Testicular aging: vascularization and gametogenesis modifications in the Wistar rat.

A light microscopic study was carried out on testicular aging in the Wistar rat at the ages of 7, 12, 24, 40, 56, 72, 104, and 124 weeks. The following tissular modifications were observed: a progressive decrease in capillary density, a gradually reduced spermatogenic production, and a progressive increase of degenerating tubular areas. The following two questions were raised: (1) Are the vascular modifications responsible for the other alterations? (2) Do the anomalies inducing a decreased number of spermatozoa simultaneously lead to genetic alterations in the morphologically normal spermatozoa with fertilizing ability? This question is particularly interesting owing to our current knowledge of the consequences of the father's age on offspring.