Effects of Administration of Estrogens upon Enzymes of Rat Pituitary II. Aconitase, Succinoxidase, and Transaminase

Summary Succinoxidase, aconitase, and glutamic-oxalacetic transaminase 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 representatives 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 remained constant, whereas the pituitary slowly underwent marked gross alterations. Pituitary transaminase first increased and then decreased in both diethylstilbestrol- and placebo-treated animals; thus any effects of the diethylstilbestrol are masked by the placebo effect.