The effects of
abamectin pesticide on fertility of adult male Sprague-Dawley rats were investigated. Adult male rats were exposed to tap water containing 0, 571, 857, or 1714 ppm
abamectin for 6 weeks. Based on fluid consumption, animals received 0, 1.19, 1.87, and 2.13 mg/animal/day
abamectin, respectively. Fertility was significantly reduced in male rats ingesting
abamectin at all three doses in that the number of females impregnated by them was significantly reduced. The number of viable fetuses was significantly reduced in females mated with males that ingested
abamectin at 1.87 or 2.13 mg/animal/day. Significant increases in the total number of resorptions and the number of females with resorptions were observed in females mated with the exposed males at all three concentrations. The
body weight gain and water consumption were significantly lower in males that ingested 2.13 mg/animal/day
abamectin. Likewise, ingestion of
abamectin at all three concentrations caused a significant increase in the weight of testes. Epididymal and testicular sperm counts and daily sperm production were significantly decreased in exposed males. The serum level of
testosterone was significantly reduced, whereas the serum level of
follicle-stimulating hormone was significantly increased in males that ingested
abamectin at a concentration of 2.13 mg/animal/day. Histological evaluation of the testes revealed several abnormalities including infiltration with congested blood vessels with marked
hemorrhage and a significant accumulation of connective tissue surrounding the seminiferous tubules. These results strongly suggest the adverse effects of
abamectin pesticide on male rat fertility.