Effects of 3-Methyl-4-nitrophenol on the Reproductive Toxicity in Female Japanese Quail (Coturnix japonica)(Miscellaneous)

We previously showed that 3-methyl-4-nitrophenol (4-nitro-m-cresol, PNMC), a component of diesel exhaust particles and a degradation product of the insecticide fenitrothion, has reproductive toxicity in adult male and immature female Japanese quail (Coturnix japonica). Here we investigated effects of PNMC on the reproductive toxicity of mature female Japanese quail. The experiment consists of 3 periods of pretreatment, treatment, and post-treatment for 5d each. The birds were reared, bred naturally for 1 week, and after 5d of pretreatment, then injected intramuscularly with PNMC at doses 1,10, or 100mg/kg body weight daily for 5d. Body weight, egg weight, and hatchability did not differ among the observation periods. However, at all doses of PNMC, the egglaying rate showed a modest decrease during the treatment period, with recovery during the post-treatment period. Plasma concentrations of luteinizing hormone (LH) and estrodiol-17β, were significantly decreased (p<0.05), and plasma concentrations of progesterone significantly increased (p<0.05) in birds treated with 10 and 100mg/kg PNMC. These results suggest that PNMC have acute toxicity, and inhibited LH secretion, disturbing egg-laying in mature female quail. Our findings indicate that PNMC induces endocrine malfunction at the central level and subsequently disrupts reproductive processes in mature female quails.