Histopathological Changes of the Testis in Rats Caused by Subcutaneous Injection of 2-Bromopropane

Mature male rats were injected subcutaneously with 1,355 mg/kg of 2-bromopropane five days a week for two weeks. In addition to the routine examinations concerning the effect on male reproductive system, we carried out an evaluation of change in the numbers of various types of germ cells in the seminiferous tubule at stages I, V. VII, X and XII to clarify germ cells which were affected by 2-bromopropane. 2-Bromopropane caused mild atrophy of the seminal vesicle, but did not show any adverse effects on spermatid/sperm count, sperm motility or sperm morphology. In the histopathological examination of the testis, the numbers of spermatogonia, preleptotene spermatocyte, leptotene spermatocyte, zygotene spermatocyte and pachytene spermatocyte at stages I and V decreased in the rats treated with 2-bromopropane. However, the numbers of pachytene spermatocyte at stages VII, X and XII and round spermatids in these rats were comparable with those in control rats. In two weeks, spermatocytes develop to pachytene spermatocyte at stage VII or more developed germ cells in rats. Therefore, it seemed likely that 2-bromopropane had no adverse effects on spermatocytes but affected spermatogonia, assuming that 2-bromopropane affected germ cells immediately after the injection. In conclusion, we estimated that spermatogonia were the target cells of 2-bromopropane in the testis in rats.