在雪貂心室肌细胞肌浆网钙释放过程中，钙激活氯电流和钠钙交换具有不同的时间进程。

Ca-activated chloride current and Na-Ca exchange have different timecourses during sarcoplasmic reticulum Ca release in ferret ventricular myocytes.

作者信息

Trafford A W, Díaz M E, Eisner D A

机构信息

Department of Veterinary Preclinical Sciences, The University of Liverpool, Brownlow Hill and Crown Street, Liverpool, L69 3BX, UK.

出版信息

Pflugers Arch. 1998 Apr;435(5):743-5. doi: 10.1007/s004240050577.

DOI:10.1007/s004240050577

PMID:9479029

Abstract

The aim of this work was to measure membrane currents activated by Ca release from the cardiac sarcoplasmic reticulum (s.r.). Intracellular Ca concentration ([Ca2+]i) was measured using fluo-3 in patch clamped cells. Calcium release from the s.r. (whether occurring spontaneously or evoked by caffeine) produced changes of membrane current which could be separated into a Ca-activated Cl current which was inhibited by DIDS or Cl removal and a Na-Ca exchange current. Both these currents had different time courses from the measured [Ca2+]i. Furthermore the Ca-activated Cl current decayed more quickly than did Na-Ca exchange. Possible explanations for the different kinetics of these two Ca-sensitive currents are discussed.

摘要

这项工作的目的是测量由心肌肌浆网（s.r.）释放钙所激活的膜电流。在膜片钳制的细胞中，使用荧光素-3测量细胞内钙浓度（[Ca2+]i）。肌浆网释放钙（无论是自发发生还是由咖啡因诱发）会引起膜电流变化，该变化可分为被DIDS或去除氯离子抑制的钙激活氯电流和钠钙交换电流。这两种电流与测得的[Ca2+]i具有不同的时间进程。此外，钙激活氯电流比钠钙交换电流衰减得更快。文中讨论了这两种钙敏感电流不同动力学的可能解释。