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Microsomal function in hepatitis B surface antigen healthy carriers: assessment of cytochrome P450 1A2 activity by the 14C-caffeine breath test.

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Horsmans, Yves [UCL] De Koninck, X Geubel, André [UCL] Pauwels, Stanislas [UCL]

The hepatitis B surface antigen (HBsAg) carrier state is associated with changes in hepatocellular function involving the cytochrome P450 (CYP) system. Among this system, CYP1A2 enzyme plays an important role in chemical carcinogenesis and in the metabolism of several drugs. We have thus investigated CYP1A2 function using two 14C-caffeine breath tests (3-methyl-14C; C3BT and 7-methyl-14C caffeine; C7BT) in 12 HBsAg healthy carriers and 8 healthy volunteers matched for 14C-aminopyrine breath test values. HBsAg carriers exhibited lower C3- and C7BT values than normal controls. This difference, however, did not reach statistical significance except for C7BT values normalised for aminopyrine breath test values. Our data thus do not support the association between viral presence and CYP1A2 dysfunction.

  1. Denaro Charles P, Brown Christopher R, Wilson Margaret, Jacob III Peyton, Benowitz Neal L, Dose-dependency of caffeine metabolism with repeated dosing, 10.1038/clpt.1990.150
  2. Forrester, Proc. Natl. Acad. Sci. USA, 87, 8306 (1990)
  3. Geubel, Pharmacol. Therapy., 33, 193 (1987)
  4. Guengerich, Asia Pacific J. Pharmacol., 5, 327 (1990)
  5. Hadziannis, Frontiers in liver disease, 106 (1981)
  6. Harris, Carcinogenesis, 5, 697 (1984)
  7. Kalow, Clin. Pharmacol. Therap, 50, 508 (1991)
  8. Kalow Werner, Tang Bing-Kou, The use of caffeine for enzyme assays: A critical appraisal, 10.1038/clpt.1993.63
  9. Koser, J. Biol. Chem., 263, 12584 (1988)
  10. MaManus, Cancer Res., 50, 3367 (1990)
  11. Nebert, DNA Cell Biol., 10, 1 (1991)
  12. Pauwels, Dig. Dis. Sci., 27, 49 (1982)
  13. Shimada, Proc. Natl. Acad. Sci. USA, 86, 462 (1989)
  14. Swenson, Cancer Res., 35, 3811 (1975)
  15. Swensson, Cancer Res., 37, 172 (1977)
  16. Tassaneeyakul, Pharmacogenetics, 2, 173 (1992)
  17. Wietholz, Eur. J. Clin. Pharmacol., 21, 53 (1981)
Bibliographic reference Horsmans, Yves ; De Koninck, X ; Geubel, André ; Pauwels, Stanislas. Microsomal function in hepatitis B surface antigen healthy carriers: assessment of cytochrome P450 1A2 activity by the 14C-caffeine breath test.. In: Pharmacology & toxicology, Vol. 77, no. 4, p. 247-9 (1995)
Permanent URL http://hdl.handle.net/2078.1/26375