Acid phosphatases of the rat testis in experimental conditions.

Abstract

ABSTRACT Quantitation of four different testicular acid phosphatases was carried out during pubertal maturation as well as after cryptorchidism and cadmium chloride treatment. The assay conditions were based on differential substrate and modifier characteristics and the results were correlated to the histological appearance of the testis. Enzyme I activity with naphthol AS-BI phosphate as substrate showed the highest activities in the prepubertal testis and no appreciable changes took place after cryptorchidism. Enzyme II activity with α-naphthyl phosphate as substrate was also high in the prepubertal testis and an increase occurred after cryptorchidism. The results are in agreement with a preferentially interstitial origin of enzymes I and II. Enzyme III was quantified using β-naphthyl phosphate as substrate with sodium fluoride (5 mm) to inactivate enzymes I and II. A moderate increase of this enzyme activity during the pubertal development and a gradual decrease after cryptorchidism suggested tubular origin. Enzyme IV activity was followed using p-nitrophenyl phosphate as substrate in the presence of sodium fluoride (5 mm) and Co2+ (5 mm) as a specific activator. A rapid potentiation of activity took place during pubertal development and a precipitous decrease after cryptorchidism. The results indicate a tubular origin of enzyme IV, which was confirmed by fractionation studies. Cadmium chloride treatment caused a rapid decrease of all enzyme activities, but the decline was more abrupt for the tubular enzymes III and IV. The results indicate that the specific testicular acid phosphatase IV may be useful in studies on the hormonal control of spermatogenesis.