Limitations Imposed by Testicular Blood Flow on the Function of Leydig Cells in Rats in vivo

Abstract

Testis blood flow per testis closely follows testis weight in rats made aspermatogenic by a single exposure of the testis to 43°C for 30 min or 500 rad (5 Gy) of irradiation from a caesium source, or following ligation of the efferent ducts. Aspermatogenesis following these treatments was associated with only minor changes in the concentrations of testosterone in peripheral blood before stimulation with human chorionic gonadotrophin (hCG), and a reduced responsiveness to hCG when testis weight had fallen after heating. The concentrations of testosterone in testicular venous blood was normal or above normal during aspermatogenesis resulting from heat or irradiation, and only slightly reduced following efferent duct ligation.