Reproductive toxicity of 2,4-toluenediamine in the rat. 2. Spermatogenic and hormonal effects

The present study was undertaken to evaluate the endocrinologic and spermatogenic effects of 2,4-toluenediamine (TDA) in the rat. Adult male rats were fed 0,0.01, and 0.03% TDA ad libitum for 10 wk. At the end of wk 10 and at 11 wk post TDA treatment, the animals were killed, and cauda epididymal sperm counts and reproductive organ weights were determined. Blood samples were obtained for analyses of testosterone and gonadotropins. Treatment with 0.03% TDA for 10 wk reduced the weight of the seminal vesicles and epididymides and reduced serum testosterone levels. Cauda epididymal sperm counts were decreased in animals treated with 0.03% TDA for 10 wk and in TDA-treated animals placed on normal diet for 11 wk. Serum luteinizing hormone (LH) concentrations were increased and weights of epididymides and testes were reduced in 0.03%-TDA-treated animals placed on normal diet for 11 wk. The results indicate that TDA exerts a toxic effect on spermatogenesis and appears to affect androgen action and production in the male rat. Since the males exhibited reduced cauda epididymal sperm counts 11 wk after 0.03% TDA treatment, it appears that TDA induced damage to the germinal components of the testes.