SARCOLEMMAL CHLORIDE AND POTASSIUM CHANNELS FROM NORMAL AND MYOTONIC MOUSE MUSCLE STUDIED IN LIPID SUPPLEMENTED VESICLES

By patch-clamp analysis of lipid supplemented vesicles prepared from t he sarcolemma of mouse wildtype skeletal muscle, we could identify two known types of potassium channels, the inward rectifier and Ca2+ acti vated BK channels, and five types of chloride channels designated GIG- a, CIC-b, CIC-c, CIC-d, and CIC-e. CIC-b corresponds to a known chlori de channel, whereas CICa, -c, -d and -e have not been described previo usly. The diversity may be due to a heterooligomeric composition of di fferent subunits. None of these chloride channels nor the potassium ch annels were found in the sarcoplasmic reticulum fraction. In vesicles from myotonic mice, Clc-d and -e were not found. (C) 1995 Academic Pre ss, Inc.