Review of testicular toxicity of dinitrophenolic compounds, 2-sec-butyl-4,6-dinitrophenol, 4,6-dinitro-o-cresol and 2,4-dinitrophenol.

The present review paper summarizes the data available in the literature concerning dinitrophenolic compounds and evaluates male reproductive toxicity in experimental animals. Gavage and feeding doses of 2-sec-butyl-4,6-dinitrophenol (dinoseb; CAS No. 88-85-7) manifested testicular toxicity, and 4,6-dinitro-o-cresol (DNOC; CAS No. 534-52-1) showed similar but weaker testicular toxicity in laboratory animals. Consecutive doses of dinoseb and DNOC by gavage seemed to induce spermatotoxicity by disturbing spermiogenesis or the maturation process of sperm in the epididymis, and the most probable target cells of spermatotoxicity were thought to be testicular spermatids in rats. Prolonged exposure to dinoseb and DNOC in the diet also induced testicular toxicity in rats. However, the feeding dose of dinoseb irreversibly affected the early stage of spermatogenesis and produced infertility in rats. On the other hand, 2,4-dinitrophenol (DNP; CAS No. 51-28-5) did not show testicular toxicity in laboratory animals according to available literature. Further studies in laboratory animals with nitrophenolic compounds are required for clarification of their testicular toxicity and for risk assessment in humans.