Regulation of adenylate cyclase activity mediated by muscarinic acetylcholine receptors.

Abstract

Carbachol, an activator of muscarinic acetylcholine receptors of NG108-15 mouse neuroblastoma X rat glioma hybrid cells, inhibits adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] rapidly and reversibly and slowly evokes a 200-300% increase in adenylate cyclase activity over a period of 24-30 h. The inhibition of adenylate cyclase and the gradual increase in enzyme activity are dependent on muscarinic acetylcholine receptors and receptor activator. Withdrawal of carbachol results in a gradual return of adenylate cyclase activity to control levels over a period of 6 h. The half-life for decay of enzyme activity is 1.6 h. These results show that muscarinic acetylcholine receptors mediate transient and long-lived effects on adenylate cyclase activity that resemble those of opiates.