Abnormal spermiogenesis in bulls treated with ethylene dibromide: an ultrastructural and ultracytochemical study

Abstract

Spermatid differentiation was studied by electron microscopy in bulls treated with a single peritesticular injection of ethylene dibromide (270 mg/testis) and castrated 3, 4, and 5 days after injection, and in bulls treated orally with 10 doses (4 mg/kg body wt/dose) of the compound given on alternate days and castrated 6 days after the last dose. In both cases the morphogenesis of spermatids was impaired. The organelles most affected were the nucleus, the perinuclear substance, the perinuclear ring, and the acrosome. The differentiation of many spermatid nuclei seemed to be arrested or slowed down in comparison with the differentiation of the adjacent cytoplasm. Bromine was ultracytochemically localized at the affected sites of the cells. The action of ethylene dibromide seems to be a direct alkylating one on several cysteine-rich spermatid organelles. Earlier-than-spermatids germ cells were also affected by the prolonged oral treatment.