Study on the frequency distribution of debrisoquine hydroxylation deficiency in Chinese healthy Zang and Wei volunteers

The metabolic ratio of debrisoquine hydroxylation (MR) determined as the ratio of debrisoquine over 4-OH-debrisoquine in 8 h urine after a single oral dose of DB (10 mg) in unrelated Chinese Zang and Wei volunteers was studied by using gas chromatography. The MR of 132 healthy Chinese Zang subjects ranged from 0.20 to 34.32, and that of 158 healthy Chinese Wei subjects ranged from 0.13 to 29.73. Two phenotypes were apparent in the frequency distribution histograms with an antimode at log MR = 1.10 (MR = 12.6). Two subjects were therefore identified as poor metabolizers (PMs) of DB in 132 Zang volunteers (the frequency of PMs was found to be 1.52%), and only one in 158 Wei volunteers (0.63%). Neither sex nor smoking habit affected the DB hydroxylation (P greater than 0.2). The recoveries of DB and 4-OH-DB in Zang volunteers were 19.83 +/- 10.99 and 11.57 +/- 7.04%, and in Wei volunteers they were 22.74 +/- 14.41 and 17.77 +/- 10.82%, respectively.