[Effects of Rbl on action potentials and force of contraction in guinea pig ventricular papillary muscles].
OBJECTIVE
To evaluate the effects of Rbl on action potentials and force of contraction in guinea pig ventricular papillary muscles.


METHODS
The ventricular papillary muscles of guinea pig were isolated regularly and immersed with Tyrode, s solution. The effects of Rbl (purified saponins of panaxnotoginseng) on the action potentials (AP), the slow action potentials and the force of contraction (FC) of the muscles were studied. The AP and FC were measured synchronously.


RESULTS
Rbl shortened the duration of AP, including APD2O and APD90, and reduced the FC(n = 5, P < 0.01), but didn't affect the rest potential (RP), the amplitude of action potential (APA), overshot (OS) and maximal upstrok velocity (Vmax). Rbl also decreased the APA of slow action potential, but quinidine had no such effects.


CONCLUSIONS
Rbl may be a channel blocker.
Zhang
Bin
B
Hospital of Chinese Traditional Medicine of Guangdong Province, Foshan 528000, Guangdong, China.
Jin
Shi-ao
SA
Kuang
Xian
X
Yao
Wei-xing
WX
Xia
Guo-jing
GJ
Jiang
Ming-xing
MX
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D004365:Drugs, Chinese Herbal / Q000302:isolation & purification / Q000494:pharmacology*; D005260:Female; D036145:Ginsenosides / Q000302:isolation & purification / Q000494:pharmacology*; D006168:Guinea Pigs; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D005894:Panax / Q000737:chemistry; D010210:Papillary Muscles / Q000502:physiology*
D002121:Calcium Channel Blockers; D004365:Drugs, Chinese Herbal; D036145:Ginsenosides; C055570:sanchinoside Rb