Abstract
The reproductive toxicity of the insecticide methamidophos was studied in male mice. Adult male mice were treated by gavage with methamidophos at doses of 0, 1, 2 and 3 mg kg-1 day-1 for 4 weeks before mating with untreated females. Brain and skeletal muscle acetylcholinesterase activity was inhibited in the middle- and high-treated groups. Methamidophos treatment was associated with a decreased number of live foetuses and an increased number of dead and resorption foetuses at 2 and 3 mg kg-1 day-1 treated groups. The per cent morphologically normal spermatozoa were affected in the 2 and 3 mg kg-1 day-1 dose groups; however, sperm motility and count were decreased in the same treated groups compared to the control. Histological examination of brain, muscles, testes and epididymis revealed histological abnormalities in a dose-dependent manner. The current study demonstrated adverse effects of male methamidophos exposure on pregnancy outcome with effects on sperm parameters at 2 and 3 mg kg-1 day-1.