Elevated levels of prostaglandin E2 in the liver of rats fed a choline deficient diet: possible involvement in liver tumor promotion

• Published in: Cancer letters Vol. 46; no. 2; pp. 129 - 135
• Main Authors: GUPTA, C, BANKS, M, SHINOZUKA, H
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier 15.07.1989
• Subjects: Animals; Biological and medical sciences; Carcinogenesis, carcinogens and anticarcinogens; Choline Deficiency - metabolism; Diethylhexyl Phthalate - pharmacology; Dinoprostone - metabolism; Fish Oils - pharmacology; gamma-Glutamyltransferase - metabolism; General aspects; Indomethacin - pharmacology; Liver - metabolism; Liver Neoplasms - etiology; Liver Neoplasms - metabolism; Male; Medical sciences; Pyrimidines - pharmacology; Rats; Rats, Inbred Strains; Tumors; Deficient diet; Rat; Arachidonic acid derivatives; Liver; Rodentia; Prostaglandin E2; Metabolism; Vertebrata; Mammalia; Animal; Choline; Digestive diseases; Tumor promotion; Antilipemic agent
• ISSN: 0304-3835; 1872-7980
• DOI: 10.1016/0304-3835(89)90020-7

The effect of feeding a choline deficient (CD) diet, an efficient liver tumor promoting regimen, on the prostaglandin metabolism in the liver of male Sprague-Dawley rats was investigated. The possible biological significance of the alteration was examined using hypolipidemic peroxisome proliferators and modifiers of prostaglandin metabolism such as indomethacin and menhaden oil in the short term assay of the induction of enzyme altered foci in the liver. A CD diet, when fed for 10-30 days, induced 2-2.5 times increases in the levels of prostaglandin E2 (PGE2) in the liver, while the hypolipidemic peroxisome proliferators, 4-chloro-6(2,3-xylidino) pyrimidinylthio(N-hydroxyethyl)-acetamide (BR931) and di(2-ethylhexyl)-phthalate (DEHP), markedly reduced the levels of this metabolite. The addition of BR931 or indomethacin to a CD diet suppressed the diet-induced elevations of PGE2 and a substitution of fats in a CD diet with menhaden oil had the same effect. Furthermore, both indomethacin and menhaden oil added to a CD diet suppressed the induction of gamma-glutamyltranspeptidase positive hepatocyte foci in the liver of rats initiated with a single dose of diethylnitrosamine after 8 weeks of the dietary promotion. The results suggest that altered prostaglandin metabolism may be involved in the liver tumor promoting effect of a CD diet.