Moderate alcohol consumption is related to a reduction in cardiovascular deaths. Lysophosphatidylcholine (LPC) produces arrhythmias similar to those induced by ischemia most likely due to its uncoupling properties. We assessed effects of LPC in the presence of ethanol in cardiac myocyte pairs using the double whole-cell voltage-clamp technique. Ethanol 11, 22 and 44 mmol.l(-1) did not change junctional conductance for up to 25 min but postponed the time for total uncoupling induced by 20 micromol.l(-1) LPC from 11.3+/-3.0 min ( n=4), respectively, to 16.0+/-0.5 ( n=3; P=0.05), 20.5+/-1.9 min ( n=4; P<0.05) and 27.0+/-3.5 min ( n=3; P=0.01; mean+/-SEM). LPC-induced uncoupling which might occur during ischemia may be counteracted by ethanol.