Morphological changes produced in rat testis by anticancer drugs

Testicular side effects of procarbazine (Proc: 50 or 200 mg/kg i.p.), vincristine (Vin: 0.15 or 0.6 mg/kg i.p.) or busulfan (Bu: 10 mg/kg p.o.) were examined by morphological methods 3 days, 1 week and weekly thereafter until week 10 after a single exposure. With Proc a degeneration of the germ cells, particularly of mid primary spermatocytes, was seen first. Morphogenesis of early spermatids was disturbed, especially of those subcellular elements depending on an intact RNA metabolism. Later, giant cells were frequent. Vin led first to a malformation of late spermatids and arrest of cell division of spermatocytes and especially of spermatogonia, indicating microtubule dysfunction. After 2 and 4 weeks Bu showed a disappearance of spermatogonia and early spermatocytes leading to a depletion of the germinal epithelium by maturation. Late effects were rather similar in all the groups.