CHEMICALLY-INDUCED ALTERATION OF UDP-GLUCURONIC ACID CONCENTRATION IN RAT-LIVER

  • 1 January 1983
    • journal article
    • research article
    • Vol. 11  (1) , 37-40
Abstract
Since many xenobiotics alter hepatic UDP-glucuronosyltransferase activity, their effect on UDPGA [UDP-glucuronic acid] concentration was determined. Rats were pretreated with: microsomal enzyme inducers (7,8-benzoflavone, benzo[a]pyrene, butylated, hydroxyanisole, isosafrole, 3-methylcholanthrene, phenobarbital, pregnenolone-16.alpha.-carbonitrile (PCN), 2,3,7,8-tetrachlorodibenzo-p-dioxin, trans-stilbene oxide), inhibitors of microsomal enzymes (cobaltous chloride, piperonyl butoxide, SKF 525-A [proadifen hydrochloride], borneol, galactosamine), hepatotoxins (allyl alcohol, aflatoxin B1, .alpha.-naphthylisothiocyanate, bromobenzene, cadmium chloride, carbon tetrachloride, 1,1-dichloroethylene) and commonly used anesthetics (pentobarbital, urethane, diethyl ether, halothane, enflurane, methoxyflurane). Rats were decapitated before removal of the liver. All inducers except PCN and isosafrole increased UDPGA 36-85% above control. Mixed-function oxidase inhibitors had no effect; borneol and galactosamine reduced UDPGA 85-90%. Aflatoxin B1 and Cd produced decreases of 59 and 25%, respectively. Hepatic UDPGA content was diminished 70-95% for exposure to the inhalation anesthetics; the other anesthetics reduced UDPGA .apprx. 25%. Xenobiotics altered the concentration of UDPGA in rat liver, which may have influenced the rate of glucuronidation.