Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The biliary metabolites of isotretinoin were examined after iv administration of 4-20-mg/kg doses to vitamin A-normal bile duct-cannulated rats. Analysis of bile by reverse phase high performance liquid chromatography showed that injection of isotretinoin is followed by a rapid excretion of metabolites in bile. Isotretinoin glucuronide was identified as the major metabolite in bile. A specific high performance liquid chromatography method based on the assay of generated isotretinoin in beta-glucuronidase-treated bile was developed for the determination of isotretinoin glucuronide in bile samples. The excretion rate of isotretinoin glucuronide increased rapidly to reach a maximum 55 min after dosing and then declined exponentially. After 330 min of collection, biliary excretion of isotretinoin glucuronide was almost complete, and the metabolite accounted for 34.8-37.9% of the dose. These results indicate that conjugation with glucuronic acid represents a major pathway for the metabolism of pharmacological doses of isotretinoin. The maximum excretion rate of isotretinoin glucuronide in bile increased in a linear manner with the dose of isotretinoin, and no delay was observed after the larger doses. These data suggest that glucuronidation and biliary excretion are not saturated at high pharmacological doses of isotretinoin.
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PMID:Metabolism of isotretinoin. Biliary excretion of isotretinoin glucuronide in the rat. 287 Sep 1

Retinoic acid (0.5% in acetone) was applied topically to the back skin of five juvenile rhesus monkeys once a day for 7 successive days. Two control animals were given vehicle alone. Skin specimens were taken from each animal at 0, 1, 2, and 4 weeks. The tissues were prepared for both histology (1-micron plastic sections) and split epidermal sheets (after incubation with EDTA solution, 17 mM). The split epidermal sheets were stained with ATPase and anti-Ia antibody, and the number of Langerhans cells was counted. The activity of beta-glucuronidase in the split epidermis was assayed by Fishman's method. After one week of treatment, the epidermis showed marked acanthosis and hyperkeratosis. The Langerhans cells showed severe degeneration, and the number of cells had dropped to approximately one-third of the number in the control skins. Concomitantly, the activity of beta-glucuronidase in the epidermis had also decreased to one-third of the control levels. After withdrawal, the number of Langerhans cells and activity of beta-glucuronidase showed gradual recovery, and by the fourth week they were back to the ranges of pretreatment or control skins, but acanthotic change remained. The results suggest that retinoid applied topically to normal primate skin induces reversible degeneration and desquamation of the Langerhans cells, while the epidermis shows prolonged proliferative change.
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PMID:Effects of retinoic acid on the epidermal Langerhans cells and beta-glucuronidase activity in macaque skin. 295 32