Morphological pattern of response after administration of procarbazine: alteration of specific cell associations during the cycle of the seminiferous epithelium of the rat.
Procarbazine, an anti-cancer agent, administered intraperitoneally to adult, male rats induced a characteristic morphological pattern of response in the seminiferous epithelium. Seminiferous tubules of rats receiving 100 mg/kg procarbazine and higher dosages displayed spermatids which were less mature than those normally found within seminiferous tubules which show a particular cell association. Early spermatids in steps 1-7 of spermiogenesis appeared arrested in their development and were present in cell associations which had advanced normally. The most probable cause of this apparent germ cell arrest was a retardation of acrosomal development since procarbazine is known to affect RNA and consequently protein synthesis. Other features which indicated defective RNA synthesis were the presence of abnormal spermatid nucleoli and abnormally configured chromatoid bodies. This study demonstrates, in contrast to what is indicated by present dogma, that apparent and temporary germ cell arrest may occur under certain deleterious conditions. It also illustrates that particular cell types within a cell association may be out of synchrony with the remainder of the cells in a cell association.