The effect of testosterone and related steroids on the oxidative and glycolytic activity and on lipid synthesis of testicular and ejaculated bull spermatozoa.

Abstract

ABSTRACT The effect of testosterone and ten related steroids on the oxidative and glycolytic metabolism and on lipid synthesis of washed bull ejaculated spermatozoa in vitro have been studied and comparisons made with spermatozoa collected from the rete testis of the same animal. Testicular spermatozoa differed from ejaculated spermatozoa in their response to steroids. At a concentration of 100 μg/ml androstanedione and 5β-epiandrosterone depressed the oxidative metabolism of testicular spermatozoa, whereas androsterone and 5β-androsterone had the reverse effect; they stimulated rather than depressed the respiration and oxidation of glucose by these cells. By contrast, with the exception of androstenedione, dihydrotestosterone and 5β-androstanediol, the steroids always depressed the respiration of ejaculated spermatozoa. The effective steroids always enhanced glycolysis in both testicular and ejaculated spermatozoa. However, with the exception of androstanedione, the steroids which enhanced glycolysis of ejaculated spermatozoa were not the same which affected the glycolytic activity in testicular spermatozoa. Under anaerobic conditions, the steroids did not stimulate glycolysis of both types of spermatozoa to any extent. Testicular spermatozoa, incubated with no added steroid, incorporated more carbon from [U-14C] glucose into lipid than did ejaculated cells. The addition of steroids significantly increased or tended to increase lipid biosynthesis in both testicular and ejaculated spermatozoa. Androstanedione, 5β-androstanedione, 5β-androsterone and 5β-epiandrosterone were the most effective steroids in altering the metabolic pattern of the spermatozoa. The results indicate that the effect of steroid hormones depends on the »maturity« of the spermatozoa and also on the nature of the steroid.