INHIBITION OF CA2+ CURRENT IN ILEAL CELLS BY CYCLOPIAZONIC ACID AND RYANODINE

被引：7

作者：

GAGOV, HS

DURIDANOVA, DB

BOEV, KK

机构：

[1] Institute of Physiology, Bulgarian Academy of Sciences, 1113 Sofia, Georgi Boncheff Street, Block 23

来源：

EUROPEAN JOURNAL OF PHARMACOLOGY | 1993年 / 243卷 / 01期

关键词：

CYCLOPIAZONIC ACID; RYANODINE; SMOOTH MUSCLE; CA2+ CHANNELS; CA2+ STORES; WHOLE-CELL VOLTAGE CLAMP;

D O I：

10.1016/0014-2999(93)90162-B

中图分类号：

R9 [药学];

学科分类号：

1007 ;

摘要：

The effects of cyclopiazonic acid and its combination with ryanodine on the inward Ca2+ current (I(Ca)) were investigated in smooth muscle cells isolated from the circular layer of guinea-pig ileum. The I(Ca) of these cells exhibited two components: a low-threshold, nicardipine (5 muM)-resistant, fast-inactivating component and a high-threshold, nicardipine-blockable and slowly inactivating component. Neither cyclopiazonic acid (up to 10 muM) nor ryanodine (10 muM) was able to affect both these components of I(Ca), when applied separately. Cyclopiazonic acid and ryanodine combination led to total abolishment of the high-threshold component, leaving the low-threshold component unaffected. The data presented suggest a process of Ca2+-dependent inactivation of the high-threshold component, elicited by an increase in the subplasmalemmal Ca2+ concentration due to Ca2+ released from the sarcoplasmic reticulum. It is considered that the combination of cyclopiazonic acid and ryanodine can be used as a valuable method to study the calcium sensitivity of both components of the I(Ca).

引用

页码：19 / 24

页数：6

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