title: Sialic acid metabolism in rats undergoing chemically induced hepatocarcinogenesis in specific dietary states.
abstract: The sialic acid content and the activities of the enzymes responsible for the activation, transfer, and hydrolysis of sialic acid were determined in the livers of male Sprague-Dawley rats maintained on diets containing the hepatocarcinogen 2-acetylaminofluorene (AAF). The incidence of hyperplastic lesions was modulated by dietary fat and by the presence of a synthetic antioxidant. The purified diets utilized differed in the amount and degree of unsaturation of the lipid component; they contained either 20% corn oil, 18% coconut oil + 2% linoleic acid, or only 2% linoleic acid, and each diet was prepared either with or without 0.3% butylated hydroxytoluene (BHT). The supplementation of diets with BHT greatly retarded the development of hyperplastic nodules compared to unsupplemented diets. The AAF-treated rats and age-matched controls fed AAF-free diets were killed after a 12 to 17-week period of dietary treatment, and the livers were removed for histological and biochemical studies. Significant increases in sialic acid content, and in the activities of CMP-sialic acid synthetase and neuraminidase were observed in the livers from AAF-treated rats. The BHT supplementation of the AAF-containing diets resulted in livers with lower levels of sialic acid and CMP-sialic acid synthetase activities. The chemical and enzymatic changes observed in AAF-treated rats are consistent with an increased turnover of sialoglycoconjugates during the carcinogenic process.
mesh_terms: D015073:2-Acetylaminofluorene; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002084:Butylated Hydroxytoluene / Q000494:pharmacology; D004041:Dietary Fats / Q000494:pharmacology*; D008099:Liver / Q000378:metabolism; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000378:metabolism*; D008297:Male; D000216:N-Acylneuraminate Cytidylyltransferase / Q000378:metabolism; D009439:Neuraminidase / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012794:Sialic Acids / Q000378:metabolism*; D012799:Sialyltransferases / Q000378:metabolism; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
chemical_list: D000975:Antioxidants; D004041:Dietary Fats; D012794:Sialic Acids; D002084:Butylated Hydroxytoluene; D015073:2-Acetylaminofluorene; D012799:Sialyltransferases; D000216:N-Acylneuraminate Cytidylyltransferase; D009439:Neuraminidase; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase