A relationship between cord blood and maternal blood lymphocytes and term placenta in the induction of aryl hydrocarbon hydroxylase activity.

Correlations between lymphocyte aryl hydrocarbon hydroxylase (AHH) inducibility in cord blood and maternal lymphocytes and placental AHH activity were studied in 15 smokers and 11 non-smokers. Placental AHH activity was extremely low in the non-smokers regardless of the lymphocyte AHH induction ratio, but was elevated to a variable extent in the smokers, in whom it showed a statistically significant correlation (r = 0.75, P less than 0.01) with cord blood lymphocyte AHH inducibility. The correlation between maternal lymphocyte AHH inducibility and placental AHH activity was poor (r = 0.04, not significant). These findings suggest that AHH induction in man may be 'systematically' regulated and that the genetic background will determine the extent of induction at a given level of exposure to polycyclic aromatic hydrocarbons.