Myocardial function during hypoxia: Effects of dimethyl sulfoxide (DMSO) and different buffers

Stimulated rabbit left atria in various buffer solutions [bicarbonate, Tris (hydroxymethyl) aminomethane (Tris), or both] in the presence or absence of 0.84 (6%) dimethyl sulfoxide (DMSO) were subjected to mild or severe hypoxia. Contractile strength and baseline tone changes were measured and analyzed. Oxygen consumption of right and left atria was measured before and after hypoxia in the above mentioned solutions. Results indicate (1) that DMSO allows cardiac muscle to maintain contractility during hypoxia, (2) that the absence of bicarbonate during hypoxia compromises tissue function, and (3) that Tris can exhibit toxic effects which are increased in the presence of DMSO.