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 (DMS O) 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 simultaneo usly with acetylcholine, DMSO did not inhibit current amplitude of eit her receptor. Preincubation with DMSO for 1 min reduced current amplit ude 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-I-15]bungarotoxin bi nding to the nAChR agonist site or [H-3]phencyclidine binding to its h igh affinity site on resting or desensitized receptor. These data sugg est that DMSO might be affecting the electrocyte receptor through a se cond messenger system. (C) 1997 Elsevier Science Ireland Ltd.