[Effects of sex hormones on carcinogenesis of the stomach].
Influences of sex-hormones on gastric cancer development induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in Wistar rats were studied. Well-differentiated adenocarcinoma developed in glandular stomach of 81% of male rats given 50 micrograms/ml of MNNG in drinking water for 4 months and sacrificed on the 12th month of the experiment. No gastric cancer was found in female rats given MNNG. In the additional estradiol-treated or castrated male rats, and the additional testosterone-treated or oophorectomized female rats, the incidence of carcinoma was 68% and 29%, and 33% and 5%, respectively. In the latter 3 groups, gastric erosion of the early stage was also low incidence. Histologically, poorly-differentiated adenocarcinoma was observed more frequently in these groups than in the alone MNNG-treated male group. These results have sagg-suggested that female-sex-hormone may inhibit and male-sex-hormone may accelerate the gastric carcinogenesis.
D000230:Adenocarcinoma / Q000139:chemically induced*; D000818:Animals; D002369:Castration; D004958:Estradiol / Q000494:pharmacology / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008769:Methylnitronitrosoguanidine; D009374:Neoplasms, Experimental / Q000139:chemically induced; D051381:Rats; D011919:Rats, Inbred Strains; D013274:Stomach Neoplasms / Q000139:chemically induced*; D013739:Testosterone / Q000494:pharmacology / Q000502:physiology*; D013997:Time Factors
D008769:Methylnitronitrosoguanidine; D013739:Testosterone; D004958:Estradiol