Cigarette smoking during pregnancy lowers aromatase cytochrome P-450 in the human placenta. Export

@article{citeulike:2824847, abstract = {To clarify whether cigarette smoking during pregnancy causes an organic alteration in placental estrogen producing ability, we determined the catalytic activity of aromatase by the tritiated water assay, and tissue level of aromatase cytochrome P-450 (P-450arom) by the specific enzyme-linked immunosorbent assay, in placental samples from nonsmokers and smokers. As pregnancy progressed, both aromatase activity and P-450arom concentration increased in placentas from nonsmokers and smokers. However, the gradient of the increase was significantly less in heavy smokers (> or = 20 cigarettes a day) than in normal and moderate smokers (< 20 cigarettes a day). At term, the mean aromatase activity and P-450arom concentration in placentas from heavy smokers were significantly lower than in nonsmokers and moderate smokers, while aromatase activity per P-450arom (turnover rate) and the mean placental weight were comparable among the three groups. In contrast, the ratio of aryl hydrocarbon hydroxylase activity to aromatase activity was higher in placentas from heavy smokers. Immunohistochemical studies showed that P-450arom was localized in the cytoplasm of syncytiotrophoblasts of chorionic villi in placentas from both nonsmokers and smokers. These results suggest that the induction of placental P-450arom during gestation is suppressed by maternal smoking, resulting in a reduction in estrogen producing ability, while placental xenobiotic P-450 is induced.}, address = {Department of Obstetrics and Gynecology, Kyoto Prefectural University of Medicine, Japan.}, author = {Kitawaki, J. and Inoue, S. and Tamura, T. and Yamamoto, T. and Honjo, H. and Higashiyama, T. and Osawa, Y. and Okada, H.}, citeulike-article-id = {2824847}, citeulike-linkout-0 = {http://view.ncbi.nlm.nih.gov/pubmed/8518204}, citeulike-linkout-1 = {http://www.hubmed.org/display.cgi?uids=8518204}, issn = {0960-0760}, journal = {The Journal of steroid biochemistry and molecular biology}, keywords = {aromatase, cigarette, placenta, pregnancy}, month = {June}, number = {6}, pages = {485--491}, posted-at = {2008-05-23 10:54:16}, priority = {2}, title = {Cigarette smoking during pregnancy lowers aromatase cytochrome P-450 in the human placenta.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/8518204}, volume = {45}, year = {1993} }

TY - JOUR ID - citeulike:2824847 L3 - citeulike-article-id:2824847 N2 - To clarify whether cigarette smoking during pregnancy causes an organic alteration in placental estrogen producing ability, we determined the catalytic activity of aromatase by the tritiated water assay, and tissue level of aromatase cytochrome P-450 (P-450arom) by the specific enzyme-linked immunosorbent assay, in placental samples from nonsmokers and smokers. As pregnancy progressed, both aromatase activity and P-450arom concentration increased in placentas from nonsmokers and smokers. However, the gradient of the increase was significantly less in heavy smokers (> or = 20 cigarettes a day) than in normal and moderate smokers (< 20 cigarettes a day). At term, the mean aromatase activity and P-450arom concentration in placentas from heavy smokers were significantly lower than in nonsmokers and moderate smokers, while aromatase activity per P-450arom (turnover rate) and the mean placental weight were comparable among the three groups. In contrast, the ratio of aryl hydrocarbon hydroxylase activity to aromatase activity was higher in placentas from heavy smokers. Immunohistochemical studies showed that P-450arom was localized in the cytoplasm of syncytiotrophoblasts of chorionic villi in placentas from both nonsmokers and smokers. These results suggest that the induction of placental P-450arom during gestation is suppressed by maternal smoking, resulting in a reduction in estrogen producing ability, while placental xenobiotic P-450 is induced. IS - 6 JF - The Journal of steroid biochemistry and molecular biology SN - 0960-0760 AD - Department of Obstetrics and Gynecology, Kyoto Prefectural University of Medicine, Japan. EP - 491 TI - Cigarette smoking during pregnancy lowers aromatase cytochrome P-450 in the human placenta. VL - 45 SP - 485 KW - aromatase KW - cigarette KW - placenta KW - pregnancy AU - Kitawaki, J AU - Inoue, S AU - Tamura, T AU - Yamamoto, T AU - Honjo, H AU - Higashiyama, T AU - Osawa, Y AU - Okada, H PY - 1993/06// UR - http://view.ncbi.nlm.nih.gov/pubmed/8518204 ER -