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5128547 
Technical Report 
Mechanisms of inhibitory effect of oleate on glucuronidation of benzo(a)pyrene phenols 
Zhong, Z; Zhou J-L; Thurman, RG 
1992 
1 
Zhongguo Yaolixue yu Dulixue Zazhi / Chinese Journal of Pharmacology and Toxicology
ISSN: 1000-3002 
6 
2 
81-87 
English 
BIOSIS COPYRIGHT: BIOL ABS. The purpose of this study was to investigate the mechanisms by which oleate influences the glucuronidation of benzo(a)pyrene phenols (BP-P) in the isolated microsomes and perfused liver. Low doses of oleoyl CoA inhibited UDP-glucuronyl transferase (UDPG-T) non-competitively in the isolated rat microsomes with 3-hydroxy-benzopyrene (3-OH-BP) as the substrate. Albumin and Triton X-100 enhanced the inhibition of the transferase by oleoyl CoA. Infusion of oleate (600 mumol L-1) decreased the hepatic contents of UDP-glucuronic acid (UDPGA), UDP-glucose (UDPG) and ATP by 44, 49 and 44% respectively. Thus, oleate might inhibit glucuronidation by altering cofactor supply at the high concentration. In the beta-glucuronidase deficient C3He mice, infusion of oleate (250 mumolcreased the release of free BP-P by 136% and decreased the release of glucuronides by 32% in the perfusate. Concomitantly, storages of glucuronides in the liver were diminished by 64%. A similar tendency was