Effect of ginkgolide B on L-type calcium current and cytosolic Ca2+i in guinea pig ischemic ventricular myocytes.
- Author:
Zhi-Xiong ZHANG
1
;
Xiao-Yan QI
;
You-Qiu XU
Author Information
1. Department of Physiology, Shanghai University of Traditional Chinese Medicine, Shanghai 200032. zixion@online.sh.cn
- Publication Type:Journal Article
- MeSH:
Animals;
Calcium;
metabolism;
Calcium Channels, L-Type;
drug effects;
Cell Hypoxia;
Cytosol;
metabolism;
Ginkgolides;
pharmacology;
Guinea Pigs;
Heart Ventricles;
cytology;
Lactones;
pharmacology;
Male;
Myocardial Ischemia;
metabolism;
physiopathology;
Myocytes, Cardiac;
drug effects;
metabolism;
Patch-Clamp Techniques;
Plant Extracts;
pharmacology
- From:
Acta Physiologica Sinica
2003;55(1):24-28
- CountryChina
- Language:Chinese
-
Abstract:
With whole-cell variant patch-clamp and laser scanning confocal microscope technique, we examined the effect of ginkgolide B (GB) from ginkgo leaves on L-type calcium current and cytosolic [Ca(2+)](i) in guinea pig ischemic ventricular myocytes. The results showed that under normal conditions, at a test voltage of 0 mV, GB had no significant effect on I(Ca,L); and during ischemia, the peak Ca(2+) current reduced by 37.71%, and the I-V curve of I(Ca,L) was shifted upward. 1 micromol/L GB reversed the change induced by ischemia, a result being significantly different from those of the ishemia group (P<0.05).Under control condition, 0.1,1,10 micromol/L GB decreased intracellular calcium concentration by 10.58%, 17.27% and 16.35% (n=12, 12, 10, P<0.01-0.001), respectively. With perfusion of ischemic solution for 12 min, intracellular calcium concentration increased by 20.15%. After a 12 min-perfusion of ischemic solution containing 1 micromol/L nifedipine or 5 mmol/L NiCl2, intracellular calcium concentration increased by 18.18% (P>0.05 vs ischemia) and 11% (P<0.05 vs ischemia), respectively. After 12 min of perfusion with ischemic solution containing 1 micromol/L GB, intracellular calcium concentration increased by 9.6% (P<0.05 vs ischemia). It is shown that GB could reverse the decrease of I(Ca,L) and partially inhibit calcium overload during ischemia.
