[Effect of carboxyethylgermanium sesquioxide on cultured normal neonatal rat myocardial cells and cells injured by isoproterenol].

The effect of carboxyethylgermanium sesquioxide (Ge-132) on cultured neonatal rat myocytes and isoproterenol injured myocytes was studied. The results showed that Ge-132 (0.01 mmol.L-1 and 1 mmol.L-1) increased the incorporation of both [3H]-TdR and [14C]-UR, reduced the membrane lipid fluidity and inhibited the release of the cytoplasmic enzyme lactate dehydrogenase (LDH). Exposure of the myocytes to isoproterenol 0.5 mmol.L-1 for 6 hours resulted in 5-fold release of LDH compared with the control. All myocytes ceased beating. Ultrastructurally, severe sarcolemmal and mitochondrial damage was evident. When the cells were pretreated with Ge-132 before the addition of isoproterenol, the increased LDH release was inhibited significantly, and preservation of beat and ultrastructure of myocytes was observed. In addition, the activity of superoxide dismutase (SOD) was elevated by Ge-132. All the effects of Ge-132 were dose-related. The results indicate that Ge-132 may improve the metabolism of cultured neonatal rat myocytes and protect myocytes from isoproterenol-induced injury.