Differential effects of dimethyl sulfoxide on nicotinic acetylcholine receptors from mouse muscle and Torpedo electrocytes.

The present study examined the effects of 0.1% dimethyl sulfoxide (DMSO) on nicotinic acetylcholine receptors (nAChR) from mouse muscle and Torpedo californica electrocytes. Receptors were expressed in Xenopus laevis oocytes and studied with voltage-clamp. When applied simultaneously with acetylcholine, DMSO did not inhibit current amplitude of either receptor. Preincubation with DMSO for 1 min reduced current amplitude by approximately 50% from oocytes expressing electrocyte receptor. Preincubation did not affect the muscle receptor. With electric organ membranes, 0.1% DMSO did not block either [alpha-(125)I]bungarotoxin binding to the nAChR agonist site or [3H]phencyclidine binding to its high affinity site on resting or desensitized receptor. These data suggest that DMSO might be affecting the electrocyte receptor through a second messenger system.