Protective effects of S-adenosyl-L-methionine against enzyme leakage from cultured hepatocytes and hypotonic hemolysis.

Effects of S-adenosyl-L-methionine disulfate tosylate salt (SAMe-ST) and L-methionine (L-Met) on rat erythrocytes and primary cultured hepatocytes were studied. SAMe-ST in concentrations of 0.2 to 5.0 mg/ml protected erythrocytes from hypotonic hemolysis. Almost an identical level of protection was provided by SAMe chloride, suggesting that this protective effect is due to the SAMe moiety itself but not its sulfate or tosylate moiety. L-Met also showed a slight protective effect, but at higher concentrations, it slightly enhanced hemolysis. When the cultured hepatocytes were treated with SAMe-ST, the leakage of enzymes from the hepatocytes were significantly decreased compared with that in the control. L-Met also showed similar protective effects, but to a lesser degree than in the case of SAMe-ST. SAMe-ST significantly increased Na+.K(+)-ATPase activity. The present results indicate that SAMe remarkably inhibits hypotonic hemolysis and enzyme leakage from cultured hepatocytes and that its mechanism is probably related to a change in the membrane property.