The impact of on enzyme activity using phenotyping methods in urine, plasma, and saliva.

The variant is the second or third frequent reduced function allele in Chinese with a frequency of around 3-4%, while it is the major reduced function allele in Indians, Saudi Arabians and Caucasians with frequencies of around 10-20%. The present study was designed to explore the impact of on the metabolic activity of using phenotyping methods in urine, plasma, and saliva. We used dextromethorphan as the probe drug to analyze the phenotypes of 87 subjects with / ( = 22), / ( = 33), / ( = 4), / ( = 5), / ( = 3), / ( = 16), and / ( = 4) for . The ratio of parent drug to metabolite in 3 h saliva, 3 h plasma, and in 0-3 h urine was considered the metabolic ratio (MR). The allele had substantial impact on the metabolic activity of regardless of the urinary, plasma, or salivary phenotyping method used. In subjects with (or )/(or ), (or )/, / and / (all < 0.001), the salivary, plasma, or urinary MR value increased. The MRs in saliva, plasma, and urine displayed high correlations. The activity score system or the consensus activity score system, instead of the traditional phenotype classification, could predict the enzyme activity more accurately. had similar or more impact on the enzyme activity as compared with . Assigning a score of 0.5 and assigning a score of 0.25 according to the consensus AS system should be reconsidered.