Calcium channel blockade and anti-free-radical actions of panaxatriol saponins in cultured myocardiocytes.
OBJECTIVE
To identify the calcium channel blockade and anti-free-radical actions of panaxatriol saponins Re, Rf, Rg1, Rg2, Rh1, and oleanolic acid saponin Ro.


METHODS
On ventricular myocytes of Wistar rats, single channel activities of B, L, and T type calcium channels were recorded with the cell-attached configuration of patch-clamp technic, and free radical contents were measured with electron spin resenance method.


RESULTS
Re, Rg1, Rg2, and Rh1 shortened the open times, prolonged the close times, and reduced the open-state probabilities of B, L, and T type calcium channels; Rf shortened the open time, prolonged the close time and reduced the open-state probability of L type calcium channel; Ro did not influence the activity of calcium channels (60 mumol.L-1). Re, Rg1, Rg2, and Rh1 antagonized the increase of free radical content induced by xanthine 0.42 mmol.L-1-xanthine oxidase 5.3 nmol.L-1; Ro and Rf had no effect (30 mumol.L-1).


CONCLUSIONS
Re, Rg1, Rg2, and Rh1 had both the calcium channel blockade and antifree-radical actions. Rf had blockade action on L type calcium channel.
Central Laboratory of Physiology, Norman Bethune University of Medical Sciences, Changchun, China.
Y
Y
Jiang
W
W
Liu
X M
XM
Wang
G G
GG
Zhong
W J
WJ
Zhang
L
L
Chen
S
S
Zhan
H
H
Qi
C Y
CY
Zhao
X Y
XY
Ma
S J
SJ
Yang
H
H
Li
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000187:drug effects*; D002478:Cells, Cultured; D016166:Free Radical Scavengers / Q000494:pharmacology*; D036145:Ginsenosides; D009206:Myocardium / Q000166:cytology*; D051381:Rats; D017208:Rats, Wistar; D014315:Triterpenes / Q000494:pharmacology*
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D016166:Free Radical Scavengers; D036145:Ginsenosides; D014315:Triterpenes; C004563:panaxatriol