Restricted lesions after testicular biopsies in young and adult rats. 
In order to evaluate the possible harmful effects of surgical removal of a testicular biopsy, adult and immature rats were subjected to unilateral testicular biopsy and were studied 2-4 months later.  One group of adult rats were sham-operated.  Perfusion-fixed, plastic-embedded specimens of the testes were examined by light microscopy.  No morphological differences were found between rats that were immature and those that were adult at the time of biopsy.  The lesions observed were focal and occurred only in the vicinity of the site of biopsy.  Only about 0.5% (range 0.01-4.5) of the testis was affected.  No morphological signs of any immune reaction were observed.  It is suggested that the lesions are caused mainly by interference with local blood flow, and to a minor extent by disruption of the flow of seminiferous tubule fluid.