Effects of hypobaric hypoxia on the Leydig cell population of the testis of the rat.

A group of ten young adult male Wistar albino rats was exposed to hypobaric hypoxia at a barometric pressure of 380 mmHg for 28 days. After this period their testes were of smaller weight (and volume) in comparison with matched controls (1.220 vs 1.553 g; P less than 0.005). Histological examination revealed degeneration and sloughing of spermatogenic cells in occasional tubules. Quantitative methods also revealed a marked difference in the volume of the testis occupied by Leydig cells. These were of a significantly smaller total volume in the hypoxic animals (0.046 vs 0.083 ml; P less than 0.001) and this could not be accounted for merely by the smaller overall testicular volume.