Effects of l-2-pyrrolidone-5-carboxylate on hepatic adenosine triphosphate levels in the ethionine-treated rat

Abstract

L-2-Pyrrolidone-5-carboxylate, the lactam of L-glutamate, when given at the same time as DL-ethionine to female rats largely prevents the decrease in hepatic ATP brought about by this methionine analogue. Pyrrolidone carboxylate does not interfere with the "trapping" of ATP by ethionine, since the levels of S-adenosylethionine are similar to those receiving ethionine alone. The effect of pyrrolidone carboxylate was found to be primarily on the synthesis de novo of adenine nucleotides. This compound was found to produce a 70 per cent increase in this biosynthetic pathway as measured by the incorporation of 2-14C-glycine. The increase in ATP concentration was largely prevented by hadacidin. Furthermore, pyrrolidone carboxylate exerted no effect on the ATP levels several hours after ethionine administration. At this time the levels of ATP are decreased 80-85 per cent and are too low to support the de novo-synthetic pathway. © 1971.