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Source: AJP: Heart and Circulatory Physiology
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Total 82 results found since Jan 2013.
A comparison of passive hindlimb cycling and active upper-limb exercise provides new insights into systolic dysfunction after spinal cord injury
In conclusion, PHLC improves flow-derived cardiac indexes, whereas SWIM training displayed no cardiobeneficial effect. Pressure-derived deficits were corrected only with dobutamine, suggesting that reduced β-adrenergic stimulation is principally responsible for the impaired cardiac contractile function after SCI.
NEW & NOTEWORTHY This is the first direct comparison between the cardiac changes elicited by active upper-limb or passive lower-limb exercise after spinal cord injury. Here, we demonstrate that lower-limb exercise positively influences flow-derived cardiac indexes, whereas upper-limb exercise does not. Fu...
Source: AJP: Heart and Circulatory Physiology - November 1, 2017 Category: Cardiology Authors: DeVeau, K. M., Harman, K. A., Squair, J. W., Krassioukov, A. V., Magnuson, D. S. K., West, C. R. Tags: RESEARCH ARTICLE Source Type: research
Sex differences in vascular physiology and pathophysiology: estrogen and androgen signaling in health and disease
Sex differences between women and men are often overlooked and underappreciated when studying the cardiovascular system. It has been long assumed that men and women are physiologically similar, and this notion has resulted in women being clinically evaluated and treated for cardiovascular pathophysiological complications as men. Currently, there is increased recognition of fundamental sex differences in cardiovascular function, anatomy, cell signaling, and pathophysiology. The National Institutes of Health have enacted guidelines expressly to gain knowledge about ways the sexes differ in both normal function and diseases a...
Source: AJP: Heart and Circulatory Physiology - September 5, 2017 Category: Cardiology Authors: Boese, A. C., Kim, S. C., Yin, K.-J., Lee, J.-P., Hamblin, M. H. Tags: REVIEW Source Type: research
Relative contributions from the ventricle and arterial tree to arterial pressure and its amplification: an experimental study
This study offers the first comprehensive investigation of contributors to hypertensive pressure and its propagation throughout the arterial tree. Importantly, ventricular inotropy plays a crucial role in the amplification of peripheral pressure wave, which offers opportunity for noninvasive assessment of ventricular health.
NEW & NOTEWORTHY The present study distinguishes contributions from cardiac and arterial parameters to elevated blood pressure and pressure amplification. Most importantly, it offers the first evidence that ventricular inotropy, an indicator of ventricular function, is an independent determinant of...
Source: AJP: Heart and Circulatory Physiology - September 5, 2017 Category: Cardiology Authors: Gaddum, N., Alastruey, J., Chowienczyk, P., Rutten, M. C. M., Segers, P., Schaeffter, T. Tags: RESEARCH ARTICLE Source Type: research
Experimental cardiac radiation exposure induces ventricular diastolic dysfunction with preserved ejection fraction
Breast cancer radiotherapy increases the risk of heart failure with preserved ejection fraction (HFpEF). Cardiomyocytes are highly radioresistant, but radiation specifically affects coronary microvascular endothelial cells, with subsequent microvascular inflammation and rarefaction. The effects of radiation on left ventricular (LV) diastolic function are poorly characterized. We hypothesized that cardiac radiation exposure may result in diastolic dysfunction without reduced EF. Global cardiac expression of the sodium-iodide symporter (NIS) was induced by cardiotropic gene (adeno-associated virus serotype 9) delivery to 5-w...
Source: AJP: Heart and Circulatory Physiology - August 11, 2017 Category: Cardiology Authors: Saiki, H., Moulay, G., Guenzel, A. J., Liu, W., Decklever, T. D., Classic, K. L., Pham, L., Chen, H. H., Burnett, J. C., Russell, S. J., Redfield, M. M. Tags: RESEARCH ARTICLE Source Type: research
Smooth muscle cell-specific deletion of Col15a1 unexpectedly leads to impaired development of advanced atherosclerotic lesions
We report the first direct in vivo evidence that a smooth muscle cell (SMC)-produced collagen, collagen type XV (COL15A1), is critical for atherosclerotic lesion development. SMC Col15a1 knockout markedly attenuated advanced lesion formation, likely through reducing SMC proliferation and impairing multiple proatherogenic inflammatory processes.
Source: AJP: Heart and Circulatory Physiology - May 1, 2017 Category: Cardiology Authors: Durgin, B. G., Cherepanova, O. A., Gomez, D., Karaoli, T., Alencar, G. F., Butcher, J. T., Zhou, Y.-Q., Bendeck, M. P., Isakson, B. E., Owens, G. K., Connelly, J. J. Tags: RESEARCH ARTICLE Source Type: research
Dendritic cells and isolevuglandins in immunity, inflammation, and hypertension
Hypertension is the major risk factor for morbidity and mortality from myocardial infarction, stroke, heart failure, and chronic kidney disease. Despite its importance, the pathogenesis of essential hypertension is poorly understood. During the past several years, it has become evident that T cells contribute to hypertension. Activated T cells accumulate in the perivascular space and the kidney and release cytokines that promote vascular dysfunction and end-organ damage. Although dendritic cells play a pivotal role in initiating adaptive immune responses, T cells have taken center stage in studies implicating the immune sy...
Source: AJP: Heart and Circulatory Physiology - February 28, 2017 Category: Cardiology Authors: Dixon, K. B., Davies, S. S., Kirabo, A. Tags: REVIEW Source Type: research
Heart-lung interaction in a model of COPD: importance of lung volume and direct ventricular interaction
Chronic obstructive pulmonary disease (COPD) is associated with dynamic lung hyperinflation (DH), increased pulmonary vascular resistance (PVR), and large increases in negative intrathoracic pressure (nITP). The individual and interactive effect of these stressors on left ventricular (LV) filling, emptying, and geometry and the role of direct ventricular interaction (DVI) in mediating these interactions have not been fully elucidated. Twenty healthy subjects were exposed to the following stressors alone and in combination: 1) inspiratory resistive loading of –20 cmH2O (nITP), 2) expiratory resistive loading to cause ...
Source: AJP: Heart and Circulatory Physiology - November 30, 2016 Category: Cardiology Authors: Cheyne, W. S., Williams, A. M., Harper, M. I., Eves, N. D. Tags: INTEGRATIVE CARDIOVASCULAR PHYSIOLOGY AND PATHOPHYSIOLOGY Source Type: research
Ivabradine and metoprolol differentially affect cardiac glucose metabolism despite similar heart rate reduction in a mouse model of dyslipidemia
This study aimed at testing whether similar HRR with ivabradine vs. metoprolol differentially modulates cardiac energy substrate metabolism, a factor determinant for cardiac function, in a mouse model of dyslipidemia (hApoB+/+;LDLR–/–). Following a longitudinal study design, we used 3- and 6-mo-old mice, untreated or treated for 3 mo with ivabradine or metoprolol. Cardiac function was evaluated in vivo and ex vivo in working hearts perfused with 13C-labeled substrates to assess substrate fluxes through energy metabolic pathways. Compared with 3-mo-old, 6-mo-old dyslipidemic mice had similar cardiac hemodynamics...
Source: AJP: Heart and Circulatory Physiology - September 30, 2016 Category: Cardiology Authors: Vaillant, F., Lauzier, B., Ruiz, M., Shi, Y., Lachance, D., Rivard, M.-E., Bolduc, V., Thorin, E., Tardif, J.-C., Des Rosiers, C. Tags: Energetics and Metabolism Source Type: research
Right ventricular end-diastolic stiffness heralds right ventricular failure in monocrotaline-induced pulmonary hypertension
Recent studies suggest right ventricular (RV) stiffness is important in pulmonary hypertension (PH) prognosis. Smaller stroke volume (SV) variation after a certain RV end-diastolic pressure (EDP) respiratory variation as assessed by spectral transfer function (STF) may identify RV stiffness. Our aim was to evaluate RV stiffness in monocrotaline (MCT)-induced PH progression and to validate STF gain between EDP and SV as marker of stiffness. Seven-week-old male Wistar rats randomly injected with 60 mg/kg MCT or vehicle were divided into three groups (n = 12 each) according to cardiac index (CI): controls (Ctrl), preserved CI...
Source: AJP: Heart and Circulatory Physiology - September 30, 2016 Category: Cardiology Authors: Alaa, M., Abdellatif, M., Tavares-Silva, M., Oliveira-Pinto, J., Lopes, L., Leite, S., Leite-Moreira, A. F., Lourenco, A. P. Tags: Integrative Cardiovascular Physiology and Pathophysiology Source Type: research
Hyperaldosteronism induces left atrial systolic and diastolic dysfunction
Patients with hypertension and hyperaldosteronism show an increased risk of stroke compared with patients with essential hypertension. Aim of the study was to assess the effects of aldosterone on left atrial function in rats as a potential contributor to thromboembolism. Osmotic mini-pumps delivering 1.5 μg aldosterone/h were implanted in rats subcutaneously (Aldo, n = 39; controls, n = 38). After 8 wk, left ventricular pressure-volume analysis of isolated working hearts was performed, and left atrial systolic and diastolic function was also assessed by atrial pressure-diameter loops. Moreover, left atrial myocytes were...
Source: AJP: Heart and Circulatory Physiology - September 30, 2016 Category: Cardiology Authors: Reil, J.-C., Tauchnitz, M., Tian, Q., Hohl, M., Linz, D., Oberhofer, M., Kaestner, L., Reil, G.-H., Thiele, H., Steendijk, P., Böhm, M., Neuberger, H.-R., Lipp, P. Tags: Integrative Cardiovascular Physiology and Pathophysiology Source Type: research
Right ventricular metabolic adaptations to high-intensity interval and moderate-intensity continuous training in healthy middle-aged men
Despite the recent studies on structural and functional adaptations of the right ventricle (RV) to exercise training, adaptations of its metabolism remain unknown. We investigated the effects of short-term, high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on RV glucose and fat metabolism. Twenty-eight untrained, healthy 40–55 yr-old-men were randomized into HIIT (n = 14) and MICT (n = 14) groups. Subjects performed six supervised cycle ergometer training sessions within 2 wk (HIIT session: 4–6 x 30 s all-out cycling/4-min recovery; MICT session: 40–60 min at 60% pe...
Source: AJP: Heart and Circulatory Physiology - August 31, 2016 Category: Cardiology Authors: Heiskanen, M. A., Leskinen, T., Heinonen, I. H. A., Löyttyniemi, E., Eskelinen, J.-J., Virtanen, K., Hannukainen, J. C., Kalliokoski, K. K. Tags: ENERGETICS AND METABOLISM Source Type: research
Chronic vagal nerve stimulation prevents high-salt diet-induced endothelial dysfunction and aortic stiffening in stroke-prone spontaneously hypertensive rats
In conclusion, chronic VNS prevents hypertension-induced endothelial dysfunction and aortic stiffening in an animal model of severe hypertension. We speculate that anti-inflammatory mechanisms may contribute to these effects.
Source: AJP: Heart and Circulatory Physiology - July 11, 2016 Category: Cardiology Authors: Chapleau, M. W., Rotella, D. L., Reho, J. J., Rahmouni, K., Stauss, H. M. Tags: INTEGRATIVE CARDIOVASCULAR PHYSIOLOGY AND PATHOPHYSIOLOGY Source Type: research
Females have greater left ventricular twist mechanics than males during acute reductions to preload
This study investigated sex differences in LV mechanics during acute challenges to preload. With the use of conventional and speckle-tracking echocardiography, LV structure and function were assessed in 20 males (24 ± 6.2 yr) and 20 females (23 ± 3.1 yr) at baseline and during progressive levels of lower body negative pressure (LBNP). Fourteen participants (8 males, 6 females) were also assessed following a rapid infusion of saline. LV end-diastolic volume, end-systolic volume, stroke volume (SV), and EF were reduced in both groups during LBNP (P < 0.001). While males had greater absolute volumes (P < 0...
Source: AJP: Heart and Circulatory Physiology - June 30, 2016 Category: Cardiology Authors: Williams, A. M., Shave, R. E., Stembridge, M., Eves, N. D. Tags: INTEGRATIVE CARDIOVASCULAR PHYSIOLOGY AND PATHOPHYSIOLOGY Source Type: research
Context-dependent effects of SOCS3 in angiotensin II-induced vascular dysfunction and hypertension in mice: mechanisms and role of bone marrow-derived cells
We examined direct effects of Ang II on carotid arteries from SOCS3-deficient (SOCS3+/–) mice and wild-type (WT) littermates using organ culture and then tested endothelial function with acetylcholine (ACh). A low concentration of Ang II (1 nmol/l) did not affect ACh-induced vasodilation in WT but reduced that of SOCS3+/– mice by ~50% (P < 0.05). In relation to mechanisms, effects of Ang II in SOCS3+/– mice were prevented by inhibitors of STAT3, IL-6, NF-B, or superoxide. Systemic Ang II (1.4 mg/kg per day for 14 days) also reduced vasodilation to ACh in WT. Surprisingly, SOCS3 deficiency prevented mos...
Source: AJP: Heart and Circulatory Physiology - June 30, 2016 Category: Cardiology Authors: Li, Y., Kinzenbaw, D. A., Modrick, M. L., Pewe, L. L., Faraci, F. M. Tags: VASCULAR BIOLOGY AND MICROCIRCULATION Source Type: research
Chronic plus binge ethanol feeding induces myocardial oxidative stress, mitochondrial and cardiovascular dysfunction, and steatosis
Alcoholic cardiomyopathy in humans develops in response to chronic excessive alcohol consumption; however, good models of alcohol-induced cardiomyopathy in mice are lacking. Herein we describe mouse models of alcoholic cardiomyopathies induced by chronic and binge ethanol (EtOH) feeding and characterize detailed hemodynamic alterations, mitochondrial function, and redox signaling in these models. Mice were fed a liquid diet containing 5% EtOH for 10, 20, and 40 days (d) combined with single or multiple EtOH binges (5 g/kg body wt). Isocalorically pair-fed mice served as controls. Left ventricular (LV) function and morpholo...
Source: AJP: Heart and Circulatory Physiology - June 7, 2016 Category: Cardiology Authors: Matyas, C., Varga, Z. V., Mukhopadhyay, P., Paloczi, J., Lajtos, T., Erdelyi, K., Nemeth, B. T., Nan, M., Hasko, G., Gao, B., Pacher, P. Tags: Call for Papers: Cardiovascular Mitochondria and Redox Control Source Type: research
