EFFECT OF CASTRATION AND TESTOSTERONE ON PROTEIN BIOSYNTHESIS IN GUINEA PIG TISSUE PREPARATIONS

Abstract

ABSTRACT Castration and testosterone administration had no effect on the rate of incorporation of leucine-1-14C into the S 12 000 × g fraction of guinea pig kidneys. The protein biosynthetic activity of the homogenates of the seminal vesicles, however, was greatly and that of the prostate slightly reduced by castration. The administration of testosterone to castrated guinea pigs produced within four days a maximum increase in the rate of leucine incorporation of approximately 500 per cent in the seminal vesicles and about 80 per cent in the prostate. The maximum effect was maintained for at least 23 days under testosterone stimulation. Nine other amino acids gave responses which varied from equal to that of leucine-1-14C to no response. The effect of testosterone was evident in both the supernatant fraction and the sediment after centrifugation at 12 000 × g for 10 minutes of the seminal vesicle homogenate but only the supernatant fraction of the prostate. The reaction in both tissues of control and testosterone treated animals was almost completely dependent on ATP and a generating system. Omission of GTP from the reaction mixture produced only a partial decrease in the incorporating activity of both tissues but without an effect on the testosterone response. The addition of chloramphenicol to the enzyme system had no effect but puromycin almost completely inhibited the amino acid incorporating activity of the tissues of both castrated and androgen treated guinea pigs.