DETECTION OF MESSENGER-RNA ENCODING XENOBIOTIC-METABOLIZING CYTOCHROME P450S IN HUMAN BRONCHOALVEOLAR MACROPHAGES AND PERIPHERAL-BLOOD LYMPHOCYTES

Human pulmonary tissues are known to contain enzymes mediating procarc inogen activation. Peripheral blood lymphocytes and bronchoalveolar ma crophages (BAMs) have been used as surrogates for the lung in studies involving cytochrome P450 (CYP) parameters, including CYP1A1 inducibil ity in relation to susceptibility to lung cancer. In this study, a com prehensive view of the expression patterns of xenobiotic-metabolizing CYP forms in human BAMs and peripheral blood lymphocytes was obtained by using gene-specific reverse transcriptase-polymerase chain reaction analysis. These patterns were compared with that in the whole lung. m RNAs of CYP2B6/7, CYP2C, CYP2E1, CYP2F1, CYP3A5, and CYP4B1 were detec ted in all seven BAM samples studied; however, only the mRNA of CYP2E1 was found consistently in all eight lymphocyte samples. The amounts o f amplification products of CYP2B6/7, CYP2C, CYP3A5, and CYP4B1 were l ow and inconsistent, indicating low levels of expression in lymphocyte s. Consistent with previous knowledge, mRNAs of CYP1A1, CYP2B6/7, CYP2 E1, CYPZF1, CYP3A5, and CYP4B1 were detected in whole-lung tissue. The se results give an overall picture of the expression of CYP genes in t he xenobiotic-metabolizing families CYP1, CYP2, and CYP3 in BAMs, peri pheral blood lymphocytes, and whole-lung tissue and will aid in direct ing future studies on the respective protein products. The differences in the CYP gene expression patterns between lung and lymphocytes cast additional doubt on the use of lymphocytes as a surrogate for the lun g. (C) 1997 Wiley-Liss, Inc.