Effects of administration of estrogens upon enzymes of rat pituitary. II. Aconitase, succinoxidase, and transaminase.

Succinoxidase, aconitase, and glutamic-oxalacetic transalninase have been studied in the pituitary and liver of male rats during the induction of pituitary tumors by treatment with diethylstilbestrol. In the pituitary the two rcpresentatives of the tricarboxylic acid cycle were decreased by approximately the same amount. The changes in these enzymes occurred soon after the beginning of the treatment, and thereafter their activities rcmaincd constant, whereas the pituitary slowly underwent marked gross alterations. Pi tui tary transaminase first, increased and then decreased in both diethylstilbestroland placebo-treated animals; thus any effects of the diethylstilbestrol are masked by the placebo effect.