Decreased sperm counts and impaired sperm motility are present in a substantial proportion of men with varicocele. Elevations in the temperature of the affected testis, and increased spermatic vein estra-diol (E2) concentrations have been found in some of these patients. To investigate the possibility that increases in temperature lead to a pattern of testicular steroidogenesis that results in increased E2 synthesis, we have examined the effects of temperature changes on the activities of four important testicular steroidogenic enzymes. 3-β-hydroxysteroid dehydrogenase (3β-HSD), 17-hydroxylase (17-OH), 17, 20-desmolase (17, 20-D) and aromatase activities were measured in the microsomal fraction of rat, pig and horse testes. Incubations were performed at 34°C, 36°C, and 38°C. The activities of all 4 enzymes increased with each 2°C temperature elevation in roughly proportional amounts. We conclude that minor elevations in incubation temperature are associated with increases in the in vitro activity of four key testicular steroidogenic enzymes.
ASJC Scopus subject areas
- Molecular Biology