TABLE 1

Activities of different human P450 enzymes in the metabolism of nicotine and PhIP

The activities were expressed as pmol of metabolite formation/min/pmol of P450. For nicotine metabolism, the activity was determined by cotinine formation, and the values are mean ± S.D. of three separate experiments. For PhIP metabolism, the activity was determined by N-hydroxy PhIP formation, and the results are the average of duplicate experiments.