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In Vivo Study of the Elimination from Rat Brain of an Intracerebrally Formed Xenobiotic Metabolite, 1‐Naphthyl‐β‐D‐Glucuronide
Author(s) -
Leininger Brigitte,
GhersiEgea JeanFrançois,
Siest Gérard,
Minn Alain
Publication year - 1991
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1991.tb11406.x
Subject(s) - metabolite , glucuronide , in vivo , efflux , chemistry , glucuronidation , xenobiotic , biochemistry , cerebellum , blood–brain barrier , mediated transport , central nervous system , enzyme , biology , microsome , endocrinology , membrane , microbiology and biotechnology
Among the drug‐metabolizing enzymes present in the rat brain, one form of UDP‐glucuronyltransferase catalyzes the formation of the polar metabolite 1‐naphthyl‐β‐D‐glucuronide from 1‐naphthol. We measured the activity of this isoform in different brain regions and showed its heterogeneous distribution. Conjugation activities were found to be the highest in the olfactory bulbs (25.4 nmol/h/mg protein) and lowest in the cerebellum (4.5 nmol/h/mg protein). As the blood–brain barrier prevents the passage of hydrosoluble molecules, we studied in vivo the characteristics of the efflux of labeled 1‐naphthyl‐β‐D‐glucuronide injected into the lateral ventricle and the cortex tissue, using tritiated water and labeled inulin as reference compounds. The results reported here indicate that intracerebrally formed glucuronide is cleared from brain tissue by both diffusion and a saturable efflux process.