Vitamin A metabolism in rats chronically treated with 3,3',4,4',5,5'-hexabromobiphenyl.
Chronic dietary administration of 3,3',4,4',5,5'-hexabromobiphenyl (HBB), 1 mg/kg diet, caused a decrease in retinol (20-fold) and retinyl esters (23-fold) in the livers of female rats, but resulted in a 6.4-fold increase in retinol and 7.4-fold increase in retinyl esters in the kidneys. Liver acyl-CoA:retinol acyltransferase and retinyl palmitate hydrolase activities were reduced while serum concentration of retinol was unaffected by HBB feeding. Metabolism of a physiological dose of [11-3H]retinyl acetate (10 micrograms), was examined in rats fed either vitamin A-adequate diet, or marginal amounts of vitamin A, or vitamin A-adequate diet containing HBB. A 13-fold greater amount of the administered vitamin A was found in kidneys of HBB-treated rats. In rats fed adequate or low amounts of vitamin A, kidney radioactivity was primarily in the retinol fraction, while in HBB-fed rats the radioactivity was associated mostly with retinyl esters. Fecal and urinary excretion of radioactivity was greatly increased in HBB-treated rats. Chronic HBB feeding results in a loss of ability of liver to store vitamin A, and severely alters the uptake and metabolism of vitamin A in the kidneys. We conclude that HBB causes major disturbances in the regulation of vitamin A metabolism.
Jensen
R K
RK
Department of Pathology, Michigan State University, East Lansing 48824.
Cullum
M E
ME
Deyo
J
J
Zile
M H
MH
D000217:Acyltransferases / Q000378:metabolism; D000818:Animals; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D004224:Diterpenes; D005260:Female; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D011075:Polybrominated Biphenyls / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D051142:Retinol O-Fatty-Acyltransferase; D000084562:Retinyl Esters; D014801:Vitamin A / Q000031:analogs & derivatives / Q000378:metabolism*
D004224:Diterpenes; D011075:Polybrominated Biphenyls; D000084562:Retinyl Esters; C022521:retinol-palmitate esterase; D014801:Vitamin A; C009166:retinol acetate; D000217:Acyltransferases; D051142:Retinol O-Fatty-Acyltransferase; D002265:Carboxylic Ester Hydrolases; C032790:3,3',4,4',5,5'-hexabromobiphenyl