Hypoxia alters testis development in neonatal rats.

OBJECTIVE To investigate the effects of continued hypoxia on postnatal development of the rat testis. DESIGN Wistar rats were exposed to simulated hypoxia from birth to postnatal day (PND) 45. Testosterone (T) in the plasma and the testis was measured in rats at PND 3, 7, 14, 21, 28, 35 and 45 respectively. Testis histology and cellular ultrastructure were studied. RESULTS a) Hypoxia induced a significant arrest of testes weight gain after PND 28; b) T release was significantly attenuated after PND 21; c) Alterations in histology and cellular ultrastructure were found in the testis, showing the swelling of testis interstitium and the enlargement of mitochondria in Leydig cells. CONCLUSION Postnatal hypoxia stress alters testis development both in terms of function and structure, especially at the critical age of gonadal development.