[Effects of solution of dry powder of ShenSongYangXin capsule on sodium current and L-type calcium current in ventricular myocytes: experiment with guinea pig].
OBJECTIVE
To investigate the effects of dry powder of ShenSongYangXin capsule on sodium current (I(Na)) and L-type calcium current (I(Ca, L)) in ventricular myocytes.


METHODS
Ventricular myocytes were isolated from guinea pig. Solution of the dry powder of ShenSongYangXin capsule of the concentrations of 1%, 0.5%, and 0.25% was added into the suspension of the myocytes. Whole cell patch-clamp technique was used to detect the I(Na) and I(Ca, L) in the ventricular myocytes.


RESULTS
ShenSongYangXin decreased the peak I(Na) from 27.2 +/- 5.4 (pA/pF) to 14.9 +/- 2.8 (pA/pF), with a decrease rate of 44.8% +/- 7.7% (n = 5, P < 0.05). The solution of dry powder of ShenSongYangXin of the concentrations of 1%, 0.5%, and 0.25% decreased the peak L-type calcium channel current (I(ca, L)) significantly in a concentration dependent manner with the reduction rates of 50.7% +/- 5.6%, 44.8% +/- 6.5%, and 19.2% +/- 1.1% respectively (n = 5, all P < 0.05). ShenSongYangXin shifted up both the I approximately 1V curve of I(Na) and that of I(Ca, L), while their active, peak and reverse potentials didn't change.


CONCLUSIONS
ShenSongYangXin blocks both I(Na) and I(Ca, L), which may contributes to some of its antiarrhythmic effect.
Li
Ning
N
Center for Arrhythmia Diagnosis and Treatment, Fuwai Cardiovascular Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing 100037, China.
Huo
You-ping
YP
Ma
Ke-juan
KJ
Sun
Qi
Q
Pu
Jie-lin
JL
D000818:Animals; D020746:Calcium Channels, L-Type / Q000502:physiology*; D002214:Capsules; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000494:pharmacology*; D006168:Guinea Pigs; D006352:Heart Ventricles / Q000166:cytology; D008564:Membrane Potentials / Q000187:drug effects; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D018408:Patch-Clamp Techniques; D011208:Powders
D020746:Calcium Channels, L-Type; D002214:Capsules; D004338:Drug Combinations; D004365:Drugs, Chinese Herbal; D011208:Powders; C530959:shensongyangxin