Age-associated changes in microvasculature of human adult testis.

Age-associated architectural changes of the human testicular microvasculature from 70 autopsy cases were stereoscopically examined with a silicone-rubber injection technique. In the testis of a young subject, the interlobular main arteries run straight. The coiling phenomena of the interlobular centripetal or centrifugal arteries, which are commonly seen in adult testis, have been so far considered as physiological transformation of the vasculature. It was confirmed that the coiling changes in the interlobular main arteries of the human testis appear as an age-dependent alteration of the vasculature closely related to the volume of the gland. The practical importance of the spirallin or coiling of arteries is that it results in a considerable reduction of blood flow. The age-related coiling of the interlobular arteries is virtually accompanied by varying degrees of collapse of the peritubular capillary networks. The reduction of blood supply to the seminiferous tubules plays an active role in promoting aging of the testis. These stereoscopical observations of age-related transfiguration of testicular microvasculature were ascertained also by histometrical examinations.