Effect of paeonol on L-type calcium channel in rat ventricular myocytes.
In order to study the possible mechanisms of paeonol on the cardiovascular system, the effect of paeonol on L-type Ca(2+) channel current (I(Ca,L)) was studied in rat ventricular myocytes using the whole cell patch-clamp technique. Exposure to paeonol (approximately 10 to 1000 microm/l) resulted in a concentration-dependent inhibition of peak I(Ca,L), with a half maximum inhibition concentration, IC(50), of 561 microm/l. Paeonol 600 microm/l inhibited I(Ca,L) by 55.3%, shifted the steady state activation and inactivation curve of I(Ca,L) to more positive and negative potentials, respectively, tended to prolong the recovery of I(Ca,L) from inactivation and did not have a use-dependent effect. However, the current-voltage relationship and reversal potential of I(Ca,L) were not altered. These results suggest that the protection by paeonol against myocardial injury is due to its blocking effect on I(Ca,L).
Zhang
G-Q
GQ
National Laboratory of Biomembranes and Membrane Biotechnology, College of Life Sciences, Peking University, Beijing, PR China.
Hao
X-M
XM
Zhou
P-A
PA
Wu
C-H
CH
D000098:Acetophenones / Q000494:pharmacology*; D000818:Animals; D020746:Calcium Channels, L-Type / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D015640:Ion Channel Gating; D007700:Kinetics; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000502:physiology; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley
D000098:Acetophenones; D020746:Calcium Channels, L-Type; C013638:paeonol