AGE, SMOKING AND THE ACTIVITY OF THE MONOOXYGENASE ARYL-HYDROCARBON HYDROXYLASE IN ISOLATED HUMAN PERIPHERAL-BLOOD MONOCYTES

Age-associated changes in the microsomal mono-oxygenase enzyme, aryl h ydrocarbon hydroxylase (AHH), were investigated in peripheral blood mo nocytes isolated from young and elderly subjects. Young subjects were selected from the age group < 35 years; elderly subjects were > 70 yea rs. AHH activity, expressed as nM 3-hydroxy benzopyrene formed/10(6) c ells/h of incubation, was similar in young and elderly non-smokers (el derly = 6.7 +/- 1.8; young = 9.1 +/- 0.9; p > 0.05). In smokers, contr ary to some previous reports, AHH activity was not significantly highe r than in non-smokers of similar age (elderly smokers = 8.6 +/- 1.0; y oung smokers = 10.5 +/- 2.4; p > 0.05). There was no significant diffe rence between young and elderly smokers (p > 0.05). We conclude that: (a) AHH activity is similar in young and old non-smoking individuals; (b) no significant differences were detected in in vivo induction of t his enzyme activity between smokers and non-smokers.