Short-term regulation of muscarinic acetylcholine receptor binding in cultured nerve cells.

Short-term preincubation of mouse neuroblastoma cells (clone N1E-115) with the muscarinic agonist carbamylcholine at 37 degrees C resulted in a significant decrease in the binding of the muscarinic antagonist [3H]N-methylscopolamine. This agonist-induced response reached a steady state at 30 min. It was also dose dependent, saturable and sensitive to temperature, suggesting a receptor-mediated phenomenon. The significance of these findings is discussed.