We tested the hypothesis that nitric oxide-induced negative functional effects through cGMP would be reduced in aged cardiac myocytes. Maximum rate of shortening (R(max)) and percent shortening of ventricular myocytes from young (6 mo) and old (3 y) rabbits were studied using a video edge detector. cGMP-dependent phosphorylation was examined by electrophoresis and autoradiography. Myocytes rece...

Aging is associated with declining cardiac contractile function as well as changes in metabolism and mitochondrial function. The relationship between age-related changes in cardiac metabolism and declining cardiac contractile function has not been determined. In order to define the role energetics play in changes in contractile function, we measured mitochondrial NADH, [NADH]m, during continuou...

Cardiac myocytes isolated from rats with peritonitis (cecal ligation and perforation; CLP) promote PMN transendothelial migration. Herein, we assessed (1) the mechanisms involved in cardiac myocyte activation during peritonitis and (2) the means by which these activated myocytes promote PMN transendothelial migration. Plasma obtained from mice subjected to CLP (septic plasma) activated isolated...

Song, Jianliang, Xue-Qian Zhang, Lois L. Carl, Anwer Qureshi, Lawrence I. Rothblum, and Joseph Y. Cheung. Overexpression of phospholemman alters contractility and [Ca2 ]i transients in adult rat myocytes. Am J Physiol Heart Circ Physiol 283: H576–H583, 2002. First published May 2, 2002; 10.1152/ajpheart.00197.2002.—Previous studies showed increased phospholemman (PLM) mRNA after myocardial infa...

Ahlers, Belinda A., Jianliang Song, JuFang Wang, Xue-Qian Zhang, Lois L. Carl, George M. Tadros, Lawrence I. Rothblum, and Joseph Y. Cheung. Effects of sarcoplasmic reticulum Ca -ATPase overexpression in postinfarction rat myocytes. J Appl Physiol 98: 2169–2176, 2005. First published January 27, 2005 ; doi:10.1152/japplphysiol.00013.2005.—Previous studies in adult myocytes isolated from rat hea...

Our previous study demonstrated the longer duration of action potential in ventricular myocytes from genetically diabetic WBN/Kob rats without change in calcium channel density compared with age-matched controls [Tsuchida, K., H. Watajima, and S. Otamo. Am. J. Physiol. 267 ( Heart Circ. Physiol. 36): H2280-H2289, 1994]. In the present study we examined the alteration of potassium currents, espe...

1. Troglitazone, an insulin-sensitizing agent shown to improve cardiac function in both experimental animals and patients with diabetes, inhibits voltage-dependent L-type Ca(2+) currents (I(Ca,L)) in cardiac myocytes, which may underlie its cardioprotective effects. However, inhibition by troglitazone of I(Ca,L) in diabetic cardiac myocytes has not been characterized. 2. Using whole-cell voltag...

Ventricular myocytes deficient in endothelial nitric oxide synthase (NOS3(-/-)) exhibit prolonged action potential (AP) duration and enhanced spontaneous activity (early and delayed afterdepolarizations) during β-adrenergic (β-AR) stimulation. Studies have shown that nitric oxide is able to regulate various K(+) channels. Our objective was to examine if NOS3(-/-) myocytes had altered K(+) curre...

It has been proposed that dietary omega-3 polyunsaturated fatty acids (n-3 PUFAs) can reduce the risk of ventricular arrhythmias in post-MI patients. Abnormal Ca(2+) handling has been implicated in the genesis of post-MI ventricular arrhythmias. Therefore, we tested the hypothesis that dietary n-3 PUFAs alter the vulnerability of ventricular myocytes to cellular arrhythmia by stabilizing intrac...

The kinetics of contractions and Ca transients are slowed in myocytes from failing hearts. The mechanisms accounting for these abnormalities remain unclear. Myocardial infarction (MI) was produced by ligation of the circumflex artery in rabbits. We used confocal microscopy to record spatially resolved Ca transients during field stimulation in left ventricular (LV) myocytes from control and infa...