title: Reproductive toxicity of methyl-1-(butylcarbamoyl)-2-benzimidazole carbamate (benomyl) in male Wistar rats.
abstract: Methyl-1-(butylcarbamoyl)-2-benzimidazole carbamate (benomyl) is a systemic fungicide which has been implicated in producing damage to the testes. The present investigation was undertaken to evaluate the functional and behavioral significance of this reported benomyl-induced damage to male rats using a 70-day feeding study followed by a 70-day recovery study. Adult male Wistar rats were fed laboratory chow containing 1.0, 6.3, or 203 ppm benomyl, with control animals receiving standard laboratory chow. Ejaculate sperm counts were significantly depressed (P less than or equal to 0.05) in male ingesting 203 ppm benomyl during the 70 day feeding phase. A significant decrease in relative testicular weights and a lowered male fertility index were observed in all benomyl-treatment groups. No significant alterations in plasma testosterone, LH, or FSH levels were observed during the feeding phase. Benomyl ingestion did not alter male copulatory behavior, nor was benomyl found to be an inducer of dominant lethal mutations. Identical studies performed during the recovery phase demonstrated that the benomyl-induced alterations in testicular function were reversible. The male fertility index, ejaculate sperm content, and testicular weights returned to control values during this phase.
mesh_terms: D000818:Animals; D001542:Benomyl / Q000633:toxicity*; D002219:Carbamates / Q000633:toxicity*; D003307:Copulation; D005260:Female; D005333:Fetus / Q000187:drug effects; D008297:Male; D009929:Organ Size / Q000187:drug effects; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D012098:Reproduction / Q000187:drug effects*; D013091:Spermatogenesis / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects; D013737:Testis / Q000187:drug effects; D013739:Testosterone / Q000097:blood
chemical_list: D002219:Carbamates; D013739:Testosterone; D001542:Benomyl