, Laurice; Hill, Stephen J.; Gardiner, Sheila M.

    2011-01-01

    β-Adrenoceptor antagonists differ in their degree of partial agonism. In vitro assays have provided information on ligand affinity, selectivity, and intrinsic efficacy. However, the extent to which these properties are manifest in vivo is less clear. Conscious freely moving rats, instrumented for measurement of heart rate (β1; HR) and hindquarters vascular conductance (β2; HVC) were used to measure receptor selectivity and ligand efficacy in vivo. CGP 20712A caused a dose-dependent decrease in basal HR (P<0.05, ANOVA) at 5 doses between 6.7 and 670 μg/kg (i.v.) and shifted the dose-response curve for isoprenaline to higher agonist concentrations without altering HVC responses. In contrast, at doses of 67 μg/kg (i.v.) and above, ICI 118551 substantially reduced the HVC response to isoprenaline without affecting HR responses. ZD 7114, xamoterol, and bucindolol significantly increased basal HR (ΔHR: +122±12, +129±11, and +59±11 beats/min, respectively; n=6), whereas other β-blockers caused significant reductions (all at 2 mg/kg i.v.). The agonist effects of xamoterol and ZD 7114 were equivalent to that of the highest dose of isoprenaline. Bucindolol, however, significantly antagonized the response to the highest doses isoprenaline. An excellent correlation was obtained between in vivo and in vitro measures of β1-adrenoceptor efficacy (R2=0.93; P<0.0001).—Baker, J. G., Kemp, P., March, J., Fretwell, L., Hill, S. J., Gardiner, S. M. Predicting in vivo cardiovascular properties of β-blockers from cellular assays: a quantitative comparison of cellular and cardiovascular pharmacological responses. PMID:21865315

  20. Mathematical modeling of human cardiovascular system for simulation of orthostatic response

    NASA Technical Reports Server (NTRS)

    Melchior, F. M.; Srinivasan, R. S.; Charles, J. B.

    1992-01-01

    This paper deals with the short-term response of the human cardiovascular system to orthostatic stresses in the context of developing a mathematical model of the overall system. It discusses the physiological issues involved and how these issues have been handled in published cardiovascular models for simulation of orthostatic response. Most of the models are stimulus specific with no demonstrated capability for simulating the responses to orthostatic stimuli of different types. A comprehensive model incorporating all known phenomena related to cardiovascular regulation would greatly help to interpret the various orthostatic responses of the system in a consistent manner and to understand the interactions among its elements. This paper provides a framework for future efforts in mathematical modeling of the entire cardiovascular system.

  1. Mathematical modeling of human cardiovascular system for simulation of orthostatic response.

    PubMed

    Melchior, F M; Srinivasan, R S; Charles, J B

    1992-06-01

    This paper deals with the short-term response of the human cardiovascular system to orthostatic stresses in the context of developing a mathematical model of the overall system. It discusses the physiological issues involved and how these issues have been handled in published cardiovascular models for simulation of orthostatic response. Most of the models are stimulus specific with no demonstrated capability for simulating the responses to orthostatic stimuli of different types. A comprehensive model incorporating all known phenomena related to cardiovascular regulation would greatly help to interpret the various orthostatic responses of the system in a consistent manner and to understand the interactions among its elements. This paper provides a framework for future efforts in mathematical modeling of the entire cardiovascular system. PMID:1621848

  2. Effects of short-term and prolonged immersion on the cardiovascular responses to exercise.

    PubMed

    Kame, V D; Pendergast, D R

    1995-01-01

    The primary purpose of this investigation was to examine the effects of water immersion in 35 degrees C water, per se, and the effects of 3 h of water immersion on the physiological responses to exercise. Experiments in air were conducted after 15 min of water immersion and after 3 h of water immersion. After each condition, exercises of 20%, 40%, 60%, 80%, and 100% of the subject's maximum oxygen consumption were performed on a cycle ergometer. Oxygen consumption (VO2), cardiac output, heart rate (HR), stroke volume, and blood pressure were determined. At submaximal workloads, no significant differences in the data were observed. The VO2 at the maximal workload after 3 h of immersion (3.32 +/- 0.15 L.min-1) was significantly higher than the value after 15 min of immersion (3.03 +/- 0.20 L.min-1). Both of these values were significantly lower than the value in air (3.83 +/- 0.30 L.min-1). The peak HR's were significantly higher after 3 h of immersion (167 +/- 2 b.min-1). These observations suggest that 3 h of immersion can cause alterations in the cardiovascular responses to maximal exercise; however, submaximal responses were unaffected.

  3. The effects of behavior therapy, self-relaxation, and transcendental meditation on cardiovascular stress response.

    PubMed

    Puente, A E; Beiman, I

    1980-01-01

    Compared Behavior Therapy (BT), self-relaxation (SR), transcendental meditation (TM), and a waiting-list control group (WL) on measures of cardiovascular and subjective stress response. Male and female respondents (N = 60) to an ad for therapy were evaluated in assessment sessions before and after treatment. The results indicate that BT and SR were more effective than either TM or WL in reducing cardiovascular stress response. These data were interpreted as resulting from therapeutic suggestion and positively reinforced client progress.

  4. Type A Behavior and Cardiovascular Responsivity in Preschoolers.

    ERIC Educational Resources Information Center

    Brown, Marie Scott; Tanner, Christine

    This study investigated Type A behavior in preschool children and its relation to cardiovascular reactivity. One hundred forty-four children from 3.5 to 6.5 years old were categorized by their teachers according to the Matthews Youth Test for Health (MYTH) as Type A, Mixed, or Type B. The children's pulse, pulse rate variability, and blood…

  5. Abnormal cardiovascular responses induced by localized high power microwave exposure

    SciTech Connect

    Lu, S.-T; Brown, D.O.; Johnson, C.E.; Mathur, S.P. ); Elson, E.C. )

    1992-05-01

    A hypothesis of microwave-induced circulatory under perfusion was tested in ketamine anesthetized rats whose heart rate, mean arterial pressure, pulse pressure, respiration rate, and body temperatures were monitored continuously. Fifty-eight ventral head and neck exposures in a waveguide consisted of sham-exposure and exposure to continuous wave (CW) and pulsed 1.25 GHz microwaves for 5 min. The 0.5 Hz and 16 Hz pulsemodulated microwaves were delivered at 400 kW peak power. The CW microwaves were 2 and 6.4 W. The average specific absorption rate was 4.75 W/kg per watt transmitted in the brain and 17.15 W/kg per watt transmitted in the neck. Respiration rate and mean arterial pressure were not altered. Changes in heart rate and pulse pressure were observed in rats exposed to higher power but not to the lower average power microwaves. Depression of pulse pressure, an indication of a decrease in stroke volume, and increased or decreased heart rate were noted in presence of whole-body hyperthermia. The cardiac output of those animals exposed to higher average power microwaves was considered to be below normal as hypothesized. Decreased cardiac output and normal mean arterial pressure resulted in an increase in the total peripheral resistance which was contrary to the anticipated thermal response of animals.

  6. A Computational Model for Thrombus Formation in Response to Cardiovascular Implantable Devices

    NASA Astrophysics Data System (ADS)

    Horn, John; Ortega, Jason; Maitland, Duncan

    2014-11-01

    Cardiovascular implantable devices elicit complex physiological responses within blood. Notably, alterations in blood flow dynamics and interactions between blood proteins and biomaterial surface chemistry may lead to the formation of thrombus. For some devices, such as stents and heart valves, this is an adverse outcome. For other devices, such as embolic aneurysm treatments, efficient blood clot formation is desired. Thus a method to study how biomedical devices induce thrombosis is paramount to device development and optimization. A multiscale, multiphysics computational model is developed to predict thrombus formation within the vasculature. The model consists of a set of convection-diffusion-reaction partial differential equations for blood protein constituents involved in the progression of the clotting cascades. This model is used to study thrombus production from endovascular devices with the goal of optimizing the device design to generate the desired clotting response. This work was performed in part under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  7. Predictions of cardiovascular responses during STS reentry using mathematical models

    NASA Technical Reports Server (NTRS)

    Leonard, J. I.; Srinivasan, R.

    1985-01-01

    The physiological adaptation to weightless exposure includes cardiovascular deconditioning arising in part from a loss of total circulating blood volume and resulting in a reduction of orthostatic tolerance. The crew of the Shuttle orbiter are less tolerant to acceleration forces in the head-to-foot direction during the reentry phase of the flight at a time they must function at a high level of performance. The factors that contribute to orthostatic intolerance during and following reentry and to predict the likelihood of impaired crew performance are evaluated. A computer simulation approach employing a mathematical model of the cardiovascular system is employed. It is shown that depending on the severity of blood volume loss, the reentry acceleration stress may be detrimental to physiologic function and may place the physiologic status of the crew near the borderline of some type of impairment. They are in agreement with conclusions from early ground-based experiments and from observations of early Shuttle flights.

  8. Spectral analysis of resting cardiovascular variables and responses to oscillatory LBNP before and after 6 degree head dowm bedrest

    NASA Technical Reports Server (NTRS)

    Knapp, Charles F.; Evans, J. M.; Patwardhan, A.; Levenhagen, D.; Wang, M.; Charles, John B.

    1991-01-01

    A major focus of our research program is to develop noninvasive procedures for determining changes in cardiovascular function associated with the null gravity environment. We define changes in cardiovascular function to be (1) the result of the regulatory system operating at values different from 'normal' but with an overall control system basically unchanged by the null gravity exposure, or (2) the result of operating with a control system that has significantly different regulatory characteristics after an exposure. To this end, we have used a model of weightlessness that consisted of exposing humans to 2 hrs. in the launch position, followed by 20 hrs. of 6 deg head down bedrest. Our principal objective was to use this model to measure cardiovascular responses to the 6 deg head down bedrest protocol and to develop the most sensitive 'systems identification' procedure for indicating change. A second objective, related to future experiments, is to use the procedure in combination with experiments designed to determine the degree to which a regulatory pathway has been altered and to determine the mechanisms responsible for the changes.

  9. Abnormal cardiovascular responses induced by localized high power microwave exposure.

    PubMed

    Lu, S T; Brown, D O; Johnson, C E; Mathur, S P; Elson, E C

    1992-05-01

    A hypothesis of microwave-induced circulatory under perfusion was tested in ketamine anesthetized rats whose heart rate, mean arterial pressure, pulse pressure, respiration rate, and body temperatures were monitored continuously. Fifty-eight ventral head and neck exposures in a waveguide consisted of sham-exposure and exposure to continuous wave (CW) and pulsed 1.25 GHz microwaves for 5 min. The 0.5 Hz (10 microseconds, 2 W average) and 16 Hz (1 microsecond, 6.4 W average) pulse-modulated microwaves were delivered at 400 kW peak power. The CW microwaves were 2 and 6.4 W. The average specific absorption rate was 4.75 W/kg per watt transmitted in the brain and 17.15 W/kg per watt transmitted in the neck. Respiration rate and mean arterial pressure were not altered. Changes in heart rate and pulse pressure were observed in rats exposed to higher power (16 Hz pulses and 6.4 W CW) but not to the lower average power microwaves (0.5 Hz pulses and 2 W CW). Depression of pulse pressure, an indication of a decrease in stroke volume, and increased (tachycardia) or decreased (bradycardia) heart rate were noted in presence of whole-body hyperthermia. The cardiac output of those animals exposed to higher average power microwaves was considered to be below normal as hypothesized. Decreased cardiac output and normal mean arterial pressure resulted in an increase in the total peripheral resistance which was contrary to the anticipated thermal response of animals. PMID:1388133

  10. Single-unit responses of serotonergic medullary raphe neurons to cardiovascular challenges in freely moving cats.

    PubMed

    Martin-Cora, Francisco J; Fornal, Casimir A; Jacobs, Barry L

    2005-12-01

    Single-unit activity of serotonergic neurons in the nuclei raphe obscurus (NRO) and raphe pallidus (NRP) were recorded in conjunction with heart rate in freely moving cats in response to systemic administration of vasoactive drugs and to graded haemorrhage. Bolus administration of phenylephrine hydrochloride and sodium nitroprusside (20 microg/kg, i.v.) produced a marked, transient reflex bradycardia (-42 b.p.m.) and tachycardia (+60 b.p.m.), respectively. The activity of NRO/NRP serotonergic neurons remained unchanged after phenylephrine and nitroprusside administration. The administration of hydralazine (1 mg/kg, i.v.), a long-acting vasodilator, produced sustained tachycardia (+60 b.p.m.), which was not accompanied by changes in neuronal activity, despite prolonged reflex activation of the sympathetic nervous system. The initial withdrawal of up to 15% of total blood volume increased heart rate (+12 b.p.m.), whereas the removal of 22.5% of total blood decreased heart rate (-44 b.p.m.). The activity of NRO/NRP serotonergic neurons remained unaltered throughout graded haemorrhage trials, despite the changes in sympathetic outflow. Thus, serotonergic NRO and NRP neurons appear to be insensitive to alterations in blood pressure and baroreceptor activity, and this lack of responsiveness does not support a specific role for these cells in cardiovascular regulation. Furthermore, these neurons do not appear to be involved in physiological mechanisms underlying alterations in autonomic outflow invoked by hypertension and hypotension. Taken within the context of our previous work, the present data suggest that medullary serotonergic neurons may modulate autonomic outflow, but only in relation to their primary role in motor control. PMID:16367786

  11. Hydrologic Alteration and Response of Ecosystem Functions to River Restoration

    NASA Astrophysics Data System (ADS)

    Orr, C. H.; Stanley, E. H.

    2005-12-01

    Stream ecology theory suggests that physical and hydrologic setting is often a dominant determinant of ecosystem structure in fluvial systems. Restorationist practitioners may work under the assumption that if the hydrologic parameters that control biological processes are restored, biotic components of interest should be restored as well. This method is sometimes called passive habitat restoration, or an eco-hydromorphic approach. An alternate to this hypothesis is that biological recovery is constrained by a number of other limitations such as distance to a source population, site history, and presence of invasive species. In this scenario, systems will not be restored by hydrologic alterations alone. To address the influence physical setting has on ecological process, we measured three specific ecological responses of streams to hydrologic manipulations separate restoration projects in Central Wisconsin. The projects shared the common trait of being primarily hydrologic alterations. We measured phosphorus retention capacity in a second-order stream before and after a pair of small dam removals, denitrification rates following the reflooding of a leveed floodplain and an approximately 50-year time series of vegetation recolonization on exposed mud flats following dam removal. In each case the measured responses showed unexpectedly large variability and there was not close correlation between physical and ecologic parameters. Such high variability in response to alterations also made it difficult to determine if the restorations met their goals. One conclusion of these studies may be that we need to move beyond hydrologic alterations to address additional manipulations to better meet the goals of specific projects.

  12. Altered states of consciousness are related to higher sexual responsiveness.

    PubMed

    Costa, Rui M; Pestana, José; Costa, David; Wittmann, Marc

    2016-05-01

    Altered states of consciousness lead to profound changes in the sense of self, time and space. We assessed how these changes were related to sexual responsiveness during sex. 116 subjects reported (a) intensity of awareness concerning body, space and time, and (b) satisfaction, desire, arousal, and orgasm occurrence. We differentiated vaginal intercourse orgasm from noncoital orgasm. Female vaginal intercourse orgasm was further differentiated as with or without concurrent clitoral masturbation. Overall, sexual responsiveness was related to greater body awareness and lesser time and space awareness. Satisfaction, desire, and arousal were especially associated with less time awareness in women. Female orgasms during vaginal intercourse were related to greater body awareness and lesser time awareness, but noncoital orgasms were unrelated. Our findings provide empirical support for the hypotheses that altered states of consciousness with attentional absorption are strongly related to sexual responsiveness in women, and to a lesser extent in men. PMID:27003264

  13. Mitochondria DNA mutations cause sex-dependent development of hypertension and alterations in cardiovascular function.

    PubMed

    Golob, Mark J; Tian, Lian; Wang, Zhijie; Zimmerman, Todd A; Caneba, Christine A; Hacker, Timothy A; Song, Guoqing; Chesler, Naomi C

    2015-02-01

    Aging is associated with conduit artery stiffening that is a risk factor for and can precede hypertension and ventricular dysfunction. Increases in mitochondria DNA (mtDNA) frequency have been correlated with aging. Mice with a mutation in the encoding domain (D257A) of a proof-reading deficient version of mtDNA polymerase-γ (POLG) have musculoskeletal features of premature aging and a shortened lifespan. However, few studies using these mice have investigated the effects of mtDNA mutations on cardiovascular function. We hypothesized that the proof-reading deficient mtDNA POLG leads to arterial stiffening, hypertension, and ventricular hypertrophy. Ten to twelve month-old D257A mice (n=13) and age- and sex-matched wild-type controls (n=13) were catheterized for hemodynamic and ventricular function measurements. Left common carotid arteries (LCCA) were harvested for mechanical tests followed by histology. Male D257A mice had pulmonary and systemic hypertension, arterial stiffening, larger LCCA diameter (701±45 vs. 597±60μm), shorter LCCA axial length (8.96±0.56 vs. 10.10±0.80mm), and reduced hematocrit (29.1±6.1 vs. 41.3±8.1; all p<0.05). Male and female D257A mice had biventricular hypertrophy (p<0.05). Female D257A mice did not have significant increases in pressure or arterial stiffening, suggesting that the mechanisms of hypertension or arterial stiffening from mtDNA mutations differ based on sex. Our results lend insight into the mechanisms of age-related cardiovascular disease and may point to novel treatment strategies to address cardiovascular mortality in the elderly. PMID:25582357

  14. Mitochondria DNA mutations cause sex-dependent development of hypertension and alterations in cardiovascular function

    PubMed Central

    Golob, Mark J.; Tian, Lian; Wang, Zhijie; Zimmerman, Todd A.; Caneba, Christine A.; Hacker, Timothy A.; Song, Guoqing; Chesler, Naomi C.

    2015-01-01

    Aging is associated with conduit artery stiffening that is a risk factor for and can precede hypertension and ventricular dysfunction. Increases in mitochondria DNA (mtDNA) frequency have been correlated with aging. Mice with a mutation in the encoding domain (D257A) of a proof-reading deficient version of mtDNA polymerase-γ (POLG) have musculoskeletal features of premature aging and a shortened lifespan. However, few studies using these mice have investigated the effects of mtDNA mutations on cardiovascular function. We hypothesized that the proof-reading deficient mtDNA POLG leads to arterial stiffening, hypertension, and ventricular hypertrophy. Ten to twelve month-old D257A mice (n=13) and age- and sex-matched wild-type controls (n=13) were catheterized for hemodynamic and ventricular function measurements. Left common carotid arteries (LCCA) were harvested for mechanical tests followed by histology. Male D257A mice had pulmonary and systemic hypertension, arterial stiffening, larger LCCA diameter (701 ± 45 vs. 597 ± 60 μm), shorter LCCA axial length (8.96 ± 0.56 vs. 10.10 ± 0.80 mm), and reduced hematocrit (29.1 ± 6.1 vs. 41.3 ± 8.1; all p<0.05). Male and female D257A mice had biventricular hypertrophy (p<0.05). Female D257A mice did not have significant increases in pressure or arterial stiffening, suggesting that the mechanisms of hypertension or arterial stiffening from mtDNA mutations differ based on sex. Our results lend insight into the mechanisms of age-related cardiovascular disease and may point to novel treatment strategies to address cardiovascular mortality in the elderly. PMID:25582357

  15. Altered cardiovascular reactivity and osmoregulation during hyperosmotic stress in adult rats developmentally exposed to polybrominated diphenyl ethers (PBDEs)

    SciTech Connect

    Shah, Ashini; Coburn, Cary G.; Watson-Siriboe, Abena; Whitley, Rebecca; Shahidzadeh, Anoush; Gillard, Elizabeth R.; Nichol, Robert; Leon-Olea, Martha; Gaertner, Mark; Kodavanti, Prasada Rao S.

    2011-10-15

    Polybrominated diphenyl ethers (PBDEs) and the structurally similar chemicals polychlorinated biphenyls (PCBs) disrupt the function of multiple endocrine systems. PCBs and PBDEs disrupt the secretion of vasopressin (VP) from the hypothalamus during osmotic activation. Since the peripheral and central vasopressinergic axes are critical for osmotic and cardiovascular regulation, we examined whether perinatal PBDE exposure could impact these functions during physiological activation. Rats were perinatally dosed with a commercial PBDE mixture, DE-71. Dams were given 0 (corn oil control), 1.7 (low dose) or 30.6 mg/kg/day (high dose) in corn oil from gestational day (GD) 6 through postnatal day (PND) 21 by oral gavage. In the male offspring exposed to high dose PBDE plasma thyroxine and triiodothyronine levels were reduced at PND 21 and recovered to control levels by PND 60 when thyroid stimulating hormone levels were elevated. At 14-18 months of age, cardiovascular responses were measured in four groups of rats: Normal (Oil, normosmotic condition), Hyper (Oil, hyperosmotic stress), Hyper PBDE low (1.7 mg/kg/day DE-71 perinatally, hyperosmotic stress), and Hyper PBDE high (30.6 mg/kg/day DE-71 perinatally, hyperosmotic stress). Systolic blood pressure (BP), diastolic BP, and heart rate (HR) were determined using tail cuff sphygmomanometry and normalized to pretreatment values (baseline) measured under basal conditions. Hyperosmotic treatment yielded significant changes in systolic BP in PBDE exposed rats only. Hyper PBDE low and high dose rats showed 36.1 and 64.7% greater systolic BP responses at 3 h post hyperosmotic injection relative to pretreatment baseline, respectively. No treatment effects were measured for diastolic BP and HR. Hyper and Hyper PBDE rats showed increased mean plasma osmolality values by 45 min after injection relative to normosmotic controls. In contrast to Hyper rats, Hyper PBDE (high) rats showed a further increase in mean plasma osmolality at 3

  16. Myocardial failure with altered response to adrenaline in endotoxin shock

    PubMed Central

    Archer, L.T.; Black, M.R.; Hinshaw, L.B.

    1975-01-01

    1 There is a growing concensus that myocardial performance in the early stages of experimental endotoxic and septic shock is relatively normal; however, recent reports have identified an intermediate phase of shock when myocardial dysfunction is clearly apparent. 2 The mechanism of dysfunction has become a subject of intense investigation. A current view is that altered myocardial responsiveness to circulating catecholamines may play an important role in the dysfunction observed after endotoxin administration. The present studies, in which an isolated working heart preparation of the dog was used, were designed to test this hypothesis. This particular experimental preparation was selected to provide an adequate interpretation of results; cardiac output, afterload, and concentrations of adrenaline reaching the coronary vascular bed were controlled in all experiments. Responses to infusions of adrenaline were recorded in the `steady-state' condition. Control (non-shocked) heart responses to adrenaline were highly reproducible in terms of inotropic, chronotropic and coronary vascular behaviour. 3 Results from the study document myocardial dysfunction within 4-6 h following an LD70 endotoxin administration on the basis of increased left ventricular end diastolic pressure (LVEDP), decreased cardiac power and myocardial efficiency, and depressed negative and positive dP/dt parameters. 4 Findings suggest significantly altered responsiveness of the myocardium to infused adrenaline at rates of 1, 2, and 5 μg/min with concentrations between 10 and 1 ng/ml blood. LVEDP was elevated while calculated power and efficiency parameters remained significantly below control values during infusion of adrenaline in endotoxin-treated hearts. Depressions of responsiveness were interpreted to occur on the basis of failure to restore positive and negative dP/dt to normal values and depressed coronary blood flow responses during adrenaline administration. Increases in coronary flow were

  17. Computational modelling and evaluation of cardiovascular response under pulsatile impeller pump support

    PubMed Central

    Shi, Yubing; Brown, Alistair G.; Lawford, Patricia V.; Arndt, Andreas; Nuesser, Peter; Hose, D. Rodney

    2011-01-01

    This study presents a numerical simulation of cardiovascular response in the heart failure condition under the support of a Berlin Heart INCOR impeller pump-type ventricular assist device (VAD). The model is implemented using the CellML modelling language. To investigate the potential of using the Berlin Heart INCOR impeller pump to produce physiologically meaningful arterial pulse pressure within the various physiological constraints, a series of VAD-assisted cardiovascular cases are studied, in which the pulsation ratio and the phase shift of the VAD motion profile are systematically changed to observe the cardiovascular responses in each of the studied cases. An optimization process is proposed, including the introduction of a cost function to balance the importance of the characteristic cardiovascular variables. Based on this cost function it is found that a pulsation ratio of 0.35 combined with a phase shift of 200° produces the optimal cardiovascular response, giving rise to a maximal arterial pulse pressure of 12.6 mm Hg without inducing regurgitant pump flow while keeping other characteristic cardiovascular variables within appropriate physiological ranges. PMID:22670203

  18. Computational modelling and evaluation of cardiovascular response under pulsatile impeller pump support.

    PubMed

    Shi, Yubing; Brown, Alistair G; Lawford, Patricia V; Arndt, Andreas; Nuesser, Peter; Hose, D Rodney

    2011-06-01

    This study presents a numerical simulation of cardiovascular response in the heart failure condition under the support of a Berlin Heart INCOR impeller pump-type ventricular assist device (VAD). The model is implemented using the CellML modelling language. To investigate the potential of using the Berlin Heart INCOR impeller pump to produce physiologically meaningful arterial pulse pressure within the various physiological constraints, a series of VAD-assisted cardiovascular cases are studied, in which the pulsation ratio and the phase shift of the VAD motion profile are systematically changed to observe the cardiovascular responses in each of the studied cases. An optimization process is proposed, including the introduction of a cost function to balance the importance of the characteristic cardiovascular variables. Based on this cost function it is found that a pulsation ratio of 0.35 combined with a phase shift of 200° produces the optimal cardiovascular response, giving rise to a maximal arterial pulse pressure of 12.6 mm Hg without inducing regurgitant pump flow while keeping other characteristic cardiovascular variables within appropriate physiological ranges.

  19. Cardiovascular Response Identification Based on Nonlinear Support Vector Regression

    NASA Astrophysics Data System (ADS)

    Wang, Lu; Su, Steven W.; Chan, Gregory S. H.; Celler, Branko G.; Cheng, Teddy M.; Savkin, Andrey V.

    This study experimentally investigates the relationships between central cardiovascular variables and oxygen uptake based on nonlinear analysis and modeling. Ten healthy subjects were studied using cycle-ergometry exercise tests with constant workloads ranging from 25 Watt to 125 Watt. Breath by breath gas exchange, heart rate, cardiac output, stroke volume and blood pressure were measured at each stage. The modeling results proved that the nonlinear modeling method (Support Vector Regression) outperforms traditional regression method (reducing Estimation Error between 59% and 80%, reducing Testing Error between 53% and 72%) and is the ideal approach in the modeling of physiological data, especially with small training data set.

  20. Cardiovascular responses of pregnant women during aerobic exercise in water: a longitudinal study.

    PubMed

    McMurray, R G; Katz, V L; Berry, M J; Cefalo, R C

    1988-12-01

    To determine the effects of pregnancy on the cardiovascular responses to immersion and exercise in water, 12 women completed 20 min of immersion and 20 min of bicycle ergometry at 60% predicted VO2max in 30 degrees C water during their 15th, 25th, and 35th week of pregnancy as well as 8-10 weeks post partum. Immersion lowered the resting heart rate approximately 8 bts/min (P less than 0.05). Exercise in water also resulted in a lower heart rate as compared with the same level of exercise on land (132 +/- 4 vs 149 +/- 6 bts/min; P less than 0.05). Both the rest and exercise heart rate responses were independent of duration of pregnancy or pregnancy status. Post partum exercise cardiac output averaged 9.9 +/- 0.4 l/min, significantly lower (P less than 0.05) than the 15th (12.7 +/- 0.5), 25th (14.7 +/- 0.5), or 35th week (15.1 +/- 0.7 l/min). Total peripheral resistance was greatest (P less than 0.05) post partum (657 +/- 29 dyn.s/cm5) compared with either the 15th (515 +/- 27), 25th (407 +/- 18), or 35th week (450 +/- 23). The results indicate that exercise in water lowers the heart rate compared with land exercise at the same metabolic rate. The combined effect of exercise, water, and pregnancy may elevate the cardiac output more than expected on land, but the same general pattern of exercise response will be evident throughout the duration of pregnancy. The results further suggest that water alters the heart rate and blood pressure responses such that land-derived exercise target heart rates should not be used to prescribe exercise intensity in water.

  1. Cardiovascular Responses to Psychosocial Stress Reflect Motivation State in Adults Born at Extremely Low Birth Weight.

    PubMed

    Mathewson, Karen J; Pyhälä, Riikka; Hovi, Petteri; Räikkönen, Katri; Van Lieshout, Ryan J; Boyle, Michael H; Saigal, Saroj; Morrison, Katherine M; Kajantie, Eero; Schmidt, Louis A

    2015-01-01

    Background. Adults born extremely preterm appear to have more difficulty managing the stresses of early adulthood than their term-born peers. Objective. To examine the effects of being born at extremely low birth weight (ELBW; birth weight < 1000 g) versus at full term on cardiovascular responses to stress. Method. Cardiovascular responses were elicited during administration of a widely used laboratory stressor, the Trier Social Stress Test (TSST). Results. Term-born adults exhibited a larger decrease in total peripheral resistance and larger increase in cardiac output for TSST performance, reflecting greater resilience, than did ELBW adults. Furthermore, in ELBW participants but not controls, cardiovascular responses were correlated with anxiety, suggesting that their responses reflected feelings of stress. Conclusions. Skills-training and practice with relevant stressors may be necessary to increase the personal resources of ELBW participants for managing stress as they transition to adulthood. PMID:27335948

  2. Cardiovascular regulatory response to lower body negative pressure following blood volume loss

    NASA Technical Reports Server (NTRS)

    Shimizu, M.; Ghista, D. N.; Sandler, H.

    1979-01-01

    An attempt is made to explain the cardiovascular regulatory responses to lower body negative pressure (LBNP) stress, both in the absence of and following blood or plasma volume loss, the latter being factors regularly observed with short- or long-term recumbency or weightlessness and associated with resulting cardiovascular deconditioning. Analytical expressions are derived for the responses of mean venous pressure and blood volume pooled in the lower body due to LBNP. An analysis is presented for determining the HR change due to LBNP stress following blood volume loss. It is concluded that the reduced orthostatic tolerance following long-term space flight or recumbency can be mainly attributed to blood volume loss, and that the associated cardiovascular responses characterizing this orthostatic intolerance is elicited by the associated central venous pressure response.

  3. Contribution of infralimbic cortex in the cardiovascular response to acute stress.

    PubMed

    Müller-Ribeiro, Flávia Camargos de Figueirêdo; Zaretsky, Dmitry V; Zaretskaia, Maria V; Santos, Robson A S; DiMicco, Joseph A; Fontes, Marco Antônio Peliky

    2012-09-15

    The infralimbic region of the medial prefrontal cortex (IL) modulates autonomic and neuroendocrine function via projections to subcortical structures involved in the response to stress. We evaluated the contribution of the IL to the cardiovascular response evoked by acute stress. Under anesthesia (80 mg/kg ketamine-11.5 mg/kg xylazine), rats were implanted with telemetry probes or arterial lines for recording heart rate and blood pressure. Guide cannulas were implanted to target the IL for microinjection of muscimol (100 pmol/100 nl), N-methyl-d-aspartate (NMDA) (6 pmol/100 nl), or vehicle (100 nl). Microinjection of muscimol, an agonist of GABA(A) receptors, into the IL had no effect on stress-evoked cardiovascular and thermogenic changes in any of the paradigms evaluated (cage switch, restraint plus air-jet noise, or air-jet stress). However, microinjection of the excitatory amino acid NMDA into the IL attenuated the pressor and tachycardic response to air-jet stress. Pretreatment with the selective NMDA antagonist dl-2-amino-5-phosphonopentanoic acid (AP-5, 100 pmol/100 nl) blocked the effect of NMDA on the cardiovascular response to air-jet stress. We conclude that 1) the IL region is not tonically involved in cardiovascular or thermogenic control during stress or under baseline conditions, and 2) activation of NMDA receptors in the IL can suppress the cardiovascular response to acute stress exposure.

  4. Cardiovascular response of rats exposed to 60-Hz electric fields

    SciTech Connect

    Hilton, D.I.; Phillips, R.D.

    1980-01-01

    Recently, it has been reported that exposure to high-strength electric fields can influence electrocardiogram (ECG) patterns, heart rates, and blood pressures in various species of animals. Our studies were designed to evaluate these reported effects and to help clarify some of the disagreement present in the literature. Various cardiovascular variables were measured in Sprague-Dawley rats exposed or sham-exposed to 60-Hz electric fields at 80 to 100 kV/m for periods up to four months. No significant differences in heart rates, ECG patterns, blood pressures, or vascular reactivity were observed between exposed and sham-exposed rats after 8 hours, 40 hours, 1 month, or 4 months of exposure. Our studies cannot be directly compared to the work of other investigators because of differences in animal species and electric-field characteristics. However, our failure to detect any cardiovascular changes may have been the result of (1) eliminating secondary field effects such as shocks, audible noise, corona, and ozone; (2) minimizing steady-state microcurrents between the mouth of the animal and watering devices; and (3) minimizing electric-field-induced vibration of the electrodes and animal cages.

  5. Increasing blood flow to exercising muscle attenuates systemic cardiovascular responses during dynamic exercise in humans.

    PubMed

    Ichinose, Masashi; Ichinose-Kuwahara, Tomoko; Kondo, Narihiko; Nishiyasu, Takeshi

    2015-11-15

    Reducing blood flow to working muscles during dynamic exercise causes metabolites to accumulate within the active muscles and evokes systemic pressor responses. Whether a similar cardiovascular response is elicited with normal blood flow to exercising muscles during dynamic exercise remains unknown, however. To address that issue, we tested whether cardiovascular responses are affected by increases in blood flow to active muscles. Thirteen healthy subjects performed dynamic plantarflexion exercise for 12 min at 20%, 40%, and 60% of peak workload (EX20, EX40, and EX60) with their lower thigh enclosed in a negative pressure box. Under control conditions, the box pressure was the same as the ambient air pressure. Under negative pressure conditions, beginning 3 min after the start of the exercise, the box pressure was decreased by 20, 45, and then 70 mmHg in stepwise fashion with 3-min step durations. During EX20, the negative pressure had no effect on blood flow or the cardiovascular responses measured. However, application of negative pressure increased blood flow to the exercising leg during EX40 and EX60. This increase in blood flow had no significant effect on systemic cardiovascular responses during EX40, but it markedly attenuated the pressor responses otherwise seen during EX60. These results demonstrate that during mild exercise, normal blood flow to exercising muscle is not a factor eliciting cardiovascular responses, whereas it elicits an important pressor effect during moderate exercise. This suggests blood flow to exercising muscle is a major determinant of cardiovascular responses during dynamic exercise at higher than moderate intensity.

  6. Increasing blood flow to exercising muscle attenuates systemic cardiovascular responses during dynamic exercise in humans.

    PubMed

    Ichinose, Masashi; Ichinose-Kuwahara, Tomoko; Kondo, Narihiko; Nishiyasu, Takeshi

    2015-11-15

    Reducing blood flow to working muscles during dynamic exercise causes metabolites to accumulate within the active muscles and evokes systemic pressor responses. Whether a similar cardiovascular response is elicited with normal blood flow to exercising muscles during dynamic exercise remains unknown, however. To address that issue, we tested whether cardiovascular responses are affected by increases in blood flow to active muscles. Thirteen healthy subjects performed dynamic plantarflexion exercise for 12 min at 20%, 40%, and 60% of peak workload (EX20, EX40, and EX60) with their lower thigh enclosed in a negative pressure box. Under control conditions, the box pressure was the same as the ambient air pressure. Under negative pressure conditions, beginning 3 min after the start of the exercise, the box pressure was decreased by 20, 45, and then 70 mmHg in stepwise fashion with 3-min step durations. During EX20, the negative pressure had no effect on blood flow or the cardiovascular responses measured. However, application of negative pressure increased blood flow to the exercising leg during EX40 and EX60. This increase in blood flow had no significant effect on systemic cardiovascular responses during EX40, but it markedly attenuated the pressor responses otherwise seen during EX60. These results demonstrate that during mild exercise, normal blood flow to exercising muscle is not a factor eliciting cardiovascular responses, whereas it elicits an important pressor effect during moderate exercise. This suggests blood flow to exercising muscle is a major determinant of cardiovascular responses during dynamic exercise at higher than moderate intensity. PMID:26377556

  7. Does mental arithmetic before head up tilt have an effect on the orthostatic cardiovascular and hormonal responses?

    NASA Astrophysics Data System (ADS)

    Goswami, Nandu; Lackner, Helmut Karl; Papousek, Ilona; Montani, Jean-Pierre; Jezova, Daniela; Hinghofer-Szalkay, Helmut G.

    2011-05-01

    Passive head up tilt (HUT) and mental arithmetic (MA) are commonly used for providing mental and orthostatic challenges, respectively. In animal experiments, even a single exposure to a stressor has been shown to modify the response to subsequent stress stimulus. We investigated whether MA applied before HUT elicits synergistic responses in orthostatic heart rate (HR), cardiac output (CO), heart rate variability and arterial blood pressure. The 15 healthy young males were subjected to two randomized protocols: (a) HUT and (b) HUT preceded by MA, with sessions randomized and ≥2 weeks apart. Beat to beat continuous hemodynamic variables were measured and saliva samples taken for hormonal assay. HUT alone increased HR from 59±7 (baseline) to 80±10 bpm (mean±SD) and mean blood pressure (MBP) from 88±10 to 91±14 mmHg. HUT results after MA were not different from those with HUT alone. The activity of alpha amylase showed differences during the experiments irrespective of the protocols. We conclude that mental challenge does not affect orthostatic cardiovascular responses when applied before; the timing of mental loading seems to be critical if it is intended to alter cardiovascular responses to upright standing.

  8. Effects of sex and gender on adaptation to space: cardiovascular alterations.

    PubMed

    Platts, Steven H; Bairey Merz, C Noel; Barr, Yael; Fu, Qi; Gulati, Martha; Hughson, Richard; Levine, Benjamin D; Mehran, Roxana; Stachenfeld, Nina; Wenger, Nanette K

    2014-11-01

    Sex and gender differences in the cardiovascular adaptation to spaceflight were examined with the goal of optimizing the health and safety of male and female astronauts at the forefront of space exploration. Female astronauts are more susceptible to orthostatic intolerance after space flight; the visual impairment intracranial pressure syndrome predominates slightly in males. Since spaceflight simulates vascular aging, sex-specific effects on vascular endothelium and thrombotic risk warrant examination as predisposing factors to atherosclerosis, important as the current cohort of astronauts ages. Currently, 20% of astronauts are women, and the recently selected astronaut recruits are 50% women. Thus there should be expectation that future research will reflect the composition of the overall population to determine potential benefits or risks. This should apply both to clinical studies and to basic science research.

  9. Effects of sex and gender on adaptation to space: cardiovascular alterations.

    PubMed

    Platts, Steven H; Bairey Merz, C Noel; Barr, Yael; Fu, Qi; Gulati, Martha; Hughson, Richard; Levine, Benjamin D; Mehran, Roxana; Stachenfeld, Nina; Wenger, Nanette K

    2014-11-01

    Sex and gender differences in the cardiovascular adaptation to spaceflight were examined with the goal of optimizing the health and safety of male and female astronauts at the forefront of space exploration. Female astronauts are more susceptible to orthostatic intolerance after space flight; the visual impairment intracranial pressure syndrome predominates slightly in males. Since spaceflight simulates vascular aging, sex-specific effects on vascular endothelium and thrombotic risk warrant examination as predisposing factors to atherosclerosis, important as the current cohort of astronauts ages. Currently, 20% of astronauts are women, and the recently selected astronaut recruits are 50% women. Thus there should be expectation that future research will reflect the composition of the overall population to determine potential benefits or risks. This should apply both to clinical studies and to basic science research. PMID:25401939

  10. An update on calcium metabolism alterations and cardiovascular risk in patients with chronic kidney disease: questions, myths and facts.

    PubMed

    Savica, Vincenzo; Bellinghieri, Guido; Monardo, Paolo; Muraca, Ugo; Santoro, Domenico

    2013-01-01

    In 2006, the Kidney Disease Improving Global Outcomes (KDIGO) guidelines introduced, for the first time, the definition and diagnostic and therapeutic criteria for a systemic complication of the mineral metabolism dysfunction, such as vascular calcification, caused by chronic renal insufficiency. Abdominal x-ray and echocardiography rather than the more complex CT scan is suggested to make the diagnosis. This condition is associated with high cardiovascular risk and consequent poor prognosis. An alteration in total body calcium (Ca) content is one of the key factors in the cardiovascular complications observed in uremic subjects. In the general population, the addition of Ca to the diet has been to shown to improve bone mineral density (BMD) compared to controls, but it does not appear to reduce the risk of bone fractures. In patients with CKD, there are certainly some theoretical justifications for administering calcium salts: vitamin D deficiency, which reduces the intestinal absorption of Ca; hypocalcemia, which increases the risk of hyperparathyroidism; and hyperphosphatemia, which justifies the use of Ca-based P binders. There is already a large body of evidence pointing against the use of Ca-based binding agents, when there is a positive Ca balance because of the development of vascular calcification.

  11. Alteration of cardiovascular autonomic functions by vegetarian diets in postmenopausal women is related to LDL cholesterol levels.

    PubMed

    Fu, Chin-Hua; Yang, Cheryl C H; Lin, Chin-Lon; Kuo, Terry B J

    2008-04-30

    This study was designed to test the hypothesis that alteration of cardiovascular autonomic functions by vegetarian diets in healthy postmenopausal women is related to lipid metabolism. A total of 70 healthy postmenopausal women not on hormone therapy participated in this study: 35 were vegetarians (mean age 55.0 years) and 35 were omnivores (mean age 55.1 years). Cardiovascular autonomic functions and baroreflex sensitivity were evaluated by specific frequency-domain measures of heart rate variability (HRV) and arterial blood pressure fluctuation. The vegetarians had statistically significant lowered blood pressure, total cholesterol, low-density lipoprotein (LDL) cholesterol, triglyceride, and fasting glucose levels compared with the omnivores. The vegetarians exhibited a significant higher total power, low-frequency (LF; 0.04-0.15 Hz) and high-frequency (HF; 0.15-0.4 Hz) of HRV and increased baroreflex sensitivity measures [Brr(LF) and Brr(HF)] compared with the omnivores. Total power, LF and HF of HRV, Brr(LF), and Brr(HF) were significantly and negatively correlated with LDL-cholesterol concentrations (P < 0.01). We concluded that the increases of cardiac vagal activity and baroreflex sensitivity by vegetarian diets in postmenopausal women are inversely related to LDL-cholesterol levels.

  12. The inflammatory response to vaccination is altered in the elderly.

    PubMed

    El Yousfi, Mimoun; Mercier, Sabine; Breuillé, Denis; Denis, Philippe; Papet, Isabelle; Mirand, Philippe Patureau; Obled, Christiane

    2005-08-01

    To further explore whether immune function and acute phase response are altered during ageing, the response to a mild inflammatory stress (DT-Polio-Typhim vaccination) was studied in elderly and young subjects. Cytokine production (IFN-gamma, TNF-alpha, IL-6, IL-10) by whole blood cultures, circulating cytokines and acute phase proteins were analysed before and 2 days after vaccination. Prior to vaccination, only IFN-gamma production was lower in the elderly than in the young subjects due to a lower mononuclear cell number. In the same time, although in the normal range, several acute phase proteins were greater in elderly than in young subjects, suggesting a low-grade inflammatory state in the elderly. After vaccination, IFN-gamma production remained lower in the elderly than in the young, supporting an altered cell-mediated immunity with advancing age. TNF-alpha production was unaffected by either ageing or vaccination. IL-6 production was stimulated by vaccination in young subjects but not significantly in the elderly. IL-10 production was inhibited by vaccination in the elderly but not in the young. Acute phase proteins were less increased in elderly than in young subjects. Taken together, these results support a general lack of inflammatory response in the elderly exposed to an immune challenge and suggest that immune deficiency may concern both Th1 and Th2 responses. However, the interpretation must respect the limitation of small subjects number.

  13. Cardiovascular Responses during Head-Down Crooked Kneeling Position Assumed in Muslim Prayers

    PubMed Central

    Ahmad Rufa’i, Adamu; Hamu Aliyu, Hadeezah; Yunoos Oyeyemi, Adetoyeje; Lukman Oyeyemi, Adewale

    2013-01-01

    Background: Movement dysfunction may be expressed in terms of symptoms experienced in non-physiological postures, and head-down crooked kneeling (HDCK) is a posture frequently assumed by Muslims during prayer activities. The purpose of this study was to investigate the cardiovascular responses in the HDCK posture. Methods: Seventy healthy volunteers, comprising 35 males and 35 females, participated in the study. Cardiovascular parameters of blood pressure and pulse rate of the participants were measured in rested sitting position and then at one and three minutes into the HDCK posture. Two-way ANOVA was used to determine the differences between cardiovascular responses at rest and in the HDCK posture, and the Student t test was utilized to determine gender difference in cardiovascular responses at rest and at one and three minutes into the HDCK posture. Results: The study showed a significant decrease in systolic and diastolic blood pressures at one minute into the HDCK posture and an increase in pulse rate at one and three minutes into the HDCK posture, as compared to the resting values. Rate pressure product also rose at one minute into the HDCK posture, whereas pulse pressure increased at one and three minutes into the HDCK posture, as compared with the resting values. However, no significant change was observed in the mean arterial pressure values. Conclusion: The findings from this study suggest that no adverse cardiovascular event can be expected to occur for the normal duration of this posture during Muslim prayer activities. PMID:24031108

  14. Altered galectin glycosylation: potential factor for the diagnostics and therapeutics of various cardiovascular and neurological disorders.

    PubMed

    Ashraf, Ghulam Md; Perveen, Asma; Tabrez, Shams; Jabir, Nasimudeen R; Damanhouri, Ghazi A; Zaidi, Syed Kashif; Banu, Naheed

    2015-01-01

    Galectins are β-galactoside binding mammalian proteins characterized by the presence of a conserved carbohydrate recognition domain, expressed in almost all taxa of living organisms and involved in broad range of significant biological and physiological functions. Previously, we reported the purification and extensive characterization of galectin-1 from goat (Capra hircus) heart. Interestingly, the purified protein was found to have significant level of glycosylation. This intrigued us to evaluate the involvement of glycosylation in relation to protein's structural and functional integrity in its purified form. In the present study, an extensive comparative physicochemical characterization has been performed between the glycosylated and deglycosylated form of the purified protein. Deglycosylation resulted in an enhanced fluorescence quenching and marked reduction in pH and thermal stability of the purified galectin. Exposure to various biologically active chemicals showed significant differences in the properties and stability profile, causing significant deviations from its regular secondary structure in the deglycosylated form. These results clearly indicated enhanced structural and functional stabilization in the glycosylated galectin. The data revealed herein adds a vital facet demonstrating the significance of galectin expression and glycosylation in causation, progression, and possible therapeutics of associated clinical disorders. Our approach also allowed us to define some key interactions between the purified galectin and carbohydrate ligands that could well serve as an important landmark for designing new drug protocols for various cardiovascular and neurological disorders. PMID:25416978

  15. Is the risk of cardiovascular disease altered with anti-inflammatory therapies? Insights from rheumatoid arthritis.

    PubMed

    Kraakman, Michael J; Dragoljevic, Dragana; Kammoun, Helene L; Murphy, Andrew J

    2016-05-01

    Cardiovascular disease (CVD) remains the leading cause of mortality worldwide. Atherosclerosis is the most common form of CVD, which is complex and multifactorial with an elevated risk observed in people with either metabolic or inflammatory diseases. Accumulating evidence now links obesity with a state of chronic low-grade inflammation and has renewed our understanding of this condition and its associated comorbidities. An emerging theme linking disease states with atherosclerosis is the increased production of myeloid cells, which can initiate and exacerbate atherogenesis. Although anti-inflammatory drug treatments exist and have been successfully used to treat inflammatory conditions such as rheumatoid arthritis (RA), a commonly observed side effect is dyslipidemia, inadvertently, a major risk factor for the development of atherosclerosis. The mechanisms leading to dyslipidemia associated with anti-inflammatory drug use and whether CVD risk is actually increased by this dyslipidemia are of great therapeutic importance and currently remain poorly understood. Here we review recent data providing links between inflammation, hematopoiesis, dyslipidemia and CVD risk in the context of anti-inflammatory drug use. PMID:27350883

  16. Is the risk of cardiovascular disease altered with anti-inflammatory therapies? Insights from rheumatoid arthritis

    PubMed Central

    Kraakman, Michael J; Dragoljevic, Dragana; Kammoun, Helene L; Murphy, Andrew J

    2016-01-01

    Cardiovascular disease (CVD) remains the leading cause of mortality worldwide. Atherosclerosis is the most common form of CVD, which is complex and multifactorial with an elevated risk observed in people with either metabolic or inflammatory diseases. Accumulating evidence now links obesity with a state of chronic low-grade inflammation and has renewed our understanding of this condition and its associated comorbidities. An emerging theme linking disease states with atherosclerosis is the increased production of myeloid cells, which can initiate and exacerbate atherogenesis. Although anti-inflammatory drug treatments exist and have been successfully used to treat inflammatory conditions such as rheumatoid arthritis (RA), a commonly observed side effect is dyslipidemia, inadvertently, a major risk factor for the development of atherosclerosis. The mechanisms leading to dyslipidemia associated with anti-inflammatory drug use and whether CVD risk is actually increased by this dyslipidemia are of great therapeutic importance and currently remain poorly understood. Here we review recent data providing links between inflammation, hematopoiesis, dyslipidemia and CVD risk in the context of anti-inflammatory drug use. PMID:27350883

  17. An altered peripheral IL6 response in major depressive disorder.

    PubMed

    Money, Kelli M; Olah, Zita; Korade, Zeljka; Garbett, Krassimira A; Shelton, Richard C; Mirnics, Karoly

    2016-05-01

    Major depressive disorder (MDD) is one of the most prevalent major psychiatric disorders with a lifetime prevalence of 17%. Recent evidence suggests MDD is not only a brain dysfunction, but a systemic disease affecting the whole body. Central and peripheral inflammatory changes seem to be a centerpiece of MDD pathology: a subset of patients show elevated blood cytokine and chemokine levels that partially normalize with symptom improvement over the course of anti-depressant treatment. As this inflammatory process in MDD is poorly understood, we hypothesized that the peripheral tissues of MDD patients will respond differently to inflammatory stimuli, resulting in an aberrant transcriptional response to elevated pro-inflammatory cytokines. To test this, we used MDD patient- and control-derived dermal fibroblast cultures to investigate their response to an acute treatment with IL6, IL1β, TNFα, or vehicle. Following RNA isolation and subsequent cDNA synthesis, quantitative PCR was used to determine the relative expression level of several families of inflammation-responsive genes. Our results showed comparable expression of the tested genes between MDD patients and controls at baseline. In contrast, MDD patient fibroblasts had a diminished transcriptional response to IL6 in all the gene sets tested (oxidative stress response, mitochondrial function, and lipid metabolism). We also found a significant increase in baseline and IL6 stimulated transcript levels of the IL6 receptor gene. This IL6 receptor transcript increase in MDD fibroblasts was accompanied by an IL6 stimulated increase in induction of SOCS3, which dampens IL6 receptor signaling. Altogether our results demonstrate that there is an altered transcriptional response to IL6 in MDD, which may represent one of the molecular mechanisms contributing to disease pathophysiology. Ultimately we hope that these studies will lead to validation of novel MDD drug targets focused on normalizing the altered IL6 response in

  18. Curious cases: Altered dose-response relationships in addiction genetics.

    PubMed

    Uhl, George R; Drgonova, Jana; Hall, F Scott

    2014-03-01

    Dose-response relationships for most addictive substances are "inverted U"-shaped. Addictive substances produce both positive features that include reward, euphoria, anxiolysis, withdrawal-relief, and negative features that include aversion, dysphoria, anxiety and withdrawal symptoms. A simple model differentially associates ascending and descending limbs of dose-response curves with rewarding and aversive influences, respectively. However, Diagnostic and Statistical Manual (DSM) diagnoses of substance dependence fail to incorporate dose-response criteria and don't directly consider balances between euphoric and dysphoric drug effects. Classical genetic studies document substantial heritable influences on DSM substance dependence. Linkage and genome-wide association studies identify modest-sized effects at any locus. Nevertheless, clusters of SNPs within selected genes display 10(-2)>p>10(-8) associations with dependence in many independent samples. For several of these genes, evidence for cis-regulatory, level-of-expression differences supports the validity of mouse models in which levels of expression are also altered. This review documents surprising, recently defined cases in which convergent evidence from humans and mouse models supports central influences of altered dose-response relationships in mediating the impact of relevant genomic variation on addiction phenotypes. For variation at loci for the α5 nicotinic acetylcholine receptor, cadherin 13, receptor type protein tyrosine phosphatase Δ and neuronal cell adhesion molecule genes, changed dose-response relationships conferred by gene knockouts in mice are accompanied by supporting human data. These observations emphasize desirability of carefully elucidating dose-response relationships for both rewarding and aversive features of abused substances wherever possible. They motivate consideration of individual differences in dose-response relationships in addiction nosology and therapeutics.

  19. Curious cases: Altered dose-response relationships in addiction genetics.

    PubMed

    Uhl, George R; Drgonova, Jana; Hall, F Scott

    2014-03-01

    Dose-response relationships for most addictive substances are "inverted U"-shaped. Addictive substances produce both positive features that include reward, euphoria, anxiolysis, withdrawal-relief, and negative features that include aversion, dysphoria, anxiety and withdrawal symptoms. A simple model differentially associates ascending and descending limbs of dose-response curves with rewarding and aversive influences, respectively. However, Diagnostic and Statistical Manual (DSM) diagnoses of substance dependence fail to incorporate dose-response criteria and don't directly consider balances between euphoric and dysphoric drug effects. Classical genetic studies document substantial heritable influences on DSM substance dependence. Linkage and genome-wide association studies identify modest-sized effects at any locus. Nevertheless, clusters of SNPs within selected genes display 10(-2)>p>10(-8) associations with dependence in many independent samples. For several of these genes, evidence for cis-regulatory, level-of-expression differences supports the validity of mouse models in which levels of expression are also altered. This review documents surprising, recently defined cases in which convergent evidence from humans and mouse models supports central influences of altered dose-response relationships in mediating the impact of relevant genomic variation on addiction phenotypes. For variation at loci for the α5 nicotinic acetylcholine receptor, cadherin 13, receptor type protein tyrosine phosphatase Δ and neuronal cell adhesion molecule genes, changed dose-response relationships conferred by gene knockouts in mice are accompanied by supporting human data. These observations emphasize desirability of carefully elucidating dose-response relationships for both rewarding and aversive features of abused substances wherever possible. They motivate consideration of individual differences in dose-response relationships in addiction nosology and therapeutics. PMID:24189489

  20. Altered Striatal Response to Reward in Bulimia Nervosa After Recovery

    PubMed Central

    Wagner, Angela; Aizenstein, Howard; Venkatraman, Vijay K.; Bischoff-Grethe, Amanda; Fudge, Julie; May, J. Christopher; Frank, Guido K.; Bailer, Ursula F.; Fischer, Lorie; Putnam, Karen; Kaye, Walter H.

    2014-01-01

    Objective It is possible that disturbances of systems modulating reward may contribute to a vulnerability to develop an eating disorder. Method This hypothesis was tested by assessing functional magnetic resonance brain imaging response to a monetary reward task known to activate the anterior ventral striatum (AVS), a region implicated in motivational aspects toward stimuli. To avoid the confounding effects of malnutrition, 10 women who had recovered from bulimia nervosa (BN) were compared with 10 healthy comparison women (CW). Results For the AVS, CW distinguished positive and negative feedback, whereas recovered BN women had similar responses to both conditions. In addition, these groups had similar patterns of findings for the dorsal caudate. Discussion We have previously shown that individuals recovered from anorexia nervosa (AN) also had altered striatal responses and difficulties in differentiating positive and negative feedback. Thus BN and AN individuals may share a difficulty in discriminating the emotional significance of a stimulus. PMID:19434606

  1. Cardiovascular responses induced by obstructive apnea are enhanced in hypertensive rats due to enhanced chemoreceptor responsivity.

    PubMed

    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.

  2. Cardiovascular and organ responses and adaptation responses to hypogravity in an experimental animal model.

    NASA Astrophysics Data System (ADS)

    Biondi, R.; Capodicasa, E.; Tassi, C.; Mezzasomal, L.; Benedetti, C.; Valiani, M.; Marconi, P.; Rossi, R.

    1995-10-01

    The head-down suspension (i.e antiorthostatic hypokinesia) rat is used to simulate weightlessness. However, little is known about cardiovascular and organ adaptation responses which, over a long time, can become pathologically significant. The purpose of this study was therefore to evaluate regional changes in the hematology parameters, Endotheline-1 (ET-1) concentration and urinary excretion of N-acetyl-β-D-glucosaminidase (EC 3.2.1.30) (NAG) in an experimental antiorthostatic rat model. The data indicate significant variations in the plasma ET-1 level in time, in the superior and inferior cava vessel blood of animals maintained for 10 days in hypogravity with respect to controls. These changes do not seem to be due to hemoconcentration. The increase in urinary NAG was observed during the first 24h of experiment, indicating renal stress, probably due to adverse blood flow variations within the organ. We conclude that the plasma ET-1 level changes could be responsible, overall for the blood flow variations in the kidney and renal stress could be the consequence of extended antiorthostatic hypokinesia. The ET-1 behaviour and urinary NAG excretion in rats exposed to antiorthostatic hypokjnetic hydynamia offer possibilities for understanding if these changes might be reversible or when they become pathological. This could give some relevant information about the effects of prolonged hypogravity during the space voyage.

  3. Key ecological responses to nitrogen are altered by climate change

    USGS Publications Warehouse

    Greaver, T.L.; Clark, C.M.; Compton, J.E.; Vallano, D.; Talhelm, A. F.; Weaver, C.P.; Band, L.E.; Baron, J. S.; Davidson, E.A.; Tague, C.L.; Felker-Quinn, E.; Lynch, J.A.; Herrick, J.D.; Liu, L.; Goodale, C.L.; Novak, K. J.; Haeuber, R. A.

    2016-01-01

    Climate change and anthropogenic nitrogen deposition are both important ecological threats. Evaluating their cumulative effects provides a more holistic view of ecosystem vulnerability to human activities, which would better inform policy decisions aimed to protect the sustainability of ecosystems. Our knowledge of the cumulative effects of these stressors is growing, but we lack an integrated understanding. In this Review, we describe how climate change alters key processes in terrestrial and freshwater ecosystems related to nitrogen cycling and availability, and the response of ecosystems to nitrogen addition in terms of carbon cycling, acidification and biodiversity.

  4. Key ecological responses to nitrogen are altered by climate change

    NASA Astrophysics Data System (ADS)

    Greaver, T. L.; Clark, C. M.; Compton, J. E.; Vallano, D.; Talhelm, A. F.; Weaver, C. P.; Band, L. E.; Baron, J. S.; Davidson, E. A.; Tague, C. L.; Felker-Quinn, E.; Lynch, J. A.; Herrick, J. D.; Liu, L.; Goodale, C. L.; Novak, K. J.; Haeuber, R. A.

    2016-09-01

    Climate change and anthropogenic nitrogen deposition are both important ecological threats. Evaluating their cumulative effects provides a more holistic view of ecosystem vulnerability to human activities, which would better inform policy decisions aimed to protect the sustainability of ecosystems. Our knowledge of the cumulative effects of these stressors is growing, but we lack an integrated understanding. In this Review, we describe how climate change alters key processes in terrestrial and freshwater ecosystems related to nitrogen cycling and availability, and the response of ecosystems to nitrogen addition in terms of carbon cycling, acidification and biodiversity.

  5. The albino mutation of tyrosinase alters ocular angiogenic responsiveness.

    PubMed

    Rogers, Michael S; Adini, Irit; McBride, Aaron F; Birsner, Amy E; D'Amato, Robert J

    2013-07-01

    We have observed substantial differences in angiogenic responsiveness in mice and have mapped the genetic loci responsible for these differences. We have found that the albino mutation is one of the loci responsible for such differences. Using B6.A consomic strains, we determined that chromosome 7 bears a locus that inhibits VEGF-induced corneal neovascularization. F2 crosses between B6.A consomic mice and C57BL/6J parents along with AXB and BXA recombinant inbred strains demonstrated highest linkage near the tyrosinase gene. This region was named AngVq4. Congenic animals confirmed this locus, but could not demonstrate that the classical tyrosinase albino (c) mutation was causative because of the existence of additional linked loci in the congenic region. However, in 1970, a second tyrosinase albino mutation (c-2J) arose in the C57BL/6J background at Jackson Labs. Testing this strain (C57BL/6J) demonstrated that the albino mutation is sufficient to completely explain the alteration in angiogenic response that we observed in congenic animals. Thus, we conclude that the classical tyrosinase mutation is responsible for AngVq4. In contrast to the cornea, where pigmented animals exhibit increased angiogenic responsiveness, iris neovascularization was inhibited in pigmented animals. These results may partially explain increased aggressiveness in amelanotic melanoma, as well as ethnic differences in diabetic retinopathy and macular degeneration. PMID:23423728

  6. HDL-S1P: cardiovascular functions, disease-associated alterations, and therapeutic applications

    PubMed Central

    Levkau, Bodo

    2015-01-01

    Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid contained in High-density lipoproteins (HDL) and has drawn considerable attention in the lipoprotein field as numerous studies have demonstrated its contribution to several functions inherent to HDL. Some of them are partly and some entirely due to the S1P contained in HDL (HDL-S1P). Despite the presence of over 1000 different lipids in HDL, S1P stands out as it possesses its own cell surface receptors through which it exercises key physiological functions. Most of the S1P in human plasma is associated with HDL, and the amount of HDL-S1P influences the quality and quantity of HDL-dependent functions. The main binding partner of S1P in HDL is apolipoprotein M but others may also exist particularly under conditions of acute S1P elevations. HDL not only exercise functions through their S1P content but have also an impact on genuine S1P signaling by influencing S1P bioactivity and receptor presentation. HDL-S1P content is altered in human diseases such as atherosclerosis, coronary artery disease, myocardial infarction, renal insufficiency and diabetes mellitus. Low HDL-S1P has also been linked to impaired HDL functions associated with these disorders. Although the pathophysiological and molecular reasons for such disease-associated shifts in HDL-S1P are little understood, there have been successful approaches to circumvent their adverse implications by pharmacologically increasing HDL-S1P as means to improve HDL function. This mini-review will cover the current understanding of the contribution of HDL-S1P to physiological HDL function, its alteration in disease and ways for its restoration to correct HDL dysfunction. PMID:26539121

  7. Greater cardiovascular responses to laboratory mental stress are associated with poor subsequent cardiovascular risk status: a meta-analysis of prospective evidence.

    PubMed

    Chida, Yoichi; Steptoe, Andrew

    2010-04-01

    An increasing number of studies has tested whether greater cardiovascular responses to acute mental stress predict future cardiovascular disease, but results have been variable. This review aimed quantitatively to evaluate the association between cardiovascular responses to laboratory mental stress and subsequent cardiovascular risk status in prospective cohort studies. We searched general bibliographic databases, PsycINFO, Web of Science, and PubMed, up to December 2009. Two reviewers independently extracted data on study characteristics, quality, and estimates of associations. There were 169 associations (36 articles) of stress reactivity and 30 associations (5 articles) of poststress recovery in relation to future cardiovascular risk status, including elevated blood pressure, hypertension, left ventricular mass, subclinical atherosclerosis, and clinical cardiac events. The overall meta-analyses showed that greater reactivity to and poor recovery from stress were associated longitudinally with poor cardiovascular status (r=0.091 [95% CI: 0.050 to 0.132], P<0.001, and r=0.096 [95% CI: 0.058 to 0.134], P<0.001, respectively). These findings were supported by more conservative analyses of aggregate effects and by subgroup analyses of the methodologically strong associations. Notably, incident hypertension and increased carotid intima-media thickness were more consistently predicted by greater stress reactivity and poor stress recovery, respectively, whereas both factors were associated with higher future systolic and diastolic blood pressures. In conclusion, the current meta-analysis suggests that greater responsivity to acute mental stress has an adverse effect on future cardiovascular risk status, supporting the use of methods of managing stress responsivity in the prevention and treatment of cardiovascular disease.

  8. Produced water exposure alters bacterial response to biocides.

    PubMed

    Vikram, Amit; Lipus, Daniel; Bibby, Kyle

    2014-11-01

    Microbial activity during the holding and reuse of wastewater from hydraulic fracturing operations, termed produced water, may lead to issues with corrosion, sulfide release, and fouling. Biocides are applied to control biological activity, often with limited efficacy, which is typically attributed to chemical interactions with the produced water. However, it is unknown whether there is a biologically driven mechanism to biocide tolerance in produced water. Here, we demonstrate that produced water exposure results in an enhanced tolerance against the typically used biocide glutaraldehyde and increased susceptibility to the oxidative biocide hypochlorite in a native and a model bacteria and that this altered resistance is due to the salinity of the produced water. In addition, we elucidate the genetic response of the model organism Pseudomonas fluorescens to produced water exposure to provide a mechanistic interpretation of the altered biocide resistance. The RNA-seq data demonstrated the induction of genes involved in osmotic stress, energy production and conversion, membrane integrity, and protein transport following produced water exposure, which facilitates bacterial survival and alters biocide tolerance. Efforts to fundamentally understand biocide resistance mechanisms, which enable the optimization of biocide application, hold significant implications for greening of the fracturing process through encouraging produced water recycling. Specifically, these results suggest the necessity of optimizing biocide application at the level of individual shale plays, rather than historical experience, based upon produced water characteristics and salinity. PMID:25279933

  9. Concord grape juice polyphenols and cardiovascular risk factors: dose-response relationships

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pure fruit juices provide nutritional value with evidence suggesting some of their benefits on biomarkers of cardiovascular disease risk may be derived from their constituent polyphenols, particularly flavonoids. However, few data from clinical trials are available on the dose-response relationship ...

  10. Appraisal, Coping, Task Performance, and Cardiovascular Responses during the Evaluated Speaking Task.

    ERIC Educational Resources Information Center

    Baggett, H. Lane; And Others

    1996-01-01

    Appraisal, coping, task performance, and cardiovascular responses were examined among men high and low in speech anxiety who prepared and performed a speech under evaluative conditions. Speech-anxious men saw the task as more threatening. They were more stressed, anxious, distracted, and aware of their emotions, focused on the passage of time, and…

  11. Adaptive Responses to Prochloraz Exposure That Alter Dose-Response and Time-Course Behaviors

    EPA Science Inventory

    Dose response and time-course (DRTC) are, along with exposure, the major determinants of health risk. Adaptive changes within exposed organisms in response to environmental stress are common, and alter DRTC behaviors to minimize the effects caused by stressors. In this project, ...

  12. Alterations of cardiovascular functional parameters after onset of heat stroke in rats.

    PubMed

    Young, M S; Pan, H F; Kao, T Y; Lin, M T

    1993-01-01

    The effects of heat stroke formation on electrocardiogram (ECG) and blood pressure (BP) waveform parameters were assessed in rats under urethane anesthesia. Heat stroke was induced by exposing anesthetized rats to an environmental temperature of 42 degrees C. The movement in which arterial pressure began to decrease was taken as the onset of heat stroke. It was found that the duration of either P were, Q wave, R wave, S wave, T wave or QRS complex, as well as the amplitude of either P wave, Q wave, S wave or T wave were not affected after onset of heat stroke. However, the amplitude of R wave, the P-P interval, the R-R interval and the Q-T interval were significantly decreased after onset of heat stroke. In addition, the peak amplitude of systolic wave, dicrotic notch, diastolic wave, the duration of either systolic wave, a whole BP cycle, diastolic wave or dicrotic wave, the pulse pressure, as well as the mean arterial pressure were also decreased after onset of heat stroke. On the other hand, heat stroke formation increased the heart rate. The results demonstrated that alterations of these ECG and BP waveform parameters occurred after onset of heat stroke in rats.

  13. Role of the autonomic nervous system and baroreflex in stress-evoked cardiovascular responses in rats.

    PubMed

    Dos Reis, Daniel Gustavo; Fortaleza, Eduardo Albino Trindade; Tavares, Rodrigo Fiacadori; Corrêa, Fernando Morgan Aguiar

    2014-07-01

    Restraint stress (RS) is an experimental model to study stress-related cardiovascular responses, characterized by sustained pressor and tachycardiac responses. We used pharmacologic and surgical procedures to investigate the role played by sympathetic nervous system (SNS) and parasympathetic nervous system (PSNS) in the mediation of stress-evoked cardiovascular responses. Ganglionic blockade with pentolinium significantly reduced RS-evoked pressor and tachycardiac responses. Intravenous treatment with homatropine methyl bromide did not affect the pressor response but increased tachycardia. Pretreatment with prazosin reduced the pressor and increased the tachycardiac response. Pretreatment with atenolol did not affect the pressor response but reduced tachycardia. The combined treatment with atenolol and prazosin reduced both pressor and tachycardiac responses. Adrenal demedullation reduced the pressor response without affecting tachycardia. Sinoaortic denervation increased pressor and tachycardiac responses. The results indicate that: (1) the RS-evoked cardiovascular response is mediated by the autonomic nervous system without an important involvement of humoral factors; (2) hypertension results primarily from sympathovascular and sympathoadrenal activation, without a significant involvement of the cardiac sympathetic component (CSNS); (3) the abrupt initial peak in the hypertensive response to restraint is sympathovascular-mediated, whereas the less intense but sustained hypertensive response observed throughout the remaining restraint session is mainly mediated by sympathoadrenal activation and epinephrine release; (4) tachycardia results from CSNS activation, and not from PSNS inhibition; (5) RS evokes simultaneous CSNS and PSNS activation, and heart rate changes are a vector of both influences; (6) the baroreflex is functional during restraint, and modulates both the vascular and cardiac responses to restraint.

  14. Cardiovascular and respiratory responses evoked from the posterior cerebellar cortex and fastigial nucleus in the cat.

    PubMed Central

    Bradley, D J; Pascoe, J P; Paton, J F; Spyer, K M

    1987-01-01

    1. In both anaesthetized and decerebrate cats the cerebellar cortex (lobules VI, VII, VIII, IX and X) and the fastigial nucleus (f.n.) have been stimulated electrically, and chemically, while recording changes in phrenic nerve discharge, heart rate, arterial blood pressure and renal and femoral blood flow. 2. Stimulation of lobules VI, VII, VIII and Xb failed to elicit any cardiovascular or respiratory changes. Activation of lobule IX (the uvula), and in some preparations sub-lobule Xa, evoked cardiovascular and respiratory responses consistently. In the anaesthetized cat, electrical stimulation of the uvula evoked apnoea, a small bradycardia and a depressor response associated with vasodilatation in the hindlimb vascular bed. In contrast, stimulation in an equivalent region in a decerebrate preparation elicited an apneustic discharge, a pronounced tachycardia and a rise in arterial pressure with vasoconstriction in both renal and femoral vascular beds. In both the anaesthetized and decerebrate animals the pattern of response elicited by chemical activation was identical to that seen with electrical stimulation. 3. Electrical, or chemical, stimulation after administration of anaesthetic to the decerebrate cat then evoked an identical pattern of response to that seen in the 'intact' anaesthetized animal. This evidence suggests that the reversal in the pattern of the response in an effect of the anaesthetic agent and not the decerebration itself. 4. The only area of the f.n. to produce cardiovascular effects was the rostral region. Electrical stimulation of the rostral f.n. in both anaesthetized and decerebrate preparations inhibited central inspiratory activity and evoked tachycardia, along with a pressor response associated with vasoconstriction in both renal and femoral vascular beds. In contrast, chemical excitation of those sites in the rostral f.n. shown previously to produce pronounced cardiovascular and respiratory changes failed to elicit any changes in the

  15. Comparing Visible and Invisible Social Support: Non-evaluative Support Buffers Cardiovascular Responses to Stress.

    PubMed

    Kirsch, Julie A; Lehman, Barbara J

    2015-12-01

    Previous research suggests that in contrast to invisible social support, visible social support produces exaggerated negative emotional responses. Drawing on work by Bolger and colleagues, this study disentangled social support visibility from negative social evaluation in an examination of the effects of social support on negative emotions and cardiovascular responses. As part of an anticipatory speech task, 73 female participants were randomly assigned to receive no social support, invisible social support, non-confounded visible social support or visible social support as delivered in a 2007 study by Bolger and Amarel. Twelve readings, each for systolic blood pressure, diastolic blood pressure and heart rate were taken at 5-min intervals throughout the periods of baseline, reactivity and recovery. Cardiovascular outcomes were tested by incorporating a series of theoretically driven planned contrasts into tests of stress reactivity conducted through piecewise growth curve modelling. Linear and quadratic trends established cardiovascular reactivity to the task. Further, in comparison to the control and replication conditions, the non-confounded visible and invisible social support conditions attenuated cardiovascular reactivity over time. Pre- and post-speech negative emotional responses were not affected by the social support manipulations. These results suggest that appropriately delivered visible social support may be as beneficial as invisible social support.

  16. Cardiovascular response to lower body negative pressure stimulation before, during, and after space flight

    NASA Technical Reports Server (NTRS)

    Baisch, F.; Beck, L.; Blomqvist, G.; Wolfram, G.; Drescher, J.; Rome, J. L.; Drummer, C.

    2000-01-01

    BACKGROUND: It is well known that space travel cause post-flight orthostatic hypotension and it was assumed that autonomic cardiovascular control deteriorates in space. Lower body negative pressure (LBNP) was used to assess autonomic function of the cardiovascular system. METHODS: LBNP tests were performed on six crew-members before and on the first days post-flight in a series of three space missions. Additionally, two of the subjects performed LBNP tests in-flight. LBNP mimics fluid distribution of upright posture in a gravity independent way. It causes an artificial sequestration of blood, reduces preload, and filtrates plasma into the lower part of the body. Fluid distribution was assessed by bioelectrical impedance and anthropometric measurements. RESULTS: Heart rate, blood pressure, and total peripheral resistance increased significantly during LBNP experiments in-flight. The decrease in stroke volume, the increased pooling of blood, and the increased filtration of plasma into the lower limbs during LBNP indicated that a plasma volume reduction and a deficit of the interstitial volume of lower limbs rather than a change in cardiovascular control was responsible for the in-flight response. Post-flight LBNP showed no signs of cardiovascular deterioration. The still more pronounced haemodynamic changes during LBNP reflected the expected behaviour of cardiovascular control faced with less intravascular volume. In-flight, the status of an intra-and extravascular fluid deficit increases sympathetic activity, the release of vasoactive substances and consequently blood pressure. Post-flight, blood pressure decreases significantly below pre-flight values after restoration of volume deficits. CONCLUSION: We conclude that the cardiovascular changes in-flight are a consequence of a fluid deficit rather than a consequence of changes in autonomic signal processing.

  17. Asplatin enhances drug efficacy by altering the cellular response.

    PubMed

    Cheng, Qinqin; Shi, Hongdong; Wang, Hongxia; Wang, Jun; Liu, Yangzhong

    2016-07-13

    Aspirin, a widely used anti-inflammatory drug, has been shown to be effective for the prevention and remission of cancers (Science, 2012, 337(21) 1471-1473). Asplatin, a Pt(iv) prodrug of cisplatin with the ligation of aspirin (c,c,t-[PtCl2(NH3)2(OH)(aspirin)]), demonstrates significantly higher cytotoxicity than cisplatin towards tumor cells and almost fully overcomes the drug resistance of cisplatin resistant cells. In this work, we have studied the molecular mechanism of asplatin by investigating the cellular response to this compound in order to understand the prominent inhibitory effect on the proliferation of cancer cells. The apoptosis analyses and the related gene expression measurements show that aspirin released from asplatin significantly modulates the cellular response to the platinum agent. Asplatin promotes the apoptosis via the BCL-2 associated mitochondrial pathway. The down-regulation of BCL-2 along with the up-regulation of BAX and BAK enhances the mitochondrial outer membrane permeability, resulting in the cytochrome c release from mitochondria into the cytosol. This event promotes the apoptosis by activation of caspase processing. Consequently, the ligation of aspirin significantly enhances the drug efficacy of the platinum complex in the low micromolar range. The alteration of the cellular response is probably responsible for the circumvention of the cisplatin resistance by asplatin. These results provide an insight into the mechanism of asplatin and provide information for designing new classic platinum drugs. PMID:27125788

  18. Cardiovascular activity in blood-injection-injury phobia during exposure: evidence for diphasic response patterns?

    PubMed

    Ritz, Thomas; Meuret, Alicia E; Simon, Erica

    2013-08-01

    Exposure to feared stimuli in blood-injection-injury (BII)-phobia is thought to elicit a diphasic response pattern, with an initial fight-flight-like cardiovascular activation followed by a marked deactivation and possible fainting (vasovagal syncope). However, studies have remained equivocal on the importance of such patterns. We therefore sought to determine the prevalence and clinical relevance of diphasic responses using criteria that require a true diphasic response to exceed cardiovascular activation of an emotional episode of a negative valence and to exceed deactivation of an emotionally neutral episode. Sixty BII-phobia participants and 20 healthy controls were exposed to surgery, anger and neutral films while measuring heart rate, blood pressure, respiratory pattern, and end-tidal partial pressure of carbon dioxide (as indicator of hyperventilation). Diphasic response patterns were observed in up to 20% of BII-phobia participants and 26.6% of healthy controls for individual cardiovascular parameters. BII-phobia participants with diphasic patterns across multiple parameters showed more fear of injections and blood draws, reported the strongest physical symptoms during the surgery film, and showed the strongest tendency to hyperventilate. Thus, although only a minority of individuals with BII phobia shows diphasic responses, their occurrence indicates significant distress. Respiratory training may add to the treatment of BII phobia patients that show diphasic response patterns.

  19. Bisphenol A Alters Autonomic Tone and Extracellular Matrix Structure and Induces Sex-Specific Effects on Cardiovascular Function in Male and Female CD-1 Mice

    PubMed Central

    Gear, Robin B.; Kendig, Eric L.

    2015-01-01

    The aim of this study was to determine whether bisphenol A (BPA) has adverse effects on cardiovascular functions in CD-1 mice and define sex-specific modes of BPA action in the heart. Dams and analyzed progeny were maintained on a defined diet containing BPA (0.03, 0.3, 3, 30, or 300 ppm) that resulted in BPA exposures from 4–5 to approximately 5000 μg/kg · d or a diet containing 17α-ethinyl estradiol (EE; ∼0.02, 0.2, and 0.15 μg/kg · d) as an oral bioavailable estrogen control. Assessment of electrocardiogram parameters using noninvasive methods found that ventricular functions in both male and female mice were not altered by either BPA or EE. However, exposure-related changes in the rates of ventricular contraction, suggestive of a shift in sympathovagal balance of heart rate control toward increased parasympathetic activity, were detected in males. Decreased systolic blood pressure was observed in males exposed to BPA above 5 μg/kg · d and in females from the highest BPA exposure group. Morphometric histological measures revealed sexually dimorphic changes in the composition of the cardiac collagen extracellular matrix, increases in fibrosis, and evidence of modest exposure-related remodeling. Experiments using the α-selective adrenergic agonist phenylephrine found that BPA enhanced reflex bradycardia in females, but not males, revealed that BPA and EE exposure sex specifically altered the sympathetic regulation of the baroreflex circuits. Increased sensitivity to the cardiotoxic effects of the β-adrenergic agonist isoproterenol was observed in BPA- and EE-exposed females. This effect was not observed in males, in which BPA or EE exposures were protective of isoproterenol-induced ischemic damage and hypertrophy. The results of RNA sequence analysis identified significant sex-specific changes in gene expression in response to BPA that were consistent with the observed exposure-related phenotypic changes in the collagenous and noncollagenous

  20. Cardiovascular response to apneic immersion in cool and warm water

    NASA Technical Reports Server (NTRS)

    Folinsbee, L.

    1974-01-01

    The influence of prior exposure to cool water and the influence of lung volume on the responses to breath holding were examined. The bradycardia and vasoconstriction that occur during breath-hold diving in man are apparently the resultant of stimuli from apnea, relative expansion of the thorax, lung volume, esophageal pressure, face immersion, and thermal receptor stimulation. It is concluded that the bradycardia and vasoconstriction associated with breath holding during body immersion are not attenuated by a preexisting bradycardia and vasoconstriction due to cold.

  1. Endothelial Inflammatory Transcriptional Responses to an Altered Plasma Exposome Following Inhalation of Diesel Emissions

    EPA Science Inventory

    BACKGROUND:Air pollution, especially emissions derived from traffic sources, is associated with adverse cardiovascular outcomes. However, it remains unclear how inhaled factors drive extrapulmonary pathology.OBJECTIVES:Previously, we found that canonical inflammatory response tra...

  2. Pentobarbital anesthesia alters pulmonary vascular response to neural antagonists.

    PubMed

    Nyhan, D P; Goll, H M; Chen, B B; Fehr, D M; Clougherty, P W; Murray, P A

    1989-05-01

    We investigated the effects of pentobarbital sodium anesthesia on vasoregulation of the pulmonary circulation. Our specific objectives were to 1) assess the net effect of pentobarbital on the base-line pulmonary vascular pressure-to-cardiac index (P/Q) relationship compared with that measured in conscious dogs, and 2) determine whether autonomic nervous system (ANS) regulation of the intact P/Q relationship is altered during pentobarbital. P/Q plots were constructed by graded constriction of the thoracic inferior vena cava, which produced stepwise decreases in Q. Pentobarbital (30 mg/kg iv) had no net effect on the base-line P/Q relationship. In contrast, changes in the conscious intact P/Q relationship in response to ANS antagonists were markedly altered during pentobarbital. Sympathetic alpha-adrenergic receptor block with prazosin caused active pulmonary vasodilation (P less than 0.01) in conscious dogs but caused vasoconstriction (P less than 0.01) during pentobarbital. Sympathetic beta-adrenergic receptor block with propranolol caused active pulmonary vasoconstriction (P less than 0.01) in both groups, but the magnitude of the vasoconstriction was attenuated (P less than 0.05) during pentobarbital at most levels of Q. Finally, cholinergic receptor block with atropine resulted in active pulmonary vasodilation (P less than 0.01) in conscious dogs, whereas vasoconstriction (P less than 0.01) was observed during pentobarbital. Thus, although pentobarbital had no net effect on the base-line P/Q relationship measured in conscious dogs, ANS regulation of the intact pulmonary vascular P/Q relationship was altered during pentobarbital anesthesia. PMID:2566280

  3. Altered T cell responses in children with autism

    PubMed Central

    Ashwood, Paul; Krakowiak, Paula; Hertz-Picciotto, Irva; Hansen, Robin; Pessah, Isaac N.; Van de Water, Judy

    2010-01-01

    Autism spectrum disorders (ASD) are characterized by impairment in social interactions, communication deficits, and restricted repetitive interests and behaviors. A potential etiologic role for immune dysfunction in ASD has been suggested. Dynamic adaptive cellular immune function was investigated in 66 children with a confirmed diagnosis of ASD and 73 confirmed typically developing (TD) controls 2–5 years-of-age. In vitro stimulation of peripheral blood mononuclear cells with PHA and tetanus was used to compare group-associated cellular responses. The production of GM-CSF, TNFα, and IL-13 were significantly increased whereas IL-12p40 was decreased following PHA stimulation in ASD relative to TD controls. Induced cytokine production was associated with altered behaviors in ASD children such that increased pro-inflammatory or TH1 cytokines were associated with greater impairments in core features of ASD as well as aberrant behaviors. In contrast, production of GM-CSF and TH2 cytokines were associated with better cognitive and adaptive function. Following stimulation, the frequency of CD3+, CD4+ and CD8+ T cells expressing activation markers CD134 and CD25 but not CD69, HLA-DR or CD137 were significantly reduced in ASD, and suggests an altered activation profile for T cells in ASD. Overall these data indicate significantly altered adaptive cellular immune function in children with ASD that may reflect dysfunctional immune activation, along with evidence that these perturbations may be linked to disturbances in behavior and developmental functioning. Further longitudinal analyzes of cellular immunity profiles would delineate the relationship between immune dysfunction and the progression of behavioral and developmental changes throughout the course of this disorder. PMID:20833247

  4. Effects of lower body positive pressure on cardiovascular responses during walking in elderly women.

    PubMed

    Sota, T; Matsuo, S; Uchida, Y; Hagino, H; Kawai, Y

    2013-01-01

    This study was undertaken to investigate the effects of lower body positive pressure (LBPP) on cardiovascular responses during a 15-min walking trial in young (22.1+/-0.4 years) and elderly women (67.8+/-1.1 years). The application of 20 mm Hg LBPP reduced ground reaction forces by 31.2+/-0.5 kgw in both groups. We hypothesized that cardiovascular responses to LBPP during walking were different between the young and elderly subjects. Applying 20 mm Hg of LBPP increased diastolic and mean blood pressure but not systolic blood pressure in both groups. LBPP-induced reduction in heart rate (HR) occurred more quickly in the young group compared to the elderly group (p<0.05). Applying LBPP also decreased double product (systolic blood pressure x HR) in both groups, suggesting that LBPP reduces myocardial oxygen consumption during exercise. These results suggest that heart rate responses to LBPP during exercise vary with increasing age.

  5. How linear features alter predator movement and the functional response.

    PubMed

    McKenzie, Hannah W; Merrill, Evelyn H; Spiteri, Raymond J; Lewis, Mark A

    2012-04-01

    In areas of oil and gas exploration, seismic lines have been reported to alter the movement patterns of wolves (Canis lupus). We developed a mechanistic first passage time model, based on an anisotropic elliptic partial differential equation, and used this to explore how wolf movement responses to seismic lines influence the encounter rate of the wolves with their prey. The model was parametrized using 5 min GPS location data. These data showed that wolves travelled faster on seismic lines and had a higher probability of staying on a seismic line once they were on it. We simulated wolf movement on a range of seismic line densities and drew implications for the rate of predator-prey interactions as described by the functional response. The functional response exhibited a more than linear increase with respect to prey density (type III) as well as interactions with seismic line density. Encounter rates were significantly higher in landscapes with high seismic line density and were most pronounced at low prey densities. This suggests that prey at low population densities are at higher risk in environments with a high seismic line density unless they learn to avoid them. PMID:22419990

  6. Altered responsiveness to chemokines due to targeted disruption of SHIP

    PubMed Central

    Kim, Chang H.; Hangoc, Giao; Cooper, Scott; Helgason, Cheryl D.; Yew, Sandie; Humphries, R. Keith; Krystal, Gerald; Broxmeyer, Hal E.

    1999-01-01

    SHIP has been implicated in negative signaling in a number of hematopoietic cell types and is postulated to downregulate phosphatidylinositol-3-kinase– (PI-3K–) initiated events in diverse receptor signaling pathways. Because PI-3K is implicated in chemokine signaling, we investigated whether SHIP plays any role in cellular responses to chemokines. We found that a number of immature and mature hematopoietic cells from SHIP-deficient mice manifested enhanced directional migration (chemotaxis) in response to the chemokines stromal cell–derived factor-1 (SDF-1) and B-lymphocyte chemoattractant (BLC). SHIP–/– cells were also more active in calcium influx and actin polymerization in response to SDF-1. However, colony formation by SHIP-deficient hematopoietic progenitor cell (HPCs) was not inhibited by 13 myelosuppressive chemokines that normally inhibit proliferation of HPCs. These altered biologic activities of chemokines on SHIP-deficient cells are not caused by simple modulation of chemokine receptor expression in SHIP-deficient mice, implicating SHIP in the modulation of chemokine-induced signaling and downstream effects. J. Clin. Invest. 104:1751–1759 (1999). PMID:10606629

  7. Alteration of Plant Primary Metabolism in Response to Insect Herbivory.

    PubMed

    Zhou, Shaoqun; Lou, Yann-Ru; Tzin, Vered; Jander, Georg

    2015-11-01

    Plants in nature, which are continuously challenged by diverse insect herbivores, produce constitutive and inducible defenses to reduce insect damage and preserve their own fitness. In addition to inducing pathways that are directly responsible for the production of toxic and deterrent compounds, insect herbivory causes numerous changes in plant primary metabolism. Whereas the functions of defensive metabolites such as alkaloids, terpenes, and glucosinolates have been studied extensively, the fitness benefits of changes in photosynthesis, carbon transport, and nitrogen allocation remain less well understood. Adding to the complexity of the observed responses, the feeding habits of different insect herbivores can significantly influence the induced changes in plant primary metabolism. In this review, we summarize experimental data addressing the significance of insect feeding habits, as related to herbivore-induced changes in plant primary metabolism. Where possible, we link these physiological changes with current understanding of their underlying molecular mechanisms. Finally, we discuss the potential fitness benefits that host plants receive from altering their primary metabolism in response to insect herbivory.

  8. Social Support and Networks: Cardiovascular Responses Following Recall on Immigration Stress Among Chinese Americans

    PubMed Central

    Suchday, Sonia; Wylie-Rosett, Judith

    2014-01-01

    Social support has been shown to act as a buffer for cardiovascular responses to stress. However, little is known about how social support and networks are related to cardiovascular responses to immigration stress recall. The current study evaluated the impact of structural and functional support on cardiovascular reaction following immigrant stress recall provocation as well as the moderation effect of interdependent self-construal among first-generation Chinese immigrants. One hundred fifty Chinese immigrants were recruited in the New York Chinatown area. Participants completed questionnaires assessing their levels of social support and networks, and interdependent self-construal. Following adaptation, participants recalled a recent post-immigration stress-provoking situation. Cardiovascular measures were taken during adaptation, stressor task, and recovery period. Hierarchical multiple regression analysis was performed. Social network size and type, as well as perceived emotional support were positively predictive of systolic blood pressure (SBP) reactivity changes. Instrumental support seeking was a positive predictor of SBP and diastolic blood pressure (DBP) reactivity. The moderation effect between instrumental support seeking and interdependent self-construal were significantly predictive of DBP reactivity and recovery, suggesting that perceptions about themselves in relation to others is a crucial factor for determining whether support seeking is beneficial or not. Social support was not a direct buffer on cardiovascular responses to stress among Chinese immigrants. Chinese values of interdependence and collectivism may partly explain the disconfirming results. Still, when interdependent self-construal was taken into account, Chinese immigrants who had less interdependent self-construal, but solicited more instrumental support, had faster adaptation to stress over the long term. PMID:24288021

  9. Compassion training alters altruism and neural responses to suffering

    PubMed Central

    Weng, Helen Y.; Fox, Andrew S.; Shackman, Alexander J.; Stodola, Diane E.; Caldwell, Jessica Z. K.; Olson, Matthew C.; Rogers, Gregory M.; Davidson, Richard J.

    2013-01-01

    Compassion is a key motivator of altruistic behavior, but little is known about individuals’ capacity to cultivate compassion through training. We examined whether compassion may be systematically trained by testing whether (i) short-term compassion training increases altruistic behavior, and (ii) individual differences in altruism are associated with training-induced changes in neural responses to suffering. In healthy young adults, we found that compassion training increased altruistic redistribution of funds to a victim encountered outside of the training context. Furthermore, greater altruistic behavior after compassion training was associated with altered activation in regions implicated in social cognition and emotion regulation, including the inferior parietal cortex, dorsolateral prefrontal cortex (DLPFC), and DLPFC connectivity with the nucleus accumbens. These results suggest that compassion can be cultivated with training, where greater altruistic behavior may emerge from increased engagement in neural systems implicated in understanding the suffering of others, executive and emotional control, and reward processing. PMID:23696200

  10. Streamflow response to increasing precipitation extremes altered by forest management

    NASA Astrophysics Data System (ADS)

    Kelly, Charlene N.; McGuire, Kevin J.; Miniat, Chelcy Ford; Vose, James M.

    2016-04-01

    Increases in extreme precipitation events of floods and droughts are expected to occur worldwide. The increase in extreme events will result in changes in streamflow that are expected to affect water availability for human consumption and aquatic ecosystem function. We present an analysis that may greatly improve current streamflow models by quantifying the impact of the interaction between forest management and precipitation. We use daily long-term data from paired watersheds that have undergone forest harvest or species conversion. We find that interactive effects of climate change, represented by changes in observed precipitation trends, and forest management regime, significantly alter expected streamflow most often during extreme events, ranging from a decrease of 59% to an increase of 40% in streamflow, depending upon management. Our results suggest that vegetation might be managed to compensate for hydrologic responses due to climate change to help mitigate effects of extreme changes in precipitation.

  11. Cardiovascular responses during free-diving in the sea.

    PubMed

    Marongiu, E; Crisafulli, A; Ghiani, G; Olla, S; Roberto, S; Pinna, M; Pusceddu, M; Palazzolo, G; Sanna, I; Concu, A; Tocco, F

    2015-04-01

    Cardiac output has never been assessed during free-diving diving in the sea. Knowledge of human diving response in this setting is therefore scarce. 3 immersions were performed by 7 divers: at depths of 10 m, 20 m and 30 m. Each test consisted of 3 apnea phases: descent, static and ascent. An impedance cardiograph provided data on stroke volume, heart rate and cardiac output. Mean blood pressure, arterial O2 saturation and blood lactate values were also collected. Starting from a resting value of 4.5±1.6 L∙min(-1), cardiac output at 10 m showed an increase up to 7.1±2.2 L∙min(-1) (p<0.01) during the descent, while conditions during the static and ascent phases remained unchanged. At 20 m cardiac output values were 7.3±2.4 L∙min(-1) and 6.7(±1).2 L∙min(-1) during ascent and descent, respectively (p<0.01), and 4.3±0.9 L∙min(-1) during static phase. At 30 m cardiac output values were 6.5±1.8 L∙min(-1) and 7.5±2 L∙min(-1) during descent and ascent, respectively (p<0.01), and 4.7±2.1 L∙min(-1) during static phase. Arterial O2 saturation decreased with increasing dive depth, reaching 91.1±3.4% (p<0.001 vs. rest) upon emergence from a depth of 30 m. Blood lactate values increased to 4.1±1.2 mmol∙L(-1) at the end of the 30 m dive (p<0.001 vs. rest). Results seem to suggest that simultaneous activation of exercise and diving response could lead to an absence of cardiac output reduction aimed at an oxygen-conserving effect.

  12. Cardiovascular response to exercise and training in the horse.

    PubMed

    Physick-Sheard, P W

    1985-08-01

    The quality of the overall response to exercise in the horse is very similar to that seen in man and laboratory animals; differences are mainly quantitative and persist when relative body weight is taken into account. The apparently greater flow capacity of the equine muscle bed during maximal whole-body exercise implicates the extent of central circulatory adaptations as the limiting factor in performance but implies a role for increase in arteriolar capacitance/muscle capillarity as an appropriate response to intense endurance training. The blood oxygen-carrying capacity of the horse is often quoted as the major component of the animal's superior aerobic work capacity, although the measured maximal a-vO2 for the horse is only 2 to 3 ml greater than that found in elite athletes. In fact, comparison of published performance data for man and the horse reveals that improved a-vO2 accounts for 23 per cent of the difference, and increased Qc accounts for the remaining 77 per cent of the superior oxygen consumption in the horse. The extent to which the horse can increase Qc and muscle blood flow appears to represent its major adaptations for maximal aerobic performance. It is frequently observed that there have been far greater improvements in human athletic performance than in that of the race-horse, and this difference is usually attributed to the application of scientific training methods to the athlete. It has also been suggested that the horse may have reached the limit of its adaptive ability. The horse has a maximal oxygen pulse of at least 0.6 ml per kg per beat compared with 0.35 for man, a 90 per cent whole body oxygen extraction, and an 80 to 90 per cent higher muscle blood flow, with an overall capability of increasing Vo2 max by 35 times. These represent levels that would appear to be difficult to improve upon. However, insufficient research has been performed to firmly state true maxima for the horse, and current research does not reveal to what extent the

  13. A Proposed Study Examining Individual Differences in Temporal Profiles of Cardiovascular Responses to Head Down Tilt During Fluid Loading

    NASA Technical Reports Server (NTRS)

    Cowings, Patricia; Toscano, William; Winther, Sean; Martinez, Jacqueline; Dominguez, Margaret

    2012-01-01

    Susceptibility of healthy astronauts to orthostatic hypotension and presyncope is exacerbated upon return from spaceflight. The effect of altered gravity during space flight and planetary transition on human cardiovascular function is of critical importance to maintenance of astronaut health and safety. Hypovolemia, reduced plasma volume, is suspected to play an important role in cardiovascular deconditioning following exposure to spaceflight, which may lead to increased peripheral resistance, attenuated arterial baroreflex, and changes in cardiac function. A promising countermeasure for post-flight orthostatic intolerance is fluid loading used to restore lost plasma volume by giving crew salt tablets and water prior to re-entry. The main purpose of the proposed study is to define the temporal profile of cardiac responses to simulated 0-G conditions before and following a fluid loading countermeasure. 8 men and 8 women will be tested during 4 hour exposures at 6o head down tilt (HDT). Each subject will be given two exposures to HDT on separate days, one with and one without fluid loading (one liter of 0.9% saline solution). Stand tests (orthostatic stress) will be done before and after each HDT. Cardiac measures will be obtained with both impedance cardiography and echo ultrasound

  14. Effects of arginine vasotocin (AVT) on the behavioral, cardiovascular, and corticosterone responses of starlings (Sturnus vulgaris) to crowding.

    PubMed

    Nephew, Benjamin C; Aaron, Robert S; Romero, L Michael

    2005-03-01

    Previous studies in European starlings have concluded that conspecific crowding can be a significant stressor that is capable of simultaneously altering behavior, heart rate, and corticosterone (CORT) concentrations. It was hypothesized that the peptide hormone arginine vasotocin (AVT) has a role in the regulation of these three types of responses to crowding. Four male and four female resident starlings were submitted to nine combinations of 3 crowding treatments (0, 1, or 5 intruder starlings) and 3 subcutaneous injections (1, 4 microg AVT, and saline control). Resident starlings were given a treatment injection, their heart rate and behavior were monitored for 30 min, 0, 1, or 5 intruder Starlings were allowed to enter the residents cage, and HR and behavior were monitored for another 30 min. Blood samples were taken before and after all treatments to assess CORT concentrations. Exogenous AVT decreased the frequency of maintenance behaviors (feeding, drinking, preening, and beak wiping), as well as activity in resident starlings. Although aggressive behaviors upright posture, head feather expansion, and pecking) increased during crowding, these increases were significantly attenuated by AVT. Heart rate was significantly lower during these behavioral effects, and the CORT data indicate that the cardiovascular and behavioral effects are not dependent on significant increases in CORT. These data support the hypothesis that AVT's attenuation of general behavior and crowding induced aggression are modulated by a cardiovascular mechanism. PMID:15708756

  15. Habitual alcohol consumption is associated with lower cardiovascular stress responses--a novel explanation for the known cardiovascular benefits of alcohol?

    PubMed

    Jones, Alexander; McMillan, Merlin R; Jones, Russell W; Kowalik, Grzegorz T; Steeden, Jennifer A; Pruessner, Jens C; Taylor, Andrew M; Deanfield, John E; Muthurangu, Vivek

    2013-07-01

    In contrast to heavy alcohol consumption, which is harmful, light to moderate drinking has been linked to reduced cardiovascular morbidity and mortality. Effects on lipid status or clotting do not fully explain these benefits. Exaggerated cardiovascular responses to mental stress are detrimental to cardiovascular health. We hypothesized that habitual alcohol consumption might reduce these responses, with potential benefits. Advanced magnetic resonance techniques were used to accurately measure cardiovascular responses to an acute mental stressor (Montreal Imaging Stress Task) in 88 healthy adults (∼1:1 male:female). Salivary cortisol and task performance measures were used to assess endocrine and cognitive responses. Habitual alcohol consumption and confounding factors were assessed by questionnaire. Alcohol consumption was inversely related to responses of heart rate (HR) (r = -0.31, p = 0.01), cardiac output (CO) (r = -0.32, p = 0.01), vascular resistance (r = 0.25, p = 0.04) and mean blood pressure (r = -0.31, p = 0.01) provoked by stress, but not to stroke volume (SV), or arterial compliance changes. However, high alcohol consumers had greater cortisol stress responses, compared to moderate consumers (3.5 versus 0.7 nmol/L, p = 0.04). Cognitive measures did not differ. Findings were not explained by variations in age, sex, social class, ethnicity, physical activity, adrenocortical activity, adiposity, smoking, menstrual phase and chronic stress. Habitual alcohol consumption is associated with reduced cardiac responsiveness during mental stress, which has been linked to lower risk of hypertension and vascular disease. Consistent with established evidence, our findings suggest a mechanism by which moderate alcohol consumption might reduce cardiovascular disease, but not high consumption, where effects such as greater cortisol stress responses may negate any benefits.

  16. The role of neuropeptide Y in the ovine fetal cardiovascular response to reduced oxygenation

    PubMed Central

    Sanhueza, Emilia M; Johansen-Bibby, Anja A; Fletcher, Andrew J W; Riquelme, Raquel A; Daniels, Alejandro J; Serón-Ferré, Maria; Gaete, Cristián R; Carrasco, Jorge E; Llanos, Aníbal J; Giussani, Dino A

    2003-01-01

    This study investigated the role of neuropeptide Y (NPY) in mediating cardiovascular responses to reduced oxygenation in the late gestation ovine fetus by: (1) comparing the effects on the cardiovascular system of an exogenous infusion of NPY with those elicited by moderate or severe reductions in fetal oxygenation; and (2) determining the effect of fetal i.v. treatment with a selective NPY-Y1 receptor antagonist on the fetal cardiovascular responses to acute moderate hypoxaemia. Under general anaesthesia, 14 sheep fetuses (0.8–0.9 of gestation) were surgically prepared with vascular and amniotic catheters. In 5 of these fetuses, a Transonic flow probe was also implanted around a femoral artery. Following at least 5 days of recovery, one group of fetuses (n = 9) was subjected to a 30 min treatment period with exogenous NPY (17 μg kg−1 bolus plus 0.85 μg kg−1 min−1 infusion). In this group, fetal blood pressure and heart rate were monitored continuously and the distribution of the fetal combined ventricular output was assessed via injection of radiolabelled microspheres before and during treatment. The second group of fetuses instrumented with the femoral flow probe (n = 5) were subjected to a 3 h experiment consisting of 1 h of normoxia, 1 h of hypoxaemia, and 1 h of recovery during a slow i.v. infusion of vehicle. One or two days later, the acute hypoxaemia protocol was repeated during fetal i.v. treatment with a selective NPY-Y1 receptor antagonist (50 μg kg−1bolus + 1.5 μg kg−1 min−1 infusion). In these fetuses, fetal arterial blood pressure, heart rate and femoral vascular resistance were recorded continuously. The results show that fetal treatment with exogenous NPY mimics the fetal cardiovascular responses to asphyxia, and that treatment of the sheep fetus with a selective NPY-Y1 receptor antagonist does not affect the fetal cardiovascular response to acute moderate hypoxaemia. These results support a greater role for NPY in mediating the

  17. Mind over Matter: Reappraising Arousal Improves Cardiovascular and Cognitive Responses to Stress

    PubMed Central

    Jamieson, Jeremy P.; Nock, Matthew K.; Mendes, Wendy Berry

    2012-01-01

    Researchers have theorized that changing the way we think about our bodily responses can improve our physiological and cognitive reactions to stressful events. However, the underlying processes through which mental states improve downstream outcomes are not well-understood. To this end, we examined whether reappraising stress-induced arousal could improve cardiovascular outcomes and decrease attentional bias for emotionally-negative information. Participants were randomly assigned to either a reappraisal condition in which they were instructed to think about their physiological arousal during a stressful task as functional and adaptive, or to one of two control conditions: attention reorientation and no instructions. Relative to controls, participants instructed to reappraise their arousal exhibited more adaptive cardiovascular stress responses – increased cardiac efficiency and lower vascular resistance – and decreased attentional bias. Thus, reappraising arousal shows physiological and cognitive benefits. Implications for health and potential clinical applications are discussed. PMID:21942377

  18. Mutants of PC12 cells with altered cyclic AMP responses

    SciTech Connect

    Block, T.; Kon, C.; Breckenridge, B.M.

    1984-10-01

    PCl2 cells, derived from a rat pheochromocytoma, were mutagenized and selected in media containing agents known to elevate intracellular concentrations of cyclic AMP (cAMP). More than 40 clones were isolated by selection with cholera toxin or 2-chloroadenosine or both. The variants that were deficient in accumulating cAMP were obtained by using a protocol in which 1 ..mu..m 8-bromo-cAMP was included in addition to the agonist. Certain of these variants were partially characterized with respect to the site of altered cAMP metabolism. The profiles of adenylate cyclase activity responsiveness of certain variants to guanosine-5'-(BETA,..gamma..-imido) triphosphate and to forskolin resembled those of UNC and cyc phenotypes of S49 lymphoma cells, which are functionally deficient in the GTP-sensitive coupling protein, N/sub s/. Other variants were characterized by increased cyclic nucleotide phosphodiesterase activity at low substrate concentration. Diverse morphological traits were observed among the variants, but it was not possible to assign them to a particular cAMP phenotype. Two revertants of a PCl2 mutant were isolated and observed to have regained a cellular cAMP response to 2-chloroadenosine and to forskolin. It is hoped that these PCl2 mutants will have utility for defining cAMP-mediated functions, including any links to the action of nerve growth factor, in cells derived from the neural crest.

  19. Amphetamine alters neural response to sucrose in healthy women.

    PubMed

    Melrose, A James; Bailer, Ursula; Wierenga, Christina E; Bischoff-Grethe, Amanda; Paulus, Martin P; Kaye, Walter H

    2016-06-30

    Amphetamine, likely via action on the brain's dopaminergic systems, induces anorectic eating behavior and blunts dopaminergic midbrain activation to rewards. Past work has hypothesized that this blunted reward responsivity is a result of increasing tonic over phasic DA activity. We sought to extend past findings to sweet taste during fMRI following single-blind administration of dextroamphetamine and placebo in 11 healthy women. We hypothesized that neural response in both limbic and cognitive sweet taste circuits would mirror past work with monetary rewards by effectively blunting sweet taste reward, and 'equalizing' it's rewarding taste with receipt of water. Behavioral results showed that amphetamine reduced self-reported hunger (supporting the existence of amphetamine anorexia) and increased self-report euphoria. In addition, region of Interest analysis revealed significant treatment by taste interactions in the middle insula and dorsal anterior cingulate confirming the 'equalizing' hypothesis in the cingulate, but unlike monetary reinforcers, the insula actually evinced enhanced separation between tastes on the amphetamine day. These results suggest a divergence from prior research using monetary reinforcers when extended to primary reinforcers, and may hint that altering dopaminergic signaling in the insula and anterior cingulate may be a target for pharmacological manipulation of appetite, and the treatment of obesity. PMID:27179312

  20. Altered brain response for semantic knowledge in Alzheimer's disease.

    PubMed

    Wierenga, Christina E; Stricker, Nikki H; McCauley, Ashley; Simmons, Alan; Jak, Amy J; Chang, Yu-Ling; Nation, Daniel A; Bangen, Katherine J; Salmon, David P; Bondi, Mark W

    2011-02-01

    Word retrieval deficits are common in Alzheimer's disease (AD) and are thought to reflect a degradation of semantic memory. Yet, the nature of semantic deterioration in AD and the underlying neural correlates of these semantic memory changes remain largely unknown. We examined the semantic memory impairment in AD by investigating the neural correlates of category knowledge (e.g., living vs. nonliving) and featural processing (global vs. local visual information). During event-related fMRI, 10 adults diagnosed with mild AD and 22 cognitively normal (CN) older adults named aloud items from three categories for which processing of specific visual features has previously been dissociated from categorical features. Results showed widespread group differences in the categorical representation of semantic knowledge in several language-related brain areas. For example, the right inferior frontal gyrus showed selective brain response for nonliving items in the CN group but living items in the AD group. Additionally, the AD group showed increased brain response for word retrieval irrespective of category in Broca's homologue in the right hemisphere and rostral cingulate cortex bilaterally, which suggests greater recruitment of frontally mediated neural compensatory mechanisms in the face of semantic alteration. PMID:21163275

  1. Welsh onion (Allium fistulosum L.) extracts alter vascular responses in rat aortae.

    PubMed

    Chen, J H; Tsai, S J; Chen, H I

    1999-04-01

    Welsh onion, a member of the genus Allium, has been consumed for prevention of cardiovascular disorders. However, its underlying mechanisms are still unclear. We investigated whether Welsh onion extracts (green or white portion, raw or boiled) can alter vascular responses in vitro in the thoracic aortae of Sprague-Dawley rats. The possible roles of endothelium-derived factors in the Welsh onion extract-induced vascular responses were examined by applying various inhibitors, such as Nomega-nitro-L-arginine (10(-4) M), tetraethylammonium (10(-3) M), and SQ29548 (10(-5) M). Our results showed that Welsh onion extracts caused vasodilation on precontracted vessel rings. These effects were most pronounced in vessel rings treated with raw green-leaf extract (RG). Low doses of RG induced vasorelaxation, which was mediated by endothelium-derived nitric oxide. High doses of RG induced endothelium-independent vasorelaxation. On the other hand, the boiled Welsh onion extract also stimulated the release of an endothelium-derived contracting factor, which might be thromboxane A2. We conclude that Welsh onion extract can modulate vascular tone in both endothelium-dependent and endothelium-independent manners. PMID:10218719

  2. Computational Models of the Cardiovascular System and Its Response to Microgravity

    NASA Technical Reports Server (NTRS)

    Kamm, Roger D.

    1999-01-01

    Computational models of the cardiovascular system are powerful adjuncts to ground-based and in-flight experiments. We will provide NSBRI with a model capable of simulating the short-term effects of gravity on cardiovascular function. The model from this project will: (1) provide a rational framework which quantitatively defines interactions among complex cardiovascular parameters and which supports the critical interpretation of experimental results and testing of hypotheses. (2) permit predictions of the impact of specific countermeasures in the context of various hypothetical cardiovascular abnormalities induced by microgravity. Major progress has been made during the first 18 months of the program: (1) We have developed an operational first-order computer model capable of simulating the cardiovascular response to orthostatic stress. The model consists of a lumped parameter hemodynamic model and a complete reflex control system. The latter includes cardiopulmonary and carotid sinus reflex limbs and interactions between the two. (2) We have modeled the physiologic stress of tilt table experiments and lower body negative pressure procedures (LBNP). We have verified our model's predictions by comparing them with experimental findings from the literature. (3) We have established collaborative efforts with leading investigators interested in experimental studies of orthostatic intolerance, cardiovascular control, and physiologic responses to space flight. (4) We have established a standardized method of transferring data to our laboratory from the ongoing NSBRI bedrest studies. We use this data to estimate input parameters to our model and compare our model predictions to actual data to further verify our model. (5) We are in the process of systematically simulating current hypotheses concerning the mechanism underlying orthostatic intolerance by matching our simulations to stand test data from astronauts pre- and post-flight. (6) We are in the process of developing a

  3. The effect of blood volume loss on cardiovascular response to lower body negative pressure using a mathematical model

    NASA Technical Reports Server (NTRS)

    Karam, E. H.; Srinivasan, R. S.; Charles, J. B.; Fortney, S. M.

    1994-01-01

    Different mathematical models of varying complexity have been proposed in recent years to study the cardiovascular (CV) system. However, only a few of them specifically address the response to lower body negative pressure (LBNP), a stress that can be applied in weightlessness to predict changes in orthostatic tolerance. Also, the simulated results produced by these models agree only partially with experimental observations. In contrast, the model proposed by Melchior et al., and modified by Karam et al. is a simple representation of the CV system capable of accurately reproducing observed LBNP responses up to presyncopal levels. There are significant changes in LBNP response due to a loss of blood volume and other alterations that occur in weightlessness and related one-g conditions such as bedrest. A few days of bedrest can cause up to 15% blood volume loss (BVL), with consequent decreases in both stroke volume and cardiac output, and increases in heart rate, mean arterial pressure, and total peripheral resistance. These changes are more pronounced at higher levels of LBNP. This paper presents the results of a simulation study using our CV model to examine the effect of BVL on LBNP response.

  4. Altered cardiorespiratory response to exercise in overweight and obese women with polycystic ovary syndrome.

    PubMed

    Rissanen, Antti-Pekka E; Koskela-Koivisto, Tiina; Hägglund, Harriet; Koponen, Anne S; Aho, Jyrki M; Pöyhönen-Alho, Maritta; Tiitinen, Aila; Tikkanen, Heikki O; Peltonen, Juha E

    2016-02-01

    In polycystic ovary syndrome (PCOS), cardiovascular risk is increased. Peak O2 uptake (V˙O2peak) predicts the cardiovascular risk. We were the first to examine the contribution of systemic O2 delivery and arteriovenous O2 difference to V˙O2peak in overweight and obese women with PCOS. Fifteen overweight or obese PCOS women and 15 age-, anthropometry-, and physical activity-matched control women performed a maximal incremental cycling exercise test. Alveolar gas exchange (volume turbine and mass spectrometry), arterial O2 saturation (pulse oximetry), and cardiac output (CO) (impedance cardiography) were monitored. Hb concentration was determined. Arterial O2 content and arteriovenous O2 difference (C(a-v)O2) (Fick equation) were calculated. Insulin resistance was evaluated by homeostasis model assessment (HOMA-IR). PCOS women had lower V˙O2peak than controls (40 ± 6 vs. 46 ± 5 mL/min/kg fat-free mass [FFM], P = 0.011). Arterial O2 content was similarly maintained in the groups throughout the exercise test (P > 0.05). Linear regression analysis revealed a pronounced response of CO to increasing V˙O2 in PCOS women during the exercise test: A ∆CO/∆V˙O2 slope was steeper in PCOS women than in controls (β = 5.84 vs. β = 5.21, P = 0.004). Eventually, the groups attained similar peak CO and peak CO scaled to FFM (P > 0.05). Instead, C(a-v)O2 at peak exercise was lower in PCOS women than in controls (13.2 ± 1.6 vs. 14.8 ± 2.4 mL O2/100 mL blood, P = 0.044). HOMA-IR was similar in the groups (P > 0.05). The altered cardiorespiratory responses to exercise in overweight and obese PCOS women indicate that PCOS per se is associated with alterations in peripheral adjustments to exercise rather than with limitations of systemic O2 delivery. PMID:26884479

  5. Altered cardiorespiratory response to exercise in overweight and obese women with polycystic ovary syndrome.

    PubMed

    Rissanen, Antti-Pekka E; Koskela-Koivisto, Tiina; Hägglund, Harriet; Koponen, Anne S; Aho, Jyrki M; Pöyhönen-Alho, Maritta; Tiitinen, Aila; Tikkanen, Heikki O; Peltonen, Juha E

    2016-02-01

    In polycystic ovary syndrome (PCOS), cardiovascular risk is increased. Peak O2 uptake (V˙O2peak) predicts the cardiovascular risk. We were the first to examine the contribution of systemic O2 delivery and arteriovenous O2 difference to V˙O2peak in overweight and obese women with PCOS. Fifteen overweight or obese PCOS women and 15 age-, anthropometry-, and physical activity-matched control women performed a maximal incremental cycling exercise test. Alveolar gas exchange (volume turbine and mass spectrometry), arterial O2 saturation (pulse oximetry), and cardiac output (CO) (impedance cardiography) were monitored. Hb concentration was determined. Arterial O2 content and arteriovenous O2 difference (C(a-v)O2) (Fick equation) were calculated. Insulin resistance was evaluated by homeostasis model assessment (HOMA-IR). PCOS women had lower V˙O2peak than controls (40 ± 6 vs. 46 ± 5 mL/min/kg fat-free mass [FFM], P = 0.011). Arterial O2 content was similarly maintained in the groups throughout the exercise test (P > 0.05). Linear regression analysis revealed a pronounced response of CO to increasing V˙O2 in PCOS women during the exercise test: A ∆CO/∆V˙O2 slope was steeper in PCOS women than in controls (β = 5.84 vs. β = 5.21, P = 0.004). Eventually, the groups attained similar peak CO and peak CO scaled to FFM (P > 0.05). Instead, C(a-v)O2 at peak exercise was lower in PCOS women than in controls (13.2 ± 1.6 vs. 14.8 ± 2.4 mL O2/100 mL blood, P = 0.044). HOMA-IR was similar in the groups (P > 0.05). The altered cardiorespiratory responses to exercise in overweight and obese PCOS women indicate that PCOS per se is associated with alterations in peripheral adjustments to exercise rather than with limitations of systemic O2 delivery.

  6. Autonomic Cardiovascular Responses in Acclimatized Lowlanders on Prolonged Stay at High Altitude: A Longitudinal Follow Up Study

    PubMed Central

    Dhar, Priyanka; Sharma, Vijay K.; Hota, Kalpana B.; Das, Saroj K.; Hota, Sunil K.; Srivastava, Ravi B.; Singh, Shashi B.

    2014-01-01

    Acute exposure to hypobaric hypoxia at high altitude is reported to cause sympathetic dominance that may contribute to the pathophysiology of high altitude illnesses. The effect of prolonged stay at high altitude on autonomic functions, however, remains to be explored. Thus, the present study aimed at investigating the effect of high altitude on autonomic neural control of cardiovascular responses by monitoring heart rate variability (HRV) during chronic hypobaric hypoxia. Baseline electrocardiography (ECG) data was acquired from the volunteers at mean sea level (MSL) (<250 m) in Rajasthan. Following induction of the study population to high altitude (4500–4800 m) in Ladakh region, ECG data was acquired from the volunteers after 6 months (ALL 6) and 18 months of induction (ALL 18). Out of 159 volunteers who underwent complete investigation during acquisition of baseline data, we have only included the data of 104 volunteers who constantly stayed at high altitude for 18 months to complete the final follow up after 18 months. HRV parameters, physiological indices and biochemical changes in serum were investigated. Our results show sympathetic hyperactivation along with compromise in parasympathetic activity in ALL 6 and ALL 18 when compared to baseline data. Reduction of sympathetic activity and increased parasympathetic response was however observed in ALL 18 when compared to ALL 6. Our findings suggest that autonomic response is regulated by two distinct mechanisms in the ALL 6 and ALL 18. While the autonomic alterations in the ALL 6 group could be attributed to increased sympathetic activity resulting from increased plasma catecholamine concentration, the sympathetic activity in ALL 18 group is associated with increased concentration of serum coronary risk factors and elevated homocysteine. These findings have important clinical implications in assessment of susceptibility to cardio-vascular risks in acclimatized lowlanders staying for prolonged duration at high

  7. Altered Functional Response to Risky Choice in HIV Infection

    PubMed Central

    Connolly, Colm G.; Bischoff-Grethe, Amanda; Jordan, Stephan J.; Woods, Steven Paul; Ellis, Ronald J.; Paulus, Martin P.; Grant, Igor

    2014-01-01

    Background Risky decision-making is commonly observed in persons at risk for and infected with HIV and is associated with executive dysfunction. Yet it is currently unknown whether HIV alters brain processing of risk-taking decision-making. Methods This study examined the neural substrate of a risky decision-making task in 21 HIV seropositive (HIV+) and 19 seronegative (HIV-) comparison participants. Functional magnetic resonance imaging was conducted while participants performed the risky-gains task, which involves choosing among safe (20 cents) and risky (40/80 cent win or loss) choices. Linear mixed effects analyses examining group and decision type were conducted. Robust regressions were performed to examine the relationship between nadir CD4 count and Kalichman sexual compulsivity and brain activation in the HIV+ group. The overlap between the task effects and robust regressions was explored. Results Although there were no serostatus effects in behavioral performance on the risky-gains task, HIV+ individuals exhibited greater activation for risky choices in the basal ganglia, i.e. the caudate nucleus, but also in the anterior cingulate, dorsolateral prefrontal cortex, and insula relative to the HIV- group. The HIV+ group also demonstrated reduced functional responses to safe choices in the anterior cingulate and dorsolateral prefrontal cortex relative to the HIV- group. HIV+ individuals with higher nadir CD4 count and greater sexual compulsivity displayed lower differential responses to safe versus risky choices in many of these regions. Conclusions This study demonstrated fronto-striatal loop dysfunction associated with HIV infection during risky decision-making. Combined with similar between-group task behavior, this suggests an adaptive functional response in regions critical to reward and behavioral control in the HIV+ group. HIV-infected individuals with higher CD4 nadirs demonstrated activation patterns more similar to seronegative individuals. This

  8. The energetic and cardiovascular response to treadmill walking and cycle ergometer exercise in obese women.

    PubMed

    Lafortuna, Claudio L; Agosti, Fiorenza; Galli, Raffaela; Busti, Carlo; Lazzer, Stefano; Sartorio, Alessandro

    2008-08-01

    Physical activity is essential in obesity management, but exercise capacity is compromised in obese individuals due to the excessive body mass, impacting on body movement's energetics, and to the dysfunctions of regulatory mechanisms, affecting cardiovascular responses. This study aims to compare the energetics and cardiovascular responses of walking and cycling in obese women, and to formulate recommendations regarding the most suitable type of exercise for obesity. Fifteen obese (OB) and six normal weight (NW) women exercised on treadmill (TM) and cycle ergometer (CE). During both exercise modalities, metabolic rate was higher in OB than in NW and correlated with measures of body mass. Leg movement metabolic rate during cycling depended upon individual adiposity, and when accounted for, mechanical efficiency was similar in the two groups. When accounting for extra mass, differences in metabolic rate among groups are abolished for CE, indicating no obesity impairment of muscle efficiency, but not for TM, suggesting that differences in biomechanics may explain the higher net cost of transport of OB. In both groups, HR was higher during CE than TM at the same oxygen uptake (VO(2)), but in OB the HR increment over VO(2) was greater for CE than for TM. Therefore, due to different cardiovascular responses to TM and CE in OB, walking is more convenient, enabling OB to attain target energy expenditure at lower HR or in a shorter time.

  9. Cardiovascular responses to sustained maximal isometric contractions of the finger flexors.

    PubMed

    Smith, D L; Misner, J E; Bloomfield, D K; Essandoh, L K

    1993-01-01

    This study investigated cardiovascular responses to 2 min sustained submaximal (20% MVC) and maximal (100% MVC) voluntary isometric contractions of the finger flexors in healthy young women. Cardiovascular variables investigated were: heart rate (fc), mean arterial pressure (Pa), and stroke volume (SV). Doppler echocardiography was used to estimate SV from measures of aortic diameter (AD) and time-velocity integrals. Preliminary studies indicated that AD did not change significantly after 2 min sustained 100% MVC. Therefore, pre-exercise AD values were used to calculate SV before, during and after exercise. During the 2-min 100% MVC period, fc and Pa increased significantly during the first 30 s of contraction. fc then remained constant during the remainder of the 2-min contraction period, while Pa continued to rise. SV did not change significantly during the 100% MVC task but increased significantly during recovery from sustained 100% MVC. The data suggest that the magnitude of cardiovascular responses to isometric exercise is dependent on the specific task performed, and that there is a different pattern of response for fc, Pa, and SV during 20% and 100% MVC tasks. Unlike fc and Pa, SV did not change significantly during isometric exercise, but increased significantly after sustained 100% MVC. PMID:8375365

  10. Reproducibility of exercise-induced modulation of cardiovascular responses to cold stress.

    PubMed

    Rashed, H M; Leventhal, G; Madu, E C; Reddy, R; Cardoso, S

    1997-04-01

    The modulation of cardiovascular responses to the cold pressor test (CPT) as produced by exercise was studied in 13 volunteers. The reproducibility of the measurements selected for the study, i.e. heart rate (HR), blood pressure (BP), blood flow (BF) and skin temperature (ST), was investigated through repeat experiments in the fall of 1994 and the winter of 1995. HR was monitored before, during and after a 10-min period of bicycling at 70% of reserve HR. BP, cutaneous BF and ST were measured before and after exercise. Two CPTs (hand into ice-cold water for 1 min) were performed: one preceding exercise and another at 3 min after exercise. The results obtained allow us to conclude that in non-hypertensive volunteers (1) the pronounced cardiovascular responses (ST, BF and BP) induced by CPT are reproducible (p > 0.2) when compared to basal level values and (2) cardiovascular responses to cold stress are significantly attenuated by exercise (p < 0.03). Our study, therefore, supports and validates the use of our coupled exercise-CPT method in ongoing epidemiological studies attempting to identify individuals at risk for the development of hypertension as well as those most likely to benefit from preventative exercise programs.

  11. Effect of Pregabalin on Cardiovascular Responses to Exercise and Postexercise Pain and Fatigue in Fibromyalgia: A Randomized, Double-Blind, Crossover Pilot Study

    PubMed Central

    White, Andrea T.; Light, Kathleen C.; Bateman, Lucinda; Hughen, Ronald W.; Vanhaitsma, Timothy A.; Light, Alan R.

    2015-01-01

    Pregabalin, an approved treatment for fibromyalgia (FM), has been shown to decrease sympathetic nervous system (SNS) activity and inhibit sympathetically maintained pain, but its effects on exercise responses have not been reported. Methods. Using a randomized double-blind crossover design, we assessed the effect of 5 weeks of pregabalin (versus placebo) on acute cardiovascular and subjective responses to moderate exercise in 19 FM patients. Blood pressure (BP), heart rate (HR), and ratings of perceived exertion (RPE) during exercise and ratings of pain, physical fatigue, and mental fatigue before, during, and for 48 hours after exercise were compared in patients on pregabalin versus placebo and also versus 18 healthy controls. Results. On placebo, exercise RPE and BP were significantly higher in FM patients than controls (p < 0.04). Pregabalin responders (n = 12, defined by patient satisfaction and symptom changes) had significantly lower exercise BP, HR, and RPE on pregabalin versus placebo (p < 0.03) and no longer differed from controls (p > 0.26). Cardiovascular responses of nonresponders (n = 7) were not altered by pregabalin. In responders, pregabalin improved ratings of fatigue and pain (p < 0.04), but negative effects on pain and fatigue were seen in nonresponders. Conclusions. These preliminary findings suggest that pregabalin may normalize cardiovascular and subjective responses to exercise in many FM patients. PMID:27026828

  12. Network-based association of hypoxia-responsive genes with cardiovascular diseases

    NASA Astrophysics Data System (ADS)

    Wang, Rui-Sheng; Oldham, William M.; Loscalzo, Joseph

    2014-10-01

    Molecular oxygen is indispensable for cellular viability and function. Hypoxia is a stress condition in which oxygen demand exceeds supply. Low cellular oxygen content induces a number of molecular changes to activate regulatory pathways responsible for increasing the oxygen supply and optimizing cellular metabolism under limited oxygen conditions. Hypoxia plays critical roles in the pathobiology of many diseases, such as cancer, heart failure, myocardial ischemia, stroke, and chronic lung diseases. Although the complicated associations between hypoxia and cardiovascular (and cerebrovascular) diseases (CVD) have been recognized for some time, there are few studies that investigate their biological link from a systems biology perspective. In this study, we integrate hypoxia genes, CVD genes, and the human protein interactome in order to explore the relationship between hypoxia and cardiovascular diseases at a systems level. We show that hypoxia genes are much closer to CVD genes in the human protein interactome than that expected by chance. We also find that hypoxia genes play significant bridging roles in connecting different cardiovascular diseases. We construct a hypoxia-CVD bipartite network and find several interesting hypoxia-CVD modules with significant gene ontology similarity. Finally, we show that hypoxia genes tend to have more CVD interactors in the human interactome than in random networks of matching topology. Based on these observations, we can predict novel genes that may be associated with CVD. This network-based association study gives us a broad view of the relationships between hypoxia and cardiovascular diseases and provides new insights into the role of hypoxia in cardiovascular biology.

  13. Network-based association of hypoxia-responsive genes with cardiovascular diseases

    PubMed Central

    Wang, Rui-Sheng; Oldham, William M.; Loscalzo, Joseph

    2014-01-01

    Molecular oxygen is indispensable for cellular viability and function. Hypoxia is a stress condition in which oxygen demand exceeds supply. Low cellular oxygen content induces a number of molecular changes to activate regulatory pathways responsible for increasing the oxygen supply and optimizing cellular metabolism under limited oxygen conditions. Hypoxia plays critical roles in the pathobiology of many diseases, such as cancer, heart failure, myocardial ischemia, stroke, and chronic lung diseases. Although the complicated associations between hypoxia and cardiovascular (and cerebrovascular) diseases (CVD) have been recognized for some time, there are few studies that investigate their biological link from a systems biology perspective. In this study, we integrate hypoxia genes, CVD genes, and the human protein interactome in order to explore the relationship between hypoxia and cardiovascular diseases at a systems level. We show that hypoxia genes are much closer to CVD genes in the human protein interactome than that expected by chance. We also find that hypoxia genes play significant bridging roles in connecting different cardiovascular diseases. We construct an hypoxia-CVD bipartite network and find several interesting hypoxia-CVD modules with significant Gene Ontology (GO) similarity. Finally, we show that hypoxia genes tend to have more CVD interactors in the human interactome than in random networks of matching topology. Based on these observations, we can predict novel genes that may be associated with CVD. This network-based association study gives us a broad view of the relationships between hypoxia and cardiovascular diseases and provides new insights into the role of hypoxia in cardiovascular biology. PMID:25530704

  14. Spaceflight Did Not Impair Cardiovascular Responses to Upright Posture in an Elderly Astronaut

    NASA Technical Reports Server (NTRS)

    Rossum, Alfred C.; Ziegler, Michael G.; Meck, Janice V.

    2001-01-01

    Some of the cardiovascular changes associated with spaceflight have similarities to those associated with aging. We studied the neuroendocrine and hemodynamic responses to upright posture in a 77 year old astronaut before and after spaceflight and compared them to those of a group of 20 younger (41 plus or minus 1 years) astronauts. While arterial pressure responses to standing were similar between the young and old astronauts, hemodynamic profiles were quite different. The elderly astronaut achieved adequate standing arterial pressure primarily by maintaining stroke volume and thus cardiac output. In spite of very high norepinephrine release, he had very little increase in heart rate or total peripheral resistance. This pattern persisted on all test occasions. These responses suggest high sympathetic responses, down-regulated adrenergic receptors and decreased venous compliance typical of aging. In contrast, younger astronauts did not maintain stroke volume or cardiac output with standing, but had significant increases in heart rate and resistance. These results suggest that this elderly subject had cardiovascular responses to standing that are expected in an aged person. These responses were not deleteriously affected by spaceflight. We suggest that healthy, fit elderly individuals are able to withstand the stresses of extreme environments and are not necessarily limited in their activities simply due to their chronological age.

  15. Altered regional homogeneity and efficient response inhibition in restrained eaters.

    PubMed

    Dong, D; Lei, X; Jackson, T; Wang, Y; Su, Y; Chen, H

    2014-04-25

    Restrained eaters (REs) characterized by less efficient response inhibition are at risk for future onset of binge eating and bulimic pathology. Previous imaging studies investigating REs have been based on task-related functional magnetic resonance imaging (fMRI) and little is known about resting-state neural activity underlying restrained eating. To illuminate this issue, we investigated resting-state fMRI differences between REs (n=22) and unrestrained eaters (UREs) (n=30) using regional homogeneity (ReHo) analysis, which measures the temporal synchronization of spontaneous fluctuations. Samples were equated on body mass index (BMI) and caloric deprivation levels (i.e., 14±2.1h since last evening meal) before undergoing fMRI. Correlation analyses were performed between the ReHo index of identified regions and response inhibition based on stop-signal reaction time (SSRT) within each sample. Compared with UREs, REs showed more ReHo in brain regions associated with food reward (i.e., orbitofrontal cortex (OFC), dorsal-lateral prefrontal cortex (dlPFC)), attention (i.e., lingual gyrus, cuneus, inferior parietal lobule) and somatosensory functioning (i.e., paracentral lobule, anterior insula). In addition, ReHo values for the left dlPFC and left anterior insula, respectively, were negatively and positively correlated with SSRT among REs but not UREs. In concert with previous studies, these results suggest altered local synchronization may help to explain why dieting to maintain or lose weight often fails or increases risk for binge eating among REs. PMID:24513387

  16. Does reduced gravity alter cellular response to ionizing radiation?

    PubMed

    Manti, Lorenzo

    2006-05-01

    This review addresses the purported interplay between actual or simulated weightlessness and cellular response to ionizing radiation. Although weightlessness is known to alter several cellular functions and to affect signaling pathways implicated in cell proliferation, differentiation and death, its influence on cellular radiosensitivity has so far proven elusive. Renewed controversy as to whether reduced gravity enhances long-term radiation risk is fueled by recently published data that claim either overall enhancement of genomic damage or no increase of radiation-induced clastogenicity by modeled microgravity in irradiated human cells. In elucidating this crucial aspect of space radiation protection, ground-based experiments, such as those based on rotating-wall bioreactors, will increasingly be used and represent a more reproducible alternative to in-flight experiments. These low-shear vessels also make three-dimensional cellular co-cultures possible and thus allow to study the gravisensitivity of radioresponse in a context that better mimics cell-to-cell communication and hence in vivo cellular behavior.

  17. Alterations of the Host Microbiome Affect Behavioral Responses to Cocaine

    PubMed Central

    Kiraly, Drew D.; Walker, Deena M.; Calipari, Erin S.; Labonte, Benoit; Issler, Orna; Pena, Catherine J.; Ribeiro, Efrain A.; Russo, Scott J.; Nestler, Eric J.

    2016-01-01

    Addiction to cocaine and other psychostimulants represents a major public health crisis. The development and persistence of addictive behaviors comes from a complex interaction of genes and environment - the precise mechanisms of which remain elusive. In recent years a surge of evidence has suggested that the gut microbiome can have tremendous impact on behavioral via the microbiota-gut-brain axis. In this study we characterized the influence of the gut microbiota on cocaine-mediated behaviors. Groups of mice were treated with a prolonged course of non-absorbable antibiotics via the drinking water, which resulted in a substantial reduction of gut bacteria. Animals with reduced gut bacteria showed an enhanced sensitivity to cocaine reward and enhanced sensitivity to the locomotor-sensitizing effects of repeated cocaine administration. These behavioral changes were correlated with adaptations in multiple transcripts encoding important synaptic proteins in the brain’s reward circuitry. This study represents the first evidence that alterations in the gut microbiota affect behavioral response to drugs of abuse. PMID:27752130

  18. Adiposity is associated with blunted cardiovascular, neuroendocrine and cognitive responses to acute mental stress.

    PubMed

    Jones, Alexander; McMillan, Merlin R; Jones, Russell W; Kowalik, Grzegorz T; Steeden, Jennifer A; Deanfield, John E; Pruessner, Jens C; Taylor, Andrew M; Muthurangu, Vivek

    2012-01-01

    Obesity and mental stress are potent risk factors for cardiovascular disease but their relationship with each other is unclear. Resilience to stress may differ according to adiposity. Early studies that addressed this are difficult to interpret due to conflicting findings and limited methods. Recent advances in assessment of cardiovascular stress responses and of fat distribution allow accurate assessment of associations between adiposity and stress responsiveness. We measured responses to the Montreal Imaging Stress Task in healthy men (N = 43) and women (N = 45) with a wide range of BMIs. Heart rate (HR) and blood pressure (BP) measures were used with novel magnetic resonance measures of stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR) and arterial compliance to assess cardiovascular responses. Salivary cortisol and the number and speed of answers to mathematics problems in the task were used to assess neuroendocrine and cognitive responses, respectively. Visceral and subcutaneous fat was measured using T(2) (*)-IDEAL. Greater BMI was associated with generalised blunting of cardiovascular (HR:β = -0.50 bpm x unit(-1), P = 0.009; SV:β = -0.33 mL x unit(-1), P = 0.01; CO:β = -61 mL x min(-1) x unit(-1), P = 0.002; systolic BP:β = -0.41 mmHg x unit(-1), P = 0.01; TPR:β = 0.11 WU x unit(-1), P = 0.02), cognitive (correct answers: r = -0.28, P = 0.01; time to answer: r = 0.26, P = 0.02) and endocrine responses (cortisol: r = -0.25, P = 0.04) to stress. These associations were largely determined by visceral adiposity except for those related to cognitive performance, which were determined by both visceral and subcutaneous adiposity. Our findings suggest that adiposity is associated with centrally reduced stress responsiveness. Although this may mitigate some long-term health risks of stress responsiveness, reduced performance under stress may be a more immediate

  19. Cardiovascular, electrodermal, and respiratory response patterns to fear- and sadness-inducing films.

    PubMed

    Kreibig, Sylvia D; Wilhelm, Frank H; Roth, Walton T; Gross, James J

    2007-09-01

    Responses to fear- and sadness-inducing films were assessed using a broad range of cardiovascular (heart rate, T-wave amplitude, low- and high-frequency heart rate variability, stroke volume, preejection period, left-ventricular ejection time, Heather index, blood pressure, pulse amplitude and transit time, and finger temperature), electrodermal (level, response rate, and response amplitude), and respiratory (rate, tidal volume and its variability, inspiratory flow rate, duty cycle, and end-tidal pCO(2)) measures. Subjective emotional experience and facial behavior (Corrugator Supercilii and Zygomaticus Major EMG) served as control measures. Results indicated robust differential physiological response patterns for fear, sadness, and neutral (mean classification accuracy 85%). Findings are discussed in terms of the fight-flight and conservation-withdrawal responses and possible limitations of a valence-arousal categorization of emotion in affective space.

  20. Amygdalar neuronal activity mediates the cardiovascular responses evoked from the dorsolateral periaqueductal gray in conscious rats.

    PubMed

    de Abreu, A R; Abreu, A R; Santos, L T; de Souza, A A; da Silva, L G; Chianca, D A; de Menezes, R C

    2015-01-22

    There is ample evidence that both lateral/dorsolateral periaqueductal gray (l/dlPAG) and basolateral amygdala (BLA) are essential for the regulation of the autonomic responses evoked during innate reactions to threatening stimuli. However, it is not well established to what extent the BLA regulates the upstream functional connection from the l/dlPAG. Here we evaluated the role of the BLA and its glutamatergic receptors in the cardiovascular responses induced by l/dlPAG stimulation in rats. We examined the influence of acute inhibition of the BLA, unilaterally, by injecting muscimol on the cardiovascular responses evoked by the injection of N-methyl D-aspartate (NMDA) into the l/dlPAG. We also evaluated the role of BLA ionotropic glutamate receptors in these responses by injecting antagonists of NMDA and AMPA/kainate receptor subtypes into the BLA. Our results show that the microinjection of NMDA in the BLA increased the mean arterial pressure (MAP) and heart rate (HR). Injection of NMDA into the l/dlPAG caused similar increases in these variables, which was prevented by the prior injection of muscimol, a GABAA agonist, into the BLA. Moreover, injection of glutamatergic antagonists (2-amino-5-phosphonopentanoate (AP5) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX)) into the BLA reduced the increase in MAP and HR induced by l/dlPAG activation. Finally, the inhibition of the central amygdala neurons failed to reduce the cardiovascular changes induced by l/dlPAG activation. These results indicate that physiological responses elicited by l/dlPAG activation require the neuronal activity in the BLA. This ascending excitatory pathway from the l/dlPAG to the BLA might ensure the expression of the autonomic component of the defense reaction. PMID:25451289

  1. Ambulatory monitoring of cardiovascular responses during behavioral modification of an aggressive dog.

    PubMed

    Williams, Nancy G; Borchelt, Peter L; Sollers, John J; Gasper, Peter W; Thayer, Julian F

    2003-01-01

    Previous work from our lab has used the Dutch Ambulatory Monitoring System (AMS) to assess the cardiovascular responses and motility of large free-ranging species (e.g. horses). To further examine the utility of using the AMS with non-humans, a study investigating the heart rate (HR) and heart period variability (HRV) of a large canine undergoing behavioral modification therapy was undertaken. This treatment emulated a restraint and tactile pressure technique that has previously been used in horses. Cardiovascular responses and motility were continuously measured pre-treatment (exposure to a stimulus dog), during treatment (in-box), and post-treatment. The treatment consisted of placing the dog in a 110 cm (long) by 45 cm (wide) by 102 cm (height) wooden box that only covered the animals' torso and legs and allowed the head to be free. Once the dog was in the box, the body was covered with a lightweight material (grain product) to effect restraint and tactile pressure, which was followed by a repeat exposure to the stimulus animal. Results indicated decreased heart rate and an increased HRV during the intervention as compared to baseline with indices of motility changing in the expected directions. Estimates of respiratory frequency derived from the autoregressive spectral analysis indicated changes in respiration did not account for the cardiovascular effects. In conclusion, tactile pressure and restraint may be an important tool for behavioral modification in both humans and animals, and the AMS is a useful tool for collecting cardiovascular data on a variety of species in a great many contexts. PMID:12724897

  2. Effect of an extruded pea or rice diet on postprandial insulin and cardiovascular responses in dogs.

    PubMed

    Adolphe, J L; Drew, M D; Silver, T I; Fouhse, J; Childs, H; Weber, L P

    2015-08-01

    Peas are increasing in popularity as a source of carbohydrate, protein and fibre in extruded canine diets. The aim of this study was to test the health effects of two canine diets with identical macronutrient profiles, but containing either yellow field peas or white rice as the carbohydrate source on metabolism, cardiovascular outcomes and adiposity. First, the acute glycemic, insulinemic and cardiovascular responses to the pea- or rice-based diets were determined in normal weight beagles (n = 7 dogs). The glycemic index did not differ between the pea diet (56 ± 12) and rice diet (63 ± 9). Next, obese beagles (n = 9) were fed the yellow field pea diet or white rice diet ad libitum for 12 weeks in a crossover study. Adiposity (measured using computed tomography), metabolic (oral glucose tolerance test, plasma leptin, adiponectin, C-reactive protein) and cardiovascular assessments (echocardiography and blood pressure) were performed before and after each crossover study period. After 12 weeks on each diet, peak insulin (p = 0.05) and area under the curve (AUC) for insulin after a 10 g oral glucose tolerance test (p = 0.05) were lower with the pea than the rice diet. Diet did not show a significant effect on body weight, fat distribution, cardiovascular variables, adiponectin or leptin. In conclusion, a diet containing yellow field peas reduced the postprandial insulin response after glucose challenge in dogs despite continued obesity, indicating improved metabolic health.

  3. Hindlimb unweighting does not alter vasoconstrictor responsiveness and nitric oxide-mediated inhibition of sympathetic vasoconstriction

    PubMed Central

    Just, Timothy P; Jendzjowsky, Nicholas G; DeLorey, Darren S

    2015-01-01

    Abstract We tested the hypothesis that physical inactivity would increase sympathetic vasoconstrictor responsiveness and diminish NO-mediated inhibition of sympathetic vasoconstriction in resting and contracting skeletal muscle. Sprague–Dawley rats (n = 33) were randomly assigned to sedentary time control (S) or hindlimb unweighted (HU) groups for 21 days. Following the intervention, rats were anaesthetized and instrumented for measurement of arterial blood pressure and femoral artery blood flow and stimulation of the lumbar sympathetic chain. The percentage change of femoral vascular conductance (%FVC) in response to sympathetic chain stimulation delivered at 2 and 5 Hz was determined at rest and during triceps surae muscle contraction before (control) and after NO synthase blockade with l-NAME (5 mg kg i.v.). Sympathetic vasoconstrictor responsiveness was not different (P > 0.05) in S and HU rats at rest (S, 2 Hz, −26 ± 8% and 5 Hz, −46 ± 12%; and HU, 2 Hz, −29 ± 9% and 5 Hz, −51 ± 10%) and during contraction (S, 2 Hz, −10 ± 7% and 5 Hz, −23 ± 11%; and HU, 2 Hz, −9 ± 5% and 5 Hz, −22 ± 7%). Nitric oxide synthase blockade caused a similar increase (P > 0.05) in sympathetic vasoconstrictor responsiveness in HU and S rats at rest (S, 2 Hz, −41 ± 7% and 5 Hz, −58 ± 8%; and HU, 2 Hz, −43 ± 6% and 5 Hz, −63 ± 8%) and during muscle contraction (S, 2 Hz, −15 ± 6% and 5 Hz, −31 ± 11%; and HU, 2 Hz, −12 ± 5% and 5 Hz, −29 ± 8%). Skeletal muscle NO synthase expression and ACh-mediated vasodilatation were also not different between HU and S rats. These data suggest that HU does not alter sympathetic vasoconstrictor responsiveness and NO-mediated inhibition of sympathetic vasoconstriction in resting and contracting skeletal muscle. Key points Physical inactivity increases the risk of cardiovascular disease and may alter sympathetic nervous system control of vascular

  4. Fine Ambient Air Particulate Matter Exposure Induces Molecular Alterations Indicative of Cardiovascular Disease Progression in Atherosclerotic Susceptible Mice -- B

    EPA Science Inventory

    Background: Epidemiology studies have reported associations between increased mortality and morbidity with exposure to particulate air pollution, particularly within individuals with pre-existing cardiovascular disease (CVD). Clinical and toxicological studies have provided evide...

  5. Methods for study of cardiovascular adaptation of small laboratory animals during exposure to altered gravity. [hypothermia for cardiovascular control and cancer therapy

    NASA Technical Reports Server (NTRS)

    Popovic, V.

    1973-01-01

    Several new techniques are reported for studying cardiovascular circulation in small laboratory animals kept in metabolic chambers. Chronical cannulation, miniaturized membrane type heart-lung machines, a prototype walking chamber, and a fluorocarbon immersion method to simulate weightlessness are outlined. Differential hypothermia work on rat cancers provides localized embedding of radionuclides and other chemotherapeutical agents in tumors and increases at the same time blood circulation through the warmed tumor as compared to the rest of the cold body. Some successful clinical applications of combined chemotherapy and differential hypothermia in skin cancer, mammary tumors, and brain gliomas are described.

  6. Cardiovascular responses to microinjections of nicotine into the caudal ventrolateral medulla of the rat.

    PubMed

    Aberger, K; Chitravanshi, V C; Sapru, H N

    2001-02-16

    This study focuses on the role of nicotinic receptors located in the caudal ventrolateral medullary depressor area (CVLM) in regulating/modulating cardiovascular function. Blood pressure and heart rate were monitored by standard techniques in urethane-anesthetized, artificially ventilated, adult male Wistar rats. Multi-barreled glass-micropipettes (tip size 20-40 microm) were used to make microinjections (100 nl) into the CVLM. Concentrations of nicotine ranging from 250 micromto 10 mM were microinjected unilaterally into the CVLM. The maximum depressor and bradycardic responses were elicited by a 1 mM concentration of nicotine. Sequential microinjections of mecamylamine (1 mM), an antagonist for nicotinic receptors containing alpha3beta4 subunits, then alpha-bungarotoxin (1 microm), an antagonist for nicotinic receptors containing alpha-7 subunits, were made into the CVLM. Microinjecting a combination of a nicotinic receptor blocker and toxin resulted in the complete blockade of the cardiovascular responses induced by nicotine (1 mM, 100 nl). These results indicate that: (1) nicotinic receptors are present in the CVLM; (2) activation of these receptors results in depressor and bradycardic responses; (3) for a complete blockade of nicotine-induced cardiovascular responses, it is necessary to use a combination of mecamylamine and alpha-bungarotoxin; (4) since mecamylamine and alpha-bungarotoxin are known to block nicotinic receptors containing alpha3beta4 and alpha-7 subunits, respectively, two different subtypes of nicotinic receptors (one which contains a combination of alpha3beta4 subunits, and one which contains alpha-7 subunits) must be present in the CVLM; and (5) it is not clear whether these two subtypes of nicotinic receptor are located on the same or different populations of CVLM-neurons.

  7. Cardiovascular responses to postural changes: differences with age for women and men

    NASA Technical Reports Server (NTRS)

    Frey, M. A.; Tomaselli, C. M.; Hoffler, W. G.

    1994-01-01

    The cardiovascular responses to postural change, and how they are affected by aging, are inadequately described in women. Therefore, the authors examined the influence of age and sex on the responses of blood pressure, cardiac output, heart rate, and other variables to change in posture. Measurements were made after 10 minutes each in the supine, seated, and standing positions in 22 men and 25 women who ranged in age from 21 to 59 years. Several variables differed, both by sex and by age, when subjects were supine. On rising, subjects' diastolic and mean arterial pressures, heart rate, total peripheral resistance (TPR), and thoracic impedance increased; cardiac output, stroke volume, and mean stroke ejection rate decreased; and changes in all variables, except heart rate, were greater from supine to sitting than sitting to standing. The increase in heart rate was greater in the younger subjects, and increases in TPR and thoracic impedance were greater in the older subjects. Stroke volume decreased less, and TPR and thoracic impedance increased more, in the women than in the men. The increase in TPR was particularly pronounced in the older women. These studies show that the cardiovascular responses to standing differ, in some respects, between the sexes and with age. The authors suggest that the sex differences are, in part, related to greater decrease of thoracic blood volume with standing in women than in men, and that the age differences result, in part, from decreased responsiveness of the high-pressure baroreceptor system.

  8. Cardiovascular response to psychosocial repeated stress in caregivers of offspring with schizophrenia.

    PubMed

    González-Bono, Esperanza; de Andrés-Garcia, Sara; Romero-Martínez, Ángel; Moya-Albiol, Luis

    2013-01-01

    Taking care of offspring suffering a long-term illness such as schizophrenia is one of the more stressful life experiences. Care conditions may act as a protective factor in the health of the caregiver. The present study assesses heart rate (HR), blood pressure (BP), and mood responses to psychosocial stress in 16 mothers receiving specialised support for the care of their offspring (CARE+) and in 11 mothers caring for their offspring without support (CARE-). The CARE- group take care of less functional and more symptomatic offspring; and display higher basal, but lower HR, responses after stress than the CARE+ group. No significant group effects were found for BP. For mood states, there were significant decreases in the anger subscale in the CARE- group that were not found in the CARE+ group. HR was related to active and passive coping styles, trait anxiety, and years spent providing care. In the total sample, other significant relationships between cardiovascular responses and life events and personality traits have been found. In sum, the data suggests that specialised support for patients may modulate cardiovascular responses to repeated stress in caregivers.

  9. Rat Cardiovascular Responses to Whole Body Suspension: Head-down and Non-Head-Down Tilt

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.; Steffen, Joseph M.; Dombrowski, Judy

    1992-01-01

    The rat whole body suspension technique mimics responses seen during exposure to microgravity and was evaluated as a model for cardiovascular responses with two series of experiments. In one series, changes were monitored in chronically catheterized rats during 7 days of Head-Down Tilt (HDT) or Non-Head-Down Tilt (N-HDT) and after several hours of recovery. Elevations of mean arterial (MAP), systolic, and diastolic pressures of approx. 20 % (P less than 0.05) in HDT rats began as early as day 1 and were maintained for the duration of suspension. Pulse pressures were relatively unaffected, but heart rates were elevated approx. 10 %. During postsuspension (2-7 h), most cardiovascular parameters returned to presuspension levels. N-HDT rats exhibited elevations chiefly on days 3 and 7. In the second series, blood pressure was monitored in 1- and 3-day HDT and N-HDT rats to evaluate responses to rapid head-up tilt. MAP, systolic and diastolic pressures, and HR were elevated (P less than 0.05) in HDT and N-HDT rats during head-up tilt after 1 day of suspension, while pulse pressures remained un changed. HDT rats exhibited elevated pretilt MAP and failed to respond to rapid head-up tilt with further increase of MAP on day 3, indicating some degree of deconditioning. The whole body suspended rat may be useful as a model to better understand responses of rats exposed to microgravity.

  10. Covariation of phasic cortical and cardiovascular responses in a detection task.

    PubMed

    van der Veen, F M; Mulder, L J; Hoekzema, A; Mulder, G

    1996-10-31

    The relationship between cardiovascular and cortical responses was examined in an experiment in which subjects performed a detection task and a simple reference task. The detection task was developed according to Skinner et al., (1987). Cortical activity was examined with event related brain potentials (ERPs). ERPs revealed more cortical activation during detection task blocks. Both tonic and phasic measures of cardiovascular activity were derived. Tonic measures were heart rate (HR), systolic blood pressure (SBP). T-wave amplitude (TWA), respiration linked HR-variability and a measure for baroreflex sensitivity. These measures revealed no important differences between the reference task and detection task blocks. Phasic cardiovascular measures were evoked HR, SBP and TWA. Evoked HR showed a larger deceleration and evoked SBP showed a smaller decrease on detection task blocks. Evoked TWA did not differentiate between both types of task. It is concluded that an adjusted version of the fronto-cortical control hypothesis of Skinner could best account for the data. PMID:8913524

  11. Cardiovascular alterations at different stages of hypertension development during ethanol consumption: time-course of vascular and autonomic changes.

    PubMed

    Crestani, Carlos C; Lopes da Silva, Andréia; Scopinho, América A; Ruginsk, Silvia G; Uchoa, Ernane T; Correa, Fernando M A; Elias, Lucila L K; Antunes-Rodrigues, José; Resstel, Leonardo B M

    2014-10-15

    The aim of the present work was to establish a time-course correlation between vascular and autonomic changes that contribute to the development of hypertension during ethanol ingestion in rats. For this, male Wistar rats were subjected to the intake of increasing ethanol concentrations in their drinking water during four weeks. Ethanol effects were investigated at the end of each week. Mild hypertension was already observed at the first week of treatment, and a progressive blood pressure increase was observed along the evaluation period. Increased pressor response to phenylephrine was observed from first to fourth week. α1-Adrenoceptor protein in the mesenteric bed was enhanced at the first week, whereas β2-adrenoceptor protein in the aorta was reduced after the second week. In the third week, ethanol intake facilitated the depressor response to sodium nitroprusside, whereas in the fourth week it reduced nitrate content in aorta and increased it plasma. The bradycardic component of the baroreflex was impaired, whereas baroreflex tachycardia was enhanced at the third and fourth weeks. AT1A receptor and C-type natriuretic peptide (CNP) mRNAs in the nucleus tractus solitarius were increased at the fourth week. These findings suggest that increased vascular responsiveness to vasoconstrictor agents is possibly a link factor in the development and maintenance of the progressive hypertension induced by ethanol consumption. Additionally, baroreflex changes are possibly mediated by alterations in angiotensinergic mechanisms and CNP content within the brainstem, which contribute to maintaining the hypertensive state in later phases of ethanol ingestion. Facilitated vascular responsiveness to nitric oxide seems to counteract ethanol-induced hypertension. PMID:25151222

  12. Cardiovascular alterations at different stages of hypertension development during ethanol consumption: Time-course of vascular and autonomic changes

    SciTech Connect

    Crestani, Carlos C.; Lopes da Silva, Andréia; Scopinho, América A.; Ruginsk, Silvia G.; Uchoa, Ernane T.; Correa, Fernando M.A.; Elias, Lucila L.K.; Antunes-Rodrigues, José; Resstel, Leonardo B.M.

    2014-10-15

    The aim of the present work was to establish a time-course correlation between vascular and autonomic changes that contribute to the development of hypertension during ethanol ingestion in rats. For this, male Wistar rats were subjected to the intake of increasing ethanol concentrations in their drinking water during four weeks. Ethanol effects were investigated at the end of each week. Mild hypertension was already observed at the first week of treatment, and a progressive blood pressure increase was observed along the evaluation period. Increased pressor response to phenylephrine was observed from first to fourth week. α{sub 1}-adrenoceptor protein in the mesenteric bed was enhanced at the first week, whereas β{sub 2}-adrenoceptor protein in the aorta was reduced after the second week. In the third week, ethanol intake facilitated the depressor response to sodium nitroprusside, whereas in the fourth week it reduced nitrate content in aorta and increased it plasma. The bradycardic component of the baroreflex was impaired, whereas baroreflex tachycardia was enhanced at the third and fourth weeks. AT{sub 1A} receptor and C-type natriuretic peptide (CNP) mRNAs in the nucleus tractus solitarius were increased at the fourth week. These findings suggest that increased vascular responsiveness to vasoconstrictor agents is possibly a link factor in the development and maintenance of the progressive hypertension induced by ethanol consumption. Additionally, baroreflex changes are possibly mediated by alterations in angiotensinergic mechanisms and CNP content within the brainstem, which contribute to maintaining the hypertensive state in later phases of ethanol ingestion. Facilitated vascular responsiveness to nitric oxide seems to counteract ethanol-induced hypertension. - Highlights: • Mild hypertension was observed during the entire period of ethanol ingestion. • Ethanol facilitated vascular reactivity to vasoactive agents. • Changes in baroreflex activity

  13. Blockade of central vasopressin receptors reduces the cardiovascular response to acute stress in freely moving rats.

    PubMed

    Stojicić, S; Milutinović-Smiljanić, S; Sarenac, O; Milosavljević, S; Paton, J F R; Murphy, D; Japundzić-Zigon, N

    2008-04-01

    To investigate the contribution of central vasopressin receptors to blood pressure (BP) and heart rate (HR) response to stress we injected non-peptide selective V(1a) (SR49059), V(1b) (SSR149415), V(2) (SR121463) receptor antagonists, diazepam or vehicle in the lateral cerebral ventricle of conscious freely moving rats stressed by blowing air on their heads for 2 min. Cardiovascular effects of stress were evaluated by analyzing maximum increase of BP and HR (MAX), latency of maximum response (LAT), integral under BP and HR curve (integral), duration of their recovery and spectral parameters of BP and HR indicative of increased sympathetic outflow (LF(BP) and LF/HF(HR)). Moreover, the increase of serum corticosterone was measured. Exposure to air-jet stress induced simultaneous increase in BP and HR followed by gradual decline during recovery while LF(BP) oscillation remained increased as well as serum corticosterone level. Rats pre-treated with vasopressin receptor antagonists were not sedated while diazepam induced sedation that persisted during exposure to stress. V(1a), V(1b) and V(2) receptor antagonists applied separately did not modify basal values of cardiovascular parameters but prevented the increase in integral(BP). In addition, V(1b) and V(2) receptor antagonists reduced BP(MAX) whereas V(1a), V(1b) antagonist and diazepam reduced HR(MAX) induced by exposure to air-jet stress. All drugs shortened the recovery period, prevented the increase of LF(BP) without affecting the increase in serum corticosterone levels. Results indicate that vasopressin receptors located within the central nervous system mediate, in part, the cardiovascular response to air-jet stress without affecting either the neuroendocrine component or inducing sedation. They support the view that the V(1b) receptor antagonist may be of potential therapeutic value in reducing arterial pressure induced by stress-related disorders.

  14. Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats

    PubMed Central

    Quagliotto, E.; Casali, K.R.; Dal Lago, P.; Rasia-Filho, A.A.

    2014-01-01

    The rat posterodorsal medial amygdala (MePD) links emotionally charged sensory stimuli to social behavior, and is part of the supramedullary control of the cardiovascular system. We studied the effects of microinjections of neuroactive peptides markedly found in the MePD, namely oxytocin (OT, 10 ng and 25 pg; n=6/group), somatostatin (SST, 1 and 0.05 μM; n=8 and 5, respectively), and angiotensin II (Ang II, 50 pmol and 50 fmol; n=7/group), on basal cardiovascular activity and on baroreflex- and chemoreflex-mediated responses in awake adult male rats. Power spectral and symbolic analyses were applied to pulse interval and systolic arterial pressure series to identify centrally mediated sympathetic/parasympathetic components in the heart rate variability (HRV) and arterial pressure variability (APV). No microinjected substance affected basal parameters. On the other hand, compared with the control data (saline, 0.3 µL; n=7), OT (10 ng) decreased mean AP (MAP50) after baroreflex stimulation and increased both the mean AP response after chemoreflex activation and the high-frequency component of the HRV. OT (25 pg) increased overall HRV but did not affect any parameter of the symbolic analysis. SST (1 μM) decreased MAP50, and SST (0.05 μM) enhanced the sympathovagal cardiac index. Both doses of SST increased HRV and its low-frequency component. Ang II (50 pmol) increased HRV and reduced the two unlike variations pattern of the symbolic analysis (P<0.05 in all cases). These results demonstrate neuropeptidergic actions in the MePD for both the increase in the range of the cardiovascular reflex responses and the involvement of the central sympathetic and parasympathetic systems on HRV and APV. PMID:25424367

  15. The prodromal phase of obesity-related chronic kidney disease: early alterations in cardiovascular and renal function in obese children and adolescents.

    PubMed

    Doyon, Anke; Schaefer, Franz

    2013-11-01

    Childhood overweight and obesity is a relevant health condition with multi-organ involvement. Obesity shows significant tracking into adult life and is associated with an increased risk of serious adverse health outcomes both during childhood and later adulthood. The classical sequelae of obesity such as hypertension, metabolic syndrome and inflammation do develop at a paediatric age. Cardiovascular consequences, such as increased carotid intima-media thickness, and left ventricular hypertrophy, as well as functional alterations of the heart and arteries, are commonly traceable at an early age. Renal involvement can occur at a young age and is associated with a high probability of progressive chronic kidney disease. There is solid evidence suggesting that consequent treatment including both lifestyle changes and pharmacological therapy can reduce cardiovascular, metabolic and renal risks in obese children and adolescents.

  16. Concord Grape Juice Polyphenols and Cardiovascular Risk Factors: Dose-Response Relationships

    PubMed Central

    Blumberg, Jeffrey B.; Vita, Joseph A.; Chen, C. -Y. Oliver

    2015-01-01

    Pure fruit juices provide nutritional value with evidence suggesting some of their benefits on biomarkers of cardiovascular disease risk may be derived from their constituent polyphenols, particularly flavonoids. However, few data from clinical trials are available on the dose-response relationship of fruit juice flavonoids to these outcomes. Utilizing the results of clinical trials testing single doses, we have analyzed data from studies of 100% Concord grape juice by placing its flavonoid content in the context of results from randomized clinical trials of other polyphenol-rich foods and beverages describing the same outcomes but covering a broader range of intake. We selected established biomarkers determined by similar methods for measuring flow-mediated vasodilation (FMD), blood pressure, platelet aggregation, and the resistance of low density lipoprotein cholesterol (LDL) to oxidation. Despite differences among the clinical trials in the treatment, subjects, and duration, correlations were observed between the dose and FMD. Inverse dose-response relationships, albeit with lower correlation coefficients, were also noted for the other outcomes. These results suggest a clear relationship between consumption of even modest serving sizes of Concord grape juice, flavonoid intake, and effects on risk factors for cardiovascular disease. This approach to dose-response relationships may prove useful for testing other individual foods and beverages. PMID:26633488

  17. Rat cardiovascular responses to whole body suspension - Head-down and non-head-down tilt

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.; Steffen, Joseph M.; Dombrowski, Judy

    1992-01-01

    Two experiments aimed at examining the versatility of the whole body suspension (WBS) system as a ground-based model for cardiovascular effects of microgravity are described. The first experiment studied heart rate and arterial pressure responses in rats during a 7-day period of head-down tilt (HDT) or nonhead-down tilt (NHDT) and after removal from whole body suspension (WBS). Mean arterial (MAP), systolic, and diastolic pressures increased about 20 percent in HDT rats on the fist day, heart rates were elevated about 10 percent. During postsuspension most cardiovascular parameters returned to presuspension levels. The second experiment evaluated responses to rapid head-up tilt in HDT and NHDT rats. It was observed that, while pulse pressures remained unchanged, MAP, systolic and diastolic pressures, and HR were elevated in HDT and NHDT rats during head-up tilt after one day of suspension. The WBS rats are considered to be useful as a model to better understand responses of rats exposed to microgravity.

  18. Concord Grape Juice Polyphenols and Cardiovascular Risk Factors: Dose-Response Relationships.

    PubMed

    Blumberg, Jeffrey B; Vita, Joseph A; Chen, C-Y Oliver

    2015-12-02

    Pure fruit juices provide nutritional value with evidence suggesting some of their benefits on biomarkers of cardiovascular disease risk may be derived from their constituent polyphenols, particularly flavonoids. However, few data from clinical trials are available on the dose-response relationship of fruit juice flavonoids to these outcomes. Utilizing the results of clinical trials testing single doses, we have analyzed data from studies of 100% Concord grape juice by placing its flavonoid content in the context of results from randomized clinical trials of other polyphenol-rich foods and beverages describing the same outcomes but covering a broader range of intake. We selected established biomarkers determined by similar methods for measuring flow-mediated vasodilation (FMD), blood pressure, platelet aggregation, and the resistance of low density lipoprotein cholesterol (LDL) to oxidation. Despite differences among the clinical trials in the treatment, subjects, and duration, correlations were observed between the dose and FMD. Inverse dose-response relationships, albeit with lower correlation coefficients, were also noted for the other outcomes. These results suggest a clear relationship between consumption of even modest serving sizes of Concord grape juice, flavonoid intake, and effects on risk factors for cardiovascular disease. This approach to dose-response relationships may prove useful for testing other individual foods and beverages.

  19. Effects of intracisternal administration of cannabidiol on the cardiovascular and behavioral responses to acute restraint stress.

    PubMed

    Granjeiro, Erica M; Gomes, Felipe V; Guimarães, Francisco S; Corrêa, Fernando M A; Resstel, Leonardo B M

    2011-10-01

    Systemic administration of cannabidiol (CBD), a non-psychotomimetic compound from Cannabis sativa, attenuates the cardiovascular and behavioral responses to restraint stress. Although the brain structures related to CBD effects are not entirely known, they could involve brainstem structures responsible for cardiovascular control. Therefore, to investigate this possibility the present study verified the effects of CBD (15, 30 and 60 nmol) injected into the cisterna magna on the autonomic and behavioral changes induced by acute restraint stress. During exposure to restraint stress (1h) there was a significant increase in mean arterial pressure (MAP) and heart rate (HR). Also, 24h later the animals showed a decreased percentage of entries onto the open arms of the elevated plus-maze. These effects were attenuated by CBD (30 nmol). The drug had no effect on MAP and HR baseline values. These results indicate that intracisternal administration of CBD can attenuate autonomic responses to stress. However, since CBD decreased the anxiogenic consequences of restraint stress, it is possible that the drug is also acting on forebrain structures. PMID:21771609

  20. Effects of whole-body cryotherapy duration on thermal and cardio-vascular response.

    PubMed

    Fonda, Borut; De Nardi, Massimo; Sarabon, Nejc

    2014-05-01

    Whole-body cryotherapy (WBC) is the exposure of minimally dressed participants to very cold air, either in a specially designed chamber (cryo-chamber) or cabin (cryo-cabin), for a short period of time. Practitioners are vague when it comes to recommendations on the duration of a single session. Recommended exposure for cryo-chamber is 150s, but no empirically based recommendations are available for a cryo-cabin. Therefore the aim of this study was to examine thermal and cardio-vascular responses after 90, 120, 150 and 180s of WBC in a cryo-cabin. Our hypothesis was that skin temperature would be significantly lower after longer exposers. Twelve male participants (age 23.9±4.2 years) completed four WBC of different durations (90, 120, 150 and 180s) in a cryo-cabin. Thermal response, heart rate and blood pressure were measured prior, immediately after, 5min after and 30min after the session. Skin temperature differed significantly among different durations, except between 150 and 180s. There was no significant difference in heart rate and blood pressure. Thermal discomfort during a single session displayed a linear increase throughout the whole session. Our results indicate that practitioners and clinicians using cryo-cabin for WBC do not need to perform sessions longer than 150s. We have shown that longer sessions do not substantially affect thermal and cardio-vascular response, but do increase thermal discomfort. PMID:24802149

  1. An Automated Fading Procedure to Alter Sexual Responsiveness in Pedophiles

    ERIC Educational Resources Information Center

    Laws, D. R.; Pawlowski, A. V.

    1975-01-01

    An automated stimulus fading procedure was used to strengthen sexual responsiveness to adult stimuli in two pedophiles. The degree of responsiveness was indicated by changes in the penile response. Implications for future research are discussed. (Author)

  2. Chemosensitivity, Cardiovascular Risk, and the Ventilatory Response to Exercise in COPD

    PubMed Central

    Stickland, Michael K.; Fuhr, Desi P.; Edgell, Heather; Byers, Brad W.; Bhutani, Mohit; Wong, Eric Y. L.; Steinback, Craig D.

    2016-01-01

    COPD is associated with elevated cardiovascular risk and a potentiated ventilatory response to exercise. Enhanced carotid chemoreceptor (CC) activity/sensitivity is present in other clinical conditions, has been shown to contribute to sympathetic vasoconstrictor outflow, and is predictive of mortality. CC activity/sensitivity, and the resulting functional significance, has not been well examined in COPD. We hypothesized that CC activity/sensitivity would be elevated in COPD, and related to increased pulse wave velocity (a marker of CV risk) and the ventilatory response to exercise. Methods: 30 COPD patients and 10 healthy age-matched controls were examined. Participants performed baseline cardiopulmonary exercise and pulmonary function testing. CC activity was later evaluated by the drop in ventilation with breathing 100% O2, and CC sensitivity was then assessed by the ventilatory response to hypoxia (ΔVE/ΔSpO2). Peripheral arterial stiffness was subsequently evaluated by measurement of pulse wave velocity (PWV) using applanation tonometry while the subjects were breathing room air, and then following chemoreceptor inhibition by breathing 100% O2 for 2 minutes. Results: CC activity, CC sensitivity, PWV and the ventilatory response to exercise were all increased in COPD relative to controls. CC sensitivity was related to PWV; however, neither CC activity nor CC sensitivity was related to the ventilatory response to exercise in COPD. CC inhibition by breathing 100% O2 normalized PWV in COPD, while no effect was observed in controls. Conclusion: CC activity and sensitivity are elevated in COPD, and appear related to cardiovascular risk; however, CC activity/sensitivity does not contribute to the potentiated ventilatory response to exercise. PMID:27355356

  3. Cardiovascular and cerebrovascular effects in response to red bull consumption combined with mental stress.

    PubMed

    Grasser, Erik Konrad; Dulloo, Abdul G; Montani, Jean-Pierre

    2015-01-15

    The sale of energy drinks is often accompanied by a comprehensive and intense marketing with claims of benefits during periods of mental stress. As it has been shown that Red Bull negatively impacts human hemodynamics at rest, we investigated the cardiovascular and cerebrovascular consequences when Red Bull is combined with mental stress. In a randomized cross-over study, 20 young healthy humans ingested either 355 ml of a can Red Bull or water and underwent 80 minutes after the respective drink a mental arithmetic test for 5 minutes. Continuous cardiovascular and cerebrovascular recordings were performed for 20 minutes before and up to 90 minutes after drink ingestion. Measurements included beat-to-beat blood pressure (BP), heart rate, stroke volume, and cerebral blood flow velocity. Red Bull increased systolic BP (+7 mm Hg), diastolic BP (+4 mm Hg), and heart rate (+7 beats/min), whereas water drinking had no significant effects. Cerebral blood flow velocity decreased more in response to Red Bull than to water (-9 vs -3 cm/s, p <0.005). Additional mental stress further increased both systolic BP and diastolic BP (+3 mm Hg, p <0.05) and heart rate (+13 beats/min, p <0.005) in response to Red Bull; similar increases were also observed after water ingestion. In combination, Red Bull and mental stress increased systolic BP by about 10 mm Hg, diastolic BP by 7 mm Hg, and heart rate by 20 beats/min and decreased cerebral blood flow velocity by -7 cm/s. In conclusion, the combination of Red Bull and mental stress impose a cumulative cardiovascular load and reduces cerebral blood flow even under a mental challenge.

  4. Adrenergic and vasopressinergic contributions to the cardiovascular response to acute hypoxaemia in the llama fetus

    PubMed Central

    Giussani, D A; Riquelme, R A; Sanhueza, E M; Hanson, M A; Blanco, C E; Llanos, A J

    1999-01-01

    The effects of fetal intravenous treatment with phentolamine or a vasopressinergic V1-receptor antagonist on the fetal cardiovascular responses to acute hypoxaemia in the llama were investigated. Six llama fetuses were surgically prepared between 60 and 70% of gestation under general halothane anaesthesia with vascular catheters and transit-time ultrasonic flow probes around a carotid artery and a femoral artery. At least 4 days after surgery all fetuses were subjected to a 3 h experiment: 1 h of normoxia, 1 h of hypoxaemia and 1 h of recovery while on slow i.v. infusion with saline. On separate days this experiment was repeated with fetal i.v. treatment with either phentolamine or a V1-receptor antagonist dissolved in saline. During saline infusion all llama fetuses responded to acute hypoxaemia with intense femoral vasoconstriction. Phentolamine during normoxia produced hypotension, tachycardia and vasodilatation in both the carotid and the femoral circulations. During hypoxaemia, fetuses treated with phentolamine did not elicit the pronounced femoral vasoconstriction and all died within 20 min of the onset of hypoxaemia. A V1-receptor antagonist produced a femoral vasodilatation during normoxia but did not affect the fetal cardiovascular responses to acute hypoxaemia. In conclusion, α-adrenergic and V1-vasopressinergic mechanisms contribute to a basal vasoconstrictor tone in the femoral circulation in the llama fetus. The enhanced femoral vasoconstriction during acute hypoxaemia in the llama fetus is not mediated by stimulation of V1-vasopressin receptors, but is dependent on α-adrenergic receptor stimulation. Such α-adrenergic efferent mechanisms are indispensable to fetal survival during hypoxaemia in the llama since their abolition leads to cardiovascular collapse and death. PMID:9925892

  5. Disruption of Responding Maintained by Conditioned Reinforcement: Alterations in Response-Conditioned-Reinforcer Relations

    ERIC Educational Resources Information Center

    Lieving, Gregory A.; Reilly, Mark P.; Lattal, Kennon A.

    2006-01-01

    An observing procedure was used to investigate the effects of alterations in response-conditioned-reinforcer relations on observing. Pigeons responded to produce schedule-correlated stimuli paired with the availability of food or extinction. The contingency between observing responses and conditioned reinforcement was altered in three experiments.…

  6. Exaggerated sympathetic and cardiovascular responses to stimulation of the mesencephalic locomotor region in spontaneously hypertensive rats.

    PubMed

    Liang, Nan; Mitchell, Jere H; Smith, Scott A; Mizuno, Masaki

    2016-01-01

    The sympathetic and pressor responses to exercise are exaggerated in hypertension. However, the underlying mechanisms causing this abnormality remain to be fully elucidated. Central command, a neural drive originating in higher brain centers, is known to activate cardiovascular and locomotor control circuits concomitantly. As such, it is a viable candidate for the generation of the augmented vascular response to exercise in this disease. We hypothesized that augmentations in central command function contribute to the heightened cardiovascular response to exercise in hypertension. To test this hypothesis, changes in renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) in response to electrical stimulation of mesencephalic locomotor region (MLR; 20-50 μA in 10-μA steps evoking fictive locomotion), a putative component of the central command pathway, were examined in decerebrate, paralyzed normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Tibial nerve discharge during MLR stimulation significantly increased in an intensity-dependent manner in both WKY and SHR but was not different between groups. Stimulation of the MLR evoked significantly larger increases in RSNA and MAP with increasing stimulation intensity in both groups. Importantly, the increases in sympathetic and pressor responses to this fictive locomotion were significantly greater in SHR compared with WKY across all stimulation intensities (e.g., at 50 μA, ΔRSNA: WKY 153 ± 31%, SHR 287 ± 42%; ΔMAP: WKY 87 ± 9 mmHg, SHR 139 ± 7 mmHg). These findings provide the first evidence that central command may be a critical contributor to the exaggerated rise in sympathetic activity and blood pressure during exercise in hypertension. PMID:26545711

  7. Acute cardiovascular responses while playing virtual games simulated by Nintendo Wii®

    PubMed Central

    Rodrigues, Gusthavo Augusto Alves; Felipe, Danilo De Souza; Silva, Elisangela; De Freitas, Wagner Zeferino; Higino, Wonder Passoni; Da Silva, Fabiano Fernandes; De Carvalho, Wellington Roberto Gomes; Aparecido de Souza, Renato

    2015-01-01

    [Purpose] This investigation evaluated the acute cardiovascular responses that occur while playing virtual games (aerobic and balance) emulated by Nintendo Wii®. [Subjects] Nineteen healthy male volunteers were recruited. [Methods] The ergospirometric variables of maximum oxygen consumption, metabolic equivalents, and heart rate were obtained during the aerobic (Obstacle Course, Hula Hoop, and Free Run) and balance (Soccer Heading, Penguin Slide, and Table Tilt) games of Wii Fit Plus® software. To access and analyze the ergospirometric information, a VO2000 analyzer was used. Normalized data (using maximum oxygen consumption and heart rate) were analyzed using repeated measures analysis of variance and Scheffe’s test. [Results] Significant differences were found among the balance and aerobic games in all variables analyzed. In addition, the Wii exercises performed were considered to be of light (balance games) and moderate (aerobic games) intensity in accordance with American College Sports Medicine exercise stratification. [Conclusion] Physical activity in a virtual environment emulated by Nintendo Wii® can change acute cardiovascular responses, primarily when Wii aerobic games are performed. These results support the use of the Nintendo Wii® in physical activity programs. PMID:26504308

  8. Alpha adrenergic receptor mediation of cardiovascular and metabolic responses to alcohol

    SciTech Connect

    Brackett, D.J.; Gauvin, D.V.; Lerner, M.R.; Holloway, F.H.; Wilson, M.F. Veterans Affairs Medical Center, Oklahoma City, OK )

    1992-02-26

    The role of alpha adrenergic receptors in acute cardiovascular and metabolic responses to alcohol (ETOH) have not been clearly defined. In this study two groups of male Sprague-Dawley rats were given intravenous phentolamine mesylate or saline prior to intragastric alcohol to blockade of alpha receptors during alcohol intoxication in conscious rats. ETOH alone evoked an increase in systemic vascular resistance (SVR), heart rate (HR), and blood glucose concentrations (G) and a decrease in mean arterial pressure (MAP), cardiac output (CO), central venous pressure (CVP), respiration rate (RR) and cardiac stroke volume (SV). Blood alcohol concentration (BAC) peaked at 30 min and remained elevated for the four hrs of monitoring. Phentolamine pretreatment produced a decrease in MAP and SV and an increase in HR. However, antagonism of the alpha receptor blocked the decrease in CO and the increase in SVR and G. The decrease in CVP was unaffected. Surprisingly, the early rise and peak in BAC in the phentolamine treated group was attenuated, but was the same as the untreated group during the final 3 hrs. These data suggest that alpha receptors are significant mediators of cardiovascular and glucoregulatory responses elicited by alcohol. Furthermore, alpha receptor blockade appears to effect the absorption and/or distribution of intragastrically administered alcohol.

  9. Acute cardiovascular responses while playing virtual games simulated by Nintendo Wii(®).

    PubMed

    Rodrigues, Gusthavo Augusto Alves; Felipe, Danilo De Souza; Silva, Elisangela; De Freitas, Wagner Zeferino; Higino, Wonder Passoni; Da Silva, Fabiano Fernandes; De Carvalho, Wellington Roberto Gomes; Aparecido de Souza, Renato

    2015-09-01

    [Purpose] This investigation evaluated the acute cardiovascular responses that occur while playing virtual games (aerobic and balance) emulated by Nintendo Wii(®). [Subjects] Nineteen healthy male volunteers were recruited. [Methods] The ergospirometric variables of maximum oxygen consumption, metabolic equivalents, and heart rate were obtained during the aerobic (Obstacle Course, Hula Hoop, and Free Run) and balance (Soccer Heading, Penguin Slide, and Table Tilt) games of Wii Fit Plus(®) software. To access and analyze the ergospirometric information, a VO2000 analyzer was used. Normalized data (using maximum oxygen consumption and heart rate) were analyzed using repeated measures analysis of variance and Scheffe's test. [Results] Significant differences were found among the balance and aerobic games in all variables analyzed. In addition, the Wii exercises performed were considered to be of light (balance games) and moderate (aerobic games) intensity in accordance with American College Sports Medicine exercise stratification. [Conclusion] Physical activity in a virtual environment emulated by Nintendo Wii(®) can change acute cardiovascular responses, primarily when Wii aerobic games are performed. These results support the use of the Nintendo Wii(®) in physical activity programs.

  10. Cardiovascular responses to exercise as functions of absolute and relative work load

    NASA Technical Reports Server (NTRS)

    Lewis, S. F.; Taylor, W. F.; Graham, R. M.; Pettinger, W. A.; Schutte, J. E.; Blomqvist, C. G.

    1983-01-01

    The roles of absolute and relative oxygen uptake (VO2 and percent of muscle group specific VO2-max) as determinants of the cardiovascular and ventilatory responses to exercise over a wide range of active muscle mass are investigated. Experiments were conducted using four types of dynamic exercise: one-arm curl, one-arm cranking, and one and two-leg cycling at four different relative work loads (25, 50, 75, and 100 percent of VO2-max) for the corresponding muscle group. Results show that VO2 during maximal one-arm curl, one-arm cranking, and one-leg cycling averaged 20, 50, and 75 percent, respectively, of that for maximal two-leg cycling. Cardiac output was determined to be linearly related to VO2 with a similar slope and intercept for each type of exercise, and the heart rate at a given percent VO2-max was higher with larger active muscle mass. It is concluded that the cardiovascular responses to exercise was determined to a large extent by the active muscle mass and the absolute oxygen uptake, with the principal feature appearing to be the tight linkage between systematic oxygen transport and utilization.

  11. Acute cardiovascular responses while playing virtual games simulated by Nintendo Wii(®).

    PubMed

    Rodrigues, Gusthavo Augusto Alves; Felipe, Danilo De Souza; Silva, Elisangela; De Freitas, Wagner Zeferino; Higino, Wonder Passoni; Da Silva, Fabiano Fernandes; De Carvalho, Wellington Roberto Gomes; Aparecido de Souza, Renato

    2015-09-01

    [Purpose] This investigation evaluated the acute cardiovascular responses that occur while playing virtual games (aerobic and balance) emulated by Nintendo Wii(®). [Subjects] Nineteen healthy male volunteers were recruited. [Methods] The ergospirometric variables of maximum oxygen consumption, metabolic equivalents, and heart rate were obtained during the aerobic (Obstacle Course, Hula Hoop, and Free Run) and balance (Soccer Heading, Penguin Slide, and Table Tilt) games of Wii Fit Plus(®) software. To access and analyze the ergospirometric information, a VO2000 analyzer was used. Normalized data (using maximum oxygen consumption and heart rate) were analyzed using repeated measures analysis of variance and Scheffe's test. [Results] Significant differences were found among the balance and aerobic games in all variables analyzed. In addition, the Wii exercises performed were considered to be of light (balance games) and moderate (aerobic games) intensity in accordance with American College Sports Medicine exercise stratification. [Conclusion] Physical activity in a virtual environment emulated by Nintendo Wii(®) can change acute cardiovascular responses, primarily when Wii aerobic games are performed. These results support the use of the Nintendo Wii(®) in physical activity programs. PMID:26504308

  12. Caterpillar feeding responses to sorghum leaves with altered lignin levels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Production of liquid fuels from biomass is impeded by the presence of lignin. Plants with lower or altered lignin are more amenable to lignocellulosic conversion to ethanol and other biofuels, but may be more susceptible to insect damage where lignin is an important resistance factor. Sorghum, Sorg...

  13. Associations between personal exposures to VOCs and alterations in cardiovascular physiology: Detroit Exposure and Aerosol Research Study (DEARS) - presentation

    EPA Science Inventory

    Introduction: An adult cohort consisting of 63 participants engaged in the US EPA’s recent Detroit Exposure and Aerosol Research Study (DEARS) and a University of Michigan cardiovascular sub-study conducted during summer and winter periods over 3 years between 2004 and 2007...

  14. Associations between Personal Exposures to VOCs and Alterations in Cardiovascular Physiology: Detroit Exposure and Aerosol Research Study (DEARS)

    EPA Science Inventory

    Background: An adult cohort consisting of 63 participants engaged in the US EPA’s recent Detroit Exposure and Aerosol Research Study (DEARS) and a University of Michigan cardiovascular sub-study conducted during summer and winter periods over 3 years between 2004 and 2007 (5 seas...

  15. Difficulty, effort and cardiovascular response to a working memory challenge: Older adults with and without mild cognitive impairment.

    PubMed

    Stewart, Christopher C; Wright, Rex A; Griffith, H Randall

    2016-06-01

    We presented cognitively healthy older adults and patients with mild cognitive impairment (MCI) three versions of a modified Sternberg memory task designed to range in difficulty from low to high. Among cognitively healthy older adults, blood pressure responses assessed during the work periods rose with difficulty. By contrast, among MCI patients, blood pressure responses assessed during the work periods were low irrespective of difficulty. Findings are discussed primarily in relation to a conceptual analysis concerned with ability determinants of effort (task engagement) and associated cardiovascular responses. They also are discussed in the context of other recent cardiovascular studies involving older adults and with regard to the potential for exaggerated cardiovascular responses to accelerate cognitive decline in advanced age. PMID:27109608

  16. Cardiovascular and neurohumoral responses to behavioral challenge as a function of race and sex.

    PubMed

    Tischenkel, N J; Saab, P G; Schneiderman, N; Nelesen, R A; Pasin, R D; Goldstein, D A; Spitzer, S B; Woo-Ming, R; Weidler, D J

    1989-01-01

    Cardiovascular and hormonal responses to a structured interview, an electronic video game, a cold pressor test, and exercise on a bicycle ergometer were assessed in eighty-three 25- to 44-year-old normotensive Black and White men and women. Blacks showed significantly greater diastolic blood pressure (DBP) responses than Whites during the cold pressor test, which were not accounted for by an increase in plasma catecholamines. Exercise produced reliably greater systolic blood pressure (SBP) increases in Black women than in Black men or White women. Men showed significantly greater SBP and DBP changes than women during the video game. These findings suggest that the pattern of physiological reactivity elicited by challenge is related to the race and sex of the subjects. PMID:2698349

  17. Assessment of the effect of anthropometric data on the alterations of cardiovascular parameters in Lithuanian elite male basketball players during physical load.

    PubMed

    Žumbakytė-Šermukšnienė, Renata; Kajėnienė, Alma; Berškienė, Kristina; Daunoravičienė, Algė; Sederevičiūtė-Kandratavičienė, Rasa

    2012-01-01

    OBJECTIVES. The aim of the study was to assess the effect of the anthropometric data of basketball players on the alterations of cardiovascular parameters during the physical load applying the model of integrated evaluation. MATERIAL AND METHODS. The research sample consisted of 113 healthy Caucasian male basketball players, candidates of the Lithuanian National men's basketball teams. Basketball players were divided into 2 groups: 69 taller and heavier male basketball players (with a higher percentage of body fat) (TMB) and 44 shorter and less heavy male basketball players (with a lower percentage of body fat) (SMB). The amount of fat, expressed in percentage, was measured using the body composition analyzer TBF-300. "Kaunas-Load," a computerized ECG analysis system, was used to evaluate the functional condition of the cardiovascular system during the load. RESULTS. The TMB group had a lower heart rate during the warming-up phase and the steady state of the load as compared with the SMB group (P<0.05). The JT interval in the TMB group was greater during the warming-up and the steady state as compared with the SMB group (P<0.05). The JT/RR ratio index in the TMB group was found to be lower in the warming-up phase and in the steady state compared with the respective parameter in the SMB group (P<0.05). CONCLUSIONS. The cardiovascular system of taller and heavier male basketball players with a greater relative amount of body fat functioned more economically.

  18. Assessment of cardiovascular response to treadmill exercise in normal healthy Indian adolescents.

    PubMed

    Pande, Sushma S; Pande, Santosh R; Dhore, Rajendra B; Daphale, Ajay V; Parate, Vrushali R; Patel, Shishir S; Agrekar, Sushil H

    2012-01-01

    The study aims to assess the cardiovascular response to treadmill exercise test in healthy Indian adolescents. A group of 50 healthy adolescents took part in the study. Cardiovascular response was assessed by using treadmill exercise test as per Bruce protocol. Pulse rate, blood pressure and ECG were recorded before, during and after undertaking the treadmill test. Mean age and body mass index (BMI) were 18.7 +/- 0.51 yrs. and 21.4 +/- 3.44 kg/m2 respectively. Karl Pearson Correlation analysis showed highly significant negative correlation between BMI and exercise time (r = -0.598, P<0.001) and between resting DBP and Exercise Time (r = -0.424, P<0.002). While BMI and DBP showed highly significant positive correlation (r = 0.463, P<0.001). During exercise pulse and SBP rose and DBP fell. SBP rose from mean 122 to 175 (rise by 53 mm of Hg) and DBP fell from mean 78 to 65 (fall by 13 mm of Hg). One min recovery pulse was 156 indicating 22% fall from target heart rate. All the parameters returned to near resting value at 6 min recovery. In 30% students DBP showed exaggerated response i.e. rise during exercise. These students had more BMI and higher resting DBP as compared to other students, which could be the reason for exaggerated response in these participants. In ECG there were no significant ST/T changes during exercise or recovery period. This study provides normal data for small sample of healthy Indian adolescents when subjected to treadmill exercise test. PMID:23029962

  19. Matricryptic sites control tissue injury responses in the cardiovascular system: relationships to pattern recognition receptor regulated events.

    PubMed

    Davis, George E

    2010-03-01

    This review addresses new concepts related to the importance of how cells within the cardiovascular system respond to matricryptic sites generated from the extracellular matrix (ECM) following tissue injury. A model is presented whereby matricryptic sites exposed from the ECM result in activation of multiple cell surface receptors including integrins, scavenger receptors, and toll-like receptors which together are hypothesized to coactivate downstream signaling pathways which alter cell behaviors following tissue injury. Of great interest are the relationships between matricryptic fragments of ECM called matricryptins and other stimuli that activate cells during injury states such as released components from cells (DNA, RNA, cytoskeletal components such as actin) or products from infectious agents in innate immunity responses. These types of cell activating molecules, which are composed of repeating molecular elements, are known to interact with pattern recognition receptors that (i) are expressed from cell surfaces, (ii) are released from cells following tissue injury, or (iii) circulate as components of plasma. Thus, cell recognition of matricryptic sites from the ECM appears to be an important component of a broad cell and tissue sensory system to detect and respond to environmental cues generated following varied types of tissue injury.

  20. The role of autacoids and the autonomic nervous system in cardiovascular responses to radio-frequency energy heating.

    PubMed

    Jauchem, J R

    2006-04-01

    Among the potential effects of exposure to high levels of radio-frequency energy (RFE) (which includes microwaves), an increase in body temperature is the primary consequence. Release of autacoids and activity of the autonomic nervous system may influence (or be directly responsible for) some of the physiological changes that occur in conjunction with this hyperthermia. The main focus of this review is the interaction of autacoids and the autonomic nervous system with cardiovascular changes during heating. Differences between environmental and RFE-induced heating (such as rate of temperature change and degree of skin vs. core heating) may be important when considering these effects. Antihistamines exhibited no beneficial effect on circulatory collapse during RFE-induced heating. The serotonergic blocker methysergide decreased survival time in rats during terminal RFE exposure, despite no effects on heart rate (HR) or blood pressure. Although blockade of platelet-activating factor resulted in lower HR before RFE exposure, there was a lack of effect on the subsequent increase in HR during heating. Nitric oxide did not contribute to the hypotension that occurs due to rapid heating by RFE exposure. There have been either no or very limited studies of effects of prostaglandins, bradykinin, or angiotensin on RFE-induced heating responses. beta-Adrenoceptor antagonism with propranolol resulted in significantly decreased survival times and lower final colonic temperatures during RFE exposure. A lack of effects of nadolol on survival time and temperature, coupled with its poor ability to traverse the blood-brain barrier, suggests that central beta-adrenergic stimulation rather than peripheral stimulation may alter thermoregulation. Effects of the autonomic nervous system (as studied by adrenoceptor blockade) on potassium changes during heating have not been fully investigated. Such changes could be important in animals' responses to RFE and other modalities of heating, and

  1. Evaluation of Anxiety Induced Cardiovascular Response in known Hypertensive Patients Undergoing Exodontia - A Prospective Study

    PubMed Central

    Rayapati, Dilip Kumar; Puttiah, Raghuveer Hosahalli; Tavane, Prashanth; Singh, Shobha Eswara; Rangan, Vinod; Kalakunta, Prithvi Raj

    2016-01-01

    Introduction Anxiety towards exodontic procedures is a common occurrence in dental practice. In hypertensive patients this anxiety induced stress may have an effect on cardiovascular system which may be clinically significant. Aim To evaluate the cardiovascular changes in hypertensive patients that may manifest following anxiety induced stress in patients undergoing exodontic procedures under local anaesthesia. Materials and Methods Eighty known hypertensive patients under medication reporting to Department of Oral and Maxillofacial surgery, Dayananda Sagar College of Dental Sciences Bangalore, Karnataka, India for extraction of teeth were taken up for the study. Anxiety was measured before local anaesthetic delivery using Amsterdam Pre-operative Anxiety and Information Scale (APAIS). Cardiovascular response data including blood pressure, heart rate, pulse rate, oxygen saturation and electrocardiographic changes were measured pre-operatively, immediately after local anaesthesia administration and Post-operatively at five, ten and fifteen minutes interval. Kruskal-Wallis test was used to compare continuous variables before and after the injection of local anaesthesia including heart rate, pulse rate, oxygen saturation, and blood pressure. Repeated-measures analysis of variance (ANOVA) was used to analyse the significance of changes in heart rate, pulse rate, blood pressure, and oxygen saturation over time between groups.Chi-square test was used to analyse the significance of electrocardiographic changes Results The results revealed that the mean anxiety score before administration of local anaesthetic was 9.91(S.D ±2.9) with a range 4-20. Severe preoperative anxiety (<12) was associated with significantly increased heart rate, pulse rate, systolic blood pressure. At the pre-injection phase the mean values were systolic blood pressure (130.72±9.2), diastolic blood pressure (81.6±7.7), heart rate (72.7±11.9) and oxygen saturation (95.2±1.9). These values were

  2. Bupropion response on sleep quality in patients with depression: implications for increased cardiovascular disease risk.

    PubMed

    Schramm, Preetam J; Poland, Russell E; Rao, Uma

    2014-02-01

    Depression could be an independent risk factor for cardiovascular disease. We assessed bupropion response in depressed patients by polysomnography (PSG) and cardiopulmonary coupling (CPC) variables. Nineteen subjects participated in a two-session, two consecutive night PSG protocol. Participants received either placebo or bupropion-SR 150 mg, orally, in a randomized, double-blind cross-over fashion on night two. Outcome variables were: sleep stages, REM latency, stable, unstable sleep and very low frequency coupling (VLFC). CPC analysis uses heart rate variability and the electrocardiogram's R-wave amplitude fluctuations associated with respiration to generate frequency maps. Bupropion increased REM latency (p=0.043) but did not impact PSG sleep continuity, architecture and CPC variables. A trend (p=0.092) was observed towards increasing VLFC duration. Bupropion increased the number of stable-unstable sleep transitions (p=0.036). Moderate to strong correlations between PSG and CPC variables were found on placebo and bupropion nights. Limitations include a small sample size, limited power to detect CPC changes and lack of normal controls for comparison. Increased stable-unstable sleep transitions and VLFC duration may indicate vulnerability to cardiovascular disease due to their association with low heart rate variability that has been associated with increased mortality raising the question whether the beneficial effects of the antidepressant medication outweighs the impact on cardiopulmonary dynamics.

  3. Minimum anesthetic concentration and cardiovascular dose-response relationship of isoflurane in cinereous vultures (Aegypius monachus).

    PubMed

    Kim, Young K; Lee, Scott S; Suh, Euy H; Lee, Lyon; Lee, Hee C; Lee, Hyo J; Yeon, Seong C

    2011-09-01

    This study aimed to determine the minimum anesthetic concentration (MAC) and dose-related cardiovascular effects of isoflurane during controlled ventilation in cinereous vultures (Aegypius monachus). The MAC was determined for 10 cinereous vultures as the midpoint between the end-tidal isoflurane concentration that allows gross purposeful movement and that which prevents the movement in response to clamping a pedal digit. Immediately after the MAC was determined, the cardiovascular effects of isoflurane at 1.0, 1.5, and 2.0 times the MAC were investigated in seven of the 10 birds. The MAC of isoflurane for 10 cinereous vultures during controlled ventilation was 1.06 +/- 0.07% (mean +/- SD). When the isoflurane concentration was increased to 1.5 and 2.0 times the MAC, there was significant dose-dependent decrease in the arterial blood pressure. However, the heart rate did not change over a range of 1.0 to 2.0 times the MAC.

  4. Changing CS Features Alters Evaluative Responses in Evaluative Conditioning

    ERIC Educational Resources Information Center

    Unkelbach, Christian; Stahl, Christoph; Forderer, Sabine

    2012-01-01

    Evaluative conditioning (EC) refers to changes in people's evaluative responses toward initially neutral stimuli (CSs) by mere spatial and temporal contiguity with other positive or negative stimuli (USs). We investigate whether changing CS features from conditioning to evaluation also changes people's evaluative response toward these CSs. We used…

  5. Spinal actions of substance P analogues on cardiovascular responses in the rat: a structure-activity analysis.

    PubMed

    Couture, R; Gupta, A; Kérouac, R; Escher, E; Regoli, D

    1987-03-01

    Ten substance P (SP) analogues were tested for their effects on mean arterial pressure and heart rate following intrathecal administration in the pentobarbital anaesthetized rat. The 10 analogues are [D-Pro4,D-alpha Npa7,9,10]SP(4-11) (A-I), (D-alpha Npa7,9,10]SP (A-II), [D-Trp7,9,10]SP (A-III), [D-Pro4,D-Npa7,9,Phe11]SP(4-11) (A-IV), [D-Pro4,D-beta Npa7,D-alpha Npa9,D-Phe11]SP(4-11) (A-V), [D-Pro4,Lys6,D-Trp7,9,10,Phe11]SP(4-11) (A-VI), [D-Pro4,D-Trp7,9,10,Phe11]SP(4-11) (A-VII), [D-Pro4,D-Trp7,9,10,Trp11]SP(4-11) (A-VIII), [D-Trp7,9,10,Trp11]SP (A-IX), and [D-Pro4,D-Phe7,9,10,Phe11]SP(4-11) (A-X). At 6.5 nmol, the analogues containing the amino acid D-Npa (A-I, A-II, A-IV, and A-V) or D-Phe (A-X) in positions 7, 9, or 10 of SP or its C-terminal octapeptide are devoid of the long-lasting cardio- and vaso-depressor effects, which are otherwise seen with analogues containing the amino acid D-Trp (A-III, A-VI, A-VII, A-VIII, and A-IX) in the same positions. Some of the analogues containing D-Npa maintain the initial hypotensive effect seen with SP while the analogue containing D-Phe produces only a small hypertensive response. The 10 analogues when tested at a dose that failed to alter basal mean arterial pressure and heart rate did not block the cardiovascular responses elicited by SP and no cross desensitization was observed between SP and these analogues. It appears that these SP analogues exert cardiovascular effects in the rat spinal cord probably without interacting with SP receptors.

  6. Alteration of somatosensory response in adulthood by early life stress.

    PubMed

    Takatsuru, Yusuke; Koibuchi, Noriyuki

    2015-01-01

    Early life stress is well-known as a critical risk factor for mental and cognitive disorders in adulthood. Such disorders are accompanied by altered neuro- (synapto-) genesis and gene expression. Because psychosomatic disorders induced by early life stress (e.g., physical and/or sexual abuse, and neglect) have become a socio-economic problem, it is very important to clarify the mechanisms underlying these changes. However, despite of intensive clinical and animal studies, such mechanisms have not yet been clarified. Although the disturbance of glucocorticoid and glutamate homeostasis by stress has been well-documented, it has not yet been clarified whether such disturbance by early life stress persists for life. Furthermore, since previous studies have focused on the detection of changes in specific brain regions, such as the hippocampus and prefrontal cortex, it has not been clarified whether early life stress induced changes in the sensory/motor system. Thus, in this review, we introduce recent studies on functional/structural changes in the somatosensory cortex induced by early life stress. We believe that this review provides new insights into the functional alteration of the somatosensory system induced by early life stress. Such information may have clinical relevance in terms of providing effective therapeutic interventions to early life stressed individuals. PMID:26041988

  7. Functional analysis of hypothalamic control of the cardiovascular responses accompanying emotional behavior.

    PubMed

    Smith, O A; Astley, C A; DeVito, J L; Stein, J M; Walsh, K E

    1980-06-01

    The cardiovascular (CV) responses to an acute emotional situation in unanesthetized, chair-restrained baboons include elevations in heart rate, blood pressure, and terminal aortic flow and a complex biphasic reduction in renal flow. The same CV responses can be produced by stimulating an area in the hypothalamus. Furthermore, bilateral ablation of the hypothalamic area eliminates CV responses to the emotional behavior while responses to exercise, free feed, and lever press remain unaltered. This effect is not due to memory loss, loss of emotionality, or a general loss of CV regulatory capacity. Efferent projections of the hypothalamic site were traced by means of autoradiography and afferent sources were traced by horseradish peroxidase injections. Efferents include projections to amygdala, central gray, zona incerta, midline thalamic nuclei, dorsal midbrain tegmentum, the parabrachial region. Afferents were widely distributed and included inputs from the subiculum, amygdala, septal area, central gray, locus ceruleus, interpeduncular nucleus, and bilateral labeling in and around the dorsal motor nucleus of X and the nucleus ambiguus.

  8. WISE-2005: Integrative Cardiovascular Responses with LBNP during 60-Day Bed Rest in Women

    NASA Technical Reports Server (NTRS)

    Hughson, R. L.; Kerbeci, P.; Arbeille, Ph.; Mattar, L.; Shoemaker, J. K.

    2005-01-01

    During 2005, 24 women will take part in the Women International Space-simulation for Exploration (WISE). In this paper we report on the first phase that studied 4 Exercise (EX+LBNP), 4 nutrition (NUT), and 4 no countermeasure control (CON) subjects. The EX+LBNP group completed regular exercise on a treadmill inside LBNP, flywheel resistive exercise and static periods of LBNP, and had recovery days. The NUT group received daily protein supplements. Integrative cardiovascular responses were obtained and here we report data for heart rate during LBNP, blood volume and angiotensin 11. LBNP was applied at 0, -10, -20 and -30 mmHg for 2-minutes for each stage. Blood was sampled prebed rest and on HDT-60. After 60-days head down bed rest, HR in the CON group increased by 6.1+/-2.8 bpm at rest and by 20.7+/-5.0 bpm at -30 mmHg LBNP. The EX+LBNP group had increases of 3.6+/-5.6 and 11.6+/-5.4 bpm, while the NUT group HR increased 2.6+/-3.1 and 9.4+/-3.6 bpm. The EX+LBNP group had almost no change in blood volume or plasma angiotensin II from pre-bed rest to HDT60, while both the CON and NUT groups had larger increases in plasma volume and almost double concentrations of angiotensin II. These data show a positive effect in the EX+LBNP group on the heart rate response as well as an unexpected possible benefit in the NUT group. Further studies are required to confirm possible cardiovascular benefits of the protein supplement.

  9. Particle-induced pulmonary acute phase response may be the causal link between particle inhalation and cardiovascular disease

    PubMed Central

    Saber, Anne T; Jacobsen, Nicklas R; Jackson, Petra; Poulsen, Sarah Søs; Kyjovska, Zdenka O; Halappanavar, Sabina; Yauk, Carole L; Wallin, Håkan; Vogel, Ulla

    2014-01-01

    Inhalation of ambient and workplace particulate air pollution is associated with increased risk of cardiovascular disease. One proposed mechanism for this association is that pulmonary inflammation induces a hepatic acute phase response, which increases risk of cardiovascular disease. Induction of the acute phase response is intimately linked to risk of cardiovascular disease as shown in both epidemiological and animal studies. Indeed, blood levels of acute phase proteins, such as C-reactive protein and serum amyloid A, are independent predictors of risk of cardiovascular disease in prospective epidemiological studies. In this review, we present and review emerging evidence that inhalation of particles (e.g., air diesel exhaust particles and nanoparticles) induces a pulmonary acute phase response, and propose that this induction constitutes the causal link between particle inhalation and risk of cardiovascular disease. Increased levels of acute phase mRNA and proteins in lung tissues, bronchoalveolar lavage fluid and plasma clearly indicate pulmonary acute phase response following pulmonary deposition of different kinds of particles including diesel exhaust particles, nanoparticles, and carbon nanotubes. The pulmonary acute phase response is dose-dependent and long lasting. Conversely, the hepatic acute phase response is reduced relative to lung or entirely absent. We also provide evidence that pulmonary inflammation, as measured by neutrophil influx, is a predictor of the acute phase response and that the total surface area of deposited particles correlates with the pulmonary acute phase response. We discuss the implications of these findings in relation to occupational exposure to nanoparticles. How to cite this article: WIREs Nanomed Nanobiotechnol 2014, 6:517–531. doi: 10.1002/wnan.1279 PMID:24920450

  10. Do Integrins Mediate the Skeletal Response to Altered Loading?

    NASA Technical Reports Server (NTRS)

    vanderMeulen, Marjolein C. H.

    2004-01-01

    In vivo experiments were performed to examine the role of B1 integrin in skeletal adaptation to reduced and increased loading. Transgenic mice were generated with a dominant negative form of the B1 integrin cytoplasmic domain with expression driven by the osteocalcin promoter (pOCb1DN). This fragment consists of the transmembrane and intracellular domains and interferes with endogenous integrin signalling in vitro. This promoter targets expression of the transgene to mature bone cells. Expression of the transgene was confirmed by immunoprecipitation and western blotting. Reduced loading was generated by hindlimb suspension and increased loading the resumption of normal loading following hindlimb suspension. Two groups of female 35-day old mice were examined: poCb1DN transgenic mice (TG) and wild-type littermate controls (WT). Animals were hindlimb suspended for 1 week (HU, n = l0/gp) or 4 weeks (HU, n = 4 - 7/gp) or suspended for 4 weeks followed by reloading by normal ambulation for 4 weeks (RL, n = l0/gp). Age-matched controls (CT) were pairfed based on the HU food intake. The protocols were approved by the NASA Ames Research Center IACUC. Upon completion of the experimental protocol, body mass was recorded and tissues of interest removed and analyzed following standard procedures. Femoral whole bone structural behavior was measured in torsion to failure to obtain whole bone strength (failure torque) and torsional rigidity. Ash content (ash) and fraction (% ash) were determined for the tibia. Total ash is indicative of bone size whereas %ash is a material property. Tibial curvature was measured from microradiographs. For each experiment, the effects of genotype (TG, WT) and treatment (CT, HU/RL) were assessed by two-factor ANOVA followed by the Tukey-Kramer posthoc to identify significant differences at an alpha level of 0.05. Our goal was to understand differences resulting from altered integrin function in the adaptation to altered loading.

  11. Cardiovascular alterations caused by the administration of 2% mepivacaine HCl with 1:20,000 levonordefrin (Carbocain) in dogs.

    PubMed

    Simone, J L; Tortamano, N; Armonia, P L; Rocha, R G

    1997-01-01

    We studied possible cardiovascular effects (systolic, diastolic, mean arterial blood pressures, and heart rate) caused by intraoral infiltrative administration of 2% mepivacaine HCl with 1:20,000 levonordefrin in dogs (Canis familiaris), using a Beckman electrophysiograph. Doses used were 0.514 and 1.542 mg/kg body weight corresponding to one and three 1.8-ml cartridges, respectively, in 70-kg average weight adult men. A statistically significant increase was observed in the systolic and the mean arterial blood pressures.

  12. The cardiovascular and endocrine responses to voluntary and forced diving in trained and untrained rats

    PubMed Central

    DiNovo, Karyn. M.; Connolly, Tiffanny M.

    2010-01-01

    The mammalian diving response, consisting of apnea, bradycardia, and increased total peripheral resistance, can be modified by conscious awareness, fear, and anticipation. We wondered whether swim and dive training in rats would 1) affect the magnitude of the cardiovascular responses during voluntary and forced diving, and 2) whether this training would reduce or eliminate any stress due to diving. Results indicate Sprague-Dawley rats have a substantial diving response. Immediately upon submersion, heart rate (HR) decreased by 78%, from 453 ± 12 to 101 ± 8 beats per minute (bpm), and mean arterial pressure (MAP) decreased 25%, from 143 ± 1 to 107 ± 5 mmHg. Approximately 4.5 s after submergence, MAP had increased to a maximum 174 ± 3 mmHg. Blood corticosterone levels indicate trained rats find diving no more stressful than being held by a human, while untrained rats find swimming and diving very stressful. Forced diving is stressful to both trained and untrained rats. The magnitude of bradycardia was similar during both voluntary and forced diving, while the increase in MAP was greater during forced diving. The diving response of laboratory rats, therefore, appears to be dissimilar from that of other animals, as most birds and mammals show intensification of diving bradycardia during forced diving compared with voluntary diving. Rats may exhibit an accentuated antagonism between the parasympathetic and sympathetic branches of the autonomic nervous system, such that in the autonomic control of HR, parasympathetic activity overpowers sympathetic activity. Additionally, laboratory rats may lack the ability to modify the degree of parasympathetic outflow to the heart during an intense cardiorespiratory response (i.e., the diving response). PMID:19923359

  13. Decreased reaction time variability is associated with greater cardiovascular responses to acute stress.

    PubMed

    Wawrzyniak, Andrew J; Hamer, Mark; Steptoe, Andrew; Endrighi, Romano

    2016-05-01

    Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75-min recovery. RT measures were generated from an ex-Gaussian distribution that yielded three predictors: mu-RT, sigma-RT, and tau-RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = -.009, SE = .005, p = .09) and diastolic (B = -.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = -.007, SE = .003, p = .03) and impaired vagal tone (B = -.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses. PMID:26894967

  14. Decreased reaction time variability is associated with greater cardiovascular responses to acute stress

    PubMed Central

    Hamer, Mark; Steptoe, Andrew; Endrighi, Romano

    2016-01-01

    Abstract Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75‐min recovery. RT measures were generated from an ex‐Gaussian distribution that yielded three predictors: mu‐RT, sigma‐RT, and tau‐RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = −.009, SE = .005, p = .09) and diastolic (B = −.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = −.007, SE = .003, p = .03) and impaired vagal tone (B = −.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses. PMID:26894967

  15. Decreased reaction time variability is associated with greater cardiovascular responses to acute stress.

    PubMed

    Wawrzyniak, Andrew J; Hamer, Mark; Steptoe, Andrew; Endrighi, Romano

    2016-05-01

    Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75-min recovery. RT measures were generated from an ex-Gaussian distribution that yielded three predictors: mu-RT, sigma-RT, and tau-RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = -.009, SE = .005, p = .09) and diastolic (B = -.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = -.007, SE = .003, p = .03) and impaired vagal tone (B = -.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses.

  16. Keratins Are Altered in Intestinal Disease-Related Stress Responses

    PubMed Central

    Helenius, Terhi O.; Antman, Cecilia A.; Asghar, Muhammad Nadeem; Nyström, Joel H.; Toivola, Diana M.

    2016-01-01

    Keratin (K) intermediate filaments can be divided into type I/type II proteins, which form obligate heteropolymers. Epithelial cells express type I-type II keratin pairs, and K7, K8 (type II) and K18, K19 and K20 (type I) are the primary keratins found in the single-layered intestinal epithelium. Keratins are upregulated during stress in liver, pancreas, lung, kidney and skin, however, little is known about their dynamics in the intestinal stress response. Here, keratin mRNA, protein and phosphorylation levels were studied in response to murine colonic stresses modeling human conditions, and in colorectal cancer HT29 cells. Dextran sulphate sodium (DSS)-colitis was used as a model for intestinal inflammatory stress, which elicited a strong upregulation and widened crypt distribution of K7 and K20. K8 levels were slightly downregulated in acute DSS, while stress-responsive K8 serine-74 phosphorylation (K8 pS74) was increased. By eliminating colonic microflora using antibiotics, K8 pS74 in proliferating cells was significantly increased, together with an upregulation of K8 and K19. In the aging mouse colon, most colonic keratins were upregulated. In vitro, K8, K19 and K8 pS74 levels were increased in response to lipopolysaccharide (LPS)-induced inflammation in HT29 cells. In conclusion, intestinal keratins are differentially and dynamically upregulated and post-translationally modified during stress and recovery. PMID:27626448

  17. Keratins Are Altered in Intestinal Disease-Related Stress Responses.

    PubMed

    Helenius, Terhi O; Antman, Cecilia A; Asghar, Muhammad Nadeem; Nyström, Joel H; Toivola, Diana M

    2016-01-01

    Keratin (K) intermediate filaments can be divided into type I/type II proteins, which form obligate heteropolymers. Epithelial cells express type I-type II keratin pairs, and K7, K8 (type II) and K18, K19 and K20 (type I) are the primary keratins found in the single-layered intestinal epithelium. Keratins are upregulated during stress in liver, pancreas, lung, kidney and skin, however, little is known about their dynamics in the intestinal stress response. Here, keratin mRNA, protein and phosphorylation levels were studied in response to murine colonic stresses modeling human conditions, and in colorectal cancer HT29 cells. Dextran sulphate sodium (DSS)-colitis was used as a model for intestinal inflammatory stress, which elicited a strong upregulation and widened crypt distribution of K7 and K20. K8 levels were slightly downregulated in acute DSS, while stress-responsive K8 serine-74 phosphorylation (K8 pS74) was increased. By eliminating colonic microflora using antibiotics, K8 pS74 in proliferating cells was significantly increased, together with an upregulation of K8 and K19. In the aging mouse colon, most colonic keratins were upregulated. In vitro, K8, K19 and K8 pS74 levels were increased in response to lipopolysaccharide (LPS)-induced inflammation in HT29 cells. In conclusion, intestinal keratins are differentially and dynamically upregulated and post-translationally modified during stress and recovery. PMID:27626448

  18. Deafness alters auditory nerve fibre responses to cochlear implant stimulation.

    PubMed

    Sly, David J; Heffer, Leon F; White, Mark W; Shepherd, Robert K; Birch, Michael G J; Minter, Ricki L; Nelson, Niles E; Wise, Andrew K; O'Leary, Stephen J

    2007-07-01

    Here we characterized the relationship between duration of sensorineural hearing loss and the response of the auditory nerve to electrical stimulus rate. Electrophysiological recordings were made from undeafened guinea pigs and those ototoxically deafened for either 5 weeks or 6 months. Auditory neuron survival decreased significantly with the duration of deafness. Extracellular recordings were made from auditory nerve fibres responding to biphasic, charge-balanced current pulses delivered at rates of 20 and 200 pulses/s via a monopolar scala tympani stimulating electrode. The response to 20 pulses/s electrical stimulation of the deafened cochlea exhibited a decrease in spike latency, unaltered temporal jitter and unaltered dynamic range (of nerve firing rate against stimulus current), and a reduction in threshold after 6 months of deafness. The response to a 200-pulse/s stimulus was similar except that the dynamic range was greater than with 20 pulses/s and was also greater in deafened animals than in undeafened animals. Deafness and pulse rate are related; in deaf animals spike recovery appears to be complete between successive stimulus pulses at a low rate (20 pulses/s), but incomplete between pulses at a moderate pulse rate (200 pulses/s). These results suggest that changes in the function of individual auditory nerve fibres after deafness may affect clinical responses during high-rate stimulation such as that used in contemporary speech processing strategies, but not during lower rate stimulation such as that used to record evoked potentials. PMID:17650121

  19. Effect of fluid countermeasures of varying osmolarity on cardiovascular responses to orthostatic stress

    NASA Technical Reports Server (NTRS)

    Davis, John E.

    1989-01-01

    Current operational procedures for shuttle crewmembers include the ingestion of a fluid countermeasure approximately 2 hours before reentry into the earth's gravitational field. The ingestion of the fluid countermeasure is thought to restore plasma volume and improve orthostatic responses upon reentry. The present countermeasure consists of ingesting salt tablets and water to achieve an isotonic solution. It has yet to be determined whether this is the optimal drink to restore orthostatic tolerance. It is also not known whether the drink solution is effective in increasing plasma volume. The purpose here is to evaluate the effectiveness of drink solutions of different osmolarity on restoring plasma volume and orthostatic responses. A hypertonic drink solution was more effective in restoring plasma volume after dehydration than an isotonic solution. However, there were no differences in their effects on an orthostatic challenge. These data suggest that the plasma volume differences produced in this study were not sufficient to produce differences in the cardiovascular responses to an orthostatic challenge, or there are other changes that occur during space flight that are more important in determining orthostatic intolerance.

  20. The effects of fasting on the thermogenic, metabolic and cardiovascular responses to infused adrenaline.

    PubMed

    Webber, J; Taylor, J; Greathead, H; Dawson, J; Buttery, P J; Macdonald, I A

    1995-10-01

    The effects of fasting on the thermogenic, lipolytic and cardiovascular responses to adrenaline were examined in nine normal, young, non-obese subjects. Each subject attended for study after 12, 36 and 72 h fasting. After basal measurements adrenaline was infused at 25 ng/min per kg ideal body weight for 90 min. Fasting increased the thermogenic effect of the adrenaline (mean 14.6 (SE 1.7), 16.6 (SE 1.8), 22.6 (SE 1.6) J/min per kg fat-free mass after 12, 36 and 72 h fasting respectively; P < 0.001, ANOVA). Basal plasma palmitate turnover increased with duration of fasting (1.48 (SE 0.22), 1.95 (SE 0.34) and 2.26 (SE 0.33) mumol/min per kg body weight; P < 0.001, ANOVA), but the response to adrenaline was unaffected by fasting. The percentage values for basal plasma palmitate turnover oxidized were 44 (SE 2; 12 h), 46 (SE 5; 36 h) and 42 (SE 4)% (72 h). In response to adrenaline this percentage fell, suggesting that adrenaline infusion may favour intra-tissue lipid oxidation.

  1. Action of adenosine receptor antagonists on the cardiovascular response to defence area stimulation in the rat.

    PubMed Central

    St Lambert, J H; Dawid-Milner, M S; Silva-Carvalho, L; Spyer, K M

    1994-01-01

    1. The action of adenosine in the mediation of the cardiovascular changes associated with the defence reaction has been investigated in the rat using two A1 receptor antagonists. 2. Cumulative doses of 1,3 dipropyl-cyclopentylxanthine (DPCPX) (0.3-3 mg kg-1) and ethanol (0.03-0.25 ml) and bolus doses of DPCPX (3 mg kg-1) and 8-sulphophenyltheophylline (8-SPT) (20 mg kg-1) were given into alpha-chloralose, paralysed and artificially ventilated rats. Recordings were made of arterial blood pressure and heart rate. 3. Ethanol, the vehicle for DPCPX, failed to modify the magnitude of the defence response; however, cumulative doses of DPCPX produced a dose-dependent decrease in the HDA (hypothalamic defence area)-evoked increase in arterial blood pressure, accompanied by a similar fall in the magnitude of the evoked heart rate response. 4. The evoked rise in arterial blood pressure was reduced significantly by intravenous injection of DPCPX (3 mg kg-1) but not 8-SPT (20 mg kg-1), a purely peripherally acting adenosine antagonist. 5. These results suggest that adenosine acting at A1 receptors located in the central nervous system, is involved in the HDA-evoked pressor response. Whilst the site of action of the A1 receptors is not known, possible locations are discussed. PMID:7812606

  2. Adaptive thermoregulation in endotherms may alter responses to climate change.

    PubMed

    Boyles, Justin G; Seebacher, Frank; Smit, Ben; McKechnie, Andrew E

    2011-11-01

    Climate change is one of the major issues facing natural populations and thus a focus of recent research has been to predict the responses of organisms to these changes. Models are becoming more complex and now commonly include physiological traits of the organisms of interest. However, endothermic species have received less attention than have ectotherms in these mechanistic models. Further, it is not clear whether responses of endotherms to climate change are modified by variation in thermoregulatory characteristics associated with phenotypic plasticity and/or adaptation to past selective pressures. Here, we review the empirical data on thermal adaptation and acclimatization in endotherms and discuss how those factors may be important in models of responses to climate change. We begin with a discussion of why thermoregulation and thermal sensitivity at high body temperatures should be co-adapted. Importantly, we show that there is, in fact, considerable variation in the ability of endotherms to tolerate high body temperatures and/or high environmental temperatures, but a better understanding of this variation will likely be critical for predicting responses to future climatic scenarios. Next, we discuss why variation in thermoregulatory characteristics should be considered when modeling the effects of climate change on heterothermic endotherms. Finally, we review some biophysical and biochemical factors that will limit adaptation and acclimation in endotherms. We consider both long-term, directional climate change and short-term (but increasingly common) anomalies in climate such as extreme heat waves and we suggest areas of important future research relating to both our basic understanding of endothermic thermoregulation and the responses of endotherms to climate change.

  3. The assessment of Big Five Personality Factors and Temperament Domains as modifiers of cardiovascular response to occupational stress.

    PubMed

    Merecz, D; Makowska, Z; Makowiec-Dabrowska, T

    1999-01-01

    The aim of the study was to explore the role of Big Five Personality Factors and Temperament Domains as the factors influencing cardiovascular response to work, and their moderating effect on the relationship between occupational stress and cardiovascular reactivity. The self-reported data on occupational stress and filled in NEO-Five Factor Inventory by Costa, and McCrae and Pavlovian Temperament Survey by Strelau et al. were collected from 97 bank clerks employed in large bank branches. The subjects also responded to the questionnaire on personal and professional background factors. A 24 hour monitoring of cardiovascular reactivity (heart rate and blood pressure) was also provided. Conscientiousness was found to be the only modifier of cardiovascular response to occupational stress reflected by systolic blood pressure. Several main, independent of stress effects of personality and temperament domains were also found. The ratio of heart rate at work to heart rate during sleep was associated with the strength of excitatory process, the percentage of maximum heart rate index with Conscientiousness, and systolic blood pressure at work was influenced by the strength of inhibitory process. However, generally speaking, physiological indicators of the cardiovascular system functioning were not very sensitive to changes in values of personality and temperament variables at the level of occupational stress reported by the bank clerks who participated in the study.

  4. Sidestream cigarette smoke effects on cardiovascular responses in conscious rats: involvement of oxidative stress in the fourth cerebral ventricle

    PubMed Central

    2012-01-01

    Background Cigarette exposure increases brain oxidative stress. The literature showed that increased brain oxidative stress affects cardiovascular regulation. However, no previous study investigated the involvement of brain oxidative stress in animals exposed to cigarette and its relationship with cardiovascular regulation. We aimed to evaluate the effects of central catalase inhibition on baroreflex and cardiovascular responses in rats exposed to sidestream cigarette smoke (SSCS). Methods We evaluated males Wistar rats (320-370 g), which were implanted with a stainless steel guide cannula into the fourth cerebral ventricle (4th V). Femoral artery and vein were cannulated for mean arterial pressure (MAP) and heart rate (HR) measurement and drug infusion, respectively. Rats were exposed to SSCS during three weeks, 180 minutes, 5 days/week (CO: 100-300 ppm). Baroreflex was tested with a pressor dose of phenylephrine (PHE, 8 μg/kg, bolus) to induce bradycardic reflex and a depressor dose of sodium nitroprusside (SNP, 50 μg/kg, bolus) to induce tachycardic reflex. Cardiovascular responses were evaluated before, 5, 15, 30 and 60 minutes after 3-amino-1,2,4-triazole (ATZ, catalase inhibitor, 0.001 g/100 μL) injection into the 4th V. Results Central catalase inhibition increased basal HR in the control group during the first 5 minutes. SSCS exposure increased basal HR and attenuated bradycardic peak during the first 15 minutes. Conclusion We suggest that SSCS exposure affects cardiovascular regulation through its influence on catalase activity. PMID:22463380

  5. Resource colimitation governs plant community responses to altered precipitation.

    PubMed

    Eskelinen, Anu; Harrison, Susan P

    2015-10-20

    Ecological theory and evidence suggest that plant community biomass and composition may often be jointly controlled by climatic water availability and soil nutrient supply. To the extent that such colimitation operates, alterations in water availability caused by climatic change may have relatively little effect on plant communities on nutrient-poor soils. We tested this prediction with a 5-y rainfall and nutrient manipulation in a semiarid annual grassland system with highly heterogeneous soil nutrient supplies. On nutrient-poor soils, rainfall addition alone had little impact, but rainfall and nutrient addition synergized to cause large increases in biomass, declines in diversity, and near-complete species turnover. Plant species with resource-conservative functional traits (low specific leaf area, short stature) were replaced by species with resource-acquisitive functional traits (high specific leaf area, tall stature). On nutrient-rich soils, in contrast, rainfall addition alone caused substantial increases in biomass, whereas fertilization had little effect. Our results highlight that multiple resource limitation is a critical aspect when predicting the relative vulnerability of natural communities to climatically induced compositional change and diversity loss. PMID:26438856

  6. Alterations in the Colonic Microbiota in Response to Osmotic Diarrhea

    PubMed Central

    Trajanoski, Slave; Lackner, Stefan; Stocker, Gernot; Hinterleitner, Thomas; Gülly, Christian; Högenauer, Christoph

    2013-01-01

    Background & Aims Diseases of the human gastrointestinal (GI) tract are often accompanied by diarrhea with profound alterations in the GI microbiota termed dysbiosis. Whether dysbiosis is due to the disease itself or to the accompanying diarrhea remains elusive. With this study we characterized the net effects of osmotic diarrhea on the composition of the GI microbiota in the absence of disease. Methods We induced osmotic diarrhea in four healthy adults by oral administration of polyethylene glycol 4000 (PEG). Stool as well as mucosa specimens were collected before, during and after diarrhea and 16S rDNA-based microbial community profiling was used to assess the microbial community structure. Results Stool and mucosal microbiotas were strikingly different, with Firmicutes dominating the mucosa and Bacteroidetes the stools. Osmotic diarrhea decreased phylotype richness and showed a strong tendency to equalize the otherwise individualized microbiotas on the mucosa. Moreover, diarrhea led to significant relative shifts in the phyla Bacteroidetes and Firmicutes and to a relative increase in the abundance of Proteobacteria on the mucosa, a phenomenon also noted in several inflammatory and diarrheal GI diseases. Conclusions Changes in microbial community structure induced by osmotic diarrhea are profound and show similarities to changes observed in other GI diseases including IBD. These effects so must be considered when specimens from diarrheal diseases (i.e. obtained by stratification of samples according to diarrheal status) or conditions wherein bowel preparations like PEG (i.e. specimens obtained during endoscopy) are used. PMID:23409050

  7. Resource colimitation governs plant community responses to altered precipitation

    PubMed Central

    Eskelinen, Anu; Harrison, Susan P.

    2015-01-01

    Ecological theory and evidence suggest that plant community biomass and composition may often be jointly controlled by climatic water availability and soil nutrient supply. To the extent that such colimitation operates, alterations in water availability caused by climatic change may have relatively little effect on plant communities on nutrient-poor soils. We tested this prediction with a 5-y rainfall and nutrient manipulation in a semiarid annual grassland system with highly heterogeneous soil nutrient supplies. On nutrient-poor soils, rainfall addition alone had little impact, but rainfall and nutrient addition synergized to cause large increases in biomass, declines in diversity, and near-complete species turnover. Plant species with resource-conservative functional traits (low specific leaf area, short stature) were replaced by species with resource-acquisitive functional traits (high specific leaf area, tall stature). On nutrient-rich soils, in contrast, rainfall addition alone caused substantial increases in biomass, whereas fertilization had little effect. Our results highlight that multiple resource limitation is a critical aspect when predicting the relative vulnerability of natural communities to climatically induced compositional change and diversity loss. PMID:26438856

  8. Alterations of a Cellular Cholesterol Metabolism Network Are a Molecular Feature of Obesity-Related Type 2 Diabetes and Cardiovascular Disease.

    PubMed

    Ding, Jingzhong; Reynolds, Lindsay M; Zeller, Tanja; Müller, Christian; Lohman, Kurt; Nicklas, Barbara J; Kritchevsky, Stephen B; Huang, Zhiqing; de la Fuente, Alberto; Soranzo, Nicola; Settlage, Robert E; Chuang, Chia-Chi; Howard, Timothy; Xu, Ning; Goodarzi, Mark O; Chen, Y-D Ida; Rotter, Jerome I; Siscovick, David S; Parks, John S; Murphy, Susan; Jacobs, David R; Post, Wendy; Tracy, Russell P; Wild, Philipp S; Blankenberg, Stefan; Hoeschele, Ina; Herrington, David; McCall, Charles E; Liu, Yongmei

    2015-10-01

    Obesity is linked to type 2 diabetes (T2D) and cardiovascular diseases; however, the underlying molecular mechanisms remain unclear. We aimed to identify obesity-associated molecular features that may contribute to obesity-related diseases. Using circulating monocytes from 1,264 Multi-Ethnic Study of Atherosclerosis (MESA) participants, we quantified the transcriptome and epigenome. We discovered that alterations in a network of coexpressed cholesterol metabolism genes are a signature feature of obesity and inflammatory stress. This network included 11 BMI-associated genes related to sterol uptake (↑LDLR, ↓MYLIP), synthesis (↑SCD, FADS1, HMGCS1, FDFT1, SQLE, CYP51A1, SC4MOL), and efflux (↓ABCA1, ABCG1), producing a molecular profile expected to increase intracellular cholesterol. Importantly, these alterations were associated with T2D and coronary artery calcium (CAC), independent from cardiometabolic factors, including serum lipid profiles. This network mediated the associations between obesity and T2D/CAC. Several genes in the network harbored C-phosphorus-G dinucleotides (e.g., ABCG1/cg06500161), which overlapped Encyclopedia of DNA Elements (ENCODE)-annotated regulatory regions and had methylation profiles that mediated the associations between BMI/inflammation and expression of their cognate genes. Taken together with several lines of previous experimental evidence, these data suggest that alterations of the cholesterol metabolism gene network represent a molecular link between obesity/inflammation and T2D/CAC.

  9. Small Ubiquitin-like Modifier Alters IFN Response.

    PubMed

    Maarifi, Ghizlane; Maroui, Mohamed Ali; Dutrieux, Jacques; Dianoux, Laurent; Nisole, Sébastien; Chelbi-Alix, Mounira K

    2015-09-01

    IFNs orchestrate immune defense through induction of hundreds of genes. Small ubiquitin-like modifier (SUMO) is involved in various cellular functions, but little is known about its role in IFN responses. Prior work identified STAT1 SUMOylation as an important mode of regulation of IFN-γ signaling. In this study, we investigated the roles of SUMO in IFN signaling, gene expression, protein stability, and IFN-induced biological responses. We first show that SUMO overexpression leads to STAT1 SUMOylation and to a decrease in IFN-induced STAT1 phosphorylation. Interestingly, IFNs exert a negative retrocontrol on their own signaling by enhancing STAT1 SUMOylation. Furthermore, we show that expression of each SUMO paralog inhibits IFN-γ-induced transcription without affecting that of IFN-α. Further, we focused on IFN-induced gene products associated to promyelocytic leukemia (PML) nuclear bodies, and we show that neither IFN-α nor IFN-γ could increase PML and Sp100 protein expression because they enhanced their SUMO3 conjugation and subsequent proteasomal degradation. Because it is known that SUMO3 is important for the recruitment of RING finger protein 4, a poly-SUMO-dependent E3 ubiquitin ligase, and that PML acts as a positive regulator of IFN-induced STAT1 phosphorylation, we went on to show that RING finger protein 4 depletion stabilizes PML and is correlated with a positive regulation of IFN signaling. Importantly, inhibition of IFN signaling by SUMO is associated with a reduction of IFN-induced apoptosis, cell growth inhibition, antiviral defense, and chemotaxis. Conversely, inhibition of SUMOylation results in higher IFN-γ-induced STAT1 phosphorylation and biological responses. Altogether, our results uncover a new role for SUMO in the modulation of IFN response. PMID:26223657

  10. The Genetic Response to Short-term Interventions Affecting Cardiovascular Function: Rationale and Design of the HAPI Heart Study

    PubMed Central

    Mitchell, Braxton D.; McArdle, Patrick F.; Shen, Haiqing; Rampersaud, Evadnie; Pollin, Toni I.; Bielak, Lawrence F.; Jaquish, Cashell; Douglas, Julie A.; Roy-Gagnon, Marie-Hélène; Sack, Paul; Naglieri, Rosalie; Hines, Scott; Horenstein, Richard B.; Chang, Yen-Pei C.; Post, Wendy; Ryan, Kathleen A.; Brereton, Nga Hong; Pakyz, Ruth E.; Sorkin, John; Damcott, Coleen M.; O’Connell, Jeffrey R.; Mangano, Charles; Corretti, Mary; Vogel, Robert; Herzog, William; Weir, Matthew R.; Peyser, Patricia A.; Shuldiner, Alan R.

    2008-01-01

    Background The etiology of cardiovascular disease (CVD) is multifactorial. Efforts to identify genes influencing CVD risk have met with limited success to date, likely due to the small effect sizes of common CVD risk alleles and the presence of gene by gene and gene by environment interactions. Methods The Heredity and Phenotype Intervention (HAPI) Heart Study was initiated in 2002 to measure the cardiovascular response to four short-term interventions affecting cardiovascular risk factors and to identify the genetic and environmental determinants of these responses. The measurements included blood pressure responses to the cold pressor stress test and to a high salt diet, triglyceride excursion in response to a high fat challenge, and response in platelet aggregation to aspirin therapy. Results The interventions were carried out in 868 relatively healthy Amish adults from large families. The heritabilities of selected response traits for each intervention ranged from 8–38%, suggesting that some of the variation associated with response to each intervention can be attributed to the additive effects of genes. Conclusions Identifying these response genes may identify new mechanisms influencing CVD and may lead to individualized preventive strategies and improved early detection of high-risk individuals. PMID:18440328

  11. How stress alters immune responses during respiratory infection.

    PubMed

    Griebel, Philip; Hill, Kevin; Stookey, Joseph

    2014-12-01

    Fall-weaned calves entering the feedlot experience a variety of psychological and physical stressors, including maternal separation, transportation, social mixing, restraint, and dietary changes. Mixing calves from multiple sources also exposes them to respiratory pathogens at a time when maternal immunity has waned. Using an experimental bovine respiratory disease (BRD) challenge, we analyzed the effects of specific stressors on clinical disease and immune responses following bovine herpes virus (BHV-1/IBR) infection of naïve calves. Transportation stress was compared to either abrupt weaning plus transportation or transportation following a two-step weaning process. Transportation alone significantly (P < 0.05) increased BHV-1 shedding in nasal secretions despite elevated interferon-gamma production in the upper respiratory tract. In contrast, abrupt weaning and transportation, significantly (P < 0.05) increased serum haptoglobin on day 3 post-infection (PI) and blood leukocyte tumor necrosis factor α secretion on day 5 PI. These systemic responses were reduced by instituting a two-step weaning process 4 days prior to transportation and BHV-1 infection. In conclusion, these observations are consistent with earlier studies implicating weaning and transportation as stressors contributing to BRD severity and mortality. Current studies also revealed that different stressors or combination of stressors have distinct effects on host responses to viral infection in naïve calves. PMID:25497501

  12. Mindfulness may both moderate and mediate the effect of physical fitness on cardiovascular responses to stress: a speculative hypothesis

    PubMed Central

    Demarzo, Marcelo M. P.; Montero-Marin, Jesús; Stein, Phyllis K.; Cebolla, Ausiàs; Provinciale, Jaime G.; García-Campayo, Javier

    2014-01-01

    The psychological construct of mindfulness refers to an awareness that emerges by intentionally paying attention to the present experience in a non-judgmental or evaluative way. This particular quality of awareness has been associated to several indicators of physical and psychological health, and can be developed using mindfulness-based interventions (MBIs), and therefore MBIs have been successfully applied as preventive and complementary interventions and therapies in medicine and psychology. Together with quiet sitting and lying meditation practices, mindful physical exercises such as “mindful walking” and “mindful movement” are key elements in MBIs and couple muscular activity with an internally directed focus, improving interoceptive attention to bodily sensations. In addition, MBIs seem to share similar mechanisms with physical fitness (PF) by which they may influence cardiovascular responses to stress. Based on these facts, it is feasible to raise the question of whether physical training itself may induce the development of that particular quality of awareness associated with mindfulness, or if one's dispositional mindfulness (DM) (the tendency to be more mindful in daily life) could moderate the effects of exercise on cardiovascular response to stress. The role of mindfulness as a mediator or moderator of the effect of exercise training on cardiovascular responses to stress has barely been studied. In this study, we have hypothesized pathways (moderation and mediation) by which mindfulness could significantly influence the effects of PF on cardiovascular responses to stress and discussed potential practical ways to test these hypotheses. PMID:24723891

  13. Susceptibility of the aging Brown Norway rat to carbaryl, an anti-cholinesterase-based insecticide: Thermoregulatory and cardiovascular responses.

    EPA Science Inventory

    The proportion of aged in the United States is projected to expand markedly for the next several decades. Hence, the U.S.EPA is assessing if the aged are more susceptible to environmental toxicants. The thermoregulatory and cardiovascular responses of young adult, mature adult, a...

  14. Mindfulness may both moderate and mediate the effect of physical fitness on cardiovascular responses to stress: a speculative hypothesis.

    PubMed

    Demarzo, Marcelo M P; Montero-Marin, Jesús; Stein, Phyllis K; Cebolla, Ausiàs; Provinciale, Jaime G; García-Campayo, Javier

    2014-01-01

    The psychological construct of mindfulness refers to an awareness that emerges by intentionally paying attention to the present experience in a non-judgmental or evaluative way. This particular quality of awareness has been associated to several indicators of physical and psychological health, and can be developed using mindfulness-based interventions (MBIs), and therefore MBIs have been successfully applied as preventive and complementary interventions and therapies in medicine and psychology. Together with quiet sitting and lying meditation practices, mindful physical exercises such as "mindful walking" and "mindful movement" are key elements in MBIs and couple muscular activity with an internally directed focus, improving interoceptive attention to bodily sensations. In addition, MBIs seem to share similar mechanisms with physical fitness (PF) by which they may influence cardiovascular responses to stress. Based on these facts, it is feasible to raise the question of whether physical training itself may induce the development of that particular quality of awareness associated with mindfulness, or if one's dispositional mindfulness (DM) (the tendency to be more mindful in daily life) could moderate the effects of exercise on cardiovascular response to stress. The role of mindfulness as a mediator or moderator of the effect of exercise training on cardiovascular responses to stress has barely been studied. In this study, we have hypothesized pathways (moderation and mediation) by which mindfulness could significantly influence the effects of PF on cardiovascular responses to stress and discussed potential practical ways to test these hypotheses. PMID:24723891

  15. Changes in cholesterol homeostasis and acute phase response link pulmonary exposure to multi-walled carbon nanotubes to risk of cardiovascular disease

    SciTech Connect

    Poulsen, Sarah S.; Saber, Anne T.; Mortensen, Alicja; Szarek, Józef; Wu, Dongmei; Williams, Andrew; Andersen, Ole; Jacobsen, Nicklas R.; Yauk, Carole L.; Wallin, Håkan; Halappanavar, Sabina; Vogel, Ulla

    2015-03-15

    Adverse lung effects following pulmonary exposure to multi-walled carbon nanotubes (MWCNTs) are well documented in rodents. However, systemic effects are less understood. Epidemiological studies have shown increased cardiovascular disease risk after pulmonary exposure to airborne particles, which has led to concerns that inhalation exposure to MWCNTs might pose similar risks. We analyzed parameters related to cardiovascular disease, including plasma acute phase response (APR) proteins and plasma lipids, in female C57BL/6 mice exposed to a single intratracheal instillation of 0, 18, 54 or 162 μg/mouse of small, entangled (CNT{sub Small}, 0.8 ± 0.1 μm long) or large, thick MWCNTs (CNT{sub Large}, 4 ± 0.4 μm long). Liver tissues and plasma were harvested 1, 3 and 28 days post-exposure. In addition, global hepatic gene expression, hepatic cholesterol content and liver histology were used to assess hepatic effects. The two MWCNTs induced similar systemic responses despite their different physicochemical properties. APR proteins SAA3 and haptoglobin, plasma total cholesterol and low-density/very low-density lipoprotein were significantly increased following exposure to either MWCNTs. Plasma SAA3 levels correlated strongly with pulmonary Saa3 levels. Analysis of global gene expression revealed perturbation of the same biological processes and pathways in liver, including the HMG-CoA reductase pathway. Both MWCNTs induced similar histological hepatic changes, with a tendency towards greater response following CNT{sub Large} exposure. Overall, we show that pulmonary exposure to two different MWCNTs induces similar systemic and hepatic responses, including changes in plasma APR, lipid composition, hepatic gene expression and liver morphology. The results link pulmonary exposure to MWCNTs with risk of cardiovascular disease. - Highlights: • Systemic and hepatic alterations were evaluated in female mice following MWCNT instillation. • Despite being physicochemically

  16. Cardiovascular responses in humans to experimental chewing of gums of different consistencies.

    PubMed

    Farella, M; Bakke, M; Michelotti, A; Marotta, G; Martina, R

    1999-10-01

    Although the cardiovascular effects of exercise have been extensively investigated in man, little attention has been paid to such responses to jaw muscle activity. The aim here was to investigate the general cardiovascular effects of chewing activity in a single-blind, cross-over design. Ten healthy individuals performed one of the following chewing tasks in four separate sessions: chewing a very hard gum, chewing a moderately hard gum, chewing a soft gum, and "empty chewing" without a bolus. Unilateral chewing of gum or empty chewing was performed for 20 min on the participant's most convenient chewing side at a constant rate of 80 cycles/min. In each session, heart rate and arterial blood pressure were recorded together with electromyographic activity in the masseter and anterior temporalis muscles on the chewing side. Ratings of perceived masticatory fatigue were recorded with visual analogue scales. The heart rate and blood pressure were significantly increased (ANOVA; p < or= 0.01) during the chewing tasks and the increases were, in parallel with the muscle activity, more pronounced the harder the gum. With the very hard gum, heart rate increased by up to 11 beats/min, the systolic blood pressure was 14 mmHg (1.9kPa) higher, and the diastolic blood pressure was 11 mmHg (1.5kPa) higher. The perceived fatigue was proportional to the level of muscle activity. After 10 min of recovery from exercise, heart rate and arterial blood pressures were slightly but still significantly elevated. The results demonstrate that chewing is associated with general circulatory effects proportional to the bolus resistance.

  17. Cardiovascular regulation in humans in response to oscillatory lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Levenhagen, D. K.; Evans, J. M.; Wang, M.; Knapp, C. F.

    1994-01-01

    The frequency response characteristics of human cardiovascular regulation during hypotensive stress have not been determined. We therefore exposed 10 male volunteers to seven frequencies (0.004-0.1 Hz) of oscillatory lower body negative pressure (OLBNP; 0-50 mmHg). Fourier spectra of arterial pressure (AP), central venous pressure (CVP), stroke volume (SV), cardiac output (CO), heart rate (HR), and total peripheral resistance (TPR) were determined and first harmonic mean, amplitude, and phase angles with respect to OLBNP are presented. AP was relatively well regulated as demonstrated by small oscillations in half amplitude (3.5 mmHg) that were independent of OLBNP frequency and similar to unstressed control spectra. Due to the biomechanics of the system, the magnitudes of oscillations in calf circumference (CC) and CVP decreased with increasing frequency; therefore, we normalized responses by these indexes of the fluid volume shifted. The ratios of oscillations in AP to oscillations in CC increased by an order of magnitude, whereas oscillations in CVP to oscillations in CC and oscillations in AP to oscillations in CVP both tripled between 0.004 and 0.1 Hz. Therefore, even though the amount of fluid shifted by OLBNP decreased with increasing frequency, the magnitude of both CVP and AP oscillations per volume of fluid shifted increased (peaking at 0.08 Hz). The phase relationships between variables, particularly the increasing lags in SV and TPR, but not CVP, indicated that efferent responses with lags of 5-6 s could account for the observed responses. We conclude that, at frequencies below 0.02 Hz, the neural system of humans functioned optimally in regulating AP; OLBNP-induced decreases in SV (by as much as 50%) were counteracted by appropriate oscillations in HR and TPR responses. As OLBNP frequency increased, SV, TPR, and HR oscillations increasingly lagged the input and became less optimally timed for AP regulation.

  18. Activation of GABAA or 5HT1A receptors in the raphé pallidus abolish the cardiovascular responses to exogenous stress in conscious rats.

    PubMed

    Pham-Le, Nhut Minh; Cockburn, Chelsea; Nowell, Katherine; Brown, Justin

    2011-11-25

    Dysfunction in serotonin (5HT) neurotransmission in the brainstem of infants may disrupt protective responses to stress and increase the risk for Sudden Infant Death Syndrome (SIDS). The raphé pallidus (NRP) and other brainstem nuclei are rich in 5HT and are thought to mediate stress responses, including increases in blood pressure (BP) and heart rate (HR). Determining how 5HT neurotransmission in the brainstem mediates responses to stress will help to explain how dysfunction in neurotransmission could increase the risk of SIDS. It was hypothesized that alterations in neurotransmission in the NRP, specifically activation of the 5HT(1A) receptor subtype, would block cardiovascular responses to various types of exogenous stress. Using aseptic techniques, male Sprague-Dawley rats were instrumented with radiotelemetry probes which enabled non-invasive measurement of BP and HR. An indwelling microinjection cannula was also stereotaxically implanted into the NRP for injection of drugs that altered local 5HT neurotransmission. Following a one week recovery period, rats were microinjected with either muscimol (GABA(A) receptor agonist), 8-OH-DPAT (agonist to the inhibitory 5HT(1A) receptor), or a vehicle control (artificial cerebral spinal fluid; ACSF) immediately prior to exposure to one of three stressors: handling, air jet, or restraint. Physical handling and restraint of the animal were designed to elicit a mild and a maximal stress response respectively; while an air jet directed at the rat's face was used to provoke a psychological stress that did not require physical contact. All three stressors elicited similar and significant elevations in HR and BP following ACSF that persisted for at least 15 min with BP and HR elevated by ∼14.0 mmHg and ∼56.3 bpm respectively. The similarity in the stress responses suggest even mild handling of a rat elicits a maximal sympathoexcitatory response. The stress response was abolished following 8-OH-DPAT or muscimol

  19. Acute cyclooxygenase inhibition does not alter muscle sympathetic nerve activity or forearm vasodilator responsiveness in lean and obese adults

    PubMed Central

    Barnes, Jill N.; Charkoudian, Nisha; Matzek, Luke J.; Johnson, Christopher P.; Joyner, Michael J.; Curry, Timothy B.

    2014-01-01

    Abstract Obesity is often characterized by chronic inflammation that may contribute to increased cardiovascular risk via sympathoexcitation and decreased vasodilator responsiveness. We hypothesized that obese individuals would have greater indices of inflammation compared with lean controls, and that cyclooxygenase inhibition using ibuprofen would reduce muscle sympathetic nerve activity (MSNA) and increase forearm blood flow in these subjects. We measured MSNA, inflammatory biomarkers (C‐reactive protein [CRP] and Interleukin‐6 [IL‐6]), and forearm vasodilator responses to brachial artery acetylcholine and sodium nitroprusside in 13 men and women (7 lean; 6 obese) on two separate study days: control (CON) and after 800 mg ibuprofen (IBU). CRP (1.7 ± 0.4 vs. 0.6 ± 0.3 mg/L; P < 0.05) and IL‐6 (4.1 ± 1.5 vs. 1.0 ± 0.1pg/mL; P < 0.05) were higher in the obese group during CON and tended to decrease with IBU (IL‐6: P < 0.05; CRP: P = 0.14). MSNA was not different between groups during CON (26 ± 4 bursts/100 heart beats (lean) versus 26 ± 4 bursts/100 heart beats (obese); P = 0.50) or IBU (25 ± 4 bursts/100 heart beats (lean) versus 30 ± 5 bursts/100 heart beats (obese); P = 0.25), and was not altered by IBU. Forearm vasodilator responses were unaffected by IBU in both groups. In summary, an acute dose of ibuprofen did not alter sympathetic nerve activity or forearm blood flow responses in healthy obese individuals, suggesting that the cyclooxygenase pathway is not a major contributor to these variables in this group. PMID:25347862

  20. Neonatal Amygdala Lesions Alter Responsiveness to Objects in Juvenile Macaques

    PubMed Central

    Bliss-Moreau, Eliza; Toscano, Jessica E.; Bauman, Melissa; Mason, William A.; Amaral, David G.

    2013-01-01

    The amygdala is widely recognized to play a central role in emotional processing. In nonhuman primates, the amygdala appears to be critical for generating appropriate behavioral responses in emotionally salient contexts. One common finding is that macaque monkeys that receive amygdala lesions as adults are behaviorally uninhibited in the presence of potentially dangerous objects. While control animals avoid these objects, amygdala-lesioned animals readily interact with them. Despite a large literature documenting the role of the amygdala in emotional processing in adult rhesus macaques, little research has assessed the role of the amygdala across the macaque neurodevelopmental trajectory. We assessed the behavioral responses of three-year-old (juvenile) rhesus macaques that received bilateral ibotenic acid lesions of the amygdala or hippocampus at two weeks of age. Animals were presented with salient objects known to produce robust fear-related responses in macaques (e.g., snakes and reptile-like objects), mammal-like objects that included animal-like features (e.g., eyes and mouths) but not reptile-like features (e.g., scales), and non-animal objects. The visual complexity of objects was scaled to vary the objects' salience. In contrast to control and hippocampus-lesioned animals, amygdale-lesioned animals were uninhibited in the presence of potentially dangerous objects. They readily retrieved food rewards placed near these objects and physically explored the objects. Furthermore, while control and hippocampus-lesioned animals differentiated between levels of object complexity, amygdala-lesioned animals did not. Taken together, these findings suggest that early damage to the amygdala, like damage during adulthood, permanently compromises emotional processing. PMID:21215794

  1. Tunicamycin-Induced Alterations in the Vasorelaxant Response in Organ-Cultured Superior Mesenteric Arteries of Rats.

    PubMed

    Matsumoto, Takayuki; Ando, Makoto; Watanabe, Shun; Iguchi, Maika; Nagata, Mako; Kobayashi, Shota; Taguchi, Kumiko; Kobayashi, Tsuneo

    2016-01-01

    In cellular events, endoplasmic reticulum (ER) stress has an important role in the development of various diseases including cardiovascular diseases. Tunicamycin, an inhibitor of N-linked glycosylation, is known to be an inducer of ER stress. However, the extent to which tunicamycin affects the vasorelaxant function is not completely understood. Thus, we investigated the effect of tunicamycin on relaxations induced by various vasorelaxant agents, including acetylcholine (ACh; endothelium-dependent vasodilator), sodium nitroprusside (SNP; endothelium-independent vasodilator), isoprenaline (ISO; beta-adrenoceptor agonist), forskolin (FSK; adenylyl cyclase activator), and cromakalim [ATP-sensitive K(+) (KATP) channel activator] in organ-cultured superior mesenteric arteries of rats, which are treated with either a vehicle [dimethyl sulfoxide (DMSO)] or tunicamycin (20 µg/mL for 22-24 h). Protein levels of the ER stress marker binding immunoglobulin protein (BiP) were determined by Western blotting. Tunicamycin increased the expression of BiP in organ-cultured arteries. Tunicamycin impaired ACh-induced relaxation, but did not alter SNP-induced relaxation. Tunicamycin also impaired vasorelaxation induced by ISO, FSK, and cromakalim; moreover, it reduced basal nitric oxide (NO) formation. In conclusion, short-term treatment with tunicamycin not only caused endothelial dysfunction but also impaired cAMP- and KATP-mediated responses in the superior mesenteric arteries of rats. These alterations in tunicamycin-treated arteries may be due to reduced basal NO formation. This work provides new insight into ER stress in vascular dysfunction. PMID:27582328

  2. Effective Bolus Dose of Sufentanil to Attenuate Cardiovascular Responses in Laryngoscopic Double-Lumen Endobronchial Intubation

    PubMed Central

    Choi, Byung-Hee; Lee, Yong-Cheol

    2016-01-01

    Background Sufentanil is a potent opioid analgesic frequently used in clinical anesthesia. Double-lumen endobronchial intubation induces profound cardiovascular responses in comparison with ordinary endotracheal intubation because of the larger tube diameter and direct irritation of the carina. Objectives The purpose of this study was to determine the effective bolus dose of sufentanil to attenuate hemodynamic changes in response to laryngoscopic double-lumen endobronchial intubation. Patients and Methods We randomly assigned 72 patients aged 18 - 65 years and with an American Society of Anesthesiologists physical status of 1 or 2 to one of four sufentanil dose groups: NS, S0.1, S0.2, or S0.3. The respective doses for the groups were as follows: normal saline, 0.1 mcg/kg of sufentanil, 0.2 mcg/kg of sufentanil, and 0.3 mcg/kg of sufentanil. Blood pressure and heart rate were recorded during the pre-anesthesia period at baseline, pre-intubation, immediate post-intubation, and every minute during 5 minutes after intubation. Results Baseline mean arterial pressures in the NS, S0.1, S0.2, and S0.3 groups were 89.8 ± 12.1, 89.2 ± 10.9, 88.8 ± 13.6, and 90.7 ± 11.1, respectively. At immediate post-intubation, the mean arterial pressures in the NS, S0.1, S0.2, and S0.3 groups were 129.7 ± 14.7, 120.7 ± 14.2, 120.8 ± 17.2, and 96.7 ± 10.4, respectively. At immediate post-intubation, the mean arterial pressure in the NS, S0.1, and S0.2 groups significantly increased from baseline (P < 0.001), but the S0.3 group showed no difference. In the time point comparison at immediate post- intubation, the S0.3 group had a significantly lower mean arterial pressure than did the NS, S0.1, and S0.2 groups (P < 0.001). Conclusions We found that 0.3 mcg/kg of sufentanil attenuates cardiovascular responses to double-lumen endobronchial intubation without adverse effects. PMID:27252903

  3. Cardiovascular adaptation to spaceflight

    NASA Technical Reports Server (NTRS)

    Hargens, A. R.; Watenpaugh, D. E.

    1996-01-01

    This article reviews recent flight and ground-based studies of cardiovascular adaptation to spaceflight. Prominent features of microgravity exposure include loss of gravitational pressures, relatively low venous pressures, headward fluid shifts, plasma volume loss, and postflight orthostatic intolerance and reduced exercise capacity. Many of these short-term responses to microgravity extend themselves during long-duration microgravity exposure and may be explained by altered pressures (blood and tissue) and fluid balance in local tissues nourished by the cardiovascular system. In this regard, it is particularly noteworthy that tissues of the lower body (e.g., foot) are well adapted to local hypertension on Earth, whereas tissues of the upper body (e.g., head) are not as well adapted to increase in local blood pressure. For these and other reasons, countermeasures for long-duration flight should include reestablishment of higher, Earth-like blood pressures in the lower body.

  4. Cerebro- and Cardio-vascular Responses to Energy Drink in Young Adults: Is there a Gender Effect?

    PubMed Central

    Monnard, Cathríona R.; Montani, Jean-Pierre; Grasser, Erik K.

    2016-01-01

    Background and Purpose: Energy drinks (EDs) are suspected to induce potential adverse cardiovascular effects and have recently been shown to reduce cerebral blood flow velocity (CBFV) in young, healthy subjects. Gender differences in CBFV in response to EDs have not previously been investigated, despite the fact that women are more prone to cardiovascular disturbances such as neurocardiogenic syncope than men. Therefore, the aim of this study was to explore gender differences in cerebrovascular and cardiovascular responses to EDs. Methods: We included 45 subjects in a retrospective analysis of pooled data from two previous randomized trials carried out in our laboratory with similar protocols. Beat-to-beat blood pressure, impedance cardiography, transcranial Doppler, and end-tidal carbon dioxide (etCO2) measurements were made for at least 20 min baseline and for 80 min following the ingestion of 355 mL of a sugar-sweetened ED. Gender and time differences in cerebrovascular and cardiovascular parameters were investigated. Results: CBFV was significantly reduced in response to ED, with the greatest reduction observed in women compared with men (−12.3 ± 0.8 vs. −9.7 ± 0.8%, P < 0.05). Analysis of variance indicated significant time (P < 0.01) and gender × time (P < 0.01) effects. The percentage change in CBFV in response to ED was independent of body weight and etCO2. No significant gender difference in major cardiovascular parameters in response to ED was observed. Conclusions: ED ingestion reduced CBFV over time, with a greater reduction observed in women compared with men. Our results have potential implications for women ED consumers, as well as high-risk individuals. PMID:27559316

  5. Mechanical signaling and the cellular response to extracellular matrix in angiogenesis and cardiovascular physiology

    NASA Technical Reports Server (NTRS)

    Ingber, Donald E.

    2002-01-01

    Great advances have been made in the identification of the soluble angiogenic factors, insoluble extracellular matrix (ECM) molecules, and receptor signaling pathways that mediate control of angiogenesis--the growth of blood capillaries. This review focuses on work that explores how endothelial cells integrate these chemical signals with mechanical cues from their local tissue microenvironment so as to produce functional capillary networks that exhibit specialized form as well as function. These studies have revealed that ECM governs whether an endothelial cell will switch between growth, differentiation, motility, or apoptosis programs in response to a soluble stimulus based on its ability to mechanically resist cell tractional forces and thereby produce cell and cytoskeletal distortion. Transmembrane integrin receptors play a key role in this mechanochemical transduction process because they both organize a cytoskeletal signaling complex within the focal adhesion and preferentially focus mechanical forces on this site. Molecular filaments within the internal cytoskeleton--microfilaments, microtubules, and intermediate filaments--also contribute to the cell's structural and functional response to mechanical stress through their role as discrete support elements within a tensegrity-stabilized cytoskeletal array. Importantly, a similar form of mechanical control also has been shown to be involved in the regulation of contractility in vascular smooth muscle cells and cardiac myocytes. Thus, the mechanism by which cells perform mechanochemical transduction and the implications of these findings for morphogenetic control are discussed in the wider context of vascular development and cardiovascular physiology.

  6. Evolution of testosterone treatment over 25 years: symptom responses, endocrine profiles and cardiovascular changes

    PubMed Central

    Carruthers, Malcolm; Cathcart, Paul; Feneley, Mark R.

    2015-01-01

    Abstract Introduction: Testosterone treatment has evolved rapidly over the past 25 years as new, more effective and convenient methods have become available. This study reports experience with seven different methods, introduced on the market in the UK. Aim: To establish the symptom response when testosterone treatment was initiated on the basis of clinical features and symptoms of androgen deficiency, and the resulting endocrine, biochemical and physiological responses. Methods: Of 2693 patients attending the 3 Men’s Health Centers – The UK Androgen Study (UKAS), 2247 were treated. Treatments included pellet implants, oral testosterone undecanoate (Testocaps), mesterolone (Proviron), testosterone gel (Testogel), testosterone scrotal cream (Andromen) and scrotal gel (Tostran). Results: There was no correlation between initial testosterone level, initial symptom score or the success of treatment as defined by adequate resolution of symptoms. Despite the diverse endocrine patterns produced, the testosterone preparations appear equally safe over prolonged periods, with either no change or improvement of cardiovascular risk factors, especially in lowering cholesterol and diastolic blood pressure. Conclusions: It is suggested that because of excessive reliance on laboratory measures of androgens and undue safety concerns, many men who could benefit from symptom relief, improvement in related clinical conditions and given preventive medical benefits remain untreated. PMID:26218766

  7. Cardiovascular responses to repetitive exposure to hyper- and hypogravity states produced by parabolic flight

    NASA Technical Reports Server (NTRS)

    Mukai, C. N.; Lathers, C. M.; Charles, J. B.; Bennett, B. S.

    1994-01-01

    Physiologic changes to repetitive hyper- and hypogravity stresses occurring during eight to ten parabolas on NASA's KC-135 aircraft were studied. Hemodynamic responses in 11 subjects in 4 different postures (supine, standing, sitting, and semisupine Space Shuttle launch position) were determined using noninvasive impedance cardiography. Five seconds of heart rate, cardiac index, thoracic fluid index, stroke index, ejection velocity index, and ventricular ejection time data were averaged during four different gravity (g) states: 1.3g (before parabola onset); 1.9g (parabola entry); 0g (parabola peak); and 1.7g (parabola exit) for each subject. The standing position was associated with the largest changes in the cardiovascular response to hypo- and hypergravity. The thoracic fluid index did not indicate a headward redistribution during transition from a simulated launch position to weightlessness. Analysis of the eight to ten parabolas revealed that, in general, values obtained at 1.8g differed from 1.6g, 0g differed from 1.6 and 1.3g, and 1.6g differed from 1.3g. The factors of gravity, thoracic fluid index, and cardiac index exhibited significant differences that were most likely to occur between parabola 1 versus parabolas 6, 7, and 8, and parabola 2 versus parabolas 4 through 8. Only the parameter of thoracic fluid index exhibited significance for parabolas 3 versus parabolas 6 and 7.

  8. Cardiovascular responses to lead are biphasic, while methylmercury, but not inorganic mercury, monotonically increases blood pressure in rats.

    PubMed

    Wildemann, Tanja M; Mirhosseini, Naghmeh; Siciliano, Steven D; Weber, Lynn P

    2015-02-01

    Cardiovascular diseases, such as heart attack and stroke, are the major cause of death worldwide. It is well known that a high number of environmental and physiological risk factors contribute to the development of cardiovascular diseases. Although risk factors are additive, increased blood pressure (hypertension) is the greatest risk factor. Over the last two decades, a growing number of epidemiological studies associate environmental exposure to lead or mercury species with hypertension. However, cardiovascular effects beyond blood pressure are rarely studied and thresholds for effect are not yet clear. To explore effects of lead or mercury species on the cardiovascular system, normal male Wistar rats were exposed to a range of doses of lead, inorganic mercury or methylmercury through the drinking water for four weeks. High-resolution ultrasound was used to measure heart and vascular function (carotid artery blood flow) at baseline and at the end of the exposure, while blood pressure was measured directly in the femoral artery at the end of the 4-week exposure. After 4 weeks, blood pressure responses to lead were biphasic. Low lead levels decreased blood pressure, dilated the carotid artery and increased cardiac output. At higher lead doses, rats had increased blood pressure. In contrast, methylmercury-exposed rats had increased blood pressure at all doses despite dilated carotid arteries. Inorganic mercury did not show any significant cardiovascular effects. Based on the current study, the benchmark dose level 10% (BMDL10s) for systolic blood pressure for lead, inorganic mercury and methylmercury are 1.1, 1.3 and 1.0 μg/kg-bw/d, respectively. However, similar total mercury blood levels attributed to inorganic mercury or methylmercury produced strikingly different results with inorganic mercury having no observable effect on the cardiovascular system but methylmercury increasing systolic and pulse pressures. Therefore, adverse cardiovascular effects cannot be

  9. [Influence of the practice of meditation on the cardiovascular response in the perception and cognitive reassessment emotiogenic stimulus].

    PubMed

    Pavlov, S V; Reva, N V; Loktev, K V; Korenek, V V; Aftanas, L

    2015-03-01

    This study examines the effects of meditation on cardiovascular activity during affective image processing. 22 meditators and 20 controls were shown affective images and were asked either to attend to the images or to down-regulate negative affect (for negative images) or to up-regulate positive affect (for positive images) while continuous cardiovascular activity were recorded. During natural viewing meditators manifested identical pre-stimulus total peripheral resistance (TPR) for all images, whereas controls exhibited greatest,pre-stimulus TPR for negative images and reduced it only in the emotion regulation condition. No between-group differences were revealed for natural viewing of positive images, whereas up-regulation was associated with greater cardiac activation in meditators. The results provide a contribution to the understanding of the mechanisms responsible for the beneficial influence of meditation on cardiovascular risk factors. PMID:26016329

  10. Thermoregulatory and cardiovascular responses to creatine, glycerol and alpha lipoic acid in trained cyclists

    PubMed Central

    2012-01-01

    Background It has been shown that supplementation with creatine (Cr) and glycerol (Gly), when combined with glucose (Glu) necessary for the enhancement of Cr uptake by skeletal muscle, induces significant improvements in thermoregulatory and cardiovascular responses during exercise in the heat. Purpose To determine whether Cr/Gly-induced thermoregulatory and cardiovascular responses are maintained when the majority (~75%) of the Glu in the Cr/Gly supplement is replaced with the insulintropic agent alpha lipoic acid (Ala). Methods 22 healthy endurance trained cyclists were randomly assigned to receive either 20 g/day (4 × 5 g/day) of Cr, 2 g .kg-1 BM per day (4 × 0.5 g .kg-1 BM per day) of Gly and 150 g/day (4 × 37.5 g/day) of Glu or 20 g/day (4 × 5 g/day) of Cr monohydrate, 2 g .kg-1 BM per day (4 × 0.5 g .kg-1 BM per day) of Gly (100 g/day (4 × 25 g/day) of Glu and 1000 mg/day (4 × 250 mg/day) of Ala for 7 days for 7 days. Exercise trials were conducted pre- and post-supplementation and involved 40 min of constant-load cycling exercise at 70% O2 max by a self-paced 16.1 km time trial at 30°C and 70% relative humidity. Results Median and range values of TBW increased significantly by 2.1 (1.3-3.3) L and 1.8 (0.2-4.6) L in Cr/Gly/Glu and Cr/Gly/Glu/Ala groups respectively (P = 0.03) and of BM not significantly by 1.8 (0.2-3.0) kg and 1.2 (0.5-2.1) kg in Cr/Gly/Glu and in Cr/Gly/Glu/Ala, respectively (P = 0.75). During constant load exercise, heart rate (HR) and core temperature (Tcore) were significantly lower post-supplementation: HR was reduced on average by 3.3 ± 2.1 beats/min and by 4.8 ± 3.3 beats/min (mean ± SD) and Tcore by 0.2 ± 0.1 (mean ± SD) in the Cr/Gly/Glu and Cr/Gly/Glu/Ala, respectively The reduction in HR and Tcore was not significantly different between the supplementation groups. Conclusions In comparison to the established hyper hydrating Cr

  11. Thermoregulatory, cardiovascular, and perceptual responses to intermittent cooling during exercise in a hot, humid outdoor environment.

    PubMed

    Cleary, Michelle A; Toy, Michelle G; Lopez, Rebecca M

    2014-03-01

    Decreasing core body temperature during exercise may improve exercise tolerance, facilitate acclimatization, and prevent heat illness during summer training. We sought to evaluate the effectiveness of intermittent superficial cooling on thermoregulatory, cardiovascular, and perceptual responses during exercise in a hot humid environment. We used a randomized, counterbalanced, repeated measures investigation with 2 conditions (control and cooling) during exercise and recovery outdoors on artificial turf in a hot, humid tropical climate in the sun (wet bulb globe temperature outdoors [WBGTo], 27.0 ± 0.8° C; range, 25.8-28.1° C) and in the shade (WBGTo, 25.4 ± 0.9° C; range, 24.3-26.8° C). Participants were 10 healthy males (age, 22.6 ± 1.6 years; height, 176.0 ± 6.9 cm; mass, 76.5 ± 7.8 kg; body fat, 15.6 ± 5.4%) who wore shorts and T-shirt (control) or "phase change cooling" vest (cooling) during 5-minute rest breaks during 60 minutes of intense American football training and conditioning exercises in the heat and 30 minutes of recovery in the shade. Throughout, we measured core (Tgi) and skin (Tchest) temperature, heart rate (HR), thermal and thirst sensations, and rating of perceived exertion. We found significant (p ≤ 0.001) hypohydration (-2.1%); for Tgi, we found no significant differences between conditions (p = 0.674) during exercise and progressive decreases during recovery (p < 0.001). For [INCREMENT]Tg,i we found no significant (p = 0.090) differences. For Tchest, we found significantly (p < 0.001) decreased skin temperature in the cooling condition (Tchest, 31.85 ± 0.43° C) compared with the control condition (Tchest, 34.38 ± 0.43° C) during exercise and significantly (p < 0.001) lower skin temperature in the cooling condition (Tchest, 31.24 ± 0.47° C) compared with the control condition (Tchest, 33.48 ± 0.47° C) during recovery. For HR, we found no significant difference (p = 0.586) between the conditions during exercise; however, we

  12. Thermoregulatory, cardiovascular, and perceptual responses to intermittent cooling during exercise in a hot, humid outdoor environment.

    PubMed

    Cleary, Michelle A; Toy, Michelle G; Lopez, Rebecca M

    2014-03-01

    Decreasing core body temperature during exercise may improve exercise tolerance, facilitate acclimatization, and prevent heat illness during summer training. We sought to evaluate the effectiveness of intermittent superficial cooling on thermoregulatory, cardiovascular, and perceptual responses during exercise in a hot humid environment. We used a randomized, counterbalanced, repeated measures investigation with 2 conditions (control and cooling) during exercise and recovery outdoors on artificial turf in a hot, humid tropical climate in the sun (wet bulb globe temperature outdoors [WBGTo], 27.0 ± 0.8° C; range, 25.8-28.1° C) and in the shade (WBGTo, 25.4 ± 0.9° C; range, 24.3-26.8° C). Participants were 10 healthy males (age, 22.6 ± 1.6 years; height, 176.0 ± 6.9 cm; mass, 76.5 ± 7.8 kg; body fat, 15.6 ± 5.4%) who wore shorts and T-shirt (control) or "phase change cooling" vest (cooling) during 5-minute rest breaks during 60 minutes of intense American football training and conditioning exercises in the heat and 30 minutes of recovery in the shade. Throughout, we measured core (Tgi) and skin (Tchest) temperature, heart rate (HR), thermal and thirst sensations, and rating of perceived exertion. We found significant (p ≤ 0.001) hypohydration (-2.1%); for Tgi, we found no significant differences between conditions (p = 0.674) during exercise and progressive decreases during recovery (p < 0.001). For [INCREMENT]Tg,i we found no significant (p = 0.090) differences. For Tchest, we found significantly (p < 0.001) decreased skin temperature in the cooling condition (Tchest, 31.85 ± 0.43° C) compared with the control condition (Tchest, 34.38 ± 0.43° C) during exercise and significantly (p < 0.001) lower skin temperature in the cooling condition (Tchest, 31.24 ± 0.47° C) compared with the control condition (Tchest, 33.48 ± 0.47° C) during recovery. For HR, we found no significant difference (p = 0.586) between the conditions during exercise; however, we

  13. Particle-Induced Pulmonary Acute Phase Response Correlates with Neutrophil Influx Linking Inhaled Particles and Cardiovascular Risk

    PubMed Central

    Saber, Anne Thoustrup; Lamson, Jacob Stuart; Jacobsen, Nicklas Raun; Ravn-Haren, Gitte; Hougaard, Karin Sørig; Nyendi, Allen Njimeri; Wahlberg, Pia; Madsen, Anne Mette; Jackson, Petra; Wallin, Håkan; Vogel, Ulla

    2013-01-01

    Background Particulate air pollution is associated with cardiovascular disease. Acute phase response is causally linked to cardiovascular disease. Here, we propose that particle-induced pulmonary acute phase response provides an underlying mechanism for particle-induced cardiovascular risk. Methods We analysed the mRNA expression of Serum Amyloid A (Saa3) in lung tissue from female C57BL/6J mice exposed to different particles including nanomaterials (carbon black and titanium dioxide nanoparticles, multi- and single walled carbon nanotubes), diesel exhaust particles and airborne dust collected at a biofuel plant. Mice were exposed to single or multiple doses of particles by inhalation or intratracheal instillation and pulmonary mRNA expression of Saa3 was determined at different time points of up to 4 weeks after exposure. Also hepatic mRNA expression of Saa3, SAA3 protein levels in broncheoalveolar lavage fluid and in plasma and high density lipoprotein levels in plasma were determined in mice exposed to multiwalled carbon nanotubes. Results Pulmonary exposure to particles strongly increased Saa3 mRNA levels in lung tissue and elevated SAA3 protein levels in broncheoalveolar lavage fluid and plasma, whereas hepatic Saa3 levels were much less affected. Pulmonary Saa3 expression correlated with the number of neutrophils in BAL across different dosing regimens, doses and time points. Conclusions Pulmonary acute phase response may constitute a direct link between particle inhalation and risk of cardiovascular disease. We propose that the particle-induced pulmonary acute phase response may predict risk for cardiovascular disease. PMID:23894396

  14. Altered responsiveness to extracellular ATP enhances acetaminophen hepatotoxicity

    PubMed Central

    2013-01-01

    Background Adenosine triphosphate (ATP) is secreted from hepatocytes under physiological conditions and plays an important role in liver biology through the activation of P2 receptors. Conversely, higher extracellular ATP concentrations, as observed during necrosis, trigger inflammatory responses that contribute to the progression of liver injury. Impaired calcium (Ca2+) homeostasis is a hallmark of acetaminophen (APAP)-induced hepatotoxicity, and since ATP induces mobilization of the intracellular Ca2+ stocks, we evaluated if the release of ATP during APAP-induced necrosis could directly contribute to hepatocyte death. Results APAP overdose resulted in liver necrosis, massive neutrophil infiltration and large non-perfused areas, as well as remote lung inflammation. In the liver, these effects were significantly abrogated after ATP metabolism by apyrase or P2X receptors blockage, but none of the treatments prevented remote lung inflammation, suggesting a confined local contribution of purinergic signaling into liver environment. In vitro, APAP administration to primary mouse hepatocytes and also HepG2 cells caused cell death in a dose-dependent manner. Interestingly, exposure of HepG2 cells to APAP elicited significant release of ATP to the supernatant in levels that were high enough to promote direct cytotoxicity to healthy primary hepatocytes or HepG2 cells. In agreement to our in vivo results, apyrase treatment or blockage of P2 receptors reduced APAP cytotoxicity. Likewise, ATP exposure caused significant higher intracellular Ca2+ signal in APAP-treated primary hepatocytes, which was reproduced in HepG2 cells. Quantitative real time PCR showed that APAP-challenged HepG2 cells expressed higher levels of several purinergic receptors, which may explain the hypersensitivity to extracellular ATP. This phenotype was confirmed in humans analyzing liver biopsies from patients diagnosed with acute hepatic failure. Conclusion We suggest that under pathological conditions

  15. Alterations in adult behavioral responses to cocaine and dopamine transporters following juvenile exposure to methamphetamine.

    PubMed

    McFadden, Lisa; Yamamoto, Bryan K; Matuszewich, Leslie

    2011-01-20

    The present experiment assessed whether preadolescent exposure to methamphetamine would alter adult behavioral responses to cocaine and dopamine transporter immunoreactivity in the striatum of male and female rats. Juvenile rats were injected once daily with 0 or 2 mg/kg methamphetamine from postnatal days 21 to 35 and tested in adulthood. Male rats, but not female rats, exposed to methamphetamine showed an increase in responsiveness to cocaine in the open field and an increase in dopamine transporter immunoreactivity in the striatum. These findings suggest that early exposure to methamphetamine can lead to sex specific altered responses to psychostimulants in adulthood, which may contribute to later vulnerability to drug use.

  16. Renal and cardiovascular responses to water immersion in trained runners and swimmers

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.; Tatro, D. L.; Rogan, R. B.

    1993-01-01

    The purpose of this study was to determine if fluid-electrolyte, renal, hormonal, and cardiovascular responses during and after multi-hour water immersion were associated with aerobic training. Additionally, we compared these responses in those who trained in a hypogravic versus a 1-g environment. Seventeen men comprised three similarly aged groups: six long-distance runners, five competitive swimmers, and six untrained control subjects. Each subject underwent 5 h of immersion in water [mean (SE)] 36.0 (0.5) degrees C to the neck. Immediately before and at each hour of immersion, blood and urine samples were collected and analyzed for sodium (Na), potassium, osmolality, and creatinine (Cr). Plasma antidiuretic hormone and aldosterone were also measured. Hematocrits were used to calculate relative changes in plasma volume (% delta Vpl). Heart rate response to submaximal cycle ergometer exercise (35% peak oxygen uptake) was measured before and after water immersion. Water immersion induced significant increases in urine flow, Na clearance (CNa), and a 3-5% decrease in Vpl. Urine flow during immersion was greater (P < 0.05) in runners [2.4 (0.4) ml.min-1] compared to controls [1.3 (0.1) ml.min-1]. However, % delta Vpl, CCr, CNa and CH2O during immersion were not different (P > 0.05) between runners, swimmers, and controls. After 5 h of immersion, there was an increase (P < 0.05) in submaximal exercise heart rate of 9 (3) and 10 (3) beats.min-1 in both runners and controls, respectively, but no change (P > 0.05) was observed in swimmers.(ABSTRACT TRUNCATED AT 250 WORDS).

  17. Renal and cardiovascular responses to water immersion in trained runners and swimmers.

    PubMed

    Convertino, V A; Tatro, D L; Rogan, R B

    1993-01-01

    The purpose of this study was to determine if fluid-electrolyte, renal, hormonal, and cardiovascular responses during and after multi-hour water immersion were associated with aerobic training. Additionally, we compared these responses in those who trained in a hypogravic versus a 1-g environment. Seventeen men comprised three similarly aged groups: six long-distance runners, five competitive swimmers, and six untrained control subjects. Each subject underwent 5 h of immersion in water [mean (SE)] 36.0 (0.5) degrees C to the neck. Immediately before and at each hour of immersion, blood and urine samples were collected and analyzed for sodium (Na), potassium, osmolality, and creatinine (Cr). Plasma antidiuretic hormone and aldosterone were also measured. Hematocrits were used to calculate relative changes in plasma volume (% delta Vpl). Heart rate response to submaximal cycle ergometer exercise (35% peak oxygen uptake) was measured before and after water immersion. Water immersion induced significant increases in urine flow, Na clearance (CNa), and a 3-5% decrease in Vpl. Urine flow during immersion was greater (P < 0.05) in runners [2.4 (0.4) ml.min-1] compared to controls [1.3 (0.1) ml.min-1]. However, % delta Vpl, CCr, CNa and CH2O during immersion were not different (P > 0.05) between runners, swimmers, and controls. After 5 h of immersion, there was an increase (P < 0.05) in submaximal exercise heart rate of 9 (3) and 10 (3) beats.min-1 in both runners and controls, respectively, but no change (P > 0.05) was observed in swimmers.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8149929

  18. Response rate in the Study of Cardiovascular Risks in Adolescents – ERICA

    PubMed Central

    da Silva, Thiago Luiz Nogueira; Klein, Carlos Henrique; Souza, Amanda de Moura; Barufaldi, Laura Augusta; Abreu, Gabriela de Azevedo; Kuschnir, Maria Cristina Caetano; de Vasconcellos, Mauricio Teixeira Leite; Bloch, Katia Vergetti

    2016-01-01

    ABSTRACT OBJECTIVE To describe the response rate and characteristics of people who either took part or not in from the Study of Cardiovascular Risks in Adolescents (ERICA) , according to information subsets. METHODS ERICA is a school-based, nation-wide investigation with a representative sample of 12 to 17-year-old adolescents attending public or private schools in municipalities with over 100,000 inhabitants in Brazil. Response rate of eligible subjects were calculated according to macro-regions, sex, age, and type of school (public or private). We also calculated the percentages of replacement schools in comparison with the ones originally selected as per the sample design, according to the types of schools in the macro-regions. The subjects and non-subjects were compared according to sex, age, and average body mass indices (kg/m2). RESULTS We had 102,327 eligible adolescents enrolled in the groups drawn. The highest percentage of complete information was obtained for the subset of the questionnaire (72.9%). Complete information regarding anthropometric measurements and the ones from the questionnaire were obtained for 72.0% of the adolescents, and the combination of these data with the 24-hour dietary recall were obtained for 70.3% of the adolescents. Complete information from the questionnaire plus biochemical blood evaluation data were obtained for 52.5% of the morning session adolescents (selected for blood tests). The response percentage in private schools was higher than the one in public schools for most of the combination of information. The ratio of older and male adolescents non-participants was higher than the ratio among participants. CONCLUSIONS The response rate for non-invasive procedures was high. The response rate for blood collection – an invasive procedure that requires a 12-hour fasting period and the informed consent form from legal guardians – was lower. The response rate observed in public schools was lower than in the private ones, and

  19. Evidence Report: Risk of Crew Adverse Health Event Due to Altered Immune Response

    NASA Technical Reports Server (NTRS)

    Crucian, Brian; Sams, Clarence F.

    2013-01-01

    The Risk of Crew Adverse Health Event Due to Altered Immune Response is identified by the National Aeronautics and Space Administration (NASA) Human Research Program (HRP) as a recognized risk to human health and performance in space. The HRP Program Requirements Document (PRD) defines these risks. This Evidence Report provides a summary of the evidence that has been used to identify and characterize this risk. It is known that human immune function is altered in- and post-flight, but it is unclear at present if such alterations lead to increased susceptibility to disease. Reactivation of latent viruses has been documented in crewmembers, although this reactivation has not been directly correlated with immune changes or with observed diseases. As described in this report, further research is required to better characterize the relationships between altered immune response and susceptibility to disease during and after spaceflight. This is particularly important for future deep-space exploration missions.

  20. β-adrenergic impact underlies the effect of mood and hedonic instrumentality on effort-related cardiovascular response.

    PubMed

    Silvestrini, Nicolas; Gendolla, Guido H E

    2011-05-01

    After habituation, participants were first induced into negative vs. positive moods and performed then an attention task with either low vs. high hedonic instrumentality of success. In the high-instrumentality condition participants expected to see a funny movie after success and an unpleasant movie after failure; in the low-instrumentality condition participants expected an unpleasant movie after success and a pleasant movie after failure. Effort-related cardiovascular response (ICG, blood pressure) was assessed during mood inductions and task performance. As predicted by the mood-behavior-model (Gendolla, 2000), responses of cardiac pre-ejection period (PEP) and systolic blood pressure were stronger in the high-instrumentality/negative-mood condition than in the other three cells. Here the high hedonic instrumentality of success justified the high effort that was perceived as necessary in a negative mood. Moreover, the PEP effects indicate that cardiovascular response was driven by beta-adrenergic impact on the heart rather than by vascular adjustments.

  1. Adulthood stress responses in rats are variably altered as a factor of adolescent stress exposure.

    PubMed

    Moore, Nicole L T; Altman, Daniel E; Gauchan, Sangeeta; Genovese, Raymond F

    2016-05-01

    Stress exposure during development may influence adulthood stress response severity. The present study investigates persisting effects of two adolescent stressors upon adulthood response to predator exposure (PE). Rats were exposed to underwater trauma (UWT) or PE during adolescence, then to PE after reaching adulthood. Rats were then exposed to predator odor (PO) to test responses to predator cues alone. Behavioral and neuroendocrine assessments were conducted to determine acute effects of each stress experience. Adolescent stress altered behavioral response to adulthood PE. Acoustic startle response was blunted. Bidirectional changes in plus maze exploration were revealed as a factor of adolescent stress type. Neuroendocrine response magnitude did not predict severity of adolescent or adult stress response, suggesting that different adolescent stress events may differentially alter developmental outcomes regardless of acute behavioral or neuroendocrine response. We report that exposure to two different stressors in adolescence may differentially affect stress response outcomes in adulthood. Acute response to an adolescent stressor may not be consistent across all stressors or all dependent measures, and may not predict alterations in developmental outcomes pertaining to adulthood stress exposure. Further studies are needed to characterize factors underlying long-term effects of a developmental stressor.

  2. Cardiovascular responses of men and women to lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Montgomery, L. D.; Kirk, P. J.; Payne, P. A.; Gerber, R. L.; Newton, S. D.; Williams, B. A.

    1977-01-01

    Changes in blood flow and blood redistribution were measured by impedance plethysmography in the pelvic and leg regions of six male and four female subjects during three 5-min exposures to -20, -40, and -60 mm Hg lower body negative pressure (LBNP). Female subjects demonstrated significantly higher mean heart rate and lower leg blood flow indices than the male subjects during the recumbent control periods. Men had slightly higher mean resting systolic and diastolic blood pressures and higher mean control pelvic blood indices. Women demonstrated significantly less blood pooling in the legs and slightly less in the pelvic region than the men. All of the 18 tests with male subjects at -60 mm Hg were completed without initial signs of syncope, while only two of the tests with women were completed successfully without the subject exhibiting presyncopal conditions. Results indicate that impedance plethysmography can be used to measure segmental cardiovascular responses during LBNP and that females may be less tolerant to -60 mm Hg LBNP than males.

  3. Antigravity suit inflation: kidney function and cardiovascular and hormonal responses in men.

    PubMed

    Geelen, G; Kravik, S E; Hadj-Aissa, A; Leftheriotis, G; Vincent, M; Bizollon, C A; Sem-Jacobsen, C W; Greenleaf, J E; Gharib, C

    1989-02-01

    To investigate the effects of lower body positive pressure (LBPP) on kidney function while controlling certain cardiovascular and endocrine responses, seven men [35 +/- 2 (SE) yr] underwent 30 min of sitting and then 4.5 h of 70 degrees head-up tilt. An antigravity suit was applied (60 Torr legs, 30 Torr abdomen) during the last 3 h of tilt. A similar noninflation experiment was conducted where the suited subjects were tilted for 3.5 h. To provide adequate urine flow, the subjects were hydrated during the course of both experiments. Immediately after inflation, mean arterial pressure increased by 8 +/- 3 Torr and pulse rate decreased by 16 +/- 3 beats/min. Plasma renin activity and aldosterone were maximally suppressed (P less than 0.05) after 2.5 h of inflation. Plasma vasopressin decreased by 40-50% (P less than 0.05) and plasma sodium and potassium remained unchanged during both experiments. Glomerular filtration rate was not increased significantly by inflation, whereas inflation induced marked increases (P less than 0.05) in effective renal plasma flow (ERPF), urine flow, osmolar and free water clearances, and total and fractional sodium excretion. No such changes occurred during control. Thus, LBPP induces 1) a significant increase in ERPF and 2) significant changes in kidney excretory patterns similar to those observed during water immersion or the early phase of bed rest, situations that also result in central vascular volume expansion.

  4. Cardiovascular System Response to Carbon Dioxide and Exercise in Oxygen-Enriched Environment at 3800 m

    PubMed Central

    Liu, Guohui; Liu, Xiaopeng; Qin, Zhifeng; Gu, Zhao; Wang, Guiyou; Shi, Weiru; Wen, Dongqing; Yu, Lihua; Luo, Yongchang; Xiao, Huajun

    2015-01-01

    Background: This study explores the responses of the cardiovascular system as humans exercise in an oxygen-enriched room at high altitude under various concentrations of CO2. Methods: The study utilized a hypobaric chamber set to the following specifications: 3800 m altitude with 25% O2 and different CO2 concentrations of 0.5% (C1), 3.0% (C2) and 5.0% (C3). Subjects exercised for 3 min three times, separated by 30 min resting periods in the above-mentioned conditions, at sea level (SL) and at 3800 m altitude (HA). The changes of heart rate variability, heart rate and blood pressure were analyzed. Results: Total power (TP) and high frequency power (HF) decreased notably during post-exercise at HA. HF increased prominently earlier the post-exercise period at 3800 m altitude with 25% O2 and 5.0% CO2 (C3), while low frequency power (LF) changed barely in all tests. The ratios of LF/HF were significantly higher during post-exercise in HA, and lower after high intensity exercise in C3. Heart rate and systolic blood pressure increased significantly in HA and C3. Conclusions: Parasympathetic activity dominated in cardiac autonomic modulation, and heart rate and blood pressure increased significantly after high intensity exercise in C3. PMID:26393634

  5. Parity and Cardiovascular Disease Mortality: a Dose-Response Meta-Analysis of Cohort Studies.

    PubMed

    Lv, Haichen; Wu, Hongyi; Yin, Jiasheng; Qian, Juying; Ge, Junbo

    2015-08-24

    Parity has been shown to inversely associate with cardiovascular disease (CVD) mortality, but the evidence of epidemiological studies is still controversial. Therefore, we quantitatively assessed the relationship between parity and CVD mortality by summarizing the evidence from prospective studies. We searched MEDLINE (PubMed), EMBASE and ISI Web of Science databases for relevant prospective studies of parity and CVD mortality through the end of March 2015. Fixed- or random-effects models were used to estimate summary relative risks (RRs) and 95% confidence intervals (CIs). Heterogeneity among studies was assessed using the I(2) statistics. All statistical tests were two-sided. Ten prospective studies were included with a total of 994,810 participants and 16,601 CVD events. A borderline significant inverse association was observed while comparing parity with nulliparous, with summarized RR = 0.79 (95% CI: 0.60-1.06; I(2) = 90.9%, P < 0.001). In dose-response analysis, we observed a significant nonlinear association between parity number and CVD mortality. The greatest risk reduction appeared when the parity number reached four. The findings of this meta-analysis suggests that ever parity is inversely related to CVD mortality. Furthermore, there is a statistically significant nonlinear inverse association between parity number and CVD mortality.

  6. The Impact of Abdominal Obesity Status on Cardiovascular Response to the Mediterranean Diet

    PubMed Central

    Bédard, Alexandra; Dodin, Sylvie; Corneau, Louise; Lemieux, Simone

    2012-01-01

    We investigated the impact of abdominal obesity status on the cardiovascular response to a fully controlled 4-week isoenergetic Mediterranean diet (MedDiet). Thirty-eight abdominally obese individuals (waist circumference >102 cm in men and >88 cm in women) and thirty-one nonabdominally obese individuals were recruited and studied before and after the MedDiet. All analyses were adjusted for the slight decrease in body weight, which occurred during the MedDiet (mean: 0.9 ± 1.2 kg). A group by time interaction was noted for waist circumference (P = 0.02), abdominally obese subjects showing a significant decrease and nonabdominally obese subjects a nonsignificant increase (resp., −1.1 and +0.3%). The MedDiet resulted in decreases in total cholesterol, LDL-C, HDL-C, apolipoprotein B, A-1, and A-2, total cholesterol/HDL-C ratio, LDL-C/HDL-C ratio, and systolic and diastolic blood pressure (time effect: P < 0.05). For all variables related to glucose/insulin homeostasis, no change was observed except for a decrease in 2 h glucose concentrations (time effect: P = 0.03). No group by time interaction was observed in any of the metabolic variables studied. Results from our study suggest that the adoption of the MedDiet leads to beneficial metabolic effects, irrespective of the abdominal obesity status. PMID:23133745

  7. The matricellular protein thrombospondin-1 globally regulates cardiovascular function and responses to stress via CD47.

    PubMed

    Roberts, David D; Miller, Thomas W; Rogers, Natasha M; Yao, Mingyi; Isenberg, Jeffrey S

    2012-04-01

    Matricellular proteins play diverse roles in modulating cell behavior by engaging specific cell surface receptors and interacting with extracellular matrix proteins, secreted enzymes, and growth factors. Studies of such interactions involving thrombospondin-1 have revealed several physiological functions and roles in the pathogenesis of injury responses and cancer, but the relatively mild phenotypes of mice lacking thrombospondin-1 suggested that thrombospondin-1 would not be a central player that could be exploited therapeutically. Recent research focusing on signaling through its receptor CD47, however, has uncovered more critical roles for thrombospondin-1 in acute regulation of cardiovascular dynamics, hemostasis, immunity, and mitochondrial homeostasis. Several of these functions are mediated by potent and redundant inhibition of the canonical nitric oxide pathway. Conversely, elevated tissue thrombospondin-1 levels in major chronic diseases of aging may account for the deficient nitric oxide signaling that characterizes these diseases, and experimental therapeutics targeting CD47 show promise for treating such chronic diseases as well as acute stress conditions that are associated with elevated thrombospondin-1 expression.

  8. Effect of mildly attenuated heart rate response during treadmill exercise testing on cardiovascular outcome in healthy men and women.

    PubMed

    Maor, Elad; Kopel, Eran; Sidi, Yechezkel; Goldenberg, Ilan; Segev, Shlomo; Kivity, Shaye

    2013-11-01

    Attenuated heart rate (HR) response during exercise is associated with adverse cardiovascular outcome. The acceptable value for HR response is 85% of the age-predicted maximal HR (APMHR). This study hypothesized that mild attenuation of HR response during exercise among healthy subjects is associated with increased cardiovascular risk. The study population comprised 10,323 healthy men and women without known cardiovascular disease (CVD) or diabetes mellitus who underwent a yearly screening program and were followed up during a mean period of 4.3 years. Participants were grouped to 3 tertiles based on the percentage of their APMHR reached at the baseline stress test. The primary end point was the occurrence of CVD or cerebrovascular disease. A total of 1,015 incident cases of CVD occurred during follow-up. A multivariate Cox proportional hazards regression model showed that the CVD risk of subjects who reached 60% to 96% of their APMHR was 35% greater compared with those who reached their APMHR (p = 0.001). A subgroup analysis among subjects who reached 85% of their APMHR showed that even mildly attenuated heart response (in the range of 85% to 96% APMHR) was independently associated with 36% increase in CVD risk (p <0.001). In conclusion, attenuated HR response during exercise is a powerful and independent predictor of adverse cardiovascular events during long-term follow-up among healthy men and women. The prognostic implications of attenuated HR response in this population are apparent even with a minor decrease of the maximal HR to <96% of the APMHR.

  9. Individual Differences in the Temporal Profile of Cardiovascular Responses to Head Down Tilt and Orthostatic Stress with and Without Fluid Loading

    NASA Technical Reports Server (NTRS)

    Cowings, Patricia; Toscano, William; Kanis, Dionisios; Gebreyesus, Fiyore

    2013-01-01

    Susceptibility of healthy astronauts to orthostatic hypotension and presyncope is exacerbated upon return from spaceflight. Hypo-volemia is suspected to play an important role in cardiovascular deconditioning following exposure to spaceflight, which may lead to increased peripheral resistance, attenuated arterial baroreflex, and changes in cardiac function. The effect of altered gravity during space flight and planetary transition on human cardiovascular function is of critical importance to maintenance of astronaut health and safety. A promising countermeasure for post-flight orthostatic intolerance is fluid loading used to restore loss fluid volume by giving crew salt tablets and water prior to re-entry. Eight men and eight women will be tested during two, 6-hour exposures to 6o HDT: 1) fluid loading, 2) no fluid loading. Before and immediately after each HDT, subjects will perform a stand test to assess their orthostatic tolerance. Physiological measures (e.g., ECG, blood pressure, peripheral blood volume) will be continuously monitored while echocardiography measures are recorded at 30-minute intervals during HDT and stand tests. Preliminary results (N=4) clearly show individual differences in responses to this countermeasure and the time course of physiological changes induced by HDT.

  10. Stressing on the nucleolus in cardiovascular disease.

    PubMed

    Hariharan, Nirmala; Sussman, Mark A

    2014-06-01

    The nucleolus is a multifunctional organelle with multiple roles involving cell proliferation, growth, survival, ribosome biogenesis and stress response signaling. Alteration of nucleolar morphology and architecture signifies an early response to increased cellular stress. This review briefly summarizes nucleolar response to cardiac stress signals and details the role played by nucleolar proteins in cardiovascular pathophysiology. This article is part of a Special Issue entitled: Role of the Nucleolus in Human Disease.

  11. Pulmonary transcriptional response to ozone in healthy and cardiovascular compromised rat models.

    PubMed

    Ward, William O; Kodavanti, Urmila P

    2015-01-01

    The genetic cardiovascular disease (CVD) and associated metabolic impairments can influence the lung injury from inhaled pollutants. We hypothesized that comparative assessment of global pulmonary expression profile of healthy and CVD-prone rat models will provide mechanistic insights into susceptibility differences to ozone. The lung expression profiles of healthy Wistar Kyoto (WKY) and CVD-compromised spontaneously hypertensive (SH), stroke-prone SH (SHSP), obese SH heart failure (SHHF) and obese, atherosclerosis-prone JCR rats were analyzed using Affymetrix platform immediately after 4-h air or 1 ppm ozone exposure. At baseline, the JCR exhibited the largest difference in the number of genes among all strains when compared with WKY. Interestingly, the number of genes affected by ozone was inversely correlated with genes different at baseline relative to WKY. A cluster of NFkB target genes involved in cell-adhesion, antioxidant response, inflammation and apoptosis was induced in all strains, albeit at different levels (JCR < WKY < SHHF < SH < SHSP). The lung metabolic syndrome gene cluster indicated expressions in opposite directions for SHHF and JCR suggesting different mechanisms for common disease phenotype and perhaps obesity-independent contribution to exacerbated lung disease. The differences in expression of adrenergic receptors and ion-channel genes suggested distinct mechanisms by which ozone might induce protein leakage in CVD models, especially SHHF and JCR. Thus, the pulmonary response to ozone in CVD strains was likely linked to the defining gene expression profiles. Differential transcriptional patterns between healthy and CVD rat strains at baseline, and after ozone suggests that lung inflammation and injury might be influenced by multiple biological pathways affecting inflammation gene signatures.

  12. Cardiovascular and Perceptual Responses to an Ultraendurance Channel Swim: A Case Study.

    PubMed

    Judelson, Daniel A; Bagley, James R; Schumacher, Jennifer M; Wiersma, Lenny D

    2015-09-01

    Ultraendurance open water swimming presents unique physiological challenges. This case study aimed to describe cardiovascular and perceptual responses during a successful solo channel swim. Investigators followed a female swimmer's Catalina Channel (32.2 km) crossing, monitoring water temperature (T(water)) and air temperature (T(air)), distance remaining (DR), average velocity, and heart rate (HR(swim)) at regular intervals. Every 24 minutes, the swimmer reported perceived pain (on a scale of 0-10), rating of perceived exertion (RPE [scale of 6-20]), perceived thermal sensation (scale 0-8), and thirst (scale 1-9). Data are presented as mean ± SD where applicable. The participant finished in 9 hours, 2 minutes, and 48 seconds; T(water) averaged 19.1 ± 0.4ºC, and T(air) averaged 18.6 ± 0.9ºC. Her HR(swim) ranged from 148 to 155 beats/min, and thermal sensation ranged from 3 to 4. Pain inconsistently varied from 0 to 5 during the swim. The RPE remained between 12 and 14 for the first 8 hours, but increased dramatically near the end (reaching 18). Thirst sensation steadily increased throughout the swim, again reaching maximal values on completion. Physiologically and statistically significant correlations existed between thirst and DR (r = -0.905), RPE and HR(swim) (r = 0.741), RPE and DR (r = -0.694), and pain and DR (r = -0.671). The primary findings were that, despite fluctuations in perceptual stressors, the swimmer maintained a consistent exercise intensity as indicated by HR(swim); and during ultraendurance swimming, pain, RPE, and thirst positively correlated with distance swum. We hope these findings aid in the preparation and performance of future athletes by providing information on what swimmers may expect during an ultraendurance attempt and by increasing the understanding of physiological and perceptual responses during open water swimming. PMID:25819111

  13. Whole body plethysmography reveals differential ventilatory responses to ozone in rat models of cardiovascular disease.

    PubMed

    Dye, Janice A; Ledbetter, Allen D; Schladweiler, Mette C; Costa, Daniel L; Kodavanti, Urmila P

    2015-01-01

    To elucidate key factors of host susceptibility to air pollution, healthy and cardiovascular (CV)-compromised rats were exposed to air or ozone (O3) at 0.25, 0.5, or 1.0 ppm for 4 h. We hypothesized that rat strains with the least cardiac reserve would be most prone to develop significant health effects. Using flow whole body plethysmography (FWBP), ventilatory responses in healthy 3-month-old male rats [i.e. Wistar-Kyoto (WKY), Wistar (WIS), and Sprague-Dawley (SD) strains] were compared with hypertensive [i.e. spontaneously hypertensive (SH), fawn-hooded-hypertensive (FHH), and SH-stroke-prone (SHSP)] strains and obese [i.e. SH-heart failure-prone (SHHF) and JCR:LA-cp, atherosclerosis-prone (JCR)] strains. SH were slower to acclimate to the FWBP chambers. At 0-h post-air-exposure, SHSP and SHHF exhibited hyperpnea, indicative of cardiopulmonary insufficiency. At 0-h-post-O3, all but one strain showed significant concentration-dependent decreases in minute volume [MV = tidal volume (TV) × breathing frequency]. Comparing air with 1.0 ppm responses, MV declined 20-27% in healthy, 21-42% in hypertensive, and 33% in JCR rats, but was unchanged in SHHF rats. Penh increased significantly in all strains, with disproportionate increases in "responder" WKY and FHH strains. By 20 h, most changes had resolved, although Penh remained elevated in WKY, SH, and SHSP. Based on the effective dose estimates (O3 ppm × h × MV), the most CV-compromised (SHSP and SHHF) strains received significantly greater O3 lung deposition (25% and 40%, respectively). Data support epidemiologic associations that individuals with cardiopulmonary insufficiency are at greater risk for urban pollutant exposure due, in part, to enhanced lung deposition and exacerbation of hypoxia and pathophysiologic processes of heart failure. PMID:26667328

  14. Evaluation of cardiovascular protective effect of different apple varieties - Correlation of response with composition.

    PubMed

    Serra, Ana Teresa; Rocha, J; Sepodes, B; Matias, Ana A; Feliciano, Rodrigo P; de Carvalho, Agostinho; Bronze, Maria R; Duarte, Catarina M M; Figueira, M E

    2012-12-15

    Epidemiological evidence supports the concept that diets rich in fruits and vegetables promote health and attenuate or delay the onset of cardiovascular disease (CVD). In particular, a reduced risk of CVD has been associated with apple consumption, probably due to the cholesterol-lowering effect of the main bioactive compounds, namely fibre and polyphenols. In this work, the effect of diet supplementation with 20% of three Portuguese apple cultivars (Bravo de Esmolfe, Malápio Serra and Golden), containing distinct phenolic and fibre concentrations, on serum lipid profile and oxLDL of male Wistar rats fed a cholesterol-enriched diet (2%) was evaluated. After 30 days, only Bravo de Esmolfe apple was able to decrease significantly serum levels of triglycerides, total and LDL cholesterol concentrations (reductions of 27.2%, 21.0% and 20.4%, respectively, in relation to the cholesterol-enriched diet group, P<0.05). The levels of oxLDL were also significantly improved with the consumption of this apple variety (reductions of 20.0% and 11.9%, in relation to the cholesterol-enriched diet group and control group, respectively, P>0.05) as well as with Malapio da Serra apple (reductions of 9.8% in relation to the cholesterol-enriched diet group, P<0.05). Correlation of the bioactive response with chemical composition showed that catechin, epicatechin, procyanidin B1 and β-carotene are the major phytocompounds responsible for the cholesterol lowering ability of apples. The antioxidant potential may have also contributed to this beneficial effect.

  15. Contrasting effects of verapamil and amlodipine on cardiovascular stress responses in hypertension

    PubMed Central

    Lefrandt, Johan D; Heitmann, Jörg; Sevre, Knut; Castellano, Maurizio; Hausberg, Martin; Fallon, Maura; Urbigkeit, Anja; Rostrup, Morten; Agabiti-Rosei, Enrico; Rahn, Karl H; Murphy, Michael; Zannad, Faiez; de Kam, Pieter-Jan; Smit, Andries J

    2001-01-01

    Aims To compare the effects of two long-acting calcium antagonists of different types on cardiovascular stress responses in hypertension. Methods One-hundred and forty-five patients with mild to moderate hypertension and a mean (± s.e.mean) age of 51 ± 0.9 years received for 8 weeks the phenylalkylamine verapamil sustained release (240 mg) and the dihydropyridine amlodipine (5 mg) in a double-blind cross-over design, both after 4 weeks of placebo. Blood pressure, heart rate and plasma noradrenaline were monitored during 3 min of sustained isometric handgrip and 2 min of cold pressor. Results Blood pressure was equally reduced by both drugs. After 3 min handgrip, systolic blood pressure, heart rate and rate-pressure product were lower with verapamil compared with amlodipine. Verapamil attenuated the increases in systolic blood pressure (25 ± 2 vs 30 ± 2 mmHg, difference 4.6, 95% CI (1.0, 8.1), P < 0.01) and rate-pressure product (3.1 ± 0.2 vs 3.6 ± 0.3 × 103 mmHg × beats min−1, difference 0.5, 95% CI (0.1, 0.9), P < 0.01) during handgrip compared with amlodipine. Similar results were observed during cold pressor. Plasma noradrenaline levels were lower with verapamil compared with amlodipine at rest and after both tests, but the increases in plasma noradrenaline were not significantly different. Conclusions Verapamil is more effective in reducing blood pressure and rate-pressure product responses to stress compared with amlodipine. Although plasma noradrenaline is lower with verapamil at rest and after stress, the increase during stress is not different. PMID:11736880

  16. Cardiovascular responses to water ingestion at rest and during isometric handgrip exercise.

    PubMed

    Mendonca, Goncalo V; Teixeira, Micael S; Pereira, Fernando D

    2012-07-01

    Water drinking activates sympathetic vasoconstriction in healthy young adults; however, this is not accompanied by a concomitant increase in resting blood pressure. It is not known whether the water pressor effect is unmasked by a physiological condition such as exercise. Therefore, we examined the effect of water ingestion (50 vs. 500 mL) on the cardiovascular and autonomic responses to isometric handgrip in 17 healthy participants (9 men, 8 women, aged 28.4 ± 9.7 years). Beat-to-beat blood pressure and R-R intervals were recorded in both conditions at rest (pre- and post-ingestion) and during handgrip at 30% of maximal voluntary contraction. R-R series were spectrally decomposed using an autoregressive approach. Water ingestion did not interact with the increase in mean arterial pressure (MAP) from rest to exercise, which was similar between conditions. In contrast, there was an overall bradycardic effect of water and this was accompanied by increased high frequency power (condition main effect, p < 0.05). When the differences in high frequency power between conditions were controlled for, MAP was significantly higher after drinking 500 mL of water (condition main effect, p < 0.05). In addition, water ingestion attenuated the increase in the low to high frequency power ratio from rest to handgrip (interaction effect, p < 0.05). In conclusion, the rise in blood pressure post-water ingestion is prevented both at rest and during isometric handgrip. Interestingly, this is not sustained after controlling for the enhanced vagal drive caused by water ingestion. Therefore, the mechanisms underlying this response most likely depend on reflex bradycardia of vagal origin.

  17. 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

  18. Cardiovascular fitness and haemodynamic responses to maximal cycle ergometer exercise test in children 6-8 years of age.

    PubMed

    Lintu, Niina; Tompuri, Tuomo; Viitasalo, Anna; Soininen, Sonja; Laitinen, Tomi; Savonen, Kai; Lindi, Virpi; Lakka, Timo A

    2014-01-01

    We investigated cardiovascular fitness and haemodynamic responses to maximal cycle ergometer exercise test in children. The participants were a population sample of 425 children (204 girls, 221 boys) aged 6-8 years. Heart rate (HR) and systolic blood pressure (SBP) were measured from the beginning of pre-exercise rest to the end of recovery period. We provided reference values for peak workload and changes in HR and SBP during and after maximal exercise test in girls and boys. Girls had a lower cardiovascular fitness, indicated by peak workload per body weight [mean (2 s) 2.7 (0.9) vs. 3.1 (1.0) W · kg(-1), P < 0.001] and lean mass [mean (2 s) 3.5 (0.9) vs. 3.8 (1.0) W · kg(-1), P < 0.001] than boys. Plateau or decline in SBP close to the end of the test was found in about third of children and was considered a normal SBP response. Girls had a slower HR decrease within 2 min after the test than boys [mean (2 s) 53 (18) vs. 59 (22) beats · min(-1), P < 0.001]. The results are useful for physicians and exercise physiologists to evaluate cardiovascular fitness and haemodynamic responses to exercise in children and to detect children with low exercise tolerance or abnormal haemodynamic responses to exercise.

  19. Effect of altering dietary n-6:n-3 PUFA ratio on cardiovascular risk measures in patients treated with statins: a pilot study.

    PubMed

    Lee, Sabrina P S; Dart, Anthony M; Walker, Karen Z; O'Dea, Kerin; Chin-Dusting, Jaye P F; Skilton, Michael R

    2012-10-01

    Increasing dietary n-3 PUFA decreases the risk of CHD. Since n-6 PUFA compete with n-3 PUFA for common metabolic enzymes, the n-6:n-3 ratio intake rather than the n-3 PUFA intake levels per se may be critical. We aimed to examine whether altering the n-6:n-3 ratio affects cardiovascular risk factors in hypercholesterolaemic patients on lipid management with statins. Adhering to a randomised, crossover study design, patients on statins (n 11) were placed on one of two dietary interventions (Diet high-ratio (HR) - n-6:n-3 = 30:1 or Diet low-ratio (LR) - n-6:n-3 = 1·7:1) for 4 weeks followed after an 8-week washout period by the alternate diet. Foods enriched with n-3 or n-6 PUFA were delivered to each patient, who were given clear guidance on consumption expectations for the study. Measures of lipid profile, blood pressure and vascular function were determined. Diet LR significantly reduced body weight, LDL-cholesterol, high-sensitivity C-reactive protein, blood pressure and the apoA-1:apoB ratio. While Diet HR trended towards a similar cardioprotective profile, most of the parameters examined did not reach statistical significance. A direct comparison between diets demonstrated no significant superiority of Diet LR over Diet HR. These results suggest that a dietary intervention focused on n-6 and n-3 fatty acids may improve cardiovascular risk factors in patients over and above standard lipid management, but there is no significant advantage of a low n-6:n-3 ratio diet when compared to a high-ratio diet. PMID:22182482

  20. Effects of NASA-Fluid Loading Protocol on Cardiovascular Responses to Orthostatic Stress

    NASA Astrophysics Data System (ADS)

    Grinberg, Anna; Edgell, Heather; Gagne, Nathalie; Beavers, Keith; Hughson, Richard L.

    Fluid volume depletion is suspected to be a major contributor to orthostatic hypotension during prolonged bed-rest and spaceflight. Significant reductions in blood and plasma volumes are known to occur with spaceflight and bed-rest. The reductions are attributed to the hormonal responses reacting to a whole-body fluid shift resulting from the removal of the gravity vector seen in upright posture. NASA's proposed fluid loading protocol seeks to replace lost plasma volume by ingestion of salt tablets and water. The dosage is 15 ml/kg water with one 1-g salt tablet for each 125 ml of water over 2 hours. To examine the physiological effects of this fluid loading protocol on blood pressure regulation, seven subjects completed a 4-hour seated period with fluid loading occurring between 1.5 and 3.5 hours. Their responses to orthostatic stress were examined before and after fluid loading by simulating orthostasis in a lower-body negative-pressure (LBNP) box during a progressive test (0, -10, -20, -30, and -40 mmHg). Physiological variables such as heart rate, mean arterial pressure, systolic and diastolic blood pressure, pulse pressure, cardiac output, stroke volume, compliance, peripheral resistance, central venous pressure, and plasma volume were monitored. Data were analyzed using a twoway ANOVA, examining the effects of fluid loading and different levels of LBNP. Fluid loading did not influence cardiovascular variables as there were no significant differences in measured values between preand post-fluid loading conditions at each level of LBNP. This indicates that fluid loading does not increase plasma volume during four hour seated tests. The ingested water does not occupy the vascular bed, instead it may be mobilized to the extracellular space or the bladder. Fluid loading did not significantly affect responses to orthostatic stress, as there were no improvements in central venous pressure, stroke volume, and cardiac output during progressive levels of LBNP, and

  1. Whole Body Plethysmography Reveals Differential Ventilatory Responses to Ozone in Rat Models of Cardiovascular Disease

    EPA Science Inventory

    Increasingly, urban air pollution is recognized as an important determinant of cardiovascular disease. Host susceptibility to air pollution can vary due to genetic predisposition and underlying disease. To elucidate key factors of host ...

  2. Pulmonary Transcriptional Response to Ozone in Healthy and Cardiovascular Compromised Rat Models

    EPA Science Inventory

    The genetic cardiovascular disease (CVD) and associated metabolic impairments can influence the lung injury from inhaled pollutants. We hypothesized that comparative assessment of global pulmonary expression profile of healthy and CVD-prone rat models will provide mechanistic ins...

  3. Fundus photography as a convenient tool to study microvascular responses to cardiovascular disease risk factors in epidemiological studies.

    PubMed

    De Boever, Patrick; Louwies, Tijs; Provost, Eline; Int Panis, Luc; Nawrot, Tim S

    2014-10-22

    The microcirculation consists of blood vessels with diameters less than 150 µm. It makes up a large part of the circulatory system and plays an important role in maintaining cardiovascular health. The retina is a tissue that lines the interior of the eye and it is the only tissue that allows for a non-invasive analysis of the microvasculature. Nowadays, high-quality fundus images can be acquired using digital cameras. Retinal images can be collected in 5 min or less, even without dilatation of the pupils. This unobtrusive and fast procedure for visualizing the microcirculation is attractive to apply in epidemiological studies and to monitor cardiovascular health from early age up to old age. Systemic diseases that affect the circulation can result in progressive morphological changes in the retinal vasculature. For example, changes in the vessel calibers of retinal arteries and veins have been associated with hypertension, atherosclerosis, and increased risk of stroke and myocardial infarction. The vessel widths are derived using image analysis software and the width of the six largest arteries and veins are summarized in the Central Retinal Arteriolar Equivalent (CRAE) and the Central Retinal Venular Equivalent (CRVE). The latter features have been shown useful to study the impact of modifiable lifestyle and environmental cardiovascular disease risk factors. The procedures to acquire fundus images and the analysis steps to obtain CRAE and CRVE are described. Coefficients of variation of repeated measures of CRAE and CRVE are less than 2% and within-rater reliability is very high. Using a panel study, the rapid response of the retinal vessel calibers to short-term changes in particulate air pollution, a known risk factor for cardiovascular mortality and morbidity, is reported. In conclusion, retinal imaging is proposed as a convenient and instrumental tool for epidemiological studies to study microvascular responses to cardiovascular disease risk factors.

  4. Fundus photography as a convenient tool to study microvascular responses to cardiovascular disease risk factors in epidemiological studies.

    PubMed

    De Boever, Patrick; Louwies, Tijs; Provost, Eline; Int Panis, Luc; Nawrot, Tim S

    2014-01-01

    The microcirculation consists of blood vessels with diameters less than 150 µm. It makes up a large part of the circulatory system and plays an important role in maintaining cardiovascular health. The retina is a tissue that lines the interior of the eye and it is the only tissue that allows for a non-invasive analysis of the microvasculature. Nowadays, high-quality fundus images can be acquired using digital cameras. Retinal images can be collected in 5 min or less, even without dilatation of the pupils. This unobtrusive and fast procedure for visualizing the microcirculation is attractive to apply in epidemiological studies and to monitor cardiovascular health from early age up to old age. Systemic diseases that affect the circulation can result in progressive morphological changes in the retinal vasculature. For example, changes in the vessel calibers of retinal arteries and veins have been associated with hypertension, atherosclerosis, and increased risk of stroke and myocardial infarction. The vessel widths are derived using image analysis software and the width of the six largest arteries and veins are summarized in the Central Retinal Arteriolar Equivalent (CRAE) and the Central Retinal Venular Equivalent (CRVE). The latter features have been shown useful to study the impact of modifiable lifestyle and environmental cardiovascular disease risk factors. The procedures to acquire fundus images and the analysis steps to obtain CRAE and CRVE are described. Coefficients of variation of repeated measures of CRAE and CRVE are less than 2% and within-rater reliability is very high. Using a panel study, the rapid response of the retinal vessel calibers to short-term changes in particulate air pollution, a known risk factor for cardiovascular mortality and morbidity, is reported. In conclusion, retinal imaging is proposed as a convenient and instrumental tool for epidemiological studies to study microvascular responses to cardiovascular disease risk factors. PMID

  5. Post-weaning environmental enrichment alters affective responses and interacts with behavioral testing to alter nNOS immunoreactivity.

    PubMed

    Workman, Joanna L; Fonken, Laura K; Gusfa, James; Kassouf, Kathleen M; Nelson, Randy J

    2011-11-01

    Challenging early life events can dramatically affect mental health and wellbeing. Childhood trauma and neglect can increase the risk for developing depressive, anxiety, and substance abuse disorders. Early maternal separation in rodents has been extensively studied and induces long-lasting alterations in affective and stress responses. However, other developmental periods (e.g., the pubertal period) comprise a critical window whereby social and environmental complexity can exert lasting changes on the brain and behavior. In this study, we tested whether early life environmental complexity impacts affective responses, aggressive behaviors, and expression of neuronal nitric oxide synthase (nNOS), the synthetic enzyme for nitric oxide, in adulthood. Mice were weaned into social+nonsocial enrichment, social only enrichment, or standard (isolated) laboratory environments and were tested in open field, elevated plus maze, forced swim, and resident-intruder aggression tests 60 days later. Social+nonsocial enrichment reduced locomotor behavior and anxiety-like responses in the open field and reduced depressive-like responses in the forced swim test. Social housing increased open arm exploration in the elevated plus maze. Both social+nonsocial enrichment and social housing only reduced aggressive behaviors compared with isolation. Social+nonsocial enrichment also increased body mass gain throughout the study. Finally, socially-housed mice had reduced corticosterone concentrations compared with social+nonsocial-enriched mice. Behavioral testing reduced nNOS-positive neurons in the basolateral amygdala and the ventral lateral septum, but not in the social+nonsocial-enriched mice, suggesting that environmental complexity may buffer the brain against some environmental perturbations. PMID:21777607

  6. Repeated Administration of a Mutant Cocaine Esterase: Effects on Plasma Cocaine Levels, Cocaine-Induced Cardiovascular Activity, and Immune Responses in Rhesus Monkeys

    PubMed Central

    Collins, Gregory T.; Brim, Remy L.; Noon, Kathleen R.; Narasimhan, Diwahar; Lukacs, Nicholas W.; Sunahara, Roger K.; Woods, James H.

    2012-01-01

    Previous studies have demonstrated the capacity of a long-acting mutant form of a naturally occurring bacterial double mutant cocaine esterase (DM CocE) to antagonize the reinforcing, discriminative, convulsant, and lethal effects of cocaine in rodents and reverse the increases in mean arterial pressure (MAP) and heart rate (HR) produced by cocaine in rhesus monkeys. This study was aimed at characterizing the immunologic responses to repeated dosing with DM CocE and determining whether the development of anti-CocE antibodies altered the capacity of DM CocE to reduce plasma cocaine levels and ameliorate the cardiovascular effects of cocaine in rhesus monkeys. Under control conditions, intravenous administration of cocaine (3 mg/kg) resulted in a rapid increase in the plasma concentration of cocaine (n = 2) and long-lasting increases in MAP and HR (n = 3). Administration of DM CocE (0.32 mg/kg i.v.) 10 min after cocaine resulted in a rapid hydrolysis of cocaine with plasma levels below detection limits within 5 to 8 min. Elevations in MAP and HR were significantly reduced within 25 and 50 min of DM CocE administration, respectively. Although slight (10-fold) increases in anti-CocE antibodies were observed after the fourth administration of DM CocE, these antibodies did not alter the capacity of DM CocE to reduce plasma cocaine levels or ameliorate cocaine's cardiovascular effects. Anti-CocE titers were transient and generally dissipated within 8 weeks. Together, these results suggest that highly efficient cocaine esterases, such as DM CocE, may provide a novel and effective therapeutic for the treatment of acute cocaine intoxication in humans. PMID:22518021

  7. Repeated administration of a mutant cocaine esterase: effects on plasma cocaine levels, cocaine-induced cardiovascular activity, and immune responses in rhesus monkeys.

    PubMed

    Collins, Gregory T; Brim, Remy L; Noon, Kathleen R; Narasimhan, Diwahar; Lukacs, Nicholas W; Sunahara, Roger K; Woods, James H; Ko, Mei-Chuan

    2012-07-01

    Previous studies have demonstrated the capacity of a long-acting mutant form of a naturally occurring bacterial double mutant cocaine esterase (DM CocE) to antagonize the reinforcing, discriminative, convulsant, and lethal effects of cocaine in rodents and reverse the increases in mean arterial pressure (MAP) and heart rate (HR) produced by cocaine in rhesus monkeys. This study was aimed at characterizing the immunologic responses to repeated dosing with DM CocE and determining whether the development of anti-CocE antibodies altered the capacity of DM CocE to reduce plasma cocaine levels and ameliorate the cardiovascular effects of cocaine in rhesus monkeys. Under control conditions, intravenous administration of cocaine (3 mg/kg) resulted in a rapid increase in the plasma concentration of cocaine (n = 2) and long-lasting increases in MAP and HR (n = 3). Administration of DM CocE (0.32 mg/kg i.v.) 10 min after cocaine resulted in a rapid hydrolysis of cocaine with plasma levels below detection limits within 5 to 8 min. Elevations in MAP and HR were significantly reduced within 25 and 50 min of DM CocE administration, respectively. Although slight (10-fold) increases in anti-CocE antibodies were observed after the fourth administration of DM CocE, these antibodies did not alter the capacity of DM CocE to reduce plasma cocaine levels or ameliorate cocaine's cardiovascular effects. Anti-CocE titers were transient and generally dissipated within 8 weeks. Together, these results suggest that highly efficient cocaine esterases, such as DM CocE, may provide a novel and effective therapeutic for the treatment of acute cocaine intoxication in humans. PMID:22518021

  8. Brain responses to altered auditory feedback during musical keyboard production: an fMRI study.

    PubMed

    Pfordresher, Peter Q; Mantell, James T; Brown, Steven; Zivadinov, Robert; Cox, Jennifer L

    2014-03-27

    Alterations of auditory feedback during piano performance can be profoundly disruptive. Furthermore, different alterations can yield different types of disruptive effects. Whereas alterations of feedback synchrony disrupt performed timing, alterations of feedback pitch contents can disrupt accuracy. The current research tested whether these behavioral dissociations correlate with differences in brain activity. Twenty pianists performed simple piano keyboard melodies while being scanned in a 3-T magnetic resonance imaging (MRI) scanner. In different conditions they experienced normal auditory feedback, altered auditory feedback (asynchronous delays or altered pitches), or control conditions that excluded movement or sound. Behavioral results replicated past findings. Neuroimaging data suggested that asynchronous delays led to increased activity in Broca's area and its right homologue, whereas disruptive alterations of pitch elevated activations in the cerebellum, area Spt, inferior parietal lobule, and the anterior cingulate cortex. Both disruptive conditions increased activations in the supplementary motor area. These results provide the first evidence of neural responses associated with perception/action mismatch during keyboard production. PMID:24513403

  9. Brain responses to altered auditory feedback during musical keyboard production: an fMRI study.

    PubMed

    Pfordresher, Peter Q; Mantell, James T; Brown, Steven; Zivadinov, Robert; Cox, Jennifer L

    2014-03-27

    Alterations of auditory feedback during piano performance can be profoundly disruptive. Furthermore, different alterations can yield different types of disruptive effects. Whereas alterations of feedback synchrony disrupt performed timing, alterations of feedback pitch contents can disrupt accuracy. The current research tested whether these behavioral dissociations correlate with differences in brain activity. Twenty pianists performed simple piano keyboard melodies while being scanned in a 3-T magnetic resonance imaging (MRI) scanner. In different conditions they experienced normal auditory feedback, altered auditory feedback (asynchronous delays or altered pitches), or control conditions that excluded movement or sound. Behavioral results replicated past findings. Neuroimaging data suggested that asynchronous delays led to increased activity in Broca's area and its right homologue, whereas disruptive alterations of pitch elevated activations in the cerebellum, area Spt, inferior parietal lobule, and the anterior cingulate cortex. Both disruptive conditions increased activations in the supplementary motor area. These results provide the first evidence of neural responses associated with perception/action mismatch during keyboard production.

  10. Immune response and insulin signalling alter mosquito feeding behaviour to enhance malaria transmission potential.

    PubMed

    Cator, Lauren J; Pietri, Jose E; Murdock, Courtney C; Ohm, Johanna R; Lewis, Edwin E; Read, Andrew F; Luckhart, Shirley; Thomas, Matthew B

    2015-01-01

    Malaria parasites alter mosquito feeding behaviour in a way that enhances parasite transmission. This is widely considered a prime example of manipulation of host behaviour to increase onward transmission, but transient immune challenge in the absence of parasites can induce the same behavioural phenotype. Here, we show that alterations in feeding behaviour depend on the timing and dose of immune challenge relative to blood ingestion and that these changes are functionally linked to changes in insulin signalling in the mosquito gut. These results suggest that altered phenotypes derive from insulin signalling-dependent host resource allocation among immunity, blood feeding, and reproduction in a manner that is not specific to malaria parasite infection. We measured large increases in mosquito survival and subsequent transmission potential when feeding patterns are altered. Leveraging these changes in physiology, behaviour and life history could promote effective and sustainable control of female mosquitoes responsible for transmission.

  11. The Implicit Positive and Negative Affect Test: Validity and Relationship with Cardiovascular Stress-Responses.

    PubMed

    van der Ploeg, Melanie M; Brosschot, Jos F; Thayer, Julian F; Verkuil, Bart

    2016-01-01

    Self-report, i.e., explicit, measures of affect cannot fully explain the cardiovascular (CV) responses to stressors. Measuring affect beyond self-report, i.e., using implicit measures, could add to our understanding of stress-related CV activity. The Implicit Positive and Negative Affect Test (IPANAT) was administered in two studies to test its ecological validity and relation with CV responses and self-report measures of affect. In Study 1 students (N = 34) viewed four film clips inducing anger, happiness, fear, or no emotion, and completed the IPANAT and the Positive And Negative Affect Scale at baseline and after each clip. Implicit negative affect (INA) was higher and implicit positive affect (IPA) was lower after the anger inducing clip and vice versa after the happiness inducing clip. In Study 2 students performed a stressful math task with (n = 14) or without anger harassment (n = 15) and completed the IPANAT and a Visual Analog Scale as an explicit measure afterwards. Systolic (SBP), diastolic (DBP) blood pressure, heart rate (HR), heart rate variability (HRV), and total peripheral resistance (TPR) were recorded throughout. SBP and DBP were higher and TPR was lower in the harassment condition during the task with a prolonged effect on SBP and DBP during recovery. As expected, explicit negative affect (ENA) was higher and explicit positive affect (EPA) lower after harassment, but ENA and EPA were not related to CV activity. Although neither INA nor IPA differed between the tasks, during both tasks higher INA was related to higher SBP, lower HRV and lower TPR and to slower recovery of DBP after both tasks. Low IPA was related to slower recovery of SBP and DBP after the tasks. Implicit affect was not related to recovery of HR, HRV, and TPR. In conclusion, the IPANAT seems to respond to film clip-induced negative and positive affect and was related to CV activity during and after stressful tasks. These findings support the theory that implicitly measured affect

  12. The Implicit Positive and Negative Affect Test: Validity and Relationship with Cardiovascular Stress-Responses.

    PubMed

    van der Ploeg, Melanie M; Brosschot, Jos F; Thayer, Julian F; Verkuil, Bart

    2016-01-01

    Self-report, i.e., explicit, measures of affect cannot fully explain the cardiovascular (CV) responses to stressors. Measuring affect beyond self-report, i.e., using implicit measures, could add to our understanding of stress-related CV activity. The Implicit Positive and Negative Affect Test (IPANAT) was administered in two studies to test its ecological validity and relation with CV responses and self-report measures of affect. In Study 1 students (N = 34) viewed four film clips inducing anger, happiness, fear, or no emotion, and completed the IPANAT and the Positive And Negative Affect Scale at baseline and after each clip. Implicit negative affect (INA) was higher and implicit positive affect (IPA) was lower after the anger inducing clip and vice versa after the happiness inducing clip. In Study 2 students performed a stressful math task with (n = 14) or without anger harassment (n = 15) and completed the IPANAT and a Visual Analog Scale as an explicit measure afterwards. Systolic (SBP), diastolic (DBP) blood pressure, heart rate (HR), heart rate variability (HRV), and total peripheral resistance (TPR) were recorded throughout. SBP and DBP were higher and TPR was lower in the harassment condition during the task with a prolonged effect on SBP and DBP during recovery. As expected, explicit negative affect (ENA) was higher and explicit positive affect (EPA) lower after harassment, but ENA and EPA were not related to CV activity. Although neither INA nor IPA differed between the tasks, during both tasks higher INA was related to higher SBP, lower HRV and lower TPR and to slower recovery of DBP after both tasks. Low IPA was related to slower recovery of SBP and DBP after the tasks. Implicit affect was not related to recovery of HR, HRV, and TPR. In conclusion, the IPANAT seems to respond to film clip-induced negative and positive affect and was related to CV activity during and after stressful tasks. These findings support the theory that implicitly measured affect

  13. The Implicit Positive and Negative Affect Test: Validity and Relationship with Cardiovascular Stress-Responses

    PubMed Central

    van der Ploeg, Melanie M.; Brosschot, Jos F.; Thayer, Julian F.; Verkuil, Bart

    2016-01-01

    Self-report, i.e., explicit, measures of affect cannot fully explain the cardiovascular (CV) responses to stressors. Measuring affect beyond self-report, i.e., using implicit measures, could add to our understanding of stress-related CV activity. The Implicit Positive and Negative Affect Test (IPANAT) was administered in two studies to test its ecological validity and relation with CV responses and self-report measures of affect. In Study 1 students (N = 34) viewed four film clips inducing anger, happiness, fear, or no emotion, and completed the IPANAT and the Positive And Negative Affect Scale at baseline and after each clip. Implicit negative affect (INA) was higher and implicit positive affect (IPA) was lower after the anger inducing clip and vice versa after the happiness inducing clip. In Study 2 students performed a stressful math task with (n = 14) or without anger harassment (n = 15) and completed the IPANAT and a Visual Analog Scale as an explicit measure afterwards. Systolic (SBP), diastolic (DBP) blood pressure, heart rate (HR), heart rate variability (HRV), and total peripheral resistance (TPR) were recorded throughout. SBP and DBP were higher and TPR was lower in the harassment condition during the task with a prolonged effect on SBP and DBP during recovery. As expected, explicit negative affect (ENA) was higher and explicit positive affect (EPA) lower after harassment, but ENA and EPA were not related to CV activity. Although neither INA nor IPA differed between the tasks, during both tasks higher INA was related to higher SBP, lower HRV and lower TPR and to slower recovery of DBP after both tasks. Low IPA was related to slower recovery of SBP and DBP after the tasks. Implicit affect was not related to recovery of HR, HRV, and TPR. In conclusion, the IPANAT seems to respond to film clip-induced negative and positive affect and was related to CV activity during and after stressful tasks. These findings support the theory that implicitly measured affect

  14. A priming dose of protons alters the early cardiac cellular and molecular response to 56Fe irradiation

    NASA Astrophysics Data System (ADS)

    Ramadan, Samy S.; Sridharan, Vijayalakshmi; Koturbash, Igor; Miousse, Isabelle R.; Hauer-Jensen, Martin; Nelson, Gregory A.; Boerma, Marjan

    2016-02-01

    Purpose: Recent evidence suggests that the heart may be injured by ionizing radiation at lower doses than was previously thought. This raises concerns about the cardiovascular risks from exposure to radiation during space travel. Since space travel is associated with exposure to both protons from solar particle events and heavy ions from galactic cosmic rays, we here examined the effects of a "priming" dose of protons on the cardiac cellular and molecular response to a "challenge" dose of 56Fe in a mouse model. Methods: Male C57BL/6 mice at 10 weeks of age were exposed to sham-irradiation, 0.1 Gy of protons (150 MeV), 0.5 Gy of 56Fe (600 MeV/n), or 0.1 Gy of protons 24 hours prior to 0.5 Gy of 56Fe. Hearts were obtained at 7 days post-irradiation and western-blots were used to determine protein markers of cardiac remodeling, inflammatory infiltration, and cell death. Results: Exposure to 56Fe caused an increase in expression of α-smooth muscle cell actin, collagen type III, the inflammatory cell markers mast cell tryptase, CD2 and CD68, the endothelial glycoprotein thrombomodulin, and cleaved caspase 3. Of all proteins investigated, protons at a dose of 0.1 Gy induced a small increase only in cleaved caspase 3 levels. On the other hand, exposure to protons 24 hours before 56Fe prevented all of the responses to 56Fe. Conclusions: This study shows that a low dose of protons may prime the heart to respond differently to a subsequent challenge dose of heavy ions. Further investigation is required to identify responses at additional time points, consequences for cardiac function, threshold dose levels, and mechanisms by which a proton priming dose may alter the response to heavy ions.

  15. Cardiovascular Responses to an Isometric Handgrip Exercise in Females with Prehypertension

    PubMed Central

    Bond, Vernon; Curry, Bryan H.; Adams, Richard G.; Obisesan, Thomas; Pemminati, Sudhakar; Gorantla, Vasavi R.; Kadur, Kishan; Millis, Richard M.

    2016-01-01

    Background: Hypertensive individuals are known to exhibit greater increases in blood pressure during an isometric handgrip exercise (IHE) than their normotensive counterparts. Aim: This study tests the hypothesis that, compared to normotensive individuals, prehypertensive individuals exhibit an exaggerated response to IHE. Materials and Methods: In this study, the effects of IHE were compared in matched prehypertensive vs. normotensive healthy African-American females. Six healthy young adult African–American female university students were screened in a physician's office for blood pressure in the range of prehypertension, systolic blood pressure (SBP) 120–139 mmHg and diastolic blood pressure (DBP) 80–89 mmHg. Six young adult African–American women were also recruited to serve as a healthy normotensive control group with SBP ≤119 mmHg and DBP ≤79 mmHg. Cardiovascular fitness was determined by peak oxygen uptake (VO2 peak) measured during a progressive exercise test. Results: During the handgrip exercise, the prehypertensive group exhibited greater increases in SBP (from 139 ± 6 to 205 ± 11 mmHg, +48%) than the controls (from 132 ± 3 to 145 ± 3 mmHg, +10%); intergroup difference P < 0.001. The prehypertensive group also exhibited greater increases in DBP (from 77 ± 2 to 112 ± 5 mmHg, +46%) compared to the controls (from 72 ± 3 to 78 ± 4 mmHg, +8%); intergroup difference P < 0.001. The increase in systemic vascular resistance was also greater in the prehypertensive group (from 1713 ± 91 to 2807 ± 370 dyne.s.cm-5, +64%) than in the controls (from 1668 ± 80 to 1812 ± 169 dyne.s.cm-5, +9%); intergroup difference P < 0.05. Conclusion: These results suggest that blood pressure measurements performed during IHE may be a useful screening tool in evaluating prehypertensive individuals for antihypertensive treatments. PMID:27500128

  16. Altered Neural Responses to Sounds in Primate Primary Auditory Cortex during Slow-Wave Sleep

    PubMed Central

    Issa, Elias B.

    2011-01-01

    How sounds are processed by the brain during sleep is an important question for understanding how we perceive the sensory environment in this unique behavioral state. While human behavioral data have indicated selective impairments of sound processing during sleep, brain imaging and neurophysiology studies have reported that overall neural activity in auditory cortex during sleep is surprisingly similar to that during wakefulness. This responsiveness to external stimuli leaves open the question of how neural responses during sleep differ, if at all, from wakefulness. Using extracellular neural recordings in the primary auditory cortex of naturally sleeping common marmosets, we show that slow-wave sleep (SWS) alters neural responses in the primate auditory cortex in two specific ways. SWS reduced the sensitivity of auditory cortex such that quiet sounds elicited weak responses in SWS compared with wakefulness, while loud sounds evoked similar responses in SWS and wakefulness. Furthermore, SWS reduced the extent of sound-evoked response suppression. This pattern of alterations was not observed during rapid eye movement sleep and could not be easily explained by the presence of slow rhythms in SWS. The alteration of excitatory and inhibitory responses during SWS suggests limitations in auditory processing and provides novel insights for understanding why certain sounds are processed while others are missed during deep sleep. PMID:21414918

  17. Skeletal muscle plasticity: cellular and molecular responses to altered physical activity paradigms

    NASA Technical Reports Server (NTRS)

    Baldwin, Kenneth M.; Haddad, Fadia

    2002-01-01

    The goal of this article is to examine our current understanding of the chain of events known to be involved in the adaptive process whereby specific genes and their protein products undergo altered expression; specifically, skeletal muscle adaptation in response to altered loading states will be discussed, with a special focus on the regulation of the contractile protein, myosin heavy chain gene expression. This protein, which is both an important structural and regulatory protein comprising the contractile apparatus, can be expressed as different isoforms, thereby having an impact on the functional diversity of the muscle. Because the regulation of the myosin gene family is under the control of a complex set of processes including, but not limited to, activity, hormonal, and metabolic factors, this protein will serve as a cellular "marker" for studies of muscle plasticity in response to various mechanical perturbations in which the quantity and type of myosin isoform, along with other important cellular proteins, are altered in expression.

  18. Beat to beat variability in cardiovascular variables: noise or music?

    NASA Technical Reports Server (NTRS)

    Appel, M. L.; Berger, R. D.; Saul, J. P.; Smith, J. M.; Cohen, R. J.

    1989-01-01

    Cardiovascular variables such as heart rate, arterial blood pressure, stroke volume and the shape of electrocardiographic complexes all fluctuate on a beat to beat basis. These fluctuations have traditionally been ignored or, at best, treated as noise to be averaged out. The variability in cardiovascular signals reflects the homeodynamic interplay between perturbations to cardiovascular function and the dynamic response of the cardiovascular regulatory systems. Modern signal processing techniques provide a means of analyzing beat to beat fluctuations in cardiovascular signals, so as to permit a quantitative, noninvasive or minimally invasive method of assessing closed loop hemodynamic regulation and cardiac electrical stability. This method promises to provide a new approach to the clinical diagnosis and management of alterations in cardiovascular regulation and stability.

  19. Adolescents with classical polycystic ovary syndrome have alterations in the surrogate markers of cardiovascular disease but not in the endothelial function. The possible benefits of metformin

    PubMed Central

    Fruzzetti, F.; Ghiadoni, L.; Virdis, A.; De Negri, F.; Perini, D.; Bucci, F.; Giannarelli, C.; Gadducci, A.; Taddei, S.

    2016-01-01

    Study Objective To study whether adolescents with the classical form of polycystic ovary syndrome have alterations in metabolic and vascular structure and function. The effect of metformin was evaluated. Design Controlled study Setting University outpatient clinic Participants Eighteen PCOS non obese adolescents were enrolled. Seventeen healthy age-matched adolescents were recruited as controls. Interventions The metabolic profile and the endothelial structure and function were evaluated. Main Outcome Measure(s) Hormonal and lipid profile, blood pressure (BP) measurement, fasting glucose and insulin levels, C-reactive protein (CRP), homocysteine, tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1) and plasmin-antiplasmin complexes (PAP) were measured. Flow mediated dilation (FMD), central pulse wave velocity (PWV), radial artery pulse wave (AIx) and common carotid intima-media thickness (IMT) were also assessed. PCOS girls were also studied 6 months after treatment with metformin (850 mg bid). Results PCOS adolescents were insulin resistant and/or hyperinsulinemic and they had higher BP values and levels of CRP and PAI-1 than the controls. The levels of t-PA and PAP were similar in both groups. FMD, PWV and IMT were also similar. Metformin significantly (p<0.05) reduced insulin, BP, CRP and PAI-1 levels. The PAP levels significantly (p<0.05) increased. Radial AIx was significantly reduced after metformin. No modifications in FMD, PWV and IMT were observed. Conclusions Adolescents with classical PCOS have alterations in some surrogate markers of cardiovascular risk and they are ameliorated by metformin. No deterioration of vascular structure and function has been detected, probably due to the short duration of exposure to the disease. PMID:27018756

  20. ALTERED TRANSCRIPTIONAL RESPONSES OF MOUSE EMBRYO CULTURES EXPOSED TO BISINDOLYLMALEIMIDE (BIS L)

    EPA Science Inventory

    Altered transcriptional responses in mouse embryos exposed to bisindolylmaleimide I (Bis I) in whole embryo culture

    Edward D. Karoly?*, Judith E. Schmid*, Maria R. Blanton*and E. Sidney Hunter III*
    ?Curriculum in Toxicology, University of North Carolina at Chapel Hill, ...

  1. Shared and unique morphological responses of stream fishes to anthropogenic habitat alteration

    PubMed Central

    Franssen, Nathan R.; Harris, Jared; Clark, Scott R.; Schaefer, Jacob F.; Stewart, Laura K.

    2013-01-01

    Understanding population-level responses to novel selective pressures can elucidate evolutionary consequences of human-altered habitats. Stream impoundments (reservoirs) alter riverine ecosystems worldwide, exposing stream fishes to uncommon selective pressures. Assessing phenotypic trait divergence in reservoir habitats will be a first step in identifying the potential evolutionary and ecological consequences of stream impoundments. We tested for body shape divergence in four stream-adapted fishes found in both habitats within three separate basins. Shape variation among fishes was partitioned into shared (exhibited by all species) and unique (species-specific) responses to reservoir habitats. All fishes demonstrated consistent significant shared and unique morphological responses to reservoir habitats. Shared responses were linked to fin positioning, decreased body depths and larger caudal areas; traits likely related to locomotion. Unique responses were linked to head shape, suggesting species-specific responses to abiotic conditions or changes to their trophic ecology in reservoirs. Our results highlight how human-altered habitats can simultaneously drive similar and unique trait divergence in native populations. PMID:23235710

  2. Motivation alters response bias and neural activation patterns in a perceptual decision-making task.

    PubMed

    Reckless, G E; Bolstad, I; Nakstad, P H; Andreassen, O A; Jensen, J

    2013-05-15

    Motivation has been demonstrated to affect individuals' response strategies in economic decision-making, however, little is known about how motivation influences perceptual decision-making behavior or its related neural activity. Given the important role motivation plays in shaping our behavior, a better understanding of this relationship is needed. A block-design, continuous performance, perceptual decision-making task where participants were asked to detect a picture of an animal among distractors was used during functional magnetic resonance imaging (fMRI). The effect of positive and negative motivation on sustained activity within regions of the brain thought to underlie decision-making was examined by altering the monetary contingency associated with the task. In addition, signal detection theory was used to investigate the effect of motivation on detection sensitivity, response bias and response time. While both positive and negative motivation resulted in increased sustained activation in the ventral striatum, fusiform gyrus, left dorsolateral prefrontal cortex (DLPFC) and ventromedial prefrontal cortex, only negative motivation resulted in the adoption of a more liberal, closer to optimal response bias. This shift toward a liberal response bias correlated with increased activation in the left DLPFC, but did not result in improved task performance. The present findings suggest that motivation alters aspects of the way perceptual decisions are made. Further, this altered response behavior is reflected in a change in left DLPFC activation, a region involved in the computation of perceptual decisions.

  3. Angiotensin-(1-7) in the basolateral amygdala attenuates the cardiovascular response evoked by acute emotional stress.

    PubMed

    Oscar, Charles Gonzaga; Müller-Ribeiro, Flávia Camargos de Figueirêdo; de Castro, Lidiane Gonzaga; Martins Lima, Augusto; Campagnole-Santos, Maria José; Santos, Robson Augusto Souza; Xavier, Carlos Henrique; Fontes, Marco Antônio Peliky

    2015-01-12

    The basolateral amygdala (BLA) plays a critical role in mediating physiological responses to emotional stress. Recent data suggest that angiotensin-(1-7) [Ang-(1-7)] can act centrally attenuating the cardiovascular response to acute stress. We investigated whether Ang-(1-7) in the BLA plays a role in the cardiovascular response to emotional stress. Under anesthesia, guide cannulas were implanted into the BLA of Wistar rats. Five days later, the femoral artery was cannulated for mean arterial pressure (MAP) and heart rate (HR) recordings. Microinjections of Ang-(1-7) (5 or 50 pmol), the Mas receptor antagonist A-779 (100 pmol), Ang-(1-7)+A-779 (50 + 100 pmol, respectively), or vehicle (NaCl 0.9%, control) were performed after 24h and rats were then submitted to stress trials. Injection of Ang-(1-7) into the BLA blocked the tachycardia (ΔHR: vehicle 135 ± 23 vs. Ang-(1-7) 9 ± 12 bpm; P<0.05) and the pressor response (ΔMAP: vehicle 28 ± 3 mmHg vs. Ang-(1-7) 6 ± 2 mmHg; P<0.05) produced by air jet stress. These effects were completely reversed by A-779 (ΔHR: 109 ± 11 bpm; ΔMAP: 18 ± 2 mmHg). Ang-(1-7) into the BLA also attenuated the pressor response evoked by cage-switch stress paradigm. These findings indicate that Ang-(1-7) can act in the BLA through the Mas receptors modulating the cardiovascular response evoked by emotional stress.

  4. Arterial Stiffness Alterations and Inflammatory Response Following Endovascular Aortic Repair: Based on a Presentation at the 2013 VEITH Symposium, November 19-23, 2013 (New York, NY, USA).

    PubMed

    Moulakakis, Konstantinos G; Mylonas, Spyridon N; Kakisis, John; Kadoglou, Nikolaos P E; Papadakis, Ioannis; Sfyroeras, George S; Antonopoulos, Constantine C N; Mantas, George; Ikonomidis, Ignatios; Liapis, Christos D

    2015-04-01

    Endovascular abdominal aortic aneurysm repair (EVAR) and thoracic aortic aneurysm repair (TEVAR) have been widely incorporated into clinical practice. However, changes in arterial stiffness and post-implantation syndrome after aortic endografting remain important issues under investigation. The aneurysm sac wall motion after successful EVAR and TEVAR reflects complex interactions between all the components of the excluded aneurysm, including true compliance of the aneurysm wall itself, intra-aneurysm sac pressure, remodeling of the thrombus, and mechanical characteristics of the endograft. Experimental and clinical studies have shown that aortic endografting results in increased arterial stiffness in animal models. It can be assumed that the alterations of aortic mechanical properties can have a direct impact on heart output. The long-term impact of these mechanical changes on cardiovascular outcomes and the potential effects of different endografts on hemodynamics are important issues under investigation. Post-implantation syndrome (PIS) is a systemic inflammatory response frequently observed after endovascular treatment of aortic pathologies. The main features of PIS include fever, leukocytosis, elevated C-reactive protein levels, and coagulation disturbances. Endograft design appears to influence this inflammatory response following aortic endografting; woven polyester endografts have been shown to be associated with greater inflammatory response compared to PTFE stent grafts. The purpose of this paper is to review the literature to elucidate arterial stiffness alterations and inflammatory response after EVAR and TEVAR and the impact of endograft design on aortic stiffness and the post-inflammatory response. PMID:26798761

  5. The effects of high-intensity intermittent exercise training on cardiovascular response to mental and physical challenge.

    PubMed

    Heydari, Mehrdad; Boutcher, Yati N; Boutcher, Stephen H

    2013-02-01

    The purpose was to examine the effect of a 12-week exercise intervention on the cardiovascular and autonomic response of males to mental and physical challenge. Thirty four young overweight males were randomly assigned to either an exercise or control group. The exercise group completed a high-intensity intermittent exercise (HIIE) program three times per week for 12weeks. Cardiovascular response to the Stroop task was determined before and after the intervention by assessing heart rate (HR), stroke volume (SV), arterial stiffness, baroreflex sensitivity (BRS), and skeletal muscle blood flow. The exercise group improved their aerobic fitness levels by 17% and reduced their body weight by 1.6kg. Exercisers compared to controls experienced a significant reduction in HR (p<0.001) and a significant increase in SV (p<0.001) at rest and during Stroop and exercise. For exercisers, arterial stiffness significantly decreased at rest and during Stroop (p<0.01), whereas BRS was increased at rest and during Stroop (p<0.01). Forearm blood flow was significantly increased during the first two minutes of Stroop (p<0.05). HIIE induced significant cardiovascular and autonomic changes at rest and during mental and physical challenge after 12weeks of training. PMID:23220158

  6. Combining Acceleration and Displacement Dependent Modal Frequency Responses Using an MSC/NASTRAN DMAP Alter

    NASA Technical Reports Server (NTRS)

    Barnett, Alan R.; Widrick, Timothy W.; Ludwiczak, Damian R.

    1996-01-01

    Solving for dynamic responses of free-free launch vehicle/spacecraft systems acted upon by buffeting winds is commonly performed throughout the aerospace industry. Due to the unpredictable nature of this wind loading event, these problems are typically solved using frequency response random analysis techniques. To generate dynamic responses for spacecraft with statically-indeterminate interfaces, spacecraft contractors prefer to develop models which have response transformation matrices developed for mode acceleration data recovery. This method transforms spacecraft boundary accelerations and displacements into internal responses. Unfortunately, standard MSC/NASTRAN modal frequency response solution sequences cannot be used to combine acceleration- and displacement-dependent responses required for spacecraft mode acceleration data recovery. External user-written computer codes can be used with MSC/NASTRAN output to perform such combinations, but these methods can be labor and computer resource intensive. Taking advantage of the analytical and computer resource efficiencies inherent within MS C/NASTRAN, a DMAP Alter has been developed to combine acceleration- and displacement-dependent modal frequency responses for performing spacecraft mode acceleration data recovery. The Alter has been used successfully to efficiently solve a common aerospace buffeting wind analysis.

  7. Predicting in vivo cardiovascular properties of β-blockers from cellular assays: a quantitative comparison of cellular and cardiovascular pharmacological responses.

    PubMed

    Baker, Jillian G; Kemp, Philip; March, Julie; Fretwell, Laurice; Hill, Stephen J; Gardiner, Sheila M

    2011-12-01

    β-Adrenoceptor antagonists differ in their degree of partial agonism. In vitro assays have provided information on ligand affinity, selectivity, and intrinsic efficacy. However, the extent to which these properties are manifest in vivo is less clear. Conscious freely moving rats, instrumented for measurement of heart rate (β1; HR) and hindquarters vascular conductance (β2; HVC) were used to measure receptor selectivity and ligand efficacy in vivo. CGP 20712A caused a dose-dependent decrease in basal HR (P<0.05, ANOVA) at 5 doses between 6.7 and 670 μg/kg (i.v.) and shifted the dose-response curve for isoprenaline to higher agonist concentrations without altering HVC responses. In contrast, at doses of 67 μg/kg (i.v.) and above, ICI 118551 substantially reduced the HVC response to isoprenaline without affecting HR responses. ZD 7114, xamoterol, and bucindolol significantly increased basal HR (ΔHR: +122 ± 12, + 129 ± 11, and + 59 ± 11 beats/min, respectively; n=6), whereas other β-blockers caused significant reductions (all at 2 mg/kg i.v.). The agonist effects of xamoterol and ZD 7114 were equivalent to that of the highest dose of isoprenaline. Bucindolol, however, significantly antagonized the response to the highest doses isoprenaline. An excellent correlation was obtained between in vivo and in vitro measures of β1-adrenoceptor efficacy (R(2)=0.93; P<0.0001). PMID:21865315

  8. CARDIOVASCULAR AND THERMOREGULATORY RESPONSES OF UNRESTRAINED RATS EXPOSED TO FILTERED OR UNFILTERED DIESEL EXHAUST

    EPA Science Inventory

    Diesel exhaust (DE) has been associated with adverse cardiovascular and pulmonary health effects. The relative contributions of the gas-phase and particulate (PM) components of DE are less well understood. We exposed WKY rats with or without implanted radiotransmitters to air or ...

  9. Central Cardiovascular Responses of Quadriplegic Subjects to Arm Exercise at Varying Levels of Oxygen Uptake.

    ERIC Educational Resources Information Center

    Figoni, Stephen F.

    The purpose of this study was to assess selected central cardiovascular functions of spinal cord injured, quadriplegic subjects at varying levels of oxygen uptake (VO sub 2). Subjects included 11 untrained, male college students with C5, C6, or C7 complete quadriplegia and 11 able-bodied reference subjects. Exercise was performed on a Monark cycle…

  10. A cardiovascular system model for lower-body negative pressure response

    NASA Technical Reports Server (NTRS)

    Mitchell, B. A., Jr.; Giese, R. P.

    1971-01-01

    Mathematical models used to study complex physiological control systems are discussed. Efforts were made to modify a model of the cardiovascular system for use in studying lower body negative pressure. A computer program was written which allows orderly, straightforward expansion to include exercise, metabolism (thermal stress), respiration, and other body functions.

  11. Community-Responsive Interventions to Reduce Cardiovascular Risk in American Indians

    ERIC Educational Resources Information Center

    Jobe, Jared B.; Adams, Alexandra K.; Henderson, Jeffrey A.; Karanja, Njeri; Lee, Elisa T.; Walters, Karina L.

    2012-01-01

    American Indian and Alaska Native (AI/AN) populations bear a heavy burden of cardiovascular disease (CVD), and they have the highest rates of risk factors for CVD, such as cigarette smoking, obesity, and diabetes, of any U.S. population group. Yet, few randomized controlled trials have been launched to test potential preventive interventions in…

  12. Altering Response Chains in Pathological Gamblers Using a Response-Cost Procedure

    ERIC Educational Resources Information Center

    Johnson, Taylor E.; Dixon, Mark R.

    2009-01-01

    Two pathological gamblers could choose between emitting or having the dealer emit the response options when playing each of three casino games. A response-cost procedure was introduced in a multiple baseline design across games in which the participant had to pay to perform the responses himself, which was somewhat effective at reducing many of…

  13. Thermoregulatory, cardiovascular, and metabolic responses to mild caloric restriction in the Brown Norway rat.

    PubMed

    Aydin, Cenk; Gordon, Christopher J

    2013-07-01

    Caloric restriction (CR) has been demonstrated to prolong the life span of a variety of species. CR-induced reduction in core temperature (Tc) is considered a key mechanism responsible for prolonging life span in rodents; however, little is known about the regulation of CR-induced hypothermia as a function of the circadian cycle. We assessed how mild CR that resulted in a 10% reduction in body weight affected the 24 h patterns of Tc as well as heart rate (HR) and motor activity (MA) of the Brown Norway rat. Telemetered rats were allowed to feed for 20 weeks ad libitum (AL) or given a CR diet. Tc, HR, and MA of CR rats exhibited nocturnal reductions and diurnal elevations, opposite to that of AL rats. The effects of CR appeared to peak at ∼4 weeks. Metabolic rate (MR) and respiratory exchange ratio (RER) were measured overnight after 18 weeks of CR. MR and RER were elevated markedly at the time of feeding in CR rats and then declined during the night. We found that the pattern of Tc was altered with CR, characterized by elimination of high nocturnal Tc's typically observed in AL animals. In terms of mechanisms to prolong life span in CR animals, we suggest that the shift in the pattern of Tc during CR (i.e., elimination of high Tc's) may be as critical as the overall mean reduction in Tc. Future studies should address how the time of feeding may affect the thermoregulatory response in calorically restricted rats. PMID:24303105

  14. Blockade of 5-HT2A receptors suppresses hyperthermic but not cardiovascular responses to psychosocial stress in rats.

    PubMed

    Beig, M I; Baumert, M; Walker, F R; Day, T A; Nalivaiko, E

    2009-03-31

    The aim of this study was to determine whether 5-HT2A receptors mediate cardiovascular and thermogenic responses to acute psychological stresses. For this purpose, adult male Wistar hooded rats instrumented for telemetric recordings of either electrocardiogram (ECG) (n=12) or arterial pressure (n=12) were subjected, on different days, to four 15-min episodes of social defeat. Prior to stress, animals received s.c. injection of the selective 5-HT2A receptor antagonist SR-46349B (trans-4-((3Z)3-[(2-dimethylaminoethyl)oxyimino]-3-(2-fluorophenyl)propen-1-yl)-phenol, hemifumarate) (at doses of 0.3, 1.0 and 3.0 mg/kg) or vehicle. The drug had no effect on basal heart rate or heart rate variability indexes, arterial pressure, and core body temperature. Social defeat elicited significant and substantial tachycardic (347+/-7 to 500+/-7 bpm), pressor (77+/-4 to 97+/-4 mm Hg) and hyperthermic (37.0+/-0.3 to 38.5+/-0.1 degrees C) responses. Blockade of 5-HT2A receptors, at all doses of the antagonist, completely prevented stress-induced hyperthermia. In contrast, stress-induced cardiovascular responses were not affected by the blockade (except small reduction of tachycardia by the highest dose of the drug). We conclude that in rats, 5-HT2A receptors mediate stress-induced hyperthermic responses, but are not involved in the genesis of stress-induced rises in heart rate or arterial pressure, and do not participate in cardiovascular control at rest. PMID:19356699

  15. Collections of simultaneously altered genes as biomarkers of cancer cell drug response.

    PubMed

    Masica, David L; Karchin, Rachel

    2013-03-15

    Computational analysis of cancer pharmacogenomics data has resulted in biomarkers predictive of drug response, but the majority of response is not captured by current methods. Methods typically select single biomarkers or groups of related biomarkers but do not account for response that is strictly dependent on many simultaneous genetic alterations. This shortcoming reflects the combinatorics and multiple-testing problem associated with many-body biologic interactions. We developed a novel approach, Multivariate Organization of Combinatorial Alterations (MOCA), to partially address these challenges. Extending on previous work that accounts for pairwise interactions, the approach rapidly combines many genomic alterations into biomarkers of drug response, using Boolean set operations coupled with optimization; in this framework, the union, intersection, and difference Boolean set operations are proxies of molecular redundancy, synergy, and resistance, respectively. The algorithm is fast, broadly applicable to cancer genomics data, is of immediate use for prioritizing cancer pharmacogenomics experiments, and recovers known clinical findings without bias. Furthermore, the results presented here connect many important, previously isolated observations.

  16. Mature natural killer cells reset their responsiveness when exposed to an altered MHC environment

    PubMed Central

    Joncker, Nathalie T.; Shifrin, Nataliya; Delebecque, Frédéric

    2010-01-01

    Some mature natural killer (NK) cells cannot be inhibited by major histocompatibility complex (MHC) I molecules, either because they lack corresponding inhibitory receptors or because the host lacks the corresponding MHC I ligands for the receptors. Such NK cells nevertheless remain self-tolerant and exhibit a generalized hyporesponsiveness to stimulation through activating receptors. To address whether NK cell responsiveness is set only during the NK cell differentiation process, we transferred mature NK cells from wild-type (WT) to MHC I–deficient hosts or vice versa. Remarkably, mature responsive NK cells from WT mice became hyporesponsive after transfer to MHC I–deficient mice, whereas mature hyporesponsive NK cells from MHC I–deficient mice became responsive after transfer to WT mice. Altered responsiveness was evident among mature NK cells that had not divided in the recipient animals, indicating that the cells were mature before transfer and that alterations in activity did not require cell division. Furthermore, the percentages of NK cells expressing KLRG1, CD11b, CD27, and Ly49 receptors specific for H-2b were not markedly altered after transfer. Thus, the functional activity of mature NK cells can be reset when the cells are exposed to a changed MHC environment. These findings have important implications for how NK cell functions may be curtailed or enhanced in the context of disease. PMID:20819928

  17. Collections of simultaneously altered genes as biomarkers of cancer cell drug response.

    PubMed

    Masica, David L; Karchin, Rachel

    2013-03-15

    Computational analysis of cancer pharmacogenomics data has resulted in biomarkers predictive of drug response, but the majority of response is not captured by current methods. Methods typically select single biomarkers or groups of related biomarkers but do not account for response that is strictly dependent on many simultaneous genetic alterations. This shortcoming reflects the combinatorics and multiple-testing problem associated with many-body biologic interactions. We developed a novel approach, Multivariate Organization of Combinatorial Alterations (MOCA), to partially address these challenges. Extending on previous work that accounts for pairwise interactions, the approach rapidly combines many genomic alterations into biomarkers of drug response, using Boolean set operations coupled with optimization; in this framework, the union, intersection, and difference Boolean set operations are proxies of molecular redundancy, synergy, and resistance, respectively. The algorithm is fast, broadly applicable to cancer genomics data, is of immediate use for prioritizing cancer pharmacogenomics experiments, and recovers known clinical findings without bias. Furthermore, the results presented here connect many important, previously isolated observations. PMID:23338612

  18. Do behavioral responses mediate or moderate the relation between cardiovascular reactivity to stress and parental history of hypertension?

    PubMed

    Frazer, Nicole L; Larkin, Kevin T; Goodie, Jeffrey L

    2002-05-01

    To examine whether differences in behavioral responses to stress mediated or moderated the relation between cardiovascular response to stress and parental history of hypertension, 64 healthy undergraduates-16 men with hypertensive parents (PH+), 16 men without hypertensive parents (PH-), 16 PH+ women, and 16 PH- women-participated in a mental arithmetic task, mirror tracing task, and 2 interpersonal role plays. PH+ participants exhibited higher resting heart rates than PH- participants and higher resting systolic blood pressures (SBPs) than PH- women. PH+ participants exhibited greater SBP responses to tasks and engaged in more negative verbal and nonverbal behavior across tasks than PH- counterparts. Differences in behavioral responding neither mediated nor moderated the observed relation between parental history status and SBP response to stress.

  19. Selective estrogen receptor modulators differentially alter the immune response of gilthead seabream juveniles.

    PubMed

    Rodenas, M C; Cabas, I; García-Alcázar, A; Meseguer, J; Mulero, V; García-Ayala, A

    2016-05-01

    17α-ethynylestradiol (EE2), a synthetic estrogen used in oral contraceptives and hormone replacement therapy, tamoxifen (Tmx), a selective estrogen-receptor modulator used in hormone replacement therapy, and G1, a G protein-coupled estrogen receptor (GPER) selective agonist, differentially increased the hepatic vitellogenin (vtg) gene expression and altered the immune response in adult gilthead seabream (Sparus aurata L.) males. However, no information exists on the effects of these compounds on the immune response of juveniles. This study aims, for the first time, to investigate the effects of the dietary intake of EE2, Tmx or G1 on the immune response of gilthead seabream juveniles and the capacity of the immune system of the specimens to recover its functionality after ceasing exposures (recovery period). The specimens were immunized with hemocyanin in the presence of aluminium adjuvant 1 (group A) or 120 (group B) days after the treatments ceased (dpt). The results indicate that EE2 and Tmx, but not G1, differentially promoted a transient alteration in hepatic vtg gene expression. Although all three compounds did not affect the production of reactive oxygen intermediates, they inhibited the induction of interleukin-1β (il1b) gene expression after priming. Interestingly, although Tmx increased the percentage of IgM-positive cells in both head kidney and spleen during the recovery period, the antibody response of vaccinated fish varied depending on the compound used and when the immunization was administered. Taken together, our results suggest that these compounds differentially alter the capacity of fish to respond to infection during ontogeny and, more interestingly, that the adaptive immune response remained altered to an extent that depends on the compound. PMID:27012396

  20. Selective estrogen receptor modulators differentially alter the immune response of gilthead seabream juveniles.

    PubMed

    Rodenas, M C; Cabas, I; García-Alcázar, A; Meseguer, J; Mulero, V; García-Ayala, A

    2016-05-01

    17α-ethynylestradiol (EE2), a synthetic estrogen used in oral contraceptives and hormone replacement therapy, tamoxifen (Tmx), a selective estrogen-receptor modulator used in hormone replacement therapy, and G1, a G protein-coupled estrogen receptor (GPER) selective agonist, differentially increased the hepatic vitellogenin (vtg) gene expression and altered the immune response in adult gilthead seabream (Sparus aurata L.) males. However, no information exists on the effects of these compounds on the immune response of juveniles. This study aims, for the first time, to investigate the effects of the dietary intake of EE2, Tmx or G1 on the immune response of gilthead seabream juveniles and the capacity of the immune system of the specimens to recover its functionality after ceasing exposures (recovery period). The specimens were immunized with hemocyanin in the presence of aluminium adjuvant 1 (group A) or 120 (group B) days after the treatments ceased (dpt). The results indicate that EE2 and Tmx, but not G1, differentially promoted a transient alteration in hepatic vtg gene expression. Although all three compounds did not affect the production of reactive oxygen intermediates, they inhibited the induction of interleukin-1β (il1b) gene expression after priming. Interestingly, although Tmx increased the percentage of IgM-positive cells in both head kidney and spleen during the recovery period, the antibody response of vaccinated fish varied depending on the compound used and when the immunization was administered. Taken together, our results suggest that these compounds differentially alter the capacity of fish to respond to infection during ontogeny and, more interestingly, that the adaptive immune response remained altered to an extent that depends on the compound.

  1. Evaluation of the ethanol antagonist' Ro15-4513 on cardiovascular and metabolic responses induced by ethanol

    SciTech Connect

    Lerner, M.R.; Gauvin, D.V.; Holloway, F.A.; Wilson, M.F.; Brackett, D.J. Veterans Affairs Medical Center, Oklahoma City, OK )

    1992-02-26

    The putative ethanol antagonist Ro15-4513 has been reported to attenuate many behavioral responses induced by ethanol, including motor coordination, narcosis, ethanol self administration and intake, and anticonvulsant actions. This study was designed to study the effect of Ro15-4513 on cardiovascular and metabolic responses elicited by intragastric ethanol in conscious rats. Four groups of rats were catheterized under enflurane anesthesia and allowed to regain consciousness. Each group was given either 3.2, 10.0, or 32.0 mg/kg Ro15-4513 or equivalent Tween (i.p.) following ethanol. Ro15-4513 had no effect at any concentration on the decreases in mean arterial pressure, cardiac output, central venous pressure, respiration rate, and cardiac stroke volume and the increases in systemic vascular resistance, heart rate, and glucose evoked by the ethanol challenge. Blood alcohol concentrations measured throughout the study were not affected by any concentration of Ro15-4513. These data suggest that even though Ro15-4513 has significant effects on behavioral responses induced by ethanol it has no effect on the cardiovascular and metabolic responses elicited during ethanol intoxication.

  2. Effect of short-term weight loss on mental stress-induced cardiovascular and pro-inflammatory responses in women

    PubMed Central

    Endrighi, Romano; Hamer, Mark; Hackett, Ruth A.; Carvalho, Livia A.; Jackson, Sarah E.; Wardle, Jane; Steptoe, Andrew

    2015-01-01

    Abstract Epidemiologic evidence links psychosocial stress with obesity but experimental studies examining the mechanisms that mediates the effect of stress on adiposity are scarce. The aim of this study was to investigate whether changes in adiposity following minimal weight loss affect heightened stress responses in women, and examine the role of the adipokine leptin in driving inflammatory responses. Twenty-three overweight or obese, but otherwise healthy, women (M age = 30.41 ± 8.0 years; BMI = 31.9 ± 4.1 kg/m2) completed standardized acute mental stress before and after a 9-week calorie restriction program designed to modify adiposity levels. Cardiovascular (blood pressure and heart rate) and inflammatory cytokines (leptin and interleukin-6; IL-6) responses to mental stress were assessed several times between baseline and a 45-min post-stress recovery period. There were modest changes in adiposity measures while the adipokine leptin was markedly reduced (−27%) after the intervention. Blood pressure reactivity was attenuated (−3.38 ± 1.39 mmHg) and heart rate recovery was improved (2.07 ± 0.96 Bpm) after weight loss. Blood pressure responses were inversely associated with changes in waist to hip ratio post intervention. Decreased levels of circulating leptin following weight loss were inversely associated with the IL-6 inflammatory response to stress (r = −0.47). We offered preliminary evidence suggesting that modest changes in adiposity following a brief caloric restriction program may yield beneficial effect on cardiovascular stress responses. In addition, reductions in basal leptin activity might be important in blunting pro-inflammatory responses. Large randomized trials of the effect of adiposity on autonomic responses are thus warranted. PMID:26181102

  3. Effect of short-term weight loss on mental stress-induced cardiovascular and pro-inflammatory responses in women.

    PubMed

    Endrighi, Romano; Hamer, Mark; Hackett, Ruth A; Carvalho, Livia A; Jackson, Sarah E; Wardle, Jane; Steptoe, Andrew

    2015-01-01

    Epidemiologic evidence links psychosocial stress with obesity but experimental studies examining the mechanisms that mediates the effect of stress on adiposity are scarce. The aim of this study was to investigate whether changes in adiposity following minimal weight loss affect heightened stress responses in women, and examine the role of the adipokine leptin in driving inflammatory responses. Twenty-three overweight or obese, but otherwise healthy, women (M age = 30.41 ± 8.0 years; BMI = 31.9 ± 4.1 kg/m(2)) completed standardized acute mental stress before and after a 9-week calorie restriction program designed to modify adiposity levels. Cardiovascular (blood pressure and heart rate) and inflammatory cytokines (leptin and interleukin-6; IL-6) responses to mental stress were assessed several times between baseline and a 45-min post-stress recovery period. There were modest changes in adiposity measures while the adipokine leptin was markedly reduced (-27%) after the intervention. Blood pressure reactivity was attenuated (-3.38 ± 1.39 mmHg) and heart rate recovery was improved (2.07 ± 0.96 Bpm) after weight loss. Blood pressure responses were inversely associated with changes in waist to hip ratio post intervention. Decreased levels of circulating leptin following weight loss were inversely associated with the IL-6 inflammatory response to stress (r = -0.47). We offered preliminary evidence suggesting that modest changes in adiposity following a brief caloric restriction program may yield beneficial effect on cardiovascular stress responses. In addition, reductions in basal leptin activity might be important in blunting pro-inflammatory responses. Large randomized trials of the effect of adiposity on autonomic responses are thus warranted. PMID:26181102

  4. Effect of short-term weight loss on mental stress-induced cardiovascular and pro-inflammatory responses in women.

    PubMed

    Endrighi, Romano; Hamer, Mark; Hackett, Ruth A; Carvalho, Livia A; Jackson, Sarah E; Wardle, Jane; Steptoe, Andrew

    2015-01-01

    Epidemiologic evidence links psychosocial stress with obesity but experimental studies examining the mechanisms that mediates the effect of stress on adiposity are scarce. The aim of this study was to investigate whether changes in adiposity following minimal weight loss affect heightened stress responses in women, and examine the role of the adipokine leptin in driving inflammatory responses. Twenty-three overweight or obese, but otherwise healthy, women (M age = 30.41 ± 8.0 years; BMI = 31.9 ± 4.1 kg/m(2)) completed standardized acute mental stress before and after a 9-week calorie restriction program designed to modify adiposity levels. Cardiovascular (blood pressure and heart rate) and inflammatory cytokines (leptin and interleukin-6; IL-6) responses to mental stress were assessed several times between baseline and a 45-min post-stress recovery period. There were modest changes in adiposity measures while the adipokine leptin was markedly reduced (-27%) after the intervention. Blood pressure reactivity was attenuated (-3.38 ± 1.39 mmHg) and heart rate recovery was improved (2.07 ± 0.96 Bpm) after weight loss. Blood pressure responses were inversely associated with changes in waist to hip ratio post intervention. Decreased levels of circulating leptin following weight loss were inversely associated with the IL-6 inflammatory response to stress (r = -0.47). We offered preliminary evidence suggesting that modest changes in adiposity following a brief caloric restriction program may yield beneficial effect on cardiovascular stress responses. In addition, reductions in basal leptin activity might be important in blunting pro-inflammatory responses. Large randomized trials of the effect of adiposity on autonomic responses are thus warranted.

  5. Drought response transcriptomes are altered in poplar with reduced tonoplast sucrose transporter expression

    PubMed Central

    Xue, Liang-Jiao; Frost, Christopher J.; Tsai, Chung-Jui; Harding, Scott A.

    2016-01-01

    Transgenic Populus tremula x alba (717-1B4) plants with reduced expression of a tonoplast sucrose efflux transporter, PtaSUT4, exhibit reduced shoot growth compared to wild type (WT) under sustained mild drought. The present study was undertaken to determine whether SUT4-RNAi directly or indirectly altered poplar predisposition and/or response to changes in soil water availability. While sucrose and hexose levels were constitutively elevated in shoot organs, expression responses to drought were most altered in the root tips of SUT4-RNAi plants. Prior to any drought treatment, constitutively elevated transcript levels of abscisic acid biosynthetic genes and bark/vegetative storage proteins suggested altered metabolism in root tips of RNAi plants. Stronger drought-stimulation of stress-inducible genes encoding late-embryogenesis-abundant proteins in transgenic roots was consistent with increased vulnerability to soil drying. Transcript evidence suggested an RNAi effect on intercellular water trafficking by aquaporins in stem xylem during soil drying and recovery. Co-expression network analysis predicted altered integration of abscisic acid sensing/signaling with ethylene and jasmonate sensing/signaling in RNAi compared to WT roots. The overall conclusion is that steepened shoot-root sugar gradient in RNAi plants increased sensitivity of root tips to decreasing soil water availability. PMID:27641356

  6. Drought response transcriptomes are altered in poplar with reduced tonoplast sucrose transporter expression.

    PubMed

    Xue, Liang-Jiao; Frost, Christopher J; Tsai, Chung-Jui; Harding, Scott A

    2016-01-01

    Transgenic Populus tremula x alba (717-1B4) plants with reduced expression of a tonoplast sucrose efflux transporter, PtaSUT4, exhibit reduced shoot growth compared to wild type (WT) under sustained mild drought. The present study was undertaken to determine whether SUT4-RNAi directly or indirectly altered poplar predisposition and/or response to changes in soil water availability. While sucrose and hexose levels were constitutively elevated in shoot organs, expression responses to drought were most altered in the root tips of SUT4-RNAi plants. Prior to any drought treatment, constitutively elevated transcript levels of abscisic acid biosynthetic genes and bark/vegetative storage proteins suggested altered metabolism in root tips of RNAi plants. Stronger drought-stimulation of stress-inducible genes encoding late-embryogenesis-abundant proteins in transgenic roots was consistent with increased vulnerability to soil drying. Transcript evidence suggested an RNAi effect on intercellular water trafficking by aquaporins in stem xylem during soil drying and recovery. Co-expression network analysis predicted altered integration of abscisic acid sensing/signaling with ethylene and jasmonate sensing/signaling in RNAi compared to WT roots. The overall conclusion is that steepened shoot-root sugar gradient in RNAi plants increased sensitivity of root tips to decreasing soil water availability. PMID:27641356

  7. Instrumentation for Non-Invasive Assessment of Cardiovascular Regulation

    NASA Technical Reports Server (NTRS)

    Cohen, Richard J.

    1999-01-01

    It is critically important to be able to assess alterations in cardiovascular regulation during and after space flight. We propose to develop an instrument for the non-invasive assessment of such alterations that can be used on the ground and potentially during space flight. This instrumentation would be used by the Cardiovascular Alterations Team at multiple sites for the study of the effects of space flight on the cardiovascular system and the evaluation of countermeasures. In particular, the Cardiovascular Alterations Team will use this instrumentation in conjunction with ground-based human bed-rest studies and during application of acute stresses e.g., tilt, lower body negative pressure, and exercise. In future studies, the Cardiovascular Alterations Team anticipates using this instrumentation to study astronauts before and after space flight and ultimately, during space flight. The instrumentation may also be used by the Bone Demineralization/Calcium Metabolism Team, the Neurovestibular Team and the Human Performance Factors, Sleep and Chronobiology Team to measure changes in autonomic nervous function. The instrumentation will be based on a powerful new technology - cardiovascular system identification (CSI) - which has been developed in our laboratory. CSI provides a non-invasive approach for the study of alterations in cardiovascular regulation. This approach involves the analysis of second-to-second fluctuations in physiologic signals such as heart rate and non-invasively measured arterial blood pressure in order to characterize quantitatively the physiologic mechanisms responsible for the couplings between these signals. Through the characterization of multiple physiologic mechanisms, CSI provides a closed-loop model of the cardiovascular regulatory state in an individual subject.

  8. Health monitoring of Japanese payload specialist: Autonomic nervous and cardiovascular responses under reduced gravity condition (L-0)

    NASA Technical Reports Server (NTRS)

    Sekiguchi, Chiharu

    1993-01-01

    In addition to health monitoring of the Japanese Payload Specialists (PS) during the flight, this investigation also focuses on the changes of cardiovascular hemodynamics during flight which will be conducted under the science collaboration with the Lower Body Negative Pressure (LBNP) Experiment of NASA. For the Japanese, this is an opportunity to examine firsthand the effects of microgravity of human physiology. We are particularly interested in the adaption process and how it relates to space motion sickness and cardiovascular deconditioning. By comparing data from our own experiment to data collected by others, we hope to understand the processes involved and find ways to avoid these problems for future Japanese astronauts onboard Space Station Freedom and other Japanese space ventures. The primary objective of this experiment is to monitor the health condition of Japanese Payload Specialists to maintain a good health status during and after space flight. The second purpose is to investigate the autonomic nervous system's response to space motion sickness. To achieve this, the function of the autonomic nervous system will be monitored using non-invasive techniques. Data obtained will be employed to evaluate the role of autonomic nervous system in space motion sickness and to predict susceptibility to space motion sickness. The third objective is evaluation of the adaption process of the cardiovascular system to microgravity. By observation of the hemodynamics using an echocardiogram we will gain insight on cardiovascular deconditioning. The last objective is to create a data base for use in the health care of Japanese astronauts by obtaining control data in experiment L-O in the SL-J mission.

  9. Sequential Infection with Common Pathogens Promotes Human-like Immune Gene Expression and Altered Vaccine Response.

    PubMed

    Reese, Tiffany A; Bi, Kevin; Kambal, Amal; Filali-Mouhim, Ali; Beura, Lalit K; Bürger, Matheus C; Pulendran, Bali; Sekaly, Rafick-Pierre; Jameson, Stephen C; Masopust, David; Haining, W Nicholas; Virgin, Herbert W

    2016-05-11

    Immune responses differ between laboratory mice and humans. Chronic infection with viruses and parasites are common in humans, but are absent in laboratory mice, and thus represent potential contributors to inter-species differences in immunity. To test this, we sequentially infected laboratory mice with herpesviruses, influenza, and an intestinal helminth and compared their blood immune signatures to mock-infected mice before and after vaccination against yellow fever virus (YFV-17D). Sequential infection altered pre- and post-vaccination gene expression, cytokines, and antibodies in blood. Sequential pathogen exposure induced gene signatures that recapitulated those seen in blood from pet store-raised versus laboratory mice, and adult versus cord blood in humans. Therefore, basal and vaccine-induced murine immune responses are altered by infection with agents common outside of barrier facilities. This raises the possibility that we can improve mouse models of vaccination and immunity by selective microbial exposure of laboratory animals to mimic that of humans. PMID:27107939

  10. In Utero Exposure to a Cardiac Teratogen Causes Reversible Deficits in Postnatal Cardiovascular Function, But Altered Adaptation to the Burden of Pregnancy.

    PubMed

    Aasa, Kristiina L; Maciver, Rebecca D; Ramchandani, Shyamlal; Adams, Michael A; Ozolinš, Terence R S

    2015-11-01

    Congenital heart defects (CHD) are the most common birth anomaly and while many resolve spontaneously by 1 year of age, the lifelong burden on survivors is poorly understood. Using a rat model of chemically induced CHD that resolve postnatally, we sought to characterize the postnatal changes in cardiac function, and to investigate whether resolved CHD affects the ability to adapt to the increased the cardiovascular (CV) burden of pregnancy. To generate rats with resolved CHD, pregnant rats were administered distilled water or dimethadione (DMO) [300 mg/kg b.i.d. on gestation day (gd) 9 and 10] and pups delivered naturally. To characterize structural and functional changes in the heart, treated and control offspring were scanned by echocardiography on postnatal day 4, 21, and 10-12 weeks. Radiotelemeters were implanted for continuous monitoring of hemodynamics. Females were mated and scanned by echocardiography on gd12 and gd18 during pregnancy. On gd18, maternal hearts were collected for structural and molecular assessment. Postnatal echocardiography revealed numerous structural and functional differences in treated offspring compared with control; however, these resolved by 10-12 weeks of age. The CV demand of pregnancy revealed differences between treated and control offspring with respect to mean arterial pressure, CV function, cardiac strain, and left ventricular gene expression. In utero exposure to DMO also affected the subsequent generation. Gd18 fetal and placental weights were increased in treated F2 offspring. This study demonstrates that in utero chemical exposure may permanently alter the capacity of the postnatal heart to adapt to pregnancy and this may have transgenerational effects.

  11. Neural regulation of cardiovascular response to exercise: role of central command and peripheral afferents.

    PubMed

    Nobrega, Antonio C L; O'Leary, Donal; Silva, Bruno Moreira; Marongiu, Elisabetta; Piepoli, Massimo F; Crisafulli, Antonio

    2014-01-01

    During dynamic exercise, mechanisms controlling the cardiovascular apparatus operate to provide adequate oxygen to fulfill metabolic demand of exercising muscles and to guarantee metabolic end-products washout. Moreover, arterial blood pressure is regulated to maintain adequate perfusion of the vital organs without excessive pressure variations. The autonomic nervous system adjustments are characterized by a parasympathetic withdrawal and a sympathetic activation. In this review, we briefly summarize neural reflexes operating during dynamic exercise. The main focus of the present review will be on the central command, the arterial baroreflex and chemoreflex, and the exercise pressure reflex. The regulation and integration of these reflexes operating during dynamic exercise and their possible role in the pathophysiology of some cardiovascular diseases are also discussed. PMID:24818143

  12. Dietary potassium: a key mediator of the cardiovascular response to dietary sodium chloride.

    PubMed

    Kanbay, Mehmet; Bayram, Yeter; Solak, Yalcin; Sanders, Paul W

    2013-01-01

    Potassium and sodium share a yin/yang relationship in the regulation of blood pressure (BP). BP is directly associated with the total body sodium and negatively correlated with the total body potassium. Epidemiologic, experimental, and clinical studies have shown that potassium is a significant regulator of BP and further improves cardiovascular outcomes. Hypertensive cardiovascular damage, stroke, and stroke-related death are accelerated by salt intake but might be curbed by increasing dietary potassium intake. The antihypertensive effect of potassium supplementation appears to occur through several mechanisms that include regulation of vascular sensitivity to catecholamines, promotion of natriuresis, limiting plasma renin activity, and improving endothelial function. In the absence of chronic kidney disease, the combined evidence suggests that a diet rich in potassium content serves a vasculoprotective function, particularly in the setting of salt-sensitive hypertension and prehypertension.

  13. Characterization of fluid physics effects on cardiovascular response to microgravity (G-572)

    NASA Technical Reports Server (NTRS)

    Pantalos, George M.; Bennett, Thomas E.; Sharp, M. Keith; Woodruff, Stewart; Oleary, Sean; Gillars, Kevin; Lemon, Mark; Sojka, Jan

    1995-01-01

    The investigation of cardiovascular adaptation to space flight has seen substantial advancement in the last several years. In-flight echocardiographic measurements of astronaut cardiac function on the Space Shuttle have documented an initial increase, followed by a progressive reduction in both left ventricular volume index and stroke volume with a compensatory increase in heart rate to maintain cardiac output. To date, the reduced cardiac size and stroke volume have been presumed to be the consequence of the reduction in circulating fluid volume within a few days after orbital insertion. However, no specific mechanism for the reduced stroke volume has been identified. The following investigation proposes the use of a hydraulic model of the cardiovascular system to examine the possibility that the observed reduction in stroke volume may, in part, be related to fluid physics effects on heart function. The automated model is being prepared to fly as a Get Away Special (GAS) payload within the next year.

  14. Strength and power training did not modify cardiovascular responses to aerobic exercise in elderly subjects.

    PubMed

    Kanegusuku, H; Queiroz, A C C; Chehuen, M R; Costa, L A R; Wallerstein, L F; Mello, M T; Ugrinowitsch, C; Forjaz, C L M

    2011-09-01

    Resistance training increases muscle strength in older adults, decreasing the effort necessary for executing physical tasks, and reducing cardiovascular load during exercise. This hypothesis has been confirmed during strength-based activities, but not during aerobic-based activities. This study determined whether different resistance training regimens, strength training (ST, constant movement velocity) or power training (PT, concentric phase performed as fast as possible) can blunt the increase in cardiovascular load during an aerobic stimulus. Older adults (63.9 ± 0.7 years) were randomly allocated to: control (N = 11), ST (N = 13, twice a week, 70-90% 1-RM) and PT (N = 15, twice a week, 30-50% 1-RM) groups. Before and after 16 weeks, oxygen uptake (VO(2)), systolic blood pressure (SBP), heart rate (HR), and rate pressure product (RPP) were measured during a maximal treadmill test. Resting SBP and RPP were similarly reduced in all groups (combined data = -5.7 ± 1.2 and -5.0 ± 1.7%, respectively, P < 0.05). Maximal SBP, HR and RPP did not change. The increase in measured VO(2), HR and RPP for the increment in estimated VO(2) (absolute load) decreased similarly in all groups (combined data = -9.1 ± 2.6, -14.1 ± 3.9, -14.2 ± 3.0%, respectively, P < 0.05), while the increments in the cardiovascular variables for the increase in measured VO(2) did not change. In elderly subjects, ST and PT did not blunt submaximal or maximal HR, SBP and RPP increases during the maximal exercise test, showing that they did not reduce cardiovascular stress during aerobic tasks.

  15. Altered response-preparation in patients with adult ADHD: A high-density ERP study.

    PubMed

    Kakuszi, Brigitta; Tombor, László; Papp, Szilvia; Bitter, István; Czobor, Pál

    2016-03-30

    Aberrations in early-developing bottom-up processes, such as stimulus-driven response preparation, are thought to play a critical role in the onset of ADHD, and in its persistence over time. Electrophysiology offers a unique tool to gain insight into response preparation, since response preparation has been associated with distinctive ERP changes, including negative potential-shifts which occur predominantly over frontal brain areas. We examined response-preceding negative potential shifts (RPNS) as a probe of response-preparation in adult ADHD patients by obtaining high-density event-related potentials from 33 ADHD and 29 matched healthy subjects during a Go/Nogo task using a 128-channel BioSemi recording-system. Compared to controls, ADHD patients showed enhancement of the RPNS in fronto-central brain regions in the Go condition during correct responses. This change was associated with poor performance in the Stroop incongruency-task: the greater the enhancement, the higher the proportion of errors. Moreover, the ERP-enhancement showed association with the severity of ADHD-symptoms; and with heightened response-variability. Thus, ADHD patients demonstrate neurophysiological alterations in response-preparation and response-preceding brain activity, suggestive of excessive activation of prefrontal neural circuits. Given the correlation with neuropsychological and psychopathological measures, these changes may constitute a pathway for core symptoms of ADHD, including premature and impaired response-preparation and motor-hyperactivity.

  16. Cardiovascular responses of semi-arboreal snakes to chronic, intermittent hypergravity

    NASA Technical Reports Server (NTRS)

    Lillywhite, H. B.; Ballard, R. E.; Hargens, A. R.

    1996-01-01

    Cardiovascular functions were studied in semi-arboreal rat snakes (Elaphe obsoleta) following long-term, intermittent exposure to +1.5 Gz (head-to-tail acceleration) on a centrifuge. Snakes were held in a nearly straight position within horizontal plastic tubes during periods of centrifugation. Centrifugal acceleration, therefore, subjected snakes to a linear force gradient with the maximal force being experienced at the tail. Compared to non-centrifuged controls, Gz-acclimated snakes showed greater increases of heart rate during head-up tilt or acceleration, greater sensitivity of arterial pressure to circulating catecholamines, higher blood levels of corticosterone, and higher blood ratios of prostaglandin F 2 alpha/prostaglandin E2. Cardiovascular tolerance to increased gravity during graded Gz acceleration was measured as the maximum (caudal) acceleration force at which carotid arterial blood flow became null. When such tolerances were adjusted for effects of body size and other continuous variables incorporated into an analysis of covariance, the difference between the adjusted mean values of control and acclimated snakes (2.37 and 2.84 Gz, respectively) corresponded closely to the 0.5 G difference between the acclimation G (1.5) and Earth gravity (1.0). As in other vertebrates, cardiovascular tolerance to Gz stress tended to be increased by acclimation, short body length, high arterial pressure, and comparatively large blood volume. Voluntary body movements were important for promoting carotid blood flow at the higher levels of Gz stress.

  17. Role of Endogenous Factors in Response of Erythrocyte Membrane in Patients with Cardiovascular Diseases under Conditions of Ischemic Exposure.

    PubMed

    Pivovarov, Yu I; Kuznetsova, E E; Koryakina, L B; Gorokhova, V G; Kuril'skaya, T E

    2015-05-01

    We studied specific features of erythrocyte membrane response to short-term occlusion of the brachial artery in patients with cardiovascular pathology. Under ischemic conditions, processes of sorption were primarily intensified in patients with effort angina and processes of hemoglobin binding with erythrocyte membrane predominated in patients with essential hypertension. These changes in the cell membrane were related to modulation of aggregation properties of erythrocytes (in patients with angina) and plasminogen activity (in patients with essential hypertension). They can also be associated with changes in glucose levels (effort angina) and uric acid (essential hypertension) whose effects can be significantly modified by other endogenous factors.

  18. Antenatal Maternal Stress Alters Functional Brain Responses In Adult Offspring During Conditioned Fear

    PubMed Central

    Sadler, Theodore R.; Nguyen, Peter T.; Yang, Jun; Givrad, Tina K.; Mayer, Emeran A.; Maarek, Jean-Michel I.; Hinton, David R.; Holschneider, Daniel P.

    2011-01-01

    Antenatal maternal stress has been shown in rodent models and in humans to result in altered behavioral and neuroendocrine responses, yet little is known about its effects on functional brain activation. Pregnant female rats received a daily foot-shock stress or sham-stress two days after testing plug-positive and continuing for the duration of their pregnancy. Adult male offspring (age 14 weeks) with and without prior maternal stress (MS) were exposed to an auditory fear conditioning (CF) paradigm. Cerebral blood flow (CBF) was assessed during recall of the tone cue in the nonsedated, nontethered animal using the 14C-iodoantipyrine method, in which the tracer was administered intravenously by remote activation of an implantable minipump. Regional CBF distribution was examined by autoradiography and analyzed by statistical parametric mapping in the three-dimensionally reconstructed brains. Presence of fear memory was confirmed by behavioral immobility (‘freezing’). Corticosterone plasma levels during the CF paradigm were measured by ELISA in a separate group of rats. Antenatal MS exposure altered functional brain responses to the fear conditioned cue in adult offspring. Rats with prior MS exposure compared to those without demonstrated heightened fear responsivity, exaggerated and prolonged corticosterone release, increased functional cerebral activation of limbic/paralimbic regions (amygdala, ventral hippocampus, insula, ventral striatum, nucleus acumbens), the locus coeruleus, and white matter, and deactivation of medial prefrontal cortical regions. Dysregulation of corticolimbic circuits may represent risk factors in the future development of anxiety disorders and associated alterations in emotional regulation. PMID:21300034

  19. β-adrenergic impact underlies the effect of mood and hedonic instrumentality on effort-related cardiovascular response.

    PubMed

    Silvestrini, Nicolas; Gendolla, Guido H E

    2011-05-01

    After habituation, participants were first induced into negative vs. positive moods and performed then an attention task with either low vs. high hedonic instrumentality of success. In the high-instrumentality condition participants expected to see a funny movie after success and an unpleasant movie after failure; in the low-instrumentality condition participants expected an unpleasant movie after success and a pleasant movie after failure. Effort-related cardiovascular response (ICG, blood pressure) was assessed during mood inductions and task performance. As predicted by the mood-behavior-model (Gendolla, 2000), responses of cardiac pre-ejection period (PEP) and systolic blood pressure were stronger in the high-instrumentality/negative-mood condition than in the other three cells. Here the high hedonic instrumentality of success justified the high effort that was perceived as necessary in a negative mood. Moreover, the PEP effects indicate that cardiovascular response was driven by beta-adrenergic impact on the heart rather than by vascular adjustments. PMID:21382436

  20. Effects of hypnosis on plasma proenkephalin peptide F and perceptual and cardiovascular responses during submaximal exercise.

    PubMed

    Kraemer, W J; Lewis, R V; Triplett, N T; Koziris, L P; Heyman, S; Noble, B J

    1992-01-01

    Little information is available concerning the influence of subconscious mechanisms on neuroendocrine function, more specifically, proenkephalin peptide F release. Ten men [5 middle distance runners (21.6 (SD 0.54 years) and 5 untrained men (24.0 (SD 4.3 years)] consented to be volunteers in this investigation. Submaximal exercise intensities of 25% and 50% of peak oxygen consumption (VO2) (8 min stages) were used for both the control and hypnosis treatments. A traditional hypnotic induction was used, with the suggestion of two higher intensities of exercise stress (50% and 75% peak VO2) previously experienced in familiarization and testing by each subject. Each minute oxygen consumption was measured using open circuit spirometry, heart rate via an ECG, and ratings of perceived exertion (RPE) using the Borg scale. Plasma peptide F immunoreactivity (ir) [preproenkephalin-(107-140)] in blood sampled from an indwelling cannula was measured by radioimmunoassay at 7-8 min of each stage of the exercise test. Expected significant increases were observed for all cardiorespiratory and perceptual variables over the increasing exercise intensities and there were no significant differences between trained and untrained groups for peptide F if response patterns. Hypnosis did not significantly affect peptide F ir concentrations (P > 0.05) and did not significantly alter exercise heart rate, RPE or minute ventilation (P > 0.05). However, hypnosis did significantly increase oxygen consumption during exercise (P = 0.0095) but not of the magnitude needed for the metabolic demands of the higher exercise intensities. Thus, traditional hypnosis was unable to make functionally significant changes in the cardiorespiratory variables.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1483448

  1. Altered prefronto-striato-parietal network response to mental rotation in HIV.

    PubMed

    Schweinsburg, Brian C; Scott, J Cobb; Schweinsburg, Alecia Dager; Jacobus, Joanna; Theilmann, Rebecca J; Frank, Larry R; Weber, Erica; Grant, Igor; Woods, Steven Paul

    2012-02-01

    The present study used functional magnetic resonance imaging to examine the neural substrates of mental rotation in 11 individuals with HIV infection and 13 demographically similar HIV seronegative volunteers. Individuals with HIV showed increased brain response to mental rotation in prefrontal and posterior parietal cortices, striatum, and thalamus, with significant HIV by angle interactions emerging in the prefrontal cortex and caudate. Results indicate that HIV infection is associated with altered brain response to mental rotation in fronto-striato-parietal pathways, which may reflect compensatory strategies, recruitment of additional brain regions, and/or increased neuroenergetic demands during mental rotation needed to offset underlying HIV-associated neural injury.

  2. Geomorphological Responses to Anthropogenic Alterations within the Nakdong and Yeongsan Estuaries, South Korea

    NASA Astrophysics Data System (ADS)

    Williams, Joshua; Dellapenna, Timothy; Lee, guan-hong

    2016-04-01

    On the Korean Peninsula, significant anthropogenic alterations have occurred to drainage basins and estuaries due to river diversion for agricultural practices, coastal construction of estuarine barrages, and extensive seawalls in land reclamation projects. Over the past century these practices have considerably modified the shoreline and altered both net transport of sediment and freshwater from these systems and modulated the timing and intensity of the discharge. As a result, the sediment dynamics and ecosystems within the estuaries have been significantly altered. Considering drainage basins >500 km2, 56% of rivers reaching the coast in South Korea have been occluded by an estuarine dam, restricting delivery of sediments and altering/preventing natural tidal exchange of fresh and saltwater. The Nakdong and Yeongsan Estuaries are prime examples and are respectively representative of micro and macro-tidal estuaries found in the region. The impacts of the modifications include a substantial decrease in the tidal prism, reduction of accommodation space in intertidal zones, and changes in the dispersal mechanisms and accumulation of sediments. In order to assess these alterations, a series of gravity and vibracores were analyzed using 210Pb and 137Cs radioisotope geochronology, laser diffraction particle analyses, and X-radiography. Additionally, side scan sonar and CHIRP seismic data were collected. Our observations have found a shift in depositional environments as a natural response to an extensive array of anthropogenic alterations. The changes in sediment trapping efficiency that have ensued resulting from extensive coastal construction provides the basis for reevaluating traditional facies models for estuaries in the Anthropocene

  3. Penetration Capacity, Color Alteration and Biological Response of Two In-office Bleaching Protocols.

    PubMed

    Cintra, Luciano Tavares Angelo; Benetti, Francine; Ferreira, Luciana Louzada; Gomes-Filho, João Eduardo; Ervolino, Edilson; Gallinari, Marjorie de Oliveira; Rahal, Vanessa; Briso, André Luiz Fraga

    2016-01-01

    Hydrogen peroxide (H2O2) penetrates into the dental hard tissues causing color alteration but also alterations in pulpal tissues. Hard-tissue penetration, color alteration and the pulp response alterations were evaluated for two in-office bleaching protocols with H2O2. For trans-enamel/dentin penetration and color alteration, discs of bovine teeth were attached to an artificial pulp chamber and bleached according to the groups: BLU (20% H2O2 - 1x50 min, Whiteness HP Blue); MAX (35% H2O2 - 3x15 min, Whiteness HP Maxx); Control (1x50 min, placebo). Trans-enamel/dentin penetration was quantified based on the reaction of H2O2 with leucocrystal violet and the color analyzed by CIELab System. Twenty Wistar rats were divided into two groups (BLU and MAX) and their maxillary right molars were treated according to the same protocols of the in vitro study; the maxillary left molars were used as controls. After 2 days, the animals were killed and their maxillae were examined by light microscopy. The inflammation of pulp tissue was scored according to the inflammatory infiltrate (1, absent; 2, mild; 3, moderate; 4, severe/necrosis). Data were analyzed by statistical tests (α=0.05). MAX showed higher trans-enamel/dentinal penetration of H2O2 (p<0.05). The color alteration was similar for both groups (p>0.05), and different when compared to Control group (p<0.05). MAX showed severe inflammation in the upper thirds of the coronal pulp, and BLU showed moderate inflammation (p<0.05). In-office bleaching protocols using lower concentrations of hydrogen peroxide should be preferred due to their reduced trans-enamel/dentinal penetration since they cause less pulp damage and provide same bleaching efficiency. PMID:27058379

  4. The role of altered cutaneous immune responses in the induction and persistence of rosacea.

    PubMed

    Margalit, Anatte; Kowalczyk, Michał J; Żaba, Ryszard; Kavanagh, Kevin

    2016-04-01

    Rosacea is a chronic inflammatory skin condition that predominantly affects the skin of the face and the eyes. Several factors are associated with the onset and persistence of the condition, including an altered immune response in the skin and elevated levels of Demodex mites. Alterations in the immune response include elevated levels of LL-37 in rosacea skin, increased expression of TLR-2 and increased amounts of vitamin D3 in epidermal tissue. The combined effect of these changes may make the skin more sensitive to external and internal stimuli. External stimuli that may trigger or sustain rosacea inflammation include exposure to ultraviolet light, while internal factors may include the presence of elevated numbers of Demodex mites. These mites may directly stimulate an immune response or release bacteria within the pilosebaceous unit that act as a trigger for inflammation. This review will highlight the changes that occur in the immune response of the skin and describe how Demodex mites and associated bacteria may activate this response and lead to the characteristics of rosacea. PMID:26747056

  5. Women with borderline personality disorder do not show altered BOLD responses during response inhibition.

    PubMed

    van Eijk, Julia; Sebastian, Alexandra; Krause-Utz, Annegret; Cackowski, Sylvia; Demirakca, Traute; Biedermann, Sarah V; Lieb, Klaus; Bohus, Martin; Schmahl, Christian; Ende, Gabriele; Tüscher, Oliver

    2015-12-30

    Impulsivity is central to borderline personality disorder (BPD). Response inhibition, addressing the ability to suppress or stop actions, is one aspect of behavioral impulse control which is frequently used to assess impulsivity. BPD patients display deficits in response inhibition under stress condition or negative emotions. We assessed whether response inhibition and its neural underpinnings are impaired in BPD when tested in an emotionally neutral setting and when co-morbid attention-deficit/hyperactivity disorder (ADHD) is excluded. To this end, we studied response inhibition in unmedicated BPD patients and healthy controls (HC) in two independent samples using functional magnetic resonance imaging during Simon-, Go/nogo-, and Stopsignal tasks. BPD patients and HC did not differ significantly in their performance in the Go/nogo and the Stopsignal tasks. Response interference in the Simon task was increased in BPD patients in one sample, but this could not be replicated in the second sample. In both samples, no significant differences in brain activation patterns during any of the tasks were present while the neural impulse control network was robustly activated during the inhibition tasks in both groups. Our results provide evidence that under emotionally neutral conditions response inhibition is not impaired in patients with BPD without co-occurring ADHD. PMID:26483213

  6. Cardiovascular responses to peripheral chemoreflex activation and comparison of different methods to evaluate baroreflex gain in conscious mice using telemetry.

    PubMed

    Braga, Valdir A; Burmeister, Melissa A; Sharma, Ram V; Davisson, Robin L

    2008-10-01

    Peripheral chemoreceptors located in the carotid bodies are the primary sensors of systemic hypoxia. Although the pattern of responses elicited by peripheral chemoreceptor activation is well established in rats, lambs, and rabbits, the cardiovascular responses to peripheral chemoreflex activation in conscious mice have not been delineated. Here we report that stimulation of peripheral chemoreceptors by potassium cyanide (KCN) in conscious mice elicits a unique biphasic response in blood pressure that is characterized by an initial and robust rise followed by a decrease in blood pressure, which is accompanied by a marked reduction in heart rate. The depressor and bradycardic responses to KCN were abolished by muscarinic receptor blockade with atropine, and the pressor response was abolished by alpha-adrenergic receptor blockade with prazosin, suggesting that vagal and sympathetic drive to the heart and sympathetic drive to the vasculature mediate these cardiovascular responses. These studies characterized the chemoreflex in conscious mice and established the reliability of using them for studying hypoxia-related diseases such as obstructive sleep apnea. In another series of experiments, two methods for analyzing baroreflex sensitivity were compared: the classical pharmacological approach using phenylephrine and sodium nitroprusside (i.e., the Oxford technique) or the sequence method for analyzing spontaneous baroreflex activity. Our findings indicate that both methods are reliable, and the sequence method certainly has its benefits as a predictive tool in the context of long-term noninvasive studies using telemetry. However, for absolute determination of baroreflex function, analysis of spontaneous baroreflex activity should be complemented by the classical pharmacological method. PMID:18667715

  7. Drug-induced and Genetic Alterations in Stress-Responsive Systems: Implications for Specific Addictive Diseases

    PubMed Central

    Zhou, Yan; Proudnikov, Dmitri; Yuferov, Vadim; Kreek, Mary Jeanne

    2009-01-01

    From the earliest work in our laboratory, we hypothesized, and with studies conducted in both clinical research and animal models, we have shown that drugs of abuse, administered or self-administered, on a chronic basis, profoundly alter stress-responsive systems. Alterations of expression of specific genes involved in stress responsivity, with increases or decreases in mRNA levels, receptor and neuropeptide levels, and resultant changes in hormone levels, have been documented to occur after chronic intermittent exposure to heroin, morphine, other opiates, cocaine, other stimulants and alcohol in animal models and in human molecular genetics. The best studied of the stress-responsive systems in humans and mammalian species in general is undoubtedly the HPA axis. In addition, there are stress-responsive systems in other parts in the brain itself, and some of these include components of the HPA axis, such as CRF and CRF receptors, along with POMC gene and gene products. Several other stress-responsive systems are known to influence the HPA axis, such as the vasopressin-vasopressin receptor system. Orexin-hypocretin, acting at its receptors, may effect changes which suggest that it should be properly categorized as a stress-responsive system. However, less is known about the interactions and connectivity of some of these different neuropeptide and receptor systems, and in particular, about the possible connectivity of fast-acting (e.g., glutamate and GABA) and slow-acting (including dopamine, serotonin and norepinephrine) neurotransmitters with each of these stress-responsive components and the resultant impact, especially in the setting of chronic exposure to drugs of abuse. Several of these stress-responsive systems and components, primarily based on our laboratory-based and human molecular genetics research of addictive diseases, will be briefly discussed in this review. PMID:19914222

  8. Role of Autonomic Reflex Arcs in Cardiovascular Responses to Air Pollution Exposure

    EPA Science Inventory

    The body responds to environmental stressors by triggering autonomic reflexes in the pulmonary receptors, baroreceptors, and chemoreceptors to maintain homeostasis. Numerous studies have shown that exposure to various gases and airborne particles can alter the functional outcome ...

  9. Altered postprandial hormone and metabolic responses in a simulated shift work environment.

    PubMed

    Ribeiro, D C; Hampton, S M; Morgan, L; Deacon, S; Arendt, J

    1998-09-01

    The circadian rhythms of most night shift workers do not adapt fully to the imposed behavioural schedule, and this factor is considered to be responsible for many of the reported health problems. One way in which such disturbances might be mediated is through inappropriate hormonal and metabolic responses to meals, on the night shift. Twelve healthy subjects (four males and eight females) were studied on three occasions at the same clock time (1330 h), but at different body clock times, after consuming test meals, first in their normal environment, secondly after a forced 9 h phase advance (body clock time approximately 2230 h) and then again 2 days later in the normal environment. They were given a low-fat pre-meal at 0800 h, then a test meal at 1330 h with blood sampling for the following 9 h. Parameters measured included plasma glucose, non-esterified fatty acids (NEFAs), triacylglycerol (TAG), insulin, C-peptide, proinsulin and glucose-dependent insulinotropic polypeptide, and urinary 6-sulphatoxymelatonin. In contrast with a previous study with a high-fat pre-meal, postprandial glucose and insulin responses were not affected by the phase shift. However, basal plasma NEFAs were lower immediately after the phase shift (P < 0.05). Incremental (difference from basal) TAG responses were significantly higher (P < 0.05) immediately after the phase shift compared with before. Two-day post-phase shift responses showed partial reversion to baseline values. This study suggests that it takes at least 2 days to adapt to eating meals on a simulated night shift, and that the nutritional content of the pre-meals consumed can have a marked effect on postprandial responses during a simulated phase shift. Such findings may provide a partial explanation for the increased occurrence of cardiovascular disease reported in shift workers.

  10. Socioeconomic and Psychosocial Gradients in Cardiovascular Pathogen Burden and Immune Response: The Multi-Ethnic Study of Atherosclerosis

    PubMed Central

    Aiello, Allison E.; Diez-Roux, Ana; Noone, Anne-Michelle; Ranjit, Nalini; Cushman, Mary; Tsai, Michael Y.; Szklo, Moyses

    2009-01-01

    Background The biologic mechanisms linking socioeconomic position and psychosocial factors to cardiovascular disease (CVD) are not well understood. Immune response to persistent pathogens may be one of these mechanisms. Methods We analyzed cross-sectional data from the Multi-Ethnic Study of Atherosclerosis (N=999) composed of adults age 45–84. Log-binomial regression and ordinal logistic regression models were used to examine associations of socioeconomic factors and psychosocial factors with pathogen burden and immune response among those infected. Pathogen burden was assessed based on seroprevalence of Helicobacter pylori, cytomegalovirus, herpes simplex virus-1, and Chlamydia pneumoniae and antibody levels were used to characterize high immune response to all four pathogens. Results Low education was a strong and significant independent predictor of higher pathogen burden after adjustment for covariates (adjusted odds ratio (OR) 95% confidence interval (CI) 1.37, 1.19–1.57). Among subjects seropositive for all four pathogens, low education and a higher level of chronic psychosocial stress showed a positive association with higher antibody response, although associations were no longer significant in models with all covariates included (OR = 1.64, 95%CI 0.82–3.31 for lowest vs. highest educational category and OR= 1.29, 95%CI 0.96–1.73 for a one level increase in chronic stress). Conclusion Pathogen burden and heightened immune response may represent a biological pathway by which low socioeconomic position and chronic stress are related to increased rates of cardiovascular disease. PMID:19150399

  11. Experimental and theoretical studies of spectral alteration in ultrasonic waves resulting from nonlinear elastic response in rock

    SciTech Connect

    Johnson, P.A.; McCall, K.R.; Meegan, G.D. Jr.

    1993-11-01

    Experiments in rock show a large nonlinear elastic wave response, far greater than that of gases, liquids and most other solids. The large response is attributed to structural defects in rock including microcracks and grain boundaries. In the earth, a large nonlinear response may be responsible for significant spectral alteration at amplitudes and distances currently considered to be well within the linear elastic regime.

  12. Short-term precipitation exclusion alters microbial responses to soil moisture in a wet tropical forest.

    PubMed

    Waring, Bonnie G; Hawkes, Christine V

    2015-05-01

    Many wet tropical forests, which contain a quarter of global terrestrial biomass carbon stocks, will experience changes in precipitation regime over the next century. Soil microbial responses to altered rainfall are likely to be an important feedback on ecosystem carbon cycling, but the ecological mechanisms underpinning these responses are poorly understood. We examined how reduced rainfall affected soil microbial abundance, activity, and community composition using a 6-month precipitation exclusion experiment at La Selva Biological Station, Costa Rica. Thereafter, we addressed the persistent effects of field moisture treatments by exposing soils to a controlled soil moisture gradient in the lab for 4 weeks. In the field, compositional and functional responses to reduced rainfall were dependent on initial conditions, consistent with a large degree of spatial heterogeneity in tropical forests. However, the precipitation manipulation significantly altered microbial functional responses to soil moisture. Communities with prior drought exposure exhibited higher respiration rates per unit microbial biomass under all conditions and respired significantly more CO2 than control soils at low soil moisture. These functional patterns suggest that changes in microbial physiology may drive positive feedbacks to rising atmospheric CO2 concentrations if wet tropical forests experience longer or more intense dry seasons in the future.

  13. Does prior sepsis alter subsequent circadian and sickness behaviour response to lipopolysaccharide treatment in mice?

    PubMed

    Anderson, Sean T; O'Callaghan, Emma K; Commins, Sean; Coogan, Andrew N

    2015-08-01

    Previous data has shown that prior history of immune challenge may affect central and behavioural responses to subsequent immune challenge, either leading to exaggerated responses via priming mechanisms or lessened responses via endotoxin tolerance. In this set of experiments we have examined how previously lipopolysaccharide (LPS)-induced sepsis shapes the response to subsequent treatment with lower dose LPS. After treatment with LPS (5 mg/kg) or saline mice were allowed to recover for 3-4 months before being challenged with a lower dose of LPS (100 μg/kg) for assessment of sickness behaviours. Performance on the open field test and the tail suspension test was assessed, and no evidence was found that prior sepsis altered sickness or depressive-like behaviour following LPS treatment. We then examined the responsiveness of the circadian system of mice to LPS. We found that in control animals, LPS induced a significant phase delay of the behavioural rhythm and that this was not the case in post-septic animals (4-6 weeks after sepsis), indicating that prior sepsis alters the responsivity of the circadian system to subsequent immune challenge. We further assessed the induction of the immediate early genes c-Fos and EGR1 in the hippocampus and the suprachiasmatic nucleus (SCN; the master circadian pacemaker) by LPS in control or post-septic animals, and found that post-septic animals show elevated expression in the hippocampus but not the SCN. These data suggest that previous sepsis has some effect on behavioural and molecular responses to subsequent immune challenge in mice.

  14. Number of Directional Changes Alters the Physiological, Perceptual, and Neuromuscular Responses of Netball Players During Intermittent Shuttle Running.

    PubMed

    Ashton, Ruth E M; Twist, Craig

    2015-10-01

    This study investigated whether an increased number of changes in direction altered the metabolic, cardiovascular, perceptual, and neuromuscular responses to intermittent shuttle running (ISR). Using a randomized crossover design, 10 female netball players completed 30 minutes of ISR over a 10-m (ISR10) and 20-m (ISR20) linear course. Measures of expired air, heart rate (HR), rating of perceived exertion, blood lactate concentration ([BLa]), and peak torque of knee extensors and flexors were measured. Differences (%change ± 90% CL) in VO2 (1.5 ± 5.6%) was unclear between conditions, whereas HR was possibly higher (1.5 ± 2.5%) and [BLa] very likely lower in ISR20 compared with ISR10 (-32.7 ± 9.9%). Rating of perceived exertion was likely lower in the ISR20 compared with the ISR10 condition at 15 (-5.0 ± 5.0%) and most likely lower at 30 minutes (-9.4 ± 2.0%). Sprint times over 20 m were likely slower during ISR20 at mid (3.9 ± 3.2%) but unclear after (2.1 ± 5.4%). Changes in muscle function were not different between ISR10 and ISR20 conditions for knee extension (-0.2 ± 0.9%) but were likely different for knee flexion (-5.7 ± 4.9%). More directional changes during shuttle running increase the physiological and perceptual load on female athletes, which also cause a greater reduction in knee extensor torque. These findings have implications for the effective conditioning and injury prevention of female team sport athletes. PMID:26402473

  15. An altered hydrotropic response (ahr1) mutant of Arabidopsis recovers root hydrotropism with cytokinin

    PubMed Central

    Saucedo, Manuel; Ponce, Georgina; Campos, María Eugenia; Eapen, Delfeena; García, Edith; Luján, Rosario; Sánchez, Yoloxóchitl; Cassab, Gladys I.

    2012-01-01

    Roots are highly plastic and can acclimate to heterogeneous and stressful conditions. However, there is little knowledge of the effect of moisture gradients on the mechanisms controlling root growth orientation and branching, and how this mechanism may help plants to avoid drought responses. The aim of this study was to isolate mutants of Arabidopsis thaliana with altered hydrotropic responses. Here, altered hydrotropic response 1 (ahr1), a semi-dominant allele segregating as a single gene mutation, was characterized. ahr1 directed the growth of its primary root towards the source of higher water availability and developed an extensive root system over time. This phenotype was intensified in the presence of abscisic acid and was not observed if ahr1 seedlings were grown in a water stress medium without a water potential gradient. In normal growth conditions, primary root growth and root branching of ahr1 were indistinguishable from those of the wild type (wt). The altered hydrotropic growth of ahr1 roots was confirmed when the water-rich source was placed at an angle of 45° from the gravity vector. In this system, roots of ahr1 seedlings grew downward and did not display hydrotropism; however, in the presence of cytokinins, they exhibited hydrotropism like those of the wt, indicating that cytokinins play a critical role in root hydrotropism. The ahr1 mutant represents a valuable genetic resource for the study of the effects of cytokinins in the differential growth of hydrotropism and control of lateral root formation during the hydrotropic response. PMID:22442413

  16. The Vestibular-Evoked Postural Response of Adolescents with Idiopathic Scoliosis Is Altered

    PubMed Central

    Pialasse, Jean-Philippe; Descarreaux, Martin; Mercier, Pierre; Blouin, Jean; Simoneau, Martin

    2015-01-01

    Adolescent idiopathic scoliosis is a multifactorial disorder including neurological factors. A dysfunction of the sensorimotor networks processing vestibular information could be related to spine deformation. This study investigates whether feed-forward vestibulomotor control or sensory reweighting mechanisms are impaired in adolescent scoliosis patients. Vestibular evoked postural responses were obtained using galvanic vestibular stimulation while participants stood with their eyes closed and head facing forward. Lateral forces under each foot and lateral displacement of the upper body of adolescents with mild (n = 20) or severe (n = 16) spine deformation were compared to those of healthy control adolescents (n = 16). Adolescent idiopathic scoliosis patients demonstrated greater lateral displacement and net lateral forces than controls both during and immediately after vestibular stimulation. Altered sensory reweighting of vestibular and proprioceptive information changed balance control of AIS patients during and after vestibular stimulation. Therefore, scoliosis onset could be related to abnormal sensory reweighting, leading to altered sensorimotor processes. PMID:26580068

  17. Connecting differential responses of native and invasive riparian plants to climate change and environmental alteration.

    PubMed

    Flanagan, Neal E; Richardson, Curtis J; Ho, Mengchi

    2015-04-01

    Climate change is predicted to impact river systems in the southeastern United States through alterations of temperature, patterns of precipitation and hydrology. Future climate scenarios for the southeastern United States predict (1) surface water temperatures will warm in concert with air temperature, (2) storm flows will increase and base flows will decrease, and (3) the annual pattern of synchronization between hydroperiod and water temperature will be altered. These alterations are expected to disturb floodplain plant communities, making them more vulnerable to establishment of invasive species. The primary objective of this study is to evaluate whether native and invasive riparian plant assemblages respond differently to alterations of climate and land use. To study the response of riparian wetlands to watershed and climate alterations, we utilized an existing natural experiment imbedded in gradients of temperature and hydrology-found among dammed and undammed rivers. We evaluated a suite of environmental variables related to water temperature, hydrology, watershed disturbance, and edaphic conditions to identify the strongest predictors of native and invasive species abundances. We found that native species abundance is strongly influenced by climate-driven variables such as temperature and hydrology, while invasive species abundance is more strongly influenced by site-specific factors such as land use and soil nutrient availability. The patterns of synchronization between plant phenology, annual hydrographs, and annual water temperature cycles may be key factors sustaining the viability of native riparian plant communities. Our results demonstrate the need to understand the interactions between climate, land use, and nutrient management in maintaining the species diversity of riparian plant communities. Future climate change is likely to result in diminished competitiveness of native plant species, while the competitiveness of invasive species will increase

  18. Connecting differential responses of native and invasive riparian plants to climate change and environmental alteration.

    PubMed

    Flanagan, Neal E; Richardson, Curtis J; Ho, Mengchi

    2015-04-01

    Climate change is predicted to impact river systems in the southeastern United States through alterations of temperature, patterns of precipitation and hydrology. Future climate scenarios for the southeastern United States predict (1) surface water temperatures will warm in concert with air temperature, (2) storm flows will increase and base flows will decrease, and (3) the annual pattern of synchronization between hydroperiod and water temperature will be altered. These alterations are expected to disturb floodplain plant communities, making them more vulnerable to establishment of invasive species. The primary objective of this study is to evaluate whether native and invasive riparian plant assemblages respond differently to alterations of climate and land use. To study the response of riparian wetlands to watershed and climate alterations, we utilized an existing natural experiment imbedded in gradients of temperature and hydrology-found among dammed and undammed rivers. We evaluated a suite of environmental variables related to water temperature, hydrology, watershed disturbance, and edaphic conditions to identify the strongest predictors of native and invasive species abundances. We found that native species abundance is strongly influenced by climate-driven variables such as temperature and hydrology, while invasive species abundance is more strongly influenced by site-specific factors such as land use and soil nutrient availability. The patterns of synchronization between plant phenology, annual hydrographs, and annual water temperature cycles may be key factors sustaining the viability of native riparian plant communities. Our results demonstrate the need to understand the interactions between climate, land use, and nutrient management in maintaining the species diversity of riparian plant communities. Future climate change is likely to result in diminished competitiveness of native plant species, while the competitiveness of invasive species will increase

  19. Human cardiovascular and vestibular responses in long minutes and low +Gz loading by short arm centrifuge.

    PubMed

    Yajima, K; Miyamoto, A; Ito, M; Maru, R; Maeda, T; Sanada, E; Nakazato, T; Saiki, C; Yamaguchi, Y; Igarashi, M; Matsumoto, S

    1994-07-01

    1.4 G, 1.7 G, and 2.0 G of +Gz and 60 minutes centrifugation was adopted to 20 healthy male subjects using 1.8 m radius centrifuge equipped to Nihon University School of Medicine. G was applied from lower G, considering G training effect for the subjects. Effects on performance decline and side effects of such a short-arm centrifugation were especially observed in the experiments, because this size of centrifuge could be used in space station in future for a strong countermeasure of cardiovascular deconditioning, demineralization from bone, etc. G training effect was observed same as higher and rapid G acceleration in fighter pilot. Subjects suffered from many types of discomfort; such as sensation of heaviness of diaphragm, cold sweat, nausea, irritable feeling, arrhythmia, tachycardia, rapid decrease of blood pressure, which sometimes caused interruption of G load. As 2.0 G and 60 minutes centrifugation seemed very tough load to the subjects, there should be necessary some G suit or other countermeasure, if we apply a higher G and/or longer G duration. Performance decline due to the load commonly continued for 1 hour or so. Side effects were observed in relation to neuro-vestibular, cardio-vascular, and autonomic nervous system. PMID:11539528

  20. Aged human muscle demonstrates an altered gene expression profile consistent with an impaired response to exercise.

    PubMed

    Jozsi, A C; Dupont-Versteegden, E E; Taylor-Jones, J M; Evans, W J; Trappe, T A; Campbell, W W; Peterson, C A

    2000-12-01

    The gene expression profile of skeletal muscle from healthy older (62-75 years old) compared with younger (20-34 years old) men demonstrated elevated expression of genes typical of a stress or damage response, and decreased expression of a gene encoding a DNA repair/cell cycle checkpoint protein. Although the expression of these genes was relatively unaffected by a single bout of resistance exercise in older men, acute exercise altered gene expression in younger men such that post-exercise gene expression in younger men was similar to baseline gene expression in older men. The lack of response of muscle from older subjects to resistance exercise was also apparent in the expression of the inflammatory response gene IL-1beta, which did not differ between the age groups at baseline, but increased within 24 h of the exercise bout only in younger subjects. Other genes with potentially important roles in the adaptation of muscle to exercise, specifically in the processes of angiogenesis and cell proliferation, showed a similar response to exercise in older compared with younger subjects. Only one gene encoding the multifunctional, early growth response transcription factor EGR-1, showed an opposite pattern of expression in response to exercise, acutely decreasing in younger and increasing in older subjects. These results may provide a molecular basis for the inherent variability in the response of muscle from older as compared with younger individuals to resistance training.

  1. Reduced responses of macrophages on nanometer surface features of altered alumina crystalline phases.

    PubMed

    Khang, Dongwoo; Liu-Snyder, Peishan; Pareta, Rajesh; Lu, Jing; Webster, Thomas J

    2009-06-01

    Extensive prolonged interactions of inflammatory cells (such as macrophages) at the host-implant interface may lead to implant failure. While previous studies have shown increased in vitro and in vivo bone cell adhesion, proliferation and mineralization on nanophase compared to currently implanted ceramics, few studies have been conducted to elucidate inflammatory cell responses on such nanophase ceramics. Controlling surface feature size and corresponding surface roughness on implants may clearly alter immune cell responses, which would be an extremely important consideration for the use of nanostructured materials as improved biomaterials. In this study, reduced macrophage density was observed on alumina (Al(2)O(3)) compacts with greater nanometer surface roughness accompanied by changes in crystallinity for up to 24 h in culture. Since alumina is a commonly used ceramic in orthopedic applications, this in vitro study continues to support the use of nanophase ceramics as improved orthopedic implants by demonstrating reduced macrophage responses.

  2. Cardiovascular responses to microinjection of L-glutamate into the NTS in AV3V-lesioned rats.

    PubMed

    Vieira, Alexandre Antonio; Colombari, Eduardo; De Luca, Laurival A; de Almeida Colombari, Débora Simões; Menani, José V

    2004-10-29

    The excitatory amino acid L-glutamate injected into the nucleus of the solitary tract (NTS) in unanesthetized rats similar to peripheral chemoreceptor activation increases mean arterial pressure (MAP) and reduces heart rate. In this study, we investigated the effects of acute (1 day) and chronic (15 days) electrolytic lesions of the preoptic-periventricular tissue surrounding the anteroventral third ventricle (AV3V region) on the pressor and bradycardic responses induced by injections of L-glutamate into the NTS or peripheral chemoreceptor activation in unanesthetized rats. Male Holtzman rats with sham or electrolytic AV3V lesions and a stainless steel cannula implanted into the NTS were used. Differently from the pressor responses (28+/-3 mm Hg) produced by injections into the NTS of sham-lesioned rats, L-glutamate (5 nmol/100 nl) injected into the NTS reduced MAP (-26+/-8 mm Hg) or produced no effect (2+/-7 mm Hg) in acute and chronic AV3V-lesioned rats, respectively. The bradycardia to l-glutamate into the NTS and the cardiovascular responses to chemoreflex activation with intravenous potassium cyanide or to baroreflex activation with intravenous phenylephrine or sodium nitroprusside were not modified by AV3V lesions. The results show that the integrity of the AV3V region is essential for the pressor responses to L-glutamate into the NTS but not for the pressor responses to chemoreflex activation, suggesting dissociation between the central mechanisms involved in these responses.

  3. Postnatal development of the pattern of respiratory and cardiovascular response to systemic hypoxia in the piglet: the roles of adenosine.

    PubMed Central

    Elnazir, B; Marshall, J M; Kumar, P

    1996-01-01

    1. In 3-day-old and 3-week-old spontaneously breathing piglets anaesthetized with Saffan, we have studied ventilatory and cardiovascular responses evoked by 5 min periods of hypoxia (breathing 10 and 6% O2). 2. In 3-day-old piglets both 10 and 6% O2 evoked an increase followed by a secondary fall in ventilation, a gradual tachycardia and a renal vasoconstriction, with an increase in femoral blood flow that was attributable to femoral vasodilatation. Arterial blood pressure rose initially but fell towards control values by the 5th minute of hypoxia. 3. The stable adenosine analogue 2-chloroadenosine (2-CA; 30 mg kg(-1) i.v.) evoked bradycardia and renal vasoconstriction, but had no effect on femoral vasculature. These responses were blocked by the adenosine receptor antagonist 8-phenyltheophylline (8-PT; 8 mg kg(-1) i.v.). 8-PT also abolished the secondary fall in ventilation evoked by 10 and 6% O2 and the renal vasoconstriction evoked by 10% O2, but had no effect on the tachycardia, or on the femoral vascular response. 4. By contrast, in 3-week-old piglets both 10 and 6% O2 evoked a sustained increase in ventilation, tachycardia and a rise in arterial pressure with renal vasoconstriction, but no change in renal blood flow and substantial femoral vasodilatation with an increase in femoral blood flow. 2-CA evoked bradycardia and renal vasoconstriction, as in 3-day-old piglets, but also evoked pronounced femoral vasodilatation. 8-PT blocked these responses and the hypoxia-induced femoral vasodilatation, but had no significant effect on other components of the hypoxia-induced response. 5. We propose that there is postnatal development of the ventilatory and cardiovascular responses evoked by systemic hypoxia and of the role of locally released adenosine in these responses: at 3 days, adenosine released within the central nervous system and within the kidney is a major contributor to the secondary fall in ventilation and renal vasoconstriction respectively, whereas at 3

  4. Chronic shear induces caveolae formation and alters ERK and Akt responses in endothelial cells

    NASA Technical Reports Server (NTRS)

    Boyd, Nolan L.; Park, Heonyong; Yi, Hong; Boo, Yong Chool; Sorescu, George P.; Sykes, Michelle; Jo, Hanjoong

    2003-01-01

    Caveolae are plasmalemmal domains enriched with cholesterol, caveolins, and signaling molecules. Endothelial cells in vivo are continuously exposed to shear conditions, and their caveolae density and location may be different from that of static cultured cells. Here, we show that chronic shear exposure regulates formation and localization of caveolae and caveolin-1 in bovine aortic endothelial cells (BAEC). Chronic exposure (1 or 3 days) of BAEC to laminar shear increased the total number of caveolae by 45-48% above static control. This increase was due to a rise in the luminal caveolae density without changing abluminal caveolae numbers or increasing caveolin-1 mRNA and protein levels. Whereas some caveolin-1 was found in the plasma membrane in static-cultured cells, it was predominantly localized in the Golgi. In contrast, chronic shear-exposed cells showed intense caveolin-1 staining in the luminal plasma membrane with minimum Golgi association. The preferential luminal localization of caveolae may play an important role in endothelial mechanosensing. Indeed, we found that chronic shear exposure (preconditioning) altered activation patterns of two well-known shear-sensitive signaling molecules (ERK and Akt) in response to a step increase in shear stress. ERK activation was blunted in shear preconditioned cells, whereas the Akt response was accelerated. These results suggest that chronic shear stimulates caveolae formation by translocating caveolin-1 from the Golgi to the luminal plasma membrane and alters cell signaling responses.

  5. Haemodynamic responses to exercise, ATP infusion and thigh compression in humans: insight into the role of muscle mechanisms on cardiovascular function

    PubMed Central

    González-Alonso, José; Mortensen, Stefan P; Jeppesen, Tina D; Ali, Leena; Barker, Horace; Damsgaard, Rasmus; Secher, Niels H; Dawson, Ellen A; Dufour, Stéphane P

    2008-01-01

    The muscle pump and muscle vasodilatory mechanims are thought to play important roles in increasing and maintaining muscle perfusion and cardiac output during exercise, but their actual contributions remain uncertain. To evaluate the role of the skeletal muscle pump and vasodilatation on cardiovascular function during exercise, we determined leg and systemic haemodynamic responses in healthy men during (1) incremental one-legged knee-extensor exercise, (2) step-wise femoral artery ATP infusion at rest, (3) passive exercise (n = 10), (4) femoral vein or artery ATP infusion (n = 6), and (5) cyclic thigh compressions at rest and during passive and voluntary exercise (n = 7). Incremental exercise resulted in progressive increases in leg blood flow (ΔLBF 7.4 ± 0.7 l min−1), cardiac output ( 8.7 ± 0.7 l min−1), mean arterial pressure (ΔMAP 51 ± 5 mmHg), and leg and systemic oxygen delivery and . Arterial ATP infusion resulted in similar increases in , LBF, and systemic and leg oxygen delivery, but central venous pressure and muscle metabolism remained unchanged and MAP was reduced. In contrast, femoral vein ATP infusion did not alter LBF, or MAP. Passive exercise also increased blood flow (ΔLBF 0.7 ± 0.1 l min−1), yet the increase in muscle and systemic perfusion, unrelated to elevations in aerobic metabolism, accounted only for ∼5% of peak exercise hyperaemia. Likewise, thigh compressions alone or in combination with passive exercise increased blood flow (ΔLBF 0.5–0.7 l min−1) without altering , MAP or . These findings suggest that the skeletal muscle pump is not obligatory for sustaining venous return, central venous pressure, stroke volume and or maintaining muscle blood flow during one-legged exercise in humans. Further, its contribution to muscle and systemic peak exercise hyperaemia appears to be minimal in comparison to the effects of muscle vasodilatation. PMID:18339690

  6. Overlapping Yet Response-Specific Transcriptome Alterations Characterize the Nature of Tobacco–Pseudomonas syringae Interactions

    PubMed Central

    Bozsó, Zoltán; Ott, Péter G.; Kámán-Tóth, Evelin; Bognár, Gábor F.; Pogány, Miklós; Szatmári, Ágnes

    2016-01-01

    In this study transcriptomic alterations of bacterially induced pattern triggered immunity (PTI) were compared with other types of tobacco–Pseudomonas interactions. In addition, using pharmacological agents we blocked some signal transduction pathways (Ca2+ influx, kinases, phospholipases, proteasomic protein degradation) to find out how they contribute to gene expression during PTI. PTI is the first defense response of plant cells to microbes, elicited by their widely conserved molecular patterns. Tobacco is an important model of Solanaceae to study resistance responses, including defense mechanisms against bacteria. In spite of these facts the transcription regulation of tobacco genes during different types of plant bacterial interactions is not well-described. In this paper we compared the tobacco transcriptomic alterations in microarray experiments induced by (i) PTI inducer Pseudomonas syringae pv. syringae type III secretion mutant (hrcC) at earlier (6 h post inoculation) and later (48 hpi) stages of defense, (ii) wild type P. syringae (6 hpi) that causes effector triggered immunity (ETI) and cell death (HR), and (iii) disease-causing P. syringae pv. tabaci (6 hpi). Among the different treatments the highest overlap was between the PTI and ETI at 6 hpi, however, there were groups of genes with specifically altered activity for either type of defenses. Instead of quantitative effects of the virulent P. tabaci on PTI-related genes it influenced transcription qualitatively and blocked the expression changes of a special set of genes including ones involved in signal transduction and transcription regulation. P. tabaci specifically activated or repressed other groups of genes seemingly not related to either PTI or ETI. Kinase and phospholipase A inhibitors had highest impacts on the PTI response and effects of these signal inhibitors on transcription greatly overlapped. Remarkable interactions of phospholipase C-related pathways with the proteasomal system were

  7. Involvement of three mechanisms in the alteration of cytokine responses by sodium methyldithiocarbamate

    SciTech Connect

    Pruett, Stephen B. . E-mail: spruet@LSUHSC.edu; Fan, Ruping; Zheng, Qiang

    2006-06-01

    Sodium methyldithiocarbamate (SMD) is the third most abundantly used conventional pesticide in the U.S. We recently reported that it alters the induction of cytokine production mediated though Toll-like receptor (TLR) 4 at relevant dosages in mice. Its chemical properties and evidence from the literature suggest thee potential mechanisms of action for this compound. It could either act as a free radical scavenger (by means of its free S{sup -}group) or promote oxidation by breaking down to form methylisothiocyanate, which can deplete glutathione. It is a potent copper chelator and may affect the availability of copper to a number of copper-dependent enzymes (including some signaling molecules). SMD induces a classical neuroendocrine stress response characterized by elevated serum corticosterone concentrations, which could affect cytokine production. Although each of these mechanisms could potentially contribute to altered cytokine responses, direct evidence is lacking. The present study was conducted to obtain such evidence. The role of redox balance was investigated by pretreating mice with N-acetyl cysteine (NAC), which increases cellular glutathione concentrations, before administration of SMD. NAC exacerbated the SMD-induced suppression of IL-12 and the SMD-induced enhancement of IL-10 in the serum. The role of copper chelation was investigated by comparing the effects of SMD with an equimolar dose to SMD that was administered in the form of a copper chelation complex. Addition of copper significantly decreased the action of SMD on IL-12 production but not on IL-10 production. The role of the stress response was investigated by pretreating mice with antagonists of corticosterone and catecholamines. This treatment partially prevented the action of SMD on IL-10 and IL-12 in the peritoneal fluid. The results suggest that all of the proposed mechanisms have some role in the alteration of cytokine production by SMD.

  8. Chronic intermittent toluene inhalation in adolescent rats alters behavioural responses to amphetamine and MK801.

    PubMed

    Duncan, Jhodie Rubina; Gibbs, Sarah Jane; Lawrence, Andrew John

    2014-03-01

    Abuse of toluene-containing inhalants is common during adolescence, with ongoing chronic misuse associated with adverse outcomes and increased risk for addictive behaviours in adulthood. However, the mechanisms mediating the adaptive processes related to these outcomes are not well defined. To model human abuse patterns we exposed male adolescent Wistar rats (postnatal day 27) to chronic intermittent inhaled toluene (CIT, 10,000 ppm) or air (control) for 1h/day, three times/week for 3 weeks. The effects of CIT on behaviour and recovery were monitored. Locomotor activity was recorded following two consecutive injections of amphetamine (1mg/kg, i.p.) 72 and 96 h after the last exposure. This was followed with injection of the NMDA receptor antagonist MK801 (0.5mg/kg, i.p.) 20 days after the last exposure. CIT resulted in a significant and persistent retardation in weight gain during the exposure period and abstinence (p<0.05). Repeated exposure resulted in tolerance to the onset of toluene-induced behaviours and recovery latency. There was a reduction in the acute stimulant effects of amphetamine in CIT-exposed animals and an increase in the magnitude of locomotor activity (p<0.0125) following a subsequent exposure when compared to the responses observed in controls; this was associated with altered locomotor responses to MK801. Repeated exposure to CIT during adolescence alters parameters of growth, as measured by body weight, and leads to tolerance, indicating that increasing concentrations of the compound may be needed to reach the same behavioural state. Toluene during this period also alters responses to a psychostimulant which may be related to long-term glutamatergic dysfunction.

  9. Overlapping Yet Response-Specific Transcriptome Alterations Characterize the Nature of Tobacco-Pseudomonas syringae Interactions.

    PubMed

    Bozsó, Zoltán; Ott, Péter G; Kámán-Tóth, Evelin; Bognár, Gábor F; Pogány, Miklós; Szatmári, Ágnes

    2016-01-01

    In this study transcriptomic alterations of bacterially induced pattern triggered immunity (PTI) were compared with other types of tobacco-Pseudomonas interactions. In addition, using pharmacological agents we blocked some signal transduction pathways (Ca(2+) influx, kinases, phospholipases, proteasomic protein degradation) to find out how they contribute to gene expression during PTI. PTI is the first defense response of plant cells to microbes, elicited by their widely conserved molecular patterns. Tobacco is an important model of Solanaceae to study resistance responses, including defense mechanisms against bacteria. In spite of these facts the transcription regulation of tobacco genes during different types of plant bacterial interactions is not well-described. In this paper we compared the tobacco transcriptomic alterations in microarray experiments induced by (i) PTI inducer Pseudomonas syringae pv. syringae type III secretion mutant (hrcC) at earlier (6 h post inoculation) and later (48 hpi) stages of defense, (ii) wild type P. syringae (6 hpi) that causes effector triggered immunity (ETI) and cell death (HR), and (iii) disease-causing P. syringae pv. tabaci (6 hpi). Among the different treatments the highest overlap was between the PTI and ETI at 6 hpi, however, there were groups of genes with specifically altered activity for either type of defenses. Instead of quantitative effects of the virulent P. tabaci on PTI-related genes it influenced transcription qualitatively and blocked the expression changes of a special set of genes including ones involved in signal transduction and transcription regulation. P. tabaci specifically activated or repressed other groups of genes seemingly not related to either PTI or ETI. Kinase and phospholipase A inhibitors had highest impacts on the PTI response and effects of these signal inhibitors on transcription greatly overlapped. Remarkable interactions of phospholipase C-related pathways with the proteasomal system were

  10. Effect of antiarrhythmic therapy with intravenous loading dose of amiodarone: evidence for an altered response in diabetic patients.

    PubMed

    Iervasi, G; Clerico, A; Bonini, R; Nannipieri, M; Manfredi, C; Sabatino, L; Biagini, A; Donato, L

    1998-01-01

    Amiodarone, a potent class III antiarrhythmic agent with adrenergic antagonism properties, is administered increasingly to diabetic patients with cardiac arrhythmias refractory to all other available forms of therapy. Because a large percentage of diabetic patients show a perturbed autonomic regulation of the cardiovascular system, including a pertubed regulation of heart rate, we studied the antiarrhythmic response as well as the early effects (within 5 days) on heart rate of an intravenous amiodarone loading dose in diabetic patients. Seven type II (noninsulin-dependent) diabetic patients (age 64.7 +/- 9.7 years), affected by uncontrolled atrial fibrilation or atrial flutter, were enrolled for the study and a group of 12 well-matched (for age, sex and arrhythmia) nondiabetic patients served as a control group. It was found that before amiodarone administration, nondiabetic patients showed significantly wider variations in the circadian rhythm of heart rate values than diabetic patients (p = 0.0062, unpaired t-test). In all patients but one (who was nondiabetic), amiodarone treatment resulted in a cardioversion to sinus rhythm. After amiodarone administration, nondiabetic patients showed a significantly greater decrease (p = 0.0011) in heart rate values in comparison with the diabetic group (-35% vs. -20% on average, at the end of the study). Furthermore, in nondiabetic patients there was also an earlier significant fall (within the first 4 h after the start of treatment with amiodarone, p < 0.001) in the heart rate values in comparison with diabetic patients, in whom a significant decrease (p < 0.001) was found only at the 4th day. A significant (p = 0.0004), more rapid onset of the antiarrhythmic response to the drug was found in nondiabetic patients (6.8 +/- 6.0 h) in comparison with diabetic patients (98.0 +/- 14.8 h). Our findings suggest that the antiarrhythmic effects of amiodarone in diabetic patients with uncontrolled atrial fibrilation or atrial flutter

  11. Primary motor cortex of the parkinsonian monkey: altered neuronal responses to muscle stretch

    PubMed Central

    Pasquereau, Benjamin; Turner, Robert S.

    2013-01-01

    Exaggeration of the long-latency stretch reflex (LLSR) is a characteristic neurophysiologic feature of Parkinson's disease (PD) that contributes to parkinsonian rigidity. To explore one frequently-hypothesized mechanism, we studied the effects of fast muscle stretches on neuronal activity in the macaque primary motor cortex (M1) before and after the induction of parkinsonism by unilateral administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). We compared results from the general population of M1 neurons and two antidromically-identified subpopulations: distant-projecting pyramidal-tract type neurons (PTNs) and intra-telecenphalic-type corticostriatal neurons (CSNs). Rapid rotations of elbow or wrist joints evoked short-latency responses in 62% of arm-related M1 neurons. As in PD, the late electromyographic responses that constitute the LLSR were enhanced following MPTP. This was accompanied by a shortening of M1 neuronal response latencies and a degradation of directional selectivity, but surprisingly, no increase in single unit response magnitudes. The results suggest that parkinsonism alters the timing and specificity of M1 responses to muscle stretch. Observation of an exaggerated LLSR with no change in the magnitude of proprioceptive responses in M1 is consistent with the idea that the increase in LLSR gain that contributes to parkinsonian rigidity is localized to the spinal cord. PMID:24324412

  12. Community-responsive interventions to reduce cardiovascular risk in American Indians.

    PubMed

    Jobe, Jared B; Adams, Alexandra K; Henderson, Jeffrey A; Karanja, Njeri; Lee, Elisa T; Walters, Karina L

    2012-08-01

    American Indian and Alaska Native (AI/AN) populations bear a heavy burden of cardiovascular disease (CVD), and they have the highest rates of risk factors for CVD, such as cigarette smoking, obesity, and diabetes, of any U.S. population group. Yet, few randomized controlled trials have been launched to test potential preventive interventions in Indian Country. Five randomized controlled trials were initiated recently in AI/AN communities to test the effectiveness of interventions targeting adults and/or children to promote healthy behaviors that are known to impact biological CVD risk factors. This article provides a context for and an overview of these five trials. The high burden of CVD among AI/AN populations will worsen unless behaviors and lifestyles affecting CVD risk can be modified. These five trials, if successful, represent a starting point in addressing these significant health disparities. PMID:22983753

  13. Testosterone differentially alters cocaine-induced ambulatory and rearing behavioral responses in adult and adolescent rats

    PubMed Central

    Minerly, AnaChristina E.; Wu, Hui Bing K.; Weierstall, Karen M.; Niyomchai, Tipyamol; Kemen, Lynne; Jenab, Shirzad; Quinones-Jenab, Vanya

    2016-01-01

    Little is known about the physiological and behavioral effects of testosterone when co-administered with cocaine during adolescence. The present study aimed to determine whether exogenous testosterone administration differentially alters psychomotor responses to cocaine in adolescent and adult male rats. To this end, intact adolescent (30-days-old) and adult (60-day-old) male Fisher rats were pretreated with vehicle (sesame oil) or testosterone (5 or 10 mg/kg) 45 minutes prior to saline or cocaine (20 mg/kg) administration. Behavioral responses were monitored 1 hour after drug treatment, and serum testosterone levels were determined. Serum testosterone levels were affected by age: saline- and cocaine-treated adults in the vehicle groups had higher serum testosterone levels than adolescents rats, but after co-administration of testosterone the adolescent rats had higher serum testosterone levels than the adults. Pretreatment with testosterone affected baseline activity in adolescent rats: 5 mg/kg of testosterone increased both rearing and ambulatory behaviors in saline-treated adolescent rats. After normalizing data to % saline, an interaction between hormone administration and cocaine-induced behavioral responses was observed; 5 mg/kg of testosterone decreased both ambulatory and rearing behaviors among adolescents whereas 10 mg/kg of testosterone decreased only rearing behaviors. Testosterone pretreatment did not alter cocaine-induced behavioral responses in adult rats. These findings suggest that adolescents are more sensitive than adults to an interaction between testosterone and cocaine, and, indirectly, suggest that androgen abuse may lessen cocaine-induced behavioral responses in younger cocaine users. PMID:19822170

  14. Computational Analysis of Single Nucleotide Polymorphisms Associated with Altered Drug Responsiveness in Type 2 Diabetes

    PubMed Central

    Costa, Valerio; Federico, Antonio; Pollastro, Carla; Ziviello, Carmela; Cataldi, Simona; Formisano, Pietro; Ciccodicola, Alfredo

    2016-01-01

    Type 2 diabetes (T2D) is one of the most frequent mortality causes in western countries, with rapidly increasing prevalence. Anti-diabetic drugs are the first therapeutic approach, although many patients develop drug resistance. Most drug responsiveness variability can be explained by genetic causes. Inter-individual variability is principally due to single nucleotide polymorphisms, and differential drug responsiveness has been correlated to alteration in genes involved in drug metabolism (CYP2C9) or insulin signaling (IRS1, ABCC8, KCNJ11 and PPARG). However, most genome-wide association studies did not provide clues about the contribution of DNA variations to impaired drug responsiveness. Thus, characterizing T2D drug responsiveness variants is needed to guide clinicians toward tailored therapeutic approaches. Here, we extensively investigated polymorphisms associated with altered drug response in T2D, predicting their effects in silico. Combining different computational approaches, we focused on the expression pattern of genes correlated to drug resistance and inferred evolutionary conservation of polymorphic residues, computationally predicting the biochemical properties of polymorphic proteins. Using RNA-Sequencing followed by targeted validation, we identified and experimentally confirmed that two nucleotide variations in the CAPN10 gene—currently annotated as intronic—fall within two new transcripts in this locus. Additionally, we found that a Single Nucleotide Polymorphism (SNP), currently reported as intergenic, maps to the intron of a new transcript, harboring CAPN10 and GPR35 genes, which undergoes non-sense mediated decay. Finally, we analyzed variants that fall into non-coding regulatory regions of yet underestimated functional significance, predicting that some of them can potentially affect gene expression and/or post-transcriptional regulation of mRNAs affecting the splicing. PMID:27347941

  15. Computational Analysis of Single Nucleotide Polymorphisms Associated with Altered Drug Responsiveness in Type 2 Diabetes.

    PubMed

    Costa, Valerio; Federico, Antonio; Pollastro, Carla; Ziviello, Carmela; Cataldi, Simona; Formisano, Pietro; Ciccodicola, Alfredo

    2016-01-01

    Type 2 diabetes (T2D) is one of the most frequent mortality causes in western countries, with rapidly increasing prevalence. Anti-diabetic drugs are the first therapeutic approach, although many patients develop drug resistance. Most drug responsiveness variability can be explained by genetic causes. Inter-individual variability is principally due to single nucleotide polymorphisms, and differential drug responsiveness has been correlated to alteration in genes involved in drug metabolism (CYP2C9) or insulin signaling (IRS1, ABCC8, KCNJ11 and PPARG). However, most genome-wide association studies did not provide clues about the contribution of DNA variations to impaired drug responsiveness. Thus, characterizing T2D drug responsiveness variants is needed to guide clinicians toward tailored therapeutic approaches. Here, we extensively investigated polymorphisms associated with altered drug response in T2D, predicting their effects in silico. Combining different computational approaches, we focused on the expression pattern of genes correlated to drug resistance and inferred evolutionary conservation of polymorphic residues, computationally predicting the biochemical properties of polymorphic proteins. Using RNA-Sequencing followed by targeted validation, we identified and experimentally confirmed that two nucleotide variations in the CAPN10 gene-currently annotated as intronic-fall within two new transcripts in this locus. Additionally, we found that a Single Nucleotide Polymorphism (SNP), currently reported as intergenic, maps to the intron of a new transcript, harboring CAPN10 and GPR35 genes, which undergoes non-sense mediated decay. Finally, we analyzed variants that fall into non-coding regulatory regions of yet underestimated functional significance, predicting that some of them can potentially affect gene expression and/or post-transcriptional regulation of mRNAs affecting the splicing. PMID:27347941

  16. Treatment with nebivolol combined with physical training promotes improvements in the cardiovascular responses of hypertensive rats.

    PubMed

    Goessler, Karla Fabiana; Martins-Pinge, Marli; Veronez da Cunha, Natalia; Karlen-Amarante, Marlusa; de Andrade, Fábio Goulart; Brum, Patricia Chakur; Polito, Marcos Doederlein

    2014-03-01

    The aim of this study was to determine whether exercise training combined with beta-blocker treatment promotes additional cardiovascular benefits compared with either intervention on its own. For this we used 76 Wistar rats distributed among different groups: normotensive sedentary (NS), normotensive trained (NT), normotensive sedentary treated with beta-blocker (NS_BB), normotensive trained treated with beta-blocker (NT_BB), hypertensive sedentary (HS), hypertensive trained (HT), hypertensive sedentary treated with a beta-blocker (HS_BB), and hypertensive trained rats treated with beta-blocker (HT_BB). Exercise training consisted of 4 weeks of swimming for 60 min a day, 5 days a week. Hypertension was induced with l-NAME (4 weeks), whereas the control rats received saline, and both the control and test rats received nebivolol. The animals underwent surgery to directly record their blood pressure. The HS group showed higher mean arterial pressure (MAP) (P = 0.000), systolic arterial pressure (P = 0.000), and diastolic arterial pressure (P = 0.000) compared with NS. MAP was higher in the HS compared with the HT (P = 0.002), HS_BB (P = 0.018), and HT_BB (P = 0.015) groups. Hearts from the HS group had a higher percentage of collagen compared with the NS and HS_BB groups. The HT_BB and HT groups only had a higher percentage of cardiac collagen by comparison with the HS_BB group. The HT_BB group showed higher levels of macrophages and neutrophils by comparison with the HT and HS_BB groups. Thus, treatment with a beta-blocker combined with physical training was associated with increased cardiovascular benefits over either intervention alone. PMID:24593788

  17. Tobacco Smoke Exposure and Altered Nasal Responses to Live Attenuated Influenza Virus

    PubMed Central

    Noah, Terry L.; Zhou, Haibo; Monaco, Jane; Horvath, Katie; Herbst, Margaret; Jaspers, Ilona

    2011-01-01

    Background Epidemiologic evidence links tobacco smoke and increased risk for influenza in humans, but the specific host defense pathways involved are unclear. Objective We developed a model to examine influenza-induced innate immune responses in humans and test the hypothesis that exposure to cigarette smoke alters nasal inflammatory and antiviral responses to live attenuated influenza virus (LAIV). Methods This was an observational cohort study comparing nasal mucosal responses to LAIV among young adult active smokers (n = 17), nonsmokers exposed to secondhand smoke (SHS; n = 20), and unexposed controls (n = 23). Virus RNA and inflammatory factors were measured in nasal lavage fluids (NLF) serially after LAIV inoculation. For key end points, peak and total (area under curve) responses were compared among groups. Results Compared with controls, NLF interleukin-6 (IL-6) responses to LAIV (peak and total) were suppressed in smokers. Virus RNA in NLF cells was significantly increased in smokers, as were interferon-inducible protein 10:virus ratios. Responses in SHS-exposed subjects were generally intermediate between controls and smokers. We observed significant associations between urine cotinine and NLF IL-6 responses (negative correlation) or virus RNA in NLF cells (positive correlation) for all subjects combined. Conclusions Nasal inoculation with LAIV results in measurable inflammatory and antiviral responses in human volunteers, thus providing a model for investigating environmental effects on influenza infections in humans. Exposure to cigarette smoke was associated with suppression of specific nasal inflammatory and antiviral responses, as well as increased virus quantity, after nasal inoculation with LAIV. These data suggest mechanisms for increased susceptibility to influenza infection among persons exposed to tobacco smoke. PMID:20920950

  18. Physiological response of cardiac tissue to bisphenol a: alterations in ventricular pressure and contractility

    PubMed Central

    Brooks, Daina; Chandra, Akhil; Jaimes, Rafael; Sarvazyan, Narine; Kay, Matthew

    2015-01-01

    Biomonitoring studies have indicated that humans are routinely exposed to bisphenol A (BPA), a chemical that is commonly used in the production of polycarbonate plastics and epoxy resins. Epidemiological studies have shown that BPA exposure in humans is associated with cardiovascular disease; however, the direct effects of BPA on cardiac physiology are largely unknown. Previously, we have shown that BPA exposure slows atrioventricular electrical conduction, decreases epicardial conduction velocity, and prolongs action potential duration in excised rat hearts. In the present study, we tested if BPA exposure also adversely affects cardiac contractile performance. We examined the impact of BPA exposure level, sex, and pacing rate on cardiac contractile function in excised rat hearts. Hearts were retrogradely perfused at constant pressure and exposed to 10−9-10−4 M BPA. Left ventricular developed pressure and contractility were measured during sinus rhythm and during pacing (5, 6.5, and 9 Hz). Ca2+ transients were imaged from whole hearts and from neonatal rat cardiomyocyte layers. During sinus rhythm in female hearts, BPA exposure decreased left ventricular developed pressure and inotropy in a dose-dependent manner. The reduced contractile performance was exacerbated at higher pacing rates. BPA-induced effects on contractile performance were also observed in male hearts, albeit to a lesser extent. Exposure to BPA altered Ca2+ handling within whole hearts (reduced diastolic and systolic Ca2+ transient potentiation) and neonatal cardiomyocytes (reduced Ca2+ transient amplitude and prolonged Ca2+ transient release time). In conclusion, BPA exposure significantly impaired cardiac performance in a dose-dependent manner, having a major negative impact upon electrical conduction, intracellular Ca2+ handing, and ventricular contractility. PMID:25980024

  19. Grapevine Plasticity in Response to an Altered Microclimate: Sauvignon Blanc Modulates Specific Metabolites in Response to Increased Berry Exposure.

    PubMed

    Young, Philip R; Eyeghe-Bickong, Hans A; du Plessis, Kari; Alexandersson, Erik; Jacobson, Dan A; Coetzee, Zelmari; Deloire, Alain; Vivier, Melané A

    2016-03-01

    In this study, the metabolic and physiological impacts of an altered microclimate on quality-associated primary and secondary metabolites in grape (Vitis vinifera) 'Sauvignon Blanc' berries was determined in a high-altitude vineyard. The leaf and lateral shoot removal in the bunch zones altered the microclimate by increasing the exposure of the berries. The physical parameters (berry diameter and weight), primary metabolites (sugars and organic acids), as well as bunch temperature and leaf water potential were predominantly not affected by the treatment. The increased exposure led to higher levels of specific carotenoids and volatile terpenoids in the exposed berries, with earlier berry stages reacting distinctly from the later developmental stages. Plastic/nonplastic metabolite responses could be further classified to identify metabolites that were developmentally controlled and/or responded to the treatment in a predictable fashion (assessed over two consecutive vintages). The study demonstrates that grapevine berries exhibit a degree of plasticity within their secondary metabolites and respond physiologically to the increased exposure by increasing metabolites with potential antioxidant activity. Taken together, the data provide evidence that the underlying physiological responses relate to the maintenance of stress pathways by modulating antioxidant molecules in the berries. PMID:26628747

  20. Parasite-induced alteration of odour responses in an amphipod-acanthocephalan system.

    PubMed

    Stone, Charles F; Moore, Janice

    2014-11-01

    Odour-related behaviours in aquatic invertebrates are important and effective anti-predator behaviours. Parasites often alter invertebrate host behaviours to increase transmission to hosts. This study investigated the responses of the amphipod Hyalella azteca when presented with two predator chemical cues: (i) alarm pheromones produced by conspecifics and (ii) kairomones produced by a predatory Green Sunfish (Lepomis cyanellus). We compared the responses of amphipods uninfected and infected with the acanthocepalan parasite Leptorhynchiodes thecatus. Uninfected amphipods reduced activity and increased refuge use after detecting both the alarm pheromones and predator kairomones. Infected amphipods spent significantly more time being active and less time on the refuge than uninfected amphipods, and behaved as if they had not detected the chemical stimulus. Therefore, L. thecatus infections disrupt the amphipods' anti-predator behaviours and likely make their hosts more susceptible to predation. PMID:25200352

  1. Toll mediated infection response is altered by gravity and spaceflight in Drosophila.

    PubMed

    Taylor, Katherine; Kleinhesselink, Kurt; George, Michael D; Morgan, Rachel; Smallwood, Tangi; Hammonds, Ann S; Fuller, Patrick M; Saelao, Perot; Alley, Jeff; Gibbs, Allen G; Hoshizaki, Deborah K; von Kalm, Laurence; Fuller, Charles A; Beckingham, Kathleen M; Kimbrell, Deborah A

    2014-01-01

    Space travel presents unlimited opportunities for exploration and discovery, but requires better understanding of the biological consequences of long-term exposure to spaceflight. Immune function in particular is relevant for space travel. Human immune responses are weakened in space, with increased vulnerability to opportunistic infections and immune-related conditions. In addition, microorganisms can become more virulent in space, causing further challenges to health. To understand these issues better and to contribute to design of effective countermeasures, we used the Drosophila model of innate immunity to study immune responses in both hypergravity and spaceflight. Focusing on infections mediated through the conserved Toll and Imd signaling pathways, we found that hypergravity improves resistance to Toll-mediated fungal infections except in a known gravitaxis mutant of the yuri gagarin gene. These results led to the first spaceflight project on Drosophila immunity, in which flies that developed to adulthood in microgravity were assessed for immune responses by transcription profiling on return to Earth. Spaceflight alone altered transcription, producing activation of the heat shock stress system. Space flies subsequently infected by fungus failed to activate the Toll pathway. In contrast, bacterial infection produced normal activation of the Imd pathway. We speculate on possible linkage between functional Toll signaling and the heat shock chaperone system. Our major findings are that hypergravity and spaceflight have opposing effects, and that spaceflight produces stress-related transcriptional responses and results in a specific inability to mount a Toll-mediated infection response. PMID:24475130

  2. Toll Mediated Infection Response Is Altered by Gravity and Spaceflight in Drosophila

    PubMed Central

    Taylor, Katherine; Kleinhesselink, Kurt; George, Michael D.; Morgan, Rachel; Smallwood, Tangi; Hammonds, Ann S.; Fuller, Patrick M.; Saelao, Perot; Alley, Jeff; Gibbs, Allen G.; Hoshizaki, Deborah K.; von Kalm, Laurence; Fuller, Charles A.; Beckingham, Kathleen M.; Kimbrell, Deborah A.

    2014-01-01

    Space travel presents unlimited opportunities for exploration and discovery, but requires better understanding of the biological consequences of long-term exposure to spaceflight. Immune function in particular is relevant for space travel. Human immune responses are weakened in space, with increased vulnerability to opportunistic infections and immune-related conditions. In addition, microorganisms can become more virulent in space, causing further challenges to health. To understand these issues better and to contribute to design of effective countermeasures, we used the Drosophila model of innate immunity to study immune responses in both hypergravity and spaceflight. Focusing on infections mediated through the conserved Toll and Imd signaling pathways, we found that hypergravity improves resistance to Toll-mediated fungal infections except in a known gravitaxis mutant of the yuri gagarin gene. These results led to the first spaceflight project on Drosophila immunity, in which flies that developed to adulthood in microgravity were assessed for immune responses by transcription profiling on return to Earth. Spaceflight alone altered transcription, producing activation of the heat shock stress system. Space flies subsequently infected by fungus failed to activate the Toll pathway. In contrast, bacterial infection produced normal activation of the Imd pathway. We speculate on possible linkage between functional Toll signaling and the heat shock chaperone system. Our major findings are that hypergravity and spaceflight have opposing effects, and that spaceflight produces stress-related transcriptional responses and results in a specific inability to mount a Toll-mediated infection response. PMID:24475130

  3. Toll mediated infection response is altered by gravity and spaceflight in Drosophila.

    PubMed

    Taylor, Katherine; Kleinhesselink, Kurt; George, Michael D; Morgan, Rachel; Smallwood, Tangi; Hammonds, Ann S; Fuller, Patrick M; Saelao, Perot; Alley, Jeff; Gibbs, Allen G; Hoshizaki, Deborah K; von Kalm, Laurence; Fuller, Charles A; Beckingham, Kathleen M; Kimbrell, Deborah A

    2014-01-01

    Space travel presents unlimited opportunities for exploration and discovery, but requires better understanding of the biological consequences of long-term exposure to spaceflight. Immune function in particular is relevant for space travel. Human immune responses are weakened in space, with increased vulnerability to opportunistic infections and immune-related conditions. In addition, microorganisms can become more virulent in space, causing further challenges to health. To understand these issues better and to contribute to design of effective countermeasures, we used the Drosophila model of innate immunity to study immune responses in both hypergravity and spaceflight. Focusing on infections mediated through the conserved Toll and Imd signaling pathways, we found that hypergravity improves resistance to Toll-mediated fungal infections except in a known gravitaxis mutant of the yuri gagarin gene. These results led to the first spaceflight project on Drosophila immunity, in which flies that developed to adulthood in microgravity were assessed for immune responses by transcription profiling on return to Earth. Spaceflight alone altered transcription, producing activation of the heat shock stress system. Space flies subsequently infected by fungus failed to activate the Toll pathway. In contrast, bacterial infection produced normal activation of the Imd pathway. We speculate on possible linkage between functional Toll signaling and the heat shock chaperone system. Our major findings are that hypergravity and spaceflight have opposing effects, and that spaceflight produces stress-related transcriptional responses and results in a specific inability to mount a Toll-mediated infection response.

  4. Potential mechanisms responsible for chlorotriazine-induced alterations in catecholamines in pheochromocytoma (PC12) cells.

    PubMed

    Das, Parikshit C; McElroy, William K; Cooper, Ralph L

    2003-10-31

    Chlorotriazines interact with undifferentiated PC12 cells in vitro to modulate catecholamine synthesis and release, but the mechanism(s) responsible for this effect had not been determined. In this study we evaluated the effect of atrazine, simazine and cyanazine on the protein expression of the enzymes responsible for the synthesis of dopamine [tyrosine hydroxylase (TH)] and norepinephrine [dopamine-beta-hydroxylase (DbetaH)]. We also examined the possible intracellular pathway associated with chlorotriazine-induced changes in catecholamine synthesis and release. Incubating PC12 cells in the presence of 100 microM atrazine and simazine decreased intracellular dopamine (DA), norepinephrine (NE) concentration and NE release, and the protein expression of TH (approximately 20%) and DbetaH (approximately 50 and 25%, respectively) after 12-24 h exposure. In contrast, cyanazine (100 microM) stimulated intracellular and released NE concentration, and the protein expression of TH (approximately 20%) and DbetaH (approximately 225%) after 12-36 h exposure. Simultaneous exposure to the essential TH co-factors (iron and tetrahydrobiopterine) was ineffective in altering cellular DA. Agents known to enhance TH and DbetaH transcription, phosphorylation or activity (e.g., 8-bromo cAMP, forskolin or dexamethasone) reversed the inhibitory effects of atrazine and simazine on the NE. Again, in contrast to atrazine and simazine, cyanazine attenuated catecholamine-depleting effect of alpha-Methyl-p-tyrosine (alphaMpT) on NE. Both DA and NE synthesis can be altered by the chlorotriazines and suggest these occur via an alteration of the synthetic enzymes TH and DbetaH.

  5. Dim light at night interacts with intermittent hypoxia to alter cognitive and affective responses

    PubMed Central

    Weil, Zachary M.; Magalang, Ulysses J.; Nelson, Randy J.

    2013-01-01

    Obstructive sleep apnea (OSA) and dim light at night (dLAN) have both been independently associated with alterations in mood and cognition. We aimed to determine whether dLAN would interact with intermittent hypoxia (IH), a condition characteristic of OSA, to alter the behavioral, cognitive, and affective responses. Adult male mice were housed in either standard lighting conditions (14:10-h light-dark cycle; 150 lux:0 lux) or dLAN (150 lux:5 lux). Mice were then exposed to IH (15 cycles/h, 8 h/day, FiO2 nadir of 5%) for 3 wk, then tested in assays of affective and cognitive responses; brains were collected for dendritic morphology and PCR analysis. Exposure to dLAN and IH increased anxiety-like behaviors, as assessed in the open field, elevated plus maze, and the light/dark box. dLAN and IH increased depressive-like behaviors in the forced swim test. IH impaired learning and memory performance in the passive avoidance task; however, no differences were observed in spatial working memory, as assessed by y-maze or object recognition. IH combined with dLAN decreased cell body area in the CA1 and CA3 regions of the hippocampus. Overall, IH decreased apical spine density in the CA3, whereas dLAN decreased spine density in the CA1 of the hippocampus. TNF-α gene expression was not altered by IH or lighting condition, whereas VEGF expression was increased by dLAN. The combination of IH and dLAN provokes negative effects on hippocampal dendritic morphology, affect, and cognition, suggesting that limiting nighttime exposure to light in combination with other established treatments may be of benefit to patients with OSA. PMID:23657638

  6. Locomotor response to acute nicotine in adolescent mice is altered by maternal undernutrition during lactation.

    PubMed

    Dutra-Tavares, Ana C; Manhães, Alex C; Silva, Juliana O; Nunes-Freitas, André L; Conceição, Ellen P S; Moura, Egberto G; Lisboa, Patrícia C; Filgueiras, Cláudio C; Abreu-Villaça, Yael; Ribeiro-Carvalho, Anderson

    2015-12-01

    Undernutrition during brain development causes long lasting alterations in different neurotransmitter systems that may alter responses to psychoactive drugs. Despite the recognized effects of early undernutrition on the cholinergic system, no evidence that demonstrates the influence of this insult on nicotine susceptibility has been reported. We investigated the effects of protein/calorie restriction during lactation on the susceptibility to nicotine in adolescent mice. Dams were randomly assigned to one of the following groups: Control (C, 20 litters)--free access to standard laboratory diet (23% protein); Protein Restricted (PR, 12 litters)--free access to a isoenergetic, 8% protein diet; Calorie Restricted (CR, 12 litters)--access to standard laboratory diet in restricted quantities (mean ingestion of PR: pair-fed group). Undernutrition extended from postnatal day 2 (PN2) to weaning (PN21). At PN30, animals either received an i.p. injection of nicotine (0.5mg/Kg) or saline and were immediately placed in open field (OF). After the OF, adrenal glands and serum were collected for the analyses of stress-related endocrine parameters and leptin concentration. PR and CR offspring showed less body mass gain and visceral fat mass. PR offspring presented reduced serum leptin concentration. In the OF, nicotine increased locomotor activity of C and PR, but not of CR. CR and PR offspring showed decreased adrenal catecholamine content, which was not dependent on nicotine exposure. Our results indicate that early undernutrition interferes with nicotine-elicited locomotor effects in adolescent mice and suggest that endocrine parameters alterations in malnourished animals do not influence the behavioral response to nicotine.

  7. [Resting heart rate and cardiovascular disease].

    PubMed

    Brito Díaz, Buenaventura; Alemán Sánchez, José Juan; Cabrera de León, Antonio

    2014-07-01

    Heart rate reflects autonomic nervous system activity. Numerous studies have demonstrated that an increased heart rate at rest is associated with cardiovascular morbidity and mortality as an independent risk factor. It has been shown a link between cardiac autonomic balance and inflammation. Thus, an elevated heart rate produces a micro-inflammatory response and is involved in the pathogenesis of endothelial dysfunction. In turn, decrease in heart rate produces benefits in congestive heart failure, myocardial infarction, atrial fibrillation, obesity, hyperinsulinemia, insulin resistance, and atherosclerosis. Alteration of other heart rate-related parameters, such as their variability and recovery after exercise, is associated with risk of cardiovascular events. Drugs reducing the heart rate (beta-blockers, calcium antagonists and inhibitors of If channels) have the potential to reduce cardiovascular events. Although not recommended in healthy subjects, interventions for reducing heart rate constitute a reasonable therapeutic goal in certain pathologies.

  8. AI-2 biosynthesis module in a magnetic nanofactory alters bacterial response via localized synthesis and delivery.

    PubMed

    Fernandes, Rohan; Bentley, William E

    2009-02-01

    Nanofactories are nano-dimensioned and comprised of modules serving various functions that alter the response of targeted cells when deployed by locally synthesizing and delivering cargo to the surfaces of the targeted cells. In its basic form, a nanofactory consists of a minimum of two functional modules: a cell capture module and a synthesis module. In this work, magnetic nanofactories that alter the response of targeted bacteria by the localized synthesis and delivery of the "universal" bacterial quorum sensing signal molecule autoinducer AI-2 are demonstrated. The magnetic nanofactories consist of a cell capture module (chitosan-mag nanoparticles) and an AI-2 biosynthesis module that contains both AI-2 biosynthetic enzymes Pfs and LuxS on a fusion protein (His-LuxS-Pfs-Tyr, HLPT) assembled together. HLPT is hypothesized to be more efficient than its constituent enzymes (used separately) at conversion of the substrate SAH to product AI-2 on account of the proximity of the two enzymes within the fusion protein. HLPT is demonstrated to be more active than the constituent enzymes, Pfs and LuxS, over a wide range of experimental conditions. The magnetic nanofactories (containing bound HLPT) are also demonstrated to be more active than free, unbound HLPT. They are also shown to elicit an increased response in targeted Escherichia coli cells, due to the localized synthesis and delivery of AI-2, when compared to the response produced by the addition of AI-2 directly to the cells. Studies investigating the universality of AI-2 and unraveling AI-2 based quorum sensing in bacteria using magnetic nanofactories are envisioned. The prospects of using such multi-modular nanofactories in developing the next generation of antimicrobials based on intercepting and interrupting quorum sensing based signaling are discussed.

  9. Predicted responses of arctic and alpine ecosystems to altered seasonality under climate change.

    PubMed

    Ernakovich, Jessica G; Hopping, Kelly A; Berdanier, Aaron B; Simpson, Rodney T; Kachergis, Emily J; Steltzer, Heidi; Wallenstein, Matthew D

    2014-10-01

    Global climate change is already having significant impacts on arctic and alpine ecosystems, and ongoing increases in temperature and altered precipitation patterns will affect the strong seasonal patterns that characterize these temperature-limited systems. The length of the potential growing season in these tundra environments is increasing due to warmer temperatures and earlier spring snow melt. Here, we compare current and projected climate and ecological data from 20 Northern Hemisphere sites to identify how seasonal changes in the physical environment due to climate change will alter the seasonality of arctic and alpine ecosystems. We find that although arctic and alpine ecosystems appear similar under historical climate conditions, climate change will lead to divergent responses, particularly in the spring and fall shoulder seasons. As seasonality changes in the Arctic, plants will advance the timing of spring phenological events, which could increase plant nutrient uptake, production, and ecosystem carbon (C) gain. In alpine regions, photoperiod will constrain spring plant phenology, limiting the extent to which the growing season can lengthen, especially if decreased water availability from earlier snow melt and warmer summer temperatures lead to earlier senescence. The result could be a shorter growing season with decreased production and increased nutrient loss. These contrasting alpine and arctic ecosystem responses will have cascading effects on ecosystems, affecting community structure, biotic interactions, and biogeochemistry.

  10. Representational cortex in musicians. Plastic alterations in response to musical practice.

    PubMed

    Pantev, C; Engelien, A; Candia, V; Elbert, T

    2001-06-01

    The lifelong ability to adapt to environmental needs is based on the capacity of the central nervous system for plastic alterations. In a series of neurophysiological experiments, we studied the impact of music and musical training in musicians on the specific functional organization in auditory and somatosensory representational cortex. In one such study, subjects listened to music from which one specific spectral frequency was removed. This led to rapid and reversible adaptation of neuronal responses in auditory cortex. Further experimental evidence demonstrated that long years of practice and training by professional musicians to enable them to reach their capacity is associated with enlarged cortical representations in the somatosensory and auditory domains. This tuning of neuronal representations was specifically observed for musical tones and was absent when pure sinusoidal tones were used as stimuli. In the somatosensory cortex, plastic changes proved to be specific for the fingers frequently used and stimulated. These changes were not detected in the fingers of the hand that were not involved in playing the particular instrument. Neuroplastic alterations also may be driven into a domain where they may become maladaptive. The clinical syndrome of focal hand dystonia that may occur in musicians who engage in forceful practice may be one such consequence. We will discuss the possibilities of reversing maladaptive responses leading to the successful treatment of focal hand dystonia, which relies on basic research about cortical reorganization. This example elucidates how neuroscientific progress can guide the development of practice guidelines and therapeutic measures for the benefit of professional musicians.

  11. Iron Deficiency in Infancy Predicts Altered Serum Prolactin Response 10 Years Later

    PubMed Central

    FELT, BARBARA; JIMENEZ, ELIAS; SMITH, JULIA; CALATRONI, AGUSTIN; KACIROTI, NIKO; WHEATCROFT, GLORIA; LOZOFF, BETSY

    2007-01-01

    Serum prolactin may reflect CNS dopaminergic function. Because iron deficiency (ID) alters brain dopamine in rats, serum prolactin levels were previously investigated in infants with varied iron status. High serum prolactin levels correlated with behaviors typical of chronic ID. The objective of this study was to determine the effect of infant iron status on serum prolactin levels after a stressor in early adolescence. One hundred fifty-nine of 191 children enrolled in infancy (chronic ID, n = 46; good iron comparison group, n = 113) had serum prolactin measurements after catheter placement at 11–14 y of age. Serum prolactin levels were compared by sex, pubertal status and infant iron status and the pattern of change over time was compared by infant iron status controlling for pubertal stage and background factors. Males and less mature adolescents had lower serum prolactin concentrations than females and more mature adolescents. Controlling for these factors, the serum prolactin response pattern differed significantly by infant iron status. Serum prolactin declined earlier for the chronic ID group. In conclusion, an altered serum prolactin response pattern was observed 10 y after chronic ID in infanc