Testicular Effects Induced by Dermal or Inhalation Exposure to Para-tertiary Butyl Benzoic Acid (ptBBA) in Fischer 344 Rats

Testicular effects induced by dermal application or dust inhalation of para-tertiary butyl benzoic acid (ptBBA) in Fischer 344 rats were investigated. Similar effects were observed from both dermal and dust inhalation studies. Reduction in testis weights, testicular sperm head counts, and LDH-X enzyme levels were observed in a dose-related fashion. A reduction or absence of spermatogenic cell types, specifically spermatids and spermato-cytes in the seminiferous tubules, was observed histologically. In affected testes, some seminiferous tubules contained only Sertoli cells and few spermatogonia, whereas other tubules contained all stages of spermatogenic cells, except differentiating spermatids. Cell types sensitive to cytotoxic effects induced by ptBBA appeared to be the early spermatids and the late spermatocytes. Other cell types, late spermatids, earlier stages of spermato-cytes, and differentiating spermatogonia, were also affected in higher dosage groups. These affected cells were undergoing degeneration and may not survive through the course of spermatogenesis. However, most testes demonstrated partial damage with the presence of Sertoli cells and spermatogonia as compared to the control testes, and recovery following cessation of exposure would be anticipated.