EFFECT OF BARIUM IONS ON EXCITATION-CONTRACTION COUPLING OF FROG TWITCH MUSCLE-FIBERS

被引：1

作者：

ZHU, PH

FU, DX

机构：

[1] Department of Cellular and Molecular Neurobiology, Shanghai Institute of Physiology, Chinese Academy of Sciences, Shanghai, 200031

来源：

JAPANESE JOURNAL OF PHYSIOLOGY | 1990年 / 40卷 / 03期

关键词：

barium Jons; calcium transients; twitch tension;

D O I：

10.2170/jjphysiol.40.429

中图分类号：

Q4 [生理学];

学科分类号：

071003 ;

摘要：

The mechanism for the Ba2+-induced potentiation of the twitch tension in frog skeletal muscle was investigated. No significant difference in the peak amplitude of the calcium transients evoked by voltage-clamp depolarizing pulse was found between the fibres bathed in Ca2+ (control) and Ba2+ Ringer's solution, whereas the calcium transients evoked by the action potentials from the fibres in Ba2+ Ringer's solution were increased by about 64%, compared with control. In comparison with control, the action potentials of the fibres in Ba2+ Ringer's solution had a similar overshoot but a significantly longer time course. Our results suggest that excitation-contraction coupling in frog twitch muscle fibres is not altered by replacing Ca2+ with Ba2+. The Ba2+-induced potentiation of contraction may be accounted for by broadening of the action potentials. © 1990, PHYSIOLOGICAL SOCIETY OF JAPAN. All rights reserved.

引用

页码：429 / 434

页数：6