Electrophysiological effects of resveratrol on guinea pig papillary muscles.
The purpose of this study was to investigate the electrophysiological effects of resveratrol on guinea pig papillary muscles and the underlying mechanism. Action potentials were recorded by using intracellular microelectrode technique. The results obtained are as follows: (1) In normal papillary muscles, resveratrol (30, 60, and 120 micromol/L) shortened the duration of action potential (APD) in a concentration-dependent manner. (2) In partially depolarized papillary muscles, resveratrol (60 micromol/L ) not only shortened APD, but also decreased the amplitude of action potential (APA), overshoot (OS) and maximal rate of depolarization in phase 0 (Vmax). (3) Perfusion with Ca2+-free K-H solution, completely abolished the effects of resveratrol (60 micromol/L) on papillary muscles. (4) Application of potassium channel blocker tetraethylammonium chloride (TEA, 20 mmol/L) did not prevent the effect of resveratrol (60 micromol/L) on action potential. (5) Pretreatment with NG-nitro-L-arginine methyl ester (L-NAME, 1 mmol/L), a nitric oxide (NO) synthase inhibitor, failed to abolish the effect of resveratrol (60 micromol/L). All these results indicate that the electrophysiological effects of resveratrol on guinea pig papillary muscles are likely due to the reduction of calcium influx, which might not be mediated by NO.
Zhao
Juan
J
Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang 050017, China.
Ma
Hui-Jie
HJ
Dong
Jing-Hui
JH
Zhang
Li-Ping
LP
Liu
Hua-Lei
HL
Wang
Qing-Shan
QS
D000200:Action Potentials / Q000187:drug effects*; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D008839:Microelectrodes; D010210:Papillary Muscles / Q000187:drug effects / Q000502:physiology*; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology*
D002121:Calcium Channel Blockers; D013267:Stilbenes; D000077185:Resveratrol