Abstract
Tolmetin glucuronide (TG), extracted and purified from human urine, was incubated with albumin in vitro. The degradation profile and irreversible binding to protein were investigated and kinetic parameters calculated. Standard conditions were as follows: TG, 30 µg/ml; human serum albumin (HSA), 3%; pH 7.45; 37°C. Lower pH enhanced TG stability and reduced both the extent and the rate of irreversible binding. HSA also increased TG stability, compared to protein-free buffer, but the opposite was observed with bovine serum albumin (BSA). With BSA, irreversible binding was much less, but the rate of adduct formation was the same as with HSA. Essentially fatty acid free HSA behaved similarly to HSA. Preincubation of HSA with warfarin, or diazepam, or an excess of tolmetin, did not influence irreversible binding significantly. In buffer, acyl migration led predominantly to one isomer. This isomer bound irreversibly to HSA, although more slowly and to a lesser extent than the β1-isomer. Incubation of TG with poly-L-lysine also resulted in irreversible binding but to a lesser extent than with HSA. Our results suggest that there is more than one binding mechanism, with the preferential pathway a function of the isomers present and the experimental conditions.
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REFERENCES
R. K. Verbeeck, J. L. Blackburn, and G. R. Loewen. Clin. Pharmacokinet. 8:297–331 (1983).
J. S. Goodwin. Am. J. Med. 77:57–64 (1984).
J. Plostnieks, W. A. Cressman, E. F. Lemanowicz, B. H. Migdalof, and J. J. S. Tam. In J. R. Ward (ed.), Tolmetin—A NewNon-steroidal Antiinflammatory Agent, Excerpta Medica, Amsterdam, 1975, pp. 23–33.
D. D. Sumner, P. G. Dayton, S. A. Cucinell, and J. Plostnieks. Drug Metab. Dispos. 3:283–286 (1975).
J. M. Grindel. Drug Metab. Rev. 12:363–377 (1981).
N. Blanckaert, F. Compernolle, P. Leroy, R. Van Houtte, J. Fevery, and K. P. M. Heirwegh. Biochem. J. 171:203–204 (1978).
J. Hasegawa, P. C. Smith, and L. Z. Benet. Drug Metab. Dispos. 10:469–473 (1982).
E. M. Faed. Drug Metab. Rev. 15:1213–1249 (1984).
A. F. McDonagh, L. A. Palma, J. J. Lauff, and T.-W. Wu. J. Clin. Invest. 74:763–770 (1984).
A. Rachmel, G. A. Hazelton, A. L. Yergey, and D. J. Liberato. Drug Metab. Dispos. 13:705–710 (1985).
P. C. Smith, J. Hasegawa, P. N. J. Langendijk, and L. Z. Benet. Drug Metab. Dispos. 13:110–112 (1985).
H. W. Ruelius, E. M. Young, S. K. Kirkman, R. T. Schilling, S. F. Sisenwine, and F. W. Janssen. Biochem. Pharmacol. 34:451–452 (1985).
K. A. Sinclair. Studies on the Metabolic Conjugation of Aryloxy Carboxylic Acids, Thesis, University of London, London, 1986, Chaps. 2–4.
O. M. Bakke, W. M. Wardell, and L. Lasagna. Clin. Pharmacol. Ther. 35:559–567 (1984).
J. A. Bretza and H. S. Novey. West J. Med. 143:55–59 (1985).
Committee on Government Operations, House of Representatives, 98th Congress. FDA's Regulation of Zomax, Apr. 26 and 27, 1983.
S. D. Nelson. J. Med. Chem. 25:753–765 (1982).
J. R. Gillette. Biochem. Pharmacol. 23:2785–2794 and 2927–2938 (1974).
J. R. Gillette. Adv. Exp. Med. Biol. 197:63–82 (1986).
A. Gautman, H. Seligson, E. R. Gordon, D. Seligson, and J. L. Boyer. J. Clin. Invest. 73:873–877 (1984).
P. C. Smith, A. F. McDonagh, and L. Z. Benet. J. Clin. Invest. 77:934–939 (1986).
H. W. Ruelius, S. K. Kirkman. E. M. Young, and F. W. Janssen. Adv. Exp. Med. Biol. 197:431–441 (1986).
D. S. Wells, F. W. Janssen, and H. W. Ruelius. Xenobiotica 17:1437–1449 (1987).
R. B. van Breemen and C. Fenselau. Drug Metab. Dispos. 13:318–320 (1985).
M. L. Hyneck, P. C. Smith, A. Munafo, A. F. McDonagh, and L. Z. Benet. Clin. Pharmacol. Ther. 44:107–114 (1988).
A. Munafo, M. L. Hyneck, A. F. McDonagh, and L. Z. Benet. Pharm. Res. 4(Suppl.):S-100 (1987).
L. Z. Benet and H. Spahn. In G. Siest, J. Magdalou, and B. Burchell (eds.), Cellular and Molecular Aspects of Glucuronidation, Collaque INSERM-John Libbey Eurotex Ltd, Montrouge, France, 1988, pp. 261–269.
R. B. van Breemen and C. Fenselau. J. Chromatogr. 383:387–392 (1986).
R. B. van Breemen and C. Fenselau. Drug Metab. Dispos. 14:197–201 (1986).
R. B. van Breemen, C. Fenselau, and D. M. Dulik. Adv. Exp. Med. Biol. 197:423–429 (1986).
A. Cerami, H. Vlassara, and M. Brownlee. Sci. Am. 256:90–96 (1987).
M. Hyneck, A. Munafo, and L. Z. Benet. Drug Metab. Dispos. 16:322–324 (1988).
M. L. Hyneck, P. C. Smith, E. Unseld, and L. Z. Benet. J. Chromatogr. 420:349–356 (1987).
L. R. Pohl and R. V. Branchflower. In W. B. Jacoby (ed.), Methods in Enzymology, Vol. 77. Detoxification and Drug Metabolism: Conjugation and Related Systems, Academic Press, New York, 1981, pp. 43–50.
L. Wilkinson and M. Bjerknes. SYSTAT: The System for Statistics, SYSTAT, Inc., Evanston, Ill., 1986.
S. L. Beal and L. B. Sheiner. Am.Stat. 34:118–119 (1980).
P. C. Smith and L. Z. Benet. Drug Metab. Dispos. 14:503–505 (1986).
S. A. Glantz. Primer of Biostatistics, 2nd ed., McGraw-Hill, New York, 1987, Chaps. 3 and 4.
J. Hasegawa, E. T. Lin, R. L. Williams, F. Sörgel, and L. Z. Benet. J. Pharmacokinet. Biopharm. 10:507–523 (1982).
H. G. Boxenbaum, S. Riegelman, and R. M. Elashoff. J. Pharmacokinet. Biopharm. 2:123–148 (1974).
K. J. Fehske, W. E. Müller, and U. Wollert. Biochem. Pharmacol. 30:687–692 (1981).
J. F. Pritchard and R. K. Desiraju. J. Pharm. Sci. 71:964–965 (1982).
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Munafo, A., McDonagh, A.F., Smith, P.C. et al. Irreversible Binding of Tolmetin Glucuronic Acid Esters to Albumin in Vitro . Pharm Res 7, 21–27 (1990). https://doi.org/10.1023/A:1015823206607
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DOI: https://doi.org/10.1023/A:1015823206607