0090-9556/04/3210-1057-1060$20.00
DMD 32:1057-1060, 2004
SHORT COMMUNICATION
SIMULTANEOUS EXPRESSION OF GUINEA PIG UDP-GLUCURONOSYLTRANSFERASE 2B21 (UGT2B21) AND 2B22 IN COS-7 CELLS ENHANCES UGT2B21-CATALYZED CHLORAMPHENICOL GLUCURONIDATION
Yuji Ishii,
Aya Miyoshi,
Daisuke Maji,
Hideyuki Yamada, and
Kazuta Oguri
Graduate School of Pharmaceutical Sciences (Y.I., A.M., D.M., H.Y.), Kyushu University, Fukuoka, Japan; and School of Pharmaceutical Sciences (K.O.), Kyushu University of Health and Welfare, Miyazaki, Japan
(Received February 26, 2004;
accepted June 29, 2004)
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Abstract
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Our previous study suggested that hetero-oligomer formation of guinea pig liver UDP-glucuronosyltransferases (UGTs) 2B21 and 2B22 enhances UGT2B21-catalyzed morphine-6-glucuronidation. In this work, further evidence for a functional hetero-oligomer between UGT2B21 and UGT2B22 was provided by studies of the glucuronidation of chloramphenicol with dual expression in COS-7 cells. UGT2B21 expressed in COS cells was capable of glucuronidating the 3-hydroxyl group of morphine, 4-hydroxybiphenyl, borneol, testosterone, androsterone, and estriol, whereas it had some effect on chloramphenicol. On the contrary, UGT2B22 does not exhibit any significant activity toward these typical substrates tested in this study. When UGT2B21 and UGT2B22 were expressed simultaneously, the chloramphenicol glucuronidation was enhanced to 4.5-fold, whereas the activities toward other substrates were little affected except that for the 6-hydroxyl group of morphine. The protein expression level of UGT2B21 was comparable when UGT2B21 was expressed with or without UGT2B22. These results suggest that simultaneous expression of UGT2B21 and UGT2B22 enhances UGT2B21-catalyzed chloramphenicol glucuronidation. Hetero-oligomer formation of UGT2B21 and UGT2B22 may act by fine-tuning the catalytic glucuronidation of chloramphenicol.
Glucuronidation is well known as a major detoxification pathway for both exogenous and endogenous compounds. Glucuronidation is catalyzed by UDP-glucuronosyltransferases (UGTs), members of a superfamily of glycosyltransferases that are found in the endoplasmic reticulum membrane (Mackenzie et al., 1997
). The two UGT gene families involved in glucuronidation are divided into two groups, UGT1 and UGT2, on the basis of evolutionary divergence. The N-terminal region of UGT is now believed to be an important determinant of substrate specificity (Mackenzie et al., 1997, references therein).
Experimental evidence suggests that UGTs function as a dimer or tetramer (Gschaidmeier and Bock, 1994; Koiwai et al., 1996; Sato et al., 1996; Ishii et al., 2001). It has been shown that rat UGT2B1, human UGT1A1, and human UGT1A9 form homo-oligomers (Meech and Mackenzie, 1997; Ghosh et al., 2001; Kurkela et al., 2003). Heterodimerization of the UGT2B1 and UGT1A subfamily has also been reported (Ikushiro et al., 1997). It remains to be clarified whether such UGT oligomerizations are functionally relevant, although a change in steroid-UGT activity by coexpression of two catalytically inactive forms of rat liver UGT2B1 has been reported (Meech and Mackenzie, 1997). Our previous study suggested that the hetero-oligomer of guinea pig UGT2B21 and UGT2B22 exhibits a regioselectivity toward morphine glucuronidation different from that of either homo-oligomer, consisting of the respective UGTs (Ishii et al., 2001). However, little is known about the effect of hetero-oligomer formation on the substrate specificity except for morphine glucuronidation. UGT2B22 shows no substantial activity as far as morphine is concerned. However, when UGT2B21 and UGT2B22 were simultaneously expressed in COS-7 cells, extensive glucuronidation at the 6-hydroxyl position of morphine was observed, whereas the 3-hydroxyl position was much less affected. The catalytic activity of UGT2B21 and UGT2B22 hetero-oligomer (Ishii et al., 2001) satisfactorily explains the marked formation of morphine-6-glucuronide (M-6-G), which is a potent metabolite of morphine (Shimomura et al., 1971), in the guinea pig under in vivo and in vitro conditions (Kuo et al., 1991). It is likely that oligomer formation is a general property of the UGT, and so such hetero-oligomer-derived alterations in substrate specificity seem to be important because the physiological function of UGT isoforms may be underestimated in current investigations connecting on polymorphisms and postsequence pharmacogenomics. In this work, further evidence of a functional hetero-oligomer between UGT2B21 and UGT2B22 is provided by studies of the glucuronidation of chloramphenicol.
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Materials and Methods
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Materials. UDP-Glucuronic acid (UDP-GlcA) was purchased from Seikagaku Kogyo Co., Ltd. (Tokyo, Japan). UDP-[U-14C]GlcA was obtained from PerkinElmer Life and Analytical Sciences (Boston, MA). Egg yolk L-
-phosphatidyl choline was obtained from Sigma-Aldrich (St. Louis, MO). Chloramphenicol was purchased from Nacalai Tesque (Kyoto, Japan). An alkaline phosphatase-labeled rabbit antibody to goat IgG was purchased from Cappel Laboratories (Durham, NC). Morphine-3-glucuronide and M-6-G were synthesized in our laboratory (Yoshimura et al., 1968).
Transient Expression of UGT2B21 and UGT2B22 in COS Cells. COS-7 cells (JCRB9127) were obtained from the Japanese Collection of Research Bioresources through the Health Science Research Resources Bank and maintained in Dulbecco's modified Eagle's medium (Invitrogen, Carlsbad, CA) supplemented with 10% fetal bovine serum (Invitrogen). The transfection was performed as described previously with expression plasmid for UGT2B21 (pSVL-UGT2B21) (DDBJ/GenBank/EMBL database with accession number AB034987
[GenBank]
) and UGT2B22 (pTARGET-UGT2B22) (DDBJ/GenBank/EMBL database with accession number AB03988). pSVL-SV40-vector (Amersham Biosciences AB, Uppsala, Sweden) was used for mock-transfection. Cells were harvested and microsomes were prepared.
Assays. UGT activity toward chloramphenicol, borneol, testosterone, androsterone, and estriol was determined according to the method of Bansal and Gessner (1980). UGT activity toward 4-hydroxybiphenyl was measured fluorometrically (Bock et al., 1979). Morphine UGT activity was assayed by a method described elsewhere (Kuo et al., 1991) with slight modifications (Oguri et al., 1996). Protein was measured by the method of Lowry et al. (1951) with bovine serum albumin as a standard.
Immunoblotting. Protein separated by SDS-polyacrylamide gel electrophoresis (Laemmli, 1970) was electroblotted on to a polyvinylidine difluoride membrane and reacted with goat anti-mouse low pI form UGT antibody (Mackenzie et al., 1984) as the primary antibody. Immunochemical staining was performed after reaction with alkaline phosphatase-labeled secondary antibody according to the procedure of Blake et al. (1984).
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Results
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Substrate Specificity of UGT2B21. The substrate specificity of UGT2B21, transiently expressed in COS cells, was examined using UDP-[U-14C]GlcA as a cosubstrate. The results showed that UGT2B21 catalyzed the glucuronidation of 4-hydroxybiphenyl, borneol, androsterone, testosterone, and estriol (Table 1). Although glucuronidation of 3-hydroxysteroids and 17ß-hydroxysteroids is catalyzed by different isoforms in rat liver (Falany et al., 1987), guinea pig liver UGT2B21 was capable of glucuronidating androsterone as well as testosterone, and these features were similar to those of human UGT2B17 (Baulieu et al., 1996). However, the UGT activity toward estriol was higher than that toward both androgens. Although M-6-G formation was not detectable in the assay condition, it was due to the incubation time of 30 min. UGT2B21 catalyzes morphine 3-glucuronidation and is also capable of glucuronidating the 6-hydroxyl group to some extent (Ishii et al., 2001).
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TABLE 1 Effect of simultaneous expression of UGT2B21 and UGT2B22 in COS cells on the substrate specificity of UGT2B21
COS cells were transfected with pSVL-expression plasmid for UGT2B21 (10 µg) and/or UGT2B22 (10 µg). pSVL (10 µg) was used as a control. For single transfection, sheared salmon sperm DNA (10 µg) was also included. The cells were harvested at 90 h post-transfection, and microsomal protein (100 µg) was used for each assay except morphine glucuronidation (200 µg). For morphine glucuronidation, incubation was performed for 30 min with 5 mM substrate. For 4-hydroxybiphenyl, incubation was performed for 4 h with 0.5 mM substrate. In both cases, 2 mM UDP-GlcA and 8.5 mM saccharic acid-1,4-lactone were also included. For other substrates, microsomes (100 µg protein) were incubated with 0.5 mM UDP-[U-14C]GlcA (0.25 µCi) with 0.1 mM concentrations of each substrate except borneol (0.5 mM), which was incubated in the presence of 8.5 mM saccharic acid-1,4-lactone. The incubation was performed for 2 h (borneol) or 16 h (testosterone, androsterone, and estriol). Values represent the mean ± S.D. of three determinations.
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Enhancement of Chloramphenicol Glucuronidation by Simultaneous Expression of UGT2B21 and UGT2B22. To examine the chloramphenicol glucuronidation activity of UGT2B21 and UGT2B22, these UGTs were transiently expressed in COS-7 cells. As shown in Figs. 1 and 2, chloramphenicol glucuronidation was catalyzed by UGT2B21-expressed COS-7 cell microsomes to some extent. However, UGT2B22 did not show any glucuronidation activity toward chloramphenicol. In accordance with our previous study describing the functional hetero-oligomer of UGT2B21 and UGT2B22 (Ishii et al., 2001), COS-7 cells were simultaneously transfected with expression plasmids for UGT2B21 and UGT2B22. The immunoblots showed that the UGT2B21 level in COS-7 cell microsomes is similar for single and dual expression (Fig. 3). The 55-kDa and 59-kDa bands were observed when COS-7 cells were transfected with UGT2B21 and UGT2B22 cDNA, respectively. COS-7 cell microsomes, simultaneously expressing UGT2B21 and UGT2B22, were investigated to determine their UGT activity toward chloramphenicol (Figs. 1 and 2). Chloramphenicol glucuronide formation was 4.5-fold higher than that of the UGT2B21 single transfection. Other activities associated with the UGT2B21 isoform (borneol, 4-hydroxybiphenyl, testosterone, androsterone, estriol, and the 3-hydroxyl group of morphine) were not markedly affected by cotransfection of UGT2B22, whereas the activity toward the 6-hydroxyl group of morphine was enhanced (Table 1). These data suggest that the simultaneous expression of UGT2B21 and UGT2B22 in COS-7 cell microsomes enhances UGT2B21-catalyzed chloramphenicol glucuronidation.
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FIG. 1. TLC analysis of the chloramphenicol glucuronidation activity of microsomes of COS-7 cells expressing UGT2B21 and/or UGT2B22. COS-7 cells were transfected with pSVL-UGT2B21 and/or pTARGET-UGT2B22, assuming each 10 µg of expression plasmid (total 20 µg) was used for the transfection to 80% confluent COS-7 cells in a flask (175 cm2). For single transfection of COS-7 cells with UGT2B21 or UGT2B22, pSVL-SV40-vector was used instead of the counterpart expression vector. Cells were harvested at 72 h post-transfection and microsomes were prepared. TLC analysis shows the reaction products generated by the incubation of UDP-[14C]GlcA with substrate catalyzed by microsomal protein of guinea pig liver (GP Ms) (50 µg, 1 h) or COS-7 cells expressing UGT2B21 and/or UGT2B22 (200 µg, 16 h). The catalytic activities were analyzed in the presence of radiolabeled UDP-GlcA (0.25 µCi, final concentration 0.5 mM) and 0.1 mM chloramphenicol, and then separated by TLC [solution: n-butanol/acetone/acetic acid/5% ammonia solution/H2O, 35:25:8:5:27 (v/v)]. Radioluminography was carried out by BAS2500 (Fuji Film, Japan). The arrowhead indicates the spot of the chloramphenicol glucuronide. B represents the assay without incubation.
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FIG. 2. Chloramphenicol UGT activity in microsomes of COS-7 cells transfected with UGT2B21 and/or UGT2B22. Effect of single or dual expression of UGT2B21 and UGT2B22 in COS-7 cell microsomes on chloramphenicol glucuronide formation was examined. The transfection and assay are described in the legend to Fig. 1. The activity relative to that of microsomes of COS-7 cells transfected with UGT2B21 is shown (UGT2B21 single transfection = 1.0). Chloramphenicol glucuronidation activity in UGT2B21 single transfection was 4.49 ± 0.21 (nmol/mg protein/16 h). Data represent the mean ± S.E. of triplicate assays. N.D., not detectable. ***, significantly different from UGT2B21-expressed microsomes (p < 0.001). Statistical significance was calculated by Scheffe's F test.
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FIG. 3. Immunoblot analysis of UGT2B21 and UGT2B22 expressed in COS-7 cell microsomes. The method of transfection is described in the legend to Fig. 1. Microsomal protein (50 µg) from COS-7 cells transfected with UGT2B21 and/or UGT2B22 was subjected to SDS-polyacrylamide gel electrophoresis (7.5%) and immunoblotted using an anti-UGT antibody (Mackenzie et al., 1984).
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Discussion
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Further evidence of a functional hetero-oligomer of UGT2B21 and UGT2B22, which are involved in the extensive formation of chloramphenicol glucuronide, has been obtained. UGT2B21 shows glucuronidation activity toward chloramphenicol to some extent, whereas UGT2B21 catalyzes glucuronidation of the 3-hydroxyl group of morphine. However, its activity toward the 6-hydroxyl group is much less (Ishii et al., 2001). It is interesting that UGT2B22 did not show any glucuronidation activity toward chloramphenicol as well as morphine (Ishii et al., 2001). Our previous study showed that simultaneous expression of UGT2B21 and UGT2B22 in COS-7 cell microsomes resulted in enhanced M-6-G formation. Therefore, cotransfection experiments with UGT2B21 and UGT2B22 were carried out to see whether chloramphenicol glucuronidation could also be affected. The chloramphenicol glucuronide formation was markedly enhanced by coexpression of UGT2B21 and UGT2B22.
It is suggested that a new substrate, chloramphenicol, has been identified, which is more extensively glucuronidated by the hetero-oligomer of UGT2B21 and UGT2B22 than by the homo-oligomer of UGT2B21. Previous work showed that detergent treatment to the mixture of independently expressed UGT2B21 and UGT2B22 did not alter UGT2B21-catalyzed morphine glucuronidation (Ishii et al., 2001). It seems reasonable to conclude that UGT hetero-oligomer formation alters the substrate specificity, rendering it different from that of the homo-oligomers.
Steroids such as estrogen, and 3-hydroxy and 17ß-hydroxy androgen are substrates of UGT2B21. 4-Hydroxybiphenyl and a terpenoid, borneol, are also substrates of UGT2B21. UGT2B21 exhibited relatively low chloramphenicol glucuronidation activity, whereas rat UGT2B1 is the only isoform that has been reported to catalyze chloramphenicol glucuronidation (Mackenzie, 1987). As far as we know, there have been no reports claiming that a UGT isoform like UGT2B22 is involved in the enhancement of chloramphenicol glucuronidation. Furthermore, the human UGT(s) involved in chloramphenicol glucuronidation remains to be identified. It is possible that similar phenomena will be observed in humans. Cotransfection of UGT2B22 did not result in a large magnitude of the activity of UGT2B21 toward the substrates other than morphine and chloramphenicol. Thus, hetero-oligomer of UGT2B21 and UGT2B22 may fine-tune this activity to be capable of glucuronidating chloramphenicol and the 6-hydroxyl group of morphine.
Although we have tested a limited range of substrates, no detectable activity of UGT2B22 was observed toward typical UGT substrates in our assay condition. Like UGT2B22, there have been reports of orphan UGT isoforms such as human UGT2B10 (Jin et al., 1993) and UGT2B11 (Baulieu et al., 1998), the substrates of which have not yet been identified. However, little attention has been paid to the active hetero-oligomers of human UGT isoforms. Thus, it is possible that the physiological functions of UGT isoforms are not fully elucidated when only one isoform expression system is used. Further investigations are necessary to investigate the impact of UGT active hetero-oligomers on polymorphisms and postsequence pharmacogenomics.
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Acknowledgments
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We are grateful to Prof. P. I. Mackenzie for providing anti-UGT antibody.
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Footnotes
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Part of this research was supported by a grant-in-aid from the Ministry of Education, Sports, Culture, Science and Technology, Japan (Research No. 08557088).
ABBREVIATIONS: UGT, UDP-glucuronosyltransferase; M-6-G, morphine-6-glucuronide; UDP-GlcA, UDP-glucuronic acid; TLC, thin-layer chromatography.
Address correspondence to: Associate Professor Dr. Yuji Ishii, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashiku, Fukuoka 812-8582, Japan. E-mail: ishii{at}xenoba.phar.kyushu-u.ac.jp
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References
|
|---|
Bansal SK and Gessner T (1980) A unified method for the assay of uridine diphosphoglucuronyltransferase activities toward various aglycones using uridine diphospho[U-14C]glucuronic acid. Anal Biochem 109: 321-329.[CrossRef][Medline]
Baulieu M, Lévesque E, Hum DW, and Bélanger A (1996) Isolation and characterization of a novel cDNA encoding a human UDP-glucuronosyltransferase active on C19 steroids. J Biol Chem 271: 22855-22862.[Abstract/Free Full Text]
Baulieu M, Lévesque E, Hum DW, and Bélanger A (1998) Isolation and characterization of a human orphan UDP-glucuronosyltransferase, UGT2B11. Biochem Biophys Res Commun 248: 44-50.[CrossRef][Medline]
Blake MS, Johnston KH, Russell-Jones GJ, and Gotschlich EC (1984) A rapid, sensitive method for detection of alkaline phosphatase-conjugated anti-antibody on Western blots. Anal Biochem 136: 175-179.[CrossRef][Medline]
Bock KW, Josting D, Lilienblum W, and Pfeil H (1979) Purification of rat-liver microsomal UDP-glucuronyltransferase. Separation of two enzyme forms inducible by 3-methylcholanthrene or phenobarbital. Eur J Biochem 98: 19-26.[Medline]
Falany CN, Green MD, and Tephly TR (1987) The enzymatic mechanism of glucuronidation catalyzed by two purified rat liver steroid UDP-glucuronosyltransferases. J Biol Chem 262: 1218-1222.[Abstract/Free Full Text]
Ghosh SS, Sappal BS, Kalpana GV, Lee SW, Chowdhury JR, and Chowdhury NR (2001) Homodimerization of human bilirubin-uridine-diphosphoglucuronate glucuronosyltransferase-1 (UGT1A1) and its functional implications. J Biol Chem 276: 42108-42115.[Abstract/Free Full Text]
Gschaidmeier H and Bock KW (1994) Radiation inactivation analysis of microsomal UDP-glucuronosyltransferases catalysing mono- and diglucuronide formation of 3,6-dihydroxybenzo(a)pyrene and 3,6-dihydroxychrysene. Biochem Pharmacol 48: 1545-1549.[CrossRef][Medline]
Ikushiro S, Emi Y, and Iyanagi T (1997) Protein-protein interactions between UDP-glucuronosyltransferase isozymes in rat hepatic microsomes. Biochemistry 36: 7154-7161.[CrossRef][Medline]
Ishii Y, Miyoshi A, Watanabe R, Tsuruda K, Tsuda M, Yamaguchi-Nagamatsu Y, Yoshisue K, Tanaka M, Maji D, Ohgiya S, and Oguri K (2001) Simultaneous expression of guinea pig UDP-glucuronosyltransferase 2B21 and 2B22 in COS-7 cells enhances UDP-glucuronosyltransferase 2B21-catalyzed morphine-6-glucuronide formation. Mol Pharmacol 60: 1040-1048.[Abstract/Free Full Text]
Jin CJ, Miners JO, Lillywhite KJ, and Mackenzie PI (1993) cDNA cloning and expression of two new members of the human liver UDP-glucuronosyltransferase 2B subfamily. Biochem Biophys Res Commun 194: 496-503.[CrossRef][Medline]
Koiwai O, Aono S, Adachi Y, Kamisako T, Yasui Y, Nishizawa M, and Sato H (1996) Crigler-Najjar syndrome type II is inherited both as a dominant and as a recessive trait. Hum Mol Genet 5: 645-647.[Abstract/Free Full Text]
Kuo CK, Hanioka N, Hoshikawa Y, Oguri K, and Yoshimura H (1991) Species difference of site-selective glucuronidation of morphine. J Pharmacobio-Dyn 14: 187-193.[Medline]
Kurkela M, Garcia-Horsman JA, Luukkanen L, Morsky S, Taskinen J, Baumann M, Kostiainen R, Hirvonen J, and Finel M (2003) Expression and characterization of recombinant human UDP-glucuronosyltransferases (UGTs). UGT1A9 is more resistant to detergent inhibition than other UGTs and was purified as an active dimeric enzyme. J Biol Chem 278: 3536-3544.[Abstract/Free Full Text]
Laemmli UK (1970) Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature (Lond) 227: 680-685.[CrossRef][Medline]
Lowry OH, Rosebrough NJ, Farr AL, and Randall RJ (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193: 265-275.[Free Full Text]
Mackenzie PI (1987) Rat liver UDP-glucuronosyltransferase. Identification of cDNAs encoding two enzymes which glucuronidate testosterone, dihydrotestosterone and ß-estradiol. J Biol Chem 262: 9744-9749.[Abstract/Free Full Text]
Mackenzie PI, Hjelmeland LM, and Owens IS (1984) Purification and immunochemical characterization of a low-pI form of UDP glucuronosyltransferase from mouse liver. Arch Biochem Biophys 231: 487-497.[CrossRef][Medline]
Mackenzie PI, Owens IS, Burchell B, Bock KW, Bairoch A, Bélanger A, Fournel-Gigleux S, Green M, Hum DW, Iyanagi T, et al. (1997) The UDP glycosyltransferase gene superfamily: recommended nomenclature update based on evolutionary divergence. Pharmacogenetics 7: 255-269.[Medline]
Meech R and Mackenzie PI (1997) UDP-glucuronosyltransferase, the role of the amino terminus in dimerization. J Biol Chem 272: 26913-26917.[Abstract/Free Full Text]
Oguri K, Kurogi A, Yamabe K, Tanaka M, Yoshisue K, Ishii Y, and Yoshimura H (1996) Purification of phenobarbital-inducible UDP-glucuronosyltransferase isoform from dog liver which catalyzes morphine and testosterone glucuronidation. Arch Biochem Biophys 325: 159-166.[CrossRef][Medline]
Sato H, Adachi Y, and Koiwai O (1996) The genetic basis of Gilbert's syndrome. Lancet 347: 557-558.[Medline]
Shimomura K, Kamata O, Ueki S, Ida S, Oguri K, Yoshimura H, and Tsukamoto H (1971) Analgesic effect of morphine glucuronides. Tohoku J Exp Med 105: 45-52.[Medline]
Yoshimura H, Oguri K, and Tsukamoto H (1968) The synthesis of codeine and morphine glucuronides. Tetrahedron Lett 4: 483-486.[Medline]
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Abstract
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