Regular Article
Purification of a Phenobarbital-Inducible UDP-Glucuronosyltransferase Isoform from Dog Liver Which Catalyzes Morphine and Testosterone Glucuronidation

https://doi.org/10.1006/abbi.1996.0020Get rights and content

Abstract

A morphine UDP-glucuronosyltransferase (UGT) which could belong to the UGT2B subfamily was isolated from liver microsomes of a male beagle dog treated with phenobarbital. Glucuronidation toward morphine in the dog liver microsomes was increased threefold by the treatment. The microsomes were solubilized with Emulgen 911 and applied on a column of hemisuccinate derivative of Sepharose 4B column which has been developed in our laboratory. An isoform of UGT in the eluate was purified further by chromatofocusing and UDP-hexanolamine-affinity chromatography. A purified enzyme, UGTDOG-PB, was homogeneous on sodium dodecyl sulfate polyacrylamide gel electrophoresis and two-dimensional electrophoresis and exhibited a subunit molecular weight of 50 kDa. This isoform showed activities toward the 3-hydroxyl group of morphine, 4-hydroxybiphenyl, 4-nitrophenol, 4-methylumbelliferone, and testosterone, but not toward chloramphenicol and the 6-hydroxyl group of morphine. The substrate specificity of UGTDOG-PBis similar to that of stably expressed UGT2B1 which is considered a phenobarbital-inducible morphine UGT in the rat except that UGTDOG-PBis capable of glucuronidating 4-nitrophenol but not chloramphenicol. The NH2-terminus until the 30th residue of UGTDOG-PBis highly homologous to UGT2B subfamily, and the NH2-terminal 15 residues of UGTDOG-PBare completely identical to those of UGT2B1, UGT2B8, and UGT2B15. This is the first report describing the UGT isoform of dog and the purification of morphine UGT which may belong to UGT2B subfamily.

References (0)

Cited by (28)

  • Hetero-oligomer formation of mouse UDP-glucuronosyltransferase (UGT) 2b1 and 1a1 results in the gain of glucuronidation activity towards morphine, an activity which is absent in homo-oligomers of either UGT

    2020, Biochemical and Biophysical Research Communications
    Citation Excerpt :

    Animal experiments in this study were approved by the institutional Animal Care and Experiment Committee of Kyushu University (application approval numbers: A26–026, A28-024, and A30-104) and they followed the ARRIVE guidelines. FVB mice (seven-week-old, male) were purchased from CLEA Japan (Tokyo, Japan) and liver microsomes were prepared by differential centrifugation described elsewhere [16]. MLM was used as a positive control in immunoblotting and Ugt assays.

  • Possible drug-drug interaction in dogs and cats resulted from alteration in drug metabolism: A mini review

    2015, Journal of Advanced Research
    Citation Excerpt :

    Phenobarbital also induces UDP-glucuronosyltransferase in dogs. Oguri et al. demonstrated 3-fold increase in morphine glucuronidation in hepatic microsomes obtained from dogs treated with phenobarbital [21]. As NSAIDs were mainly eliminated from the body by biotransformation via glucuronidation, we, therefore, examined the effects of the phenobarbital treatment (5 mg/kg/day p.o., bid) on pharmacokinetics of carprofen after intravenous and oral administration in dogs.

  • Tissue-specific regulation of canine intestinal and hepatic phenol and morphine UDP-glucuronosyltransferases by β-naphthoflavone in comparison with humans

    2002, Biochemical Pharmacology
    Citation Excerpt :

    ii) Morphine UGT activities were studied since a large database exists about the pharmacokinetics and glucuronidation of this important drug [18]. A canine phenobarbital-inducible morphine UGT has previously been purified [19]. In addition to formation of the inactive morphine-3-glucuronide (M3G), morphine is also conjugated to morphine-6-glucuronide (M6G) which is a more potent analgesic than morphine itself [20,21].

View all citing articles on Scopus
View full text