Effects of dimethyl sulfoxide on the globally ischemic heart: possible general relevance to hypothermic organ preservation.

Dimethyl sulfoxide (DMSO) is routinely used to prevent freezethaw-induced damage to a variety of biological systems. In that context, relatively high drug concentrations in excess of one molar are usually used. However, lower concentrations of the drug produce many pharmacological effects (26) which may be efficacious for reducing hypoxiaor ischemia-induced cell damage which is often encountered during organ preservation protocols that do not necessarily involve freezing. During the course of a study of several interventions which might be useful to prevent damage to the globally ischemic heart, we observed a relatively discrete but perhaps important action of dimethyl sulfoxide. When added to hypothermic cardioplegic solutions, 70 mM dimethyl sulfoxide significantly and consistently prevented alterations of mitochondrial oxidative phosphorylating activity after 2 hr of global ischemia and reperfusion. Based on these findings, the known pharmacological spectrum of action of dimethyl sulfoxide, and a postulated mechanism by which it exerted its protective effects, we were led to speculate that the drug might have more widespread applicability to organ preservation than it currently enjoys.