title: Vitamin A and its inhibitory effect as tested on Egyptian toads.
abstract: Neoplasms of the liver were induced in 18 cases out of 44 in the Egyptian toad, Bufo regularis, by injection with 20-methylcholanthrene. Dose level was 10 mg/50 g body weight once a week. However, the injection of the same dose level of this hydrocarbon together with vitamin A palmitate on the level of 20,000 IU/50 g body weight once a week was found to develop hepatomas in the liver in only 1 of 45 cases. Results of this study indicate that vitamin A palmitate inhibited the carcinogenic effect of 20-methylcholanthrene.
mesh_terms: D000818:Animals; D002025:Bufonidae; D004224:Diterpenes; D005260:Female; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced* / Q000473:pathology; D008297:Male; D008748:Methylcholanthrene / Q000037:antagonists & inhibitors*; D010168:Palmitates / Q000494:pharmacology; D000084562:Retinyl Esters; D014801:Vitamin A / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D004224:Diterpenes; D010168:Palmitates; D000084562:Retinyl Esters; D014801:Vitamin A; C014794:retinol palmitate; D008748:Methylcholanthrene