Acute effects of ethionine stereoisomers on hepatic RNA and protein synthesis in swiss mice.

The acute biochemical effects of ethionine have been well studied in rats but not in mice. These results show that both hepatic RNA and protein synthesis in Swiss mice were inhibited by DL-ethionine. Protein synthesis was inhibited 30 to 40 percent 3 hr after 2500 mg/kg DL-ethionine while RNA synthesis was inhibited 80 to 90 percent 3 hr after 625 mg/kg DL-ethionine. Thus ethionine was a far more potent inhibitor of RNA synthesis than of protein synthesis. There was no sex difference in either of these responses. While both stereoisomers were active, the L isomer was a more potent inhibitor of RNA synthesis than was the D isomer. In male mice, 3 hr after 20 mg/kg L-ethionine, RNA synthesis was inhibited 80%, while after D-ethionine it was inhibited only 51%.