Effect of continuous light on spermatogenesis and testicular steroidogenesis in rats: possible involvement of alpha 2u-globulin.

Male rats exposed to continous light for 70 days showed an increased weights of testis, accessory sex organs, serum levels of FSH, LH, testosterone, testicular 17beta-hydroxysteroid dehydrogenase (1beta-HSD) activity and alpha 2u-globulin, while 3beta-hydroxysteroid dehydrogenase activity showed no significant changes. Prolonged light exposure also stimulated sepermatogenesis in rats. These results suggest that alpha 2u-globulin possibly stimutates the male gonad by inducing pituitary gonadotropins in continuous light-exposed rats.