Calcium influx blocks the skeletal muscle acetylcholine receptor α‐subunit gene in vivo

Abstract

The transcriptional activity of the acetylcholine receptor alpha-subunit gene was measured in denervated chick skeletal muscle in response to calcium-active drugs, using a ribonuclease protection version of the conventional run-off assay. The L-channel agonist (-)Bay-K6844 and the calcium ionophore A23187 mimicked, and the intracellular chelator BAPTA and the calcium channel blockers D600 and nifedipine blocked, the effect of electrostimulation. These results suggest that influx of extracellular calcium is an integral component of the membrane depolarization-receptor gene inactivation cascade.