Effect of Ethionine Alone or with Amino Acids on Tumor Growth, Carcass Weight, and Nonprotein Amino Acids in Rat Liver^*

Studies have been made on the effect of multiple injections of ethionine alone and with arginine, glycine, or lysine on the carcass weight, growth of Sarcoma R-1, and free and combined (nonprotein) amino acids in the livers of male Wistar rats. Carcass weights were decreased, and the tumor growth was inhibited to about the same degree by ethionine as by ethionine-amino acid combinations.

With the exception of methionine, serine, and arginine, the free and bound (nonprotein) amino acids in the livers of tumorous rats generally increased percentage-wise to about the same extent following injections of ethionine or of ethionine plus an amino acid. Higher concentrations of nonprotein amino acids were observed following multiple injections of ethionine or ethionine and lysine than were obtained with a single injection of these substances.