Basic properties of a novel ryanodine‐sensitive, caffeine‐insensitive calcium‐induced calcium release mechanism in permeabilised human vascular smooth muscle cells

FEBS Letters

Lynn, Stephen¹  Gillespie, James I.¹ 

[1] Department of Physiological Sciences, The Medical School, University of Newcastle upon Tyne, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK

关键词: CICR;    Ryanodine;    Saponin;    Smooth muscle;    Human vascular;   

DOI  :  10.1016/0014-5793(95)00499-Y

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The efflux of ⁴⁵Ca²⁺ from preloaded intracellular stores of saponin-permeabilised human uterine artery smooth muscle cultured cells was used to study the mechanisms underlying Ca²⁺ release from the sarcoplasmic reticulum (SR). The present paper demonstrates directly a functional Ca²⁺ release mechanism that is dependent on an increase in free Ca²⁺ (100 nM-30 μM) and is completely inhibited by 20 μM Ruthenium red. The amount of Ca²⁺ released at 30 μM free Ca²⁺ was reduced by approximately 50% compared to the release at 10 μM. This Ca²⁺-induced Ca²⁺ release (CICR) mechanism was not sensitive to caffeine. Exposure of cells to low free Ca²⁺-containing solutions (10 nM) indicated that a component of the CICR mechanism may be functional at basal free Ca²⁺ levels of 100 nM. Application of ryanodine (0.1–100 μM) induced ⁴⁵Ca²⁺ efflux from the sarcoplasmic reticulum and this release was also inhibited by 20 μM Ruthenium red.

【 授权许可】

Unknown