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Effect of ginkgolide B on L type calcium ctrrernt and cytosolic [ Ca~(2十)]i in gtunea pig ischemic verntricular myocytes

ZHANG Zhi-Xiong, QI Xiao- Yan, XU You Qiu

Department of Physiology, Shanghai University of Traditional Chinese Medicine , Shanghai 200032；Department of Physiology, Shanghai Second Medicial University, Shanghai 200025

Abstract

With whole-cell variant patch-clamp and laser scanning confocal microscope technique，we examined the effect‘ginkgolide B(GB) from ginkgo leaves on L -type calcium current and cytosolic[Ca 2十]，in guinea pig ische mic ventricular myocytes·The results showed that under normal conditions，at a test voltage of 0 m V，GB had no significant effect on ICa,L;and during ische mia，the peak Cat十current reduced by 37. 71%，and the 1- V curve of ICa,L was shifted upward·1 p mol/ L GB reversed the change induced by ische mia，a result being significantly different from those of the ishemia group(P<0.05).Under control condition，0. 1 ,1 ,10 umol/ L GB decreased intracellular calcium concentration by 10. 58%，17.27%and 16. 35%(n一12，12，10，P<0.01一0.001)，respectively .With perfusion of ische mic solution for 12 min，intracellular calcium concentration increased by 20.15%·After a 12 min-perfusion of ischemic solution containing 1 pmol/ L nifedipine or 5 mmol/
L N 1G2，intracellular calcium concentration increased by 18.18%(P>0. 05 vs ische mia) and 11%(P<0.05vs ische mia)，respectively .After 12 min of perfusion with ische mic solution containing 1 p mol/ L GB，intracellu
lar calcium concentration increased by 9.6%(P<0.05 us ische mia).It is shown that GB could reverse the decrease of ICa,L and partially inhibit calcium overload during ischemia.

Key words: ginkgolide B;ventricular myocytes;ische mia;L -type calcium current;cytosolic[Ca~［(2十)i］

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Citing This Article：

ZHANG Zhi-Xiong, QI Xiao- Yan, XU You Qiu. Effect of ginkgolide B on L type calcium ctrrernt and cytosolic [ Ca~(2十)]i in gtunea pig ischemic verntricular myocytes. Acta Physiol Sin 2003; 55 (1): (in Chinese with English abstract).