title: Neoplastic transformation in tissues of rats exposed to monocrotaline or dehydroretronecine.
abstract: Male Sprague-Dawley rats received sc injections biweekly of either the pyrrolizidine alkaloid monocrotaline or its metabolite dehydroretronecine for 1 year. The animals were then observed for an additional 12 months for the induction of neoplasms. Of 60 rats that received dehydroretronecine, 39 developed rhabdomyosarcomas at the injection site, and 5 of these neoplasms metastasized. In the 60 monocrotaline-treated rats, 31 widely dispersed tumors of various cell types were recorded. The reason suggested for the variation in tissue response was that the metabolite dehydroretronecine is a proximate carcinogen, whereas monocrotaline must first be metabolized before its carcinogenic potential is realized.
mesh_terms: D000818:Animals; D002273:Carcinogens; D006528:Carcinoma, Hepatocellular / Q000139:chemically induced / Q000473:pathology; D007279:Injections, Subcutaneous; D008113:Liver Neoplasms; D008297:Male; D016686:Monocrotaline / Q000031:analogs & derivatives; D009362:Neoplasm Metastasis; D009374:Neoplasms, Experimental / Q000139:chemically induced* / Q000473:pathology; D011759:Pyrrolidines / Q000633:toxicity*; D011763:Pyrrolizidine Alkaloids / Q000633:toxicity*; D051381:Rats; D012208:Rhabdomyosarcoma / Q000139:chemically induced* / Q000473:pathology
chemical_list: D002273:Carcinogens; D011759:Pyrrolidines; D011763:Pyrrolizidine Alkaloids; D016686:Monocrotaline; C007241:dehydroretronecine