Circulating concentrations of testosterone, luteinizing hormone and follicle stimulating hormone in male rats after inhalation of methanol.

Male mature rats were examined for alterations in circulating free testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) after inhalation of methanol vapour in a dynamic system for up to 6 weeks at doses ranging 200 ppm to 10,000 ppm. The most extensive effects were observed after exposure to 200 ppm of methanol for 6 weeks with serum testosterone concentrations being 32% of the controls. A significant change in LH concentration after exposure to 10,000 ppm of methanol for 6 weeks was also demonstrated. FSH remained unchanged throughout these experiments. Such exposure did not change the elimination rate of testosterone from blood which indicated effects on the testicular synthesis of testosterone.