scholarly journals Ginsenosides Rb1 and Re decrease cardiac contraction in adult rat ventricular myocytes: role of nitric oxide

2001 ◽  
Vol 134 (6) ◽  
pp. 1159-1165 ◽  
Author(s):  
Glenda I Scott ◽  
Peter B Colligan ◽  
Bonnie H Ren ◽  
Jun Ren
Keyword(s):  
Nitric Oxide ◽  
Ventricular Myocytes ◽  
Cardiac Contraction ◽  
Rat Ventricular Myocytes ◽  
Adult Rat

Protein kinase Cε and the antiadrenergic action of adenosine in rat ventricular myocytes

2004 ◽  
Vol 287 (4) ◽  
pp. H1721-H1729 ◽  
Author(s):  
Koji Miyazaki ◽  
Satoshi Komatsu ◽  
Mitsuo Ikebe ◽  
Richard A. Fenton ◽  
James G. Dobson
Keyword(s):  
Electrical Stimulation ◽  
Protein Kinase ◽  
Ventricular Myocytes ◽  
Adrenergic Agonist ◽  
Inhibitory Peptide ◽  
Rat Ventricular Myocytes ◽  
Adult Rat ◽  
Tubular System ◽  
Stimulation Of

Adenosine-induced antiadrenergic effects in the heart are mediated by adenosine A1 receptors (A1R). The role of PKCε in the antiadrenergic action of adenosine was explored with adult rat ventricular myocytes in which PKCε was overexpressed. Myocytes were transfected with a pEGFP-N1 vector in the presence or absence of a PKCε construct and compared with normal myocytes. The extent of myocyte shortening elicited by electrical stimulation of quiescent normal and transfected myocytes was recorded with video imaging. PKCε was found localized primarily in transverse tubules. The A1R agonist chlorocyclopentyladenosine (CCPA) at 1 μM rendered an enhanced localization of PKCε in the t-tubular system. The β-adrenergic agonist isoproterenol (Iso; 0.4 μM) elicited a 29–36% increase in myocyte shortening in all three groups. Although CCPA significantly reduced the Iso-produced increase in shortening in all three groups, the reduction caused by CCPA was greatest with PKCε overexpression. The CCPA reduction of the Iso-elicited shortening was eliminated in the presence of a PKCε inhibitory peptide. These results suggest that the translocation of PKCε to the t-tubular system plays an important role in A1R-mediated antiadrenergic actions in the heart.

scholarly journals Nitric oxide-induced cardioprotection in cultured rat ventricular myocytes

2000 ◽  
Vol 278 (4) ◽  
pp. H1211-H1217 ◽  
Author(s):  
Roby D. Rakhit ◽  
Richard J. Edwards ◽  
James W. Mockridge ◽  
Anwar R. Baydoun ◽  
Amanda W. Wyatt ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Ventricular Myocytes ◽  
Culture Conditions ◽  
Neonatal Rat ◽  
No Donor ◽  
Rat Ventricular Myocytes ◽  
Kinase C ◽  
Neonatal Rat Ventricular Myocytes ◽  
Oxide Synthase

The aim of this study was to investigate the role of nitric oxide (NO) in a cellular model of early preconditioning (PC) in cultured neonatal rat ventricular myocytes. Cardiomyocytes “preconditioned” with 90 min of stimulated ischemia (SI) followed by 30 min reoxygenation in normal culture conditions were protected against subsequent 6 h of SI. PC was blocked by N G-monomethyl-l-arginine monoacetate but not by dexamethasone pretreatment. Inducible nitric oxide synthase (NOS) protein expression was not detected during PC ischemia. Pretreatment (90 min) with the NO donor S-nitroso- N-acetyl-l,l-penicillamine (SNAP) mimicked PC, resulting in significant protection. SNAP-triggered protection was completely abolished by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) but was unaffected by chelerythrine or the presence of glibenclamide and 5-hydroxydecanoate. With the use of RIA, SNAP treatment increased cGMP levels, which were blocked by ODQ. Hence, NO is implicated as a trigger in this model of early PC via activation of a constitutive NOS isoform. After exposure to SNAP, the mechanism of cardioprotection is cGMP dependent but independent of protein kinase C or ATP-sensitive K+ channels. This differs from the proposed mechanism of NO-induced cardioprotection in late PC.

Do β2-adrenergic receptors modulate Ca2+ in adult rat ventricular myocytes?

1998 ◽  
Vol 274 (4) ◽  
pp. H1308-H1314 ◽  
Author(s):  
Michael A. Laflamme ◽  
Peter L. Becker
Keyword(s):  
Pertussis Toxin ◽  
Calcium Homeostasis ◽  
Adrenergic Receptors ◽  
Calcium Current ◽  
Ventricular Myocytes ◽  
Camp Accumulation ◽  
Camp Production ◽  
Rat Ventricular Myocytes ◽  
Adult Rat

We examined the role of β2-adrenergic receptors (ARs) in modulating calcium homeostasis in rat ventricular myocytes. Zinterol (10 μM), an agonist with a 25-fold greater affinity for β2-ARs over β1-ARs, modestly enhanced L-type calcium current ( I Ca) magnitude by ∼30% and modestly accelerated the rate of Ca2+ concentration ([Ca2+]) decline (∼35%) but had little effect on the magnitude of the [Ca2+] transient (a nonsignificant 6% increase). However, 1 μM of the highly selective β1-AR antagonist CGP-20712A completely blocked the I Ca increase induced by 10 μM zinterol. Pretreatment of cells with pertussis toxin (PTX) did not alter I Ca enhancement by 10 μM zinterol, although it did abolish the ability of acetylcholine to block the forskolin-induced enhancement of I Ca. Zinterol (10 μM) approximately doubled adenosine 3′,5′-cyclic monophosphate (cAMP) accumulation, although one-half of this increase was blocked by CGP-20712A. In contrast, 1 μM of the nonselective β-agonist isoproterenol increased cAMP production 15-fold. Thus we found no evidence that activation of β2-ARs modulates calcium homeostasis in rat ventricular myocytes, even after treatment with PTX.

scholarly journals Role of epicardial mesothelial cells in the modification of phenotype and function of adult rat ventricular myocytes in primary coculture.

1992 ◽  
Vol 71 (1) ◽  
pp. 40-50 ◽  
Author(s):  
H Eid ◽  
D M Larson ◽  
J P Springhorn ◽  
M A Attawia ◽  
R C Nayak ◽  
...  
Keyword(s):  
Ventricular Myocytes ◽  
Mesothelial Cells ◽  
Rat Ventricular Myocytes ◽  
Adult Rat ◽  
And Function

Nitric oxide triggers programmed cell death (apoptosis) of adult rat ventricular myocytes in culture

1999 ◽  
Vol 277 (3) ◽  
pp. H1189-H1199 ◽  
Author(s):  
David J. Pinsky ◽  
Walif Aji ◽  
Matthias Szabolcs ◽  
Eleni S. Athan ◽  
Youping Liu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Cardiac Myocytes ◽  
Cardiac Myocyte ◽  
Ventricular Myocytes ◽  
No Production ◽  
P53 Expression ◽  
Rat Ventricular Myocytes ◽  
Adult Rat

Excessive nitric oxide (NO) production within the heart is implicated in the pathogenesis of myocyte death, but the mechanism whereby NO kills cardiac myocytes is not known. To determine whether NO may trigger programmed cell death (apoptosis) of adult rat ventricular myocytes in culture, the NO donor S-nitroso- N-acetylpenicillamine (SNAP) was shown to kill purified cardiac myocytes in a dose-dependent fashion. In situ analysis of ventricular myocytes plated on chamber slides using nick-end labeling of DNA demonstrated that SNAP induces cardiac myocyte apoptosis, which was confirmed by the identification of oligonucleosomal DNA fragmentation on agarose gel electrophoresis. Similarly, treatment of cardiac myocytes with cytokines that induce inducible NO synthase was shown to cause an NO-dependent induction of apoptosis. Addition of reduced hemoglobin to scavenge NO liberated by SNAP extinguished both the increase in percentage of apoptotic cells and the appearance of DNA ladders. Treatment with SNAP (but not with N-acetylpenicillamine or SNAP + hemoglobin) not only induced apoptosis but resulted in a marked increase in p53 expression in cardiac myocytes detected by Western blotting and immunohistochemistry. These data indicate that NO has the capacity to kill cardiac myocytes by triggering apoptosis and suggest the involvement of p53 in this process.

Role of nitric oxide production in carbachol-induced negative chronotropy in cultured rat ventricular myocytes

1999 ◽  
Vol 366 (1) ◽  
pp. 111-118 ◽  
Author(s):  
Shuji Yamamoto ◽  
Atsushi Miyamoto ◽  
Shin Kawana ◽  
Akiyoshi Namiki ◽  
Hideyo Ohshika
Keyword(s):  
Nitric Oxide ◽  
Ventricular Myocytes ◽  
Nitric Oxide Production ◽  
Rat Ventricular Myocytes ◽  
Oxide Production
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