Although enhanced growth of the vascular myocyte is believed to play a role in hypertensive cardiovascular disease, the cellular basis of altered growth regulation is not completely understood. The present study demonstrates that in the presence of 10% fetal calf serum, the logarithmic growth rate of cultured mesenteric artery myocytes of the spontaneously hypertensive rat (SHR) is similar to t...

In 76 patients with heart failure (HF) (New York Heart Association [NYHA] classes I through IV) and in 15 control subjects, cardiac angiotensin II (Ang II) generation and its relationship with left ventricular function were investigated by measuring aorta-coronary sinus concentration gradients of endogenous angiotensins and in a part of patients by studying (125)I-labeled Ang I kinetics. Gene e...

BACKGROUND Halothane shortens ventricular action potential duration (APD), as a consequence of its inhibitory effects on a variety of membrane currents, an effect that is greater in sub-endocardial than sub-epicardial myocytes. In hypertrophied ventricle, APD is prolonged as a consequence of electrical remodelling. In this study, we compared the effects of halothane on transmural APD in myocyte...

Ventricular pacing leads to a dilated myopathy in which cell death and myocyte hypertrophy predominate. Because angiotensin II (Ang II) stimulates myocyte growth and triggers apoptosis, we tested whether canine myocytes express the components of the renin-angiotensin system (RAS) and whether the local RAS is upregulated with heart failure. p53 modulates transcription of angiotensinogen (Aogen) ...

rhododendron dauricum l. is an ancient chinese traditional herb. the pharmacological effects of r. dauricum extract have been shown in chronic tracheitis. the aim of this study was to investigate the cardiovascular effects of rhododendron dauricum l. flavonoids (rf) on rats and its mechanisms. this study was performed in isolated vascular rings and a rat model of myocardial infarction and isola...

Single cardiac myocytes and skeletal myocyte fragments, devoid of interstitial collagen but with intact glycocalyx, were prepared by mechanical disaggregation of hamster ventricular myocardium and caudal gracilis muscle, respectively. Passive stiffness was studied by examining the sarcomere length-tension relationship over the approximate Eulerian stress range of 0-20 mN/mm2 for cardiac myocyte...

Myocytes across the left ventricular (LV) wall of the mammalian heart are known to exhibit heterogeneity of electrophysiological properties; however, the transmural variation of cellular electrophysiology and Ca(2+) homeostasis in the failing LV is incompletely understood. We studied action potentials (APs), the L-type calcium (Ca(2+)) current (I(Ca,L)), and intracellular Ca(2+) transients ([Ca...

Previous studies have shown that myocytes isolated from sedentary (Sed) rat hearts 3 wk after myocardial infarction (MI) undergo hypertrophy, exhibit altered intracellular Ca(2+) concentration ([Ca(2+)](i)) dynamics and abnormal contraction, and impaired sarcoplasmic reticulum (SR) function manifested as prolonged half-time of [Ca(2+)](i) decline. Because exercise training elicits positive adap...

OBJECTIVE Catecholamines that accompany acute physiological stress are also involved in mediating the development of hypertrophy and failure. However, the cellular mechanisms involved in catecholamine-induced cardiac hypertrophy, particularly Ca2+ handling, are largely unknown. We therefore investigated the effects of cardiac hypertrophy, produced by isoprenaline, on I(Na/Ca) and sarcoplasmic r...

BACKGROUND Atrial natriuretic peptide (ANP) depresses contractility in left ventricular myocytes. Its expression is upregulated in pressure-overloaded hypertrophied hearts; however, the effects of ANP on contractility in hypertrophied myocytes are not known. Our aims were (1) to examine the cellular mechanisms of this depression in contractility in normal myocytes and (2) to test the hypothesis...