title: Failure of methapyrilene to induce tumors in hamsters or guinea pigs.
abstract: In a small-scale experiment, 12 male and 12 female strain 2 guinea pigs were treated by gavage twice a week for 78 wk with a 200-mg/kg body weight dose of methapyrilene hydrochloride dissolved in water, a total dose of approximately 30 g/kg body weight. By the end of the treatment more than half of the animals were still alive: survivors were killed at 132 wk. A group of 20 male Syrian golden hamsters was treated twice a week by gavage with 15 mg methapyrilene hydrochloride for 58 wk, a total dose of approximately 15 g/kg body weight. Thirteen animals survived an acute convulsant effect, and the last 4 were killed at wk 61. There was no significant incidence of any tumor that could be attributed to the treatment in either guinea pigs or hamsters.
mesh_terms: D000631:Aminopyridines / Q000633:toxicity*; D000818:Animals; D006224:Cricetinae; D005260:Female; D006168:Guinea Pigs; D008297:Male; D008647:Mesocricetus; D008701:Methapyrilene / Q000633:toxicity*; D009374:Neoplasms, Experimental / Q000139:chemically induced*; D013045:Species Specificity
chemical_list: D000631:Aminopyridines; D008701:Methapyrilene