Differences of CYP1A2 Activity Between Urban and Rural People

초록

CYP1A2 is known to be responsible for the initial oxidation and generation of carcinogenic metabolites from arylamines and heterocyclic amines. Furthermore, CYP1A2 activity in man is known to be increased by air pollutants like polycyclic aromatic hydrocarbons which are produced upon combustion of fossil fuel (e.g., gasoline). A the level of air pollutants is known to be much higher in urban area than in rural area, we have compared the CYP1A2 activity between the people living in the two areas by employing the caffeine metabolism test. The urinary concentration ratio of (17X+17U)/137X was used to indicate the CYP1A2 activity and the ratio of 1X/1U was used to indicate the xanthine oxidase (XO) activity. The CYP1A2 activity in volunteers from urban (82 of which 52 are non-smokers) and rural (51 of which 42 are non-smokers) areas who had similar dietary patterns were compared. In both groups of volunteers, higher enzyme activity in the smokers than that in the non-smokers was confirmed. Comparing only the non-smokers, the CYP1A2 activity in urban and rural people were 14.08 and 8.06, respectively. However, the enzyme activity was not different when compared for age, sex and weight of volunteers. As for the XO activity, it was the same for both the urban and rural people. These results clearly indicate that although the XO activity is the same, the CYP1A2 activity in urban people is much higher (1.75-fold) than that of rural people. The obtained results suggest the people living in urban area with more air pollution as well as those who smoke may be more susceptible to cancer inducible by polycyclic hydrocarbons and arylamines.