Hillbertz-Nilsson K, Forsberg J G
Department of Anatomy, University of Lund, Sweden.
Teratog Carcinog Mutagen. 1989;9(2):97-110. doi: 10.1002/tcm.1770090205.
Epithelium from the neonatal mouse uterine cervix and uppermost part of vagina was cultured in vitro. The culture medium was supplemented with 17 beta-estradiol (E2; 10(-6)-10(-5) M) or diethylstilbestrol (DES; 10(-8)-10(-5) M) alone or in combination with different metabolic modifiers (alpha-naphthoflavone, beta-naphthoflavone, phenobarbital, metyrapone, indomethacin) with postulated activating or inhibitory effects on DES metabolizing enzymes (cytochrome P-448- and P-450-dependent microsomal monooxidases, prostaglandin cyclooxygenase). E2 at 10(-5) M and DES at 10(-6) and 10(-5) M concentrations increased the incidence of cells with a high number of sister chromatid exchanges (high-frequency chromatid exchange cells, HFCEC). Indomethacin partially depressed DES-induced HFCEC, whereas the incidence was increased by alpha-naphthoflavone, which may be a result of stimulation of the fetal type of P-448-dependent enzyme activity or of DES increasing the metabolic activation of alpha-naphthoflavone. Phenobarbital and beta-naphthoflavone did not affect the incidence of DES-induced HFCEC. Metyrapone alone induced the highest incidence of HFCEC observed in this study, and this effect was inactivated by phenobarbital and/or DES. The mechanisms behind these results are discussed. This study shows that E2 and DES have a genotoxic effect (sister chromatid exchanges) in vitro in epithelial cells from the same target organ as in which epithelial aberrations occur after in vivo estrogen treatment in the neonatal period. The difference in incidence of tetraploid cells between stroma and epithelium is stressed (less than 5% vs. 16-47% depending on experimental group).
对新生小鼠子宫颈和阴道最上部的上皮进行体外培养。培养基中单独添加17β - 雌二醇（E2；10⁻⁶ - 10⁻⁵M）或己烯雌酚（DES；10⁻⁸ - 10⁻⁵M），或与不同的代谢调节剂（α - 萘黄酮、β - 萘黄酮、苯巴比妥、甲吡酮、吲哚美辛）联合添加，这些代谢调节剂对DES代谢酶（细胞色素P - 448和P - 450依赖性微粒体单加氧酶、前列腺素环氧化酶）具有假定的激活或抑制作用。浓度为10⁻⁵M的E2以及浓度为10⁻⁶M和10⁻⁵M的DES增加了具有大量姐妹染色单体交换的细胞（高频染色单体交换细胞，HFCEC）的发生率。吲哚美辛部分抑制了DES诱导的HFCEC，而α - 萘黄酮则增加了其发生率，这可能是刺激了胎儿型P - 448依赖性酶活性或DES增加了α - 萘黄酮的代谢活化的结果。苯巴比妥和β - 萘黄酮不影响DES诱导的HFCEC的发生率。单独使用甲吡酮诱导出了本研究中观察到的最高HFCEC发生率，且该效应被苯巴比妥和/或DES灭活。对这些结果背后的机制进行了讨论。本研究表明，E2和DES在体外对来自与新生期体内雌激素处理后发生上皮畸变相同靶器官的上皮细胞具有遗传毒性作用（姐妹染色单体交换）。强调了基质和上皮之间四倍体细胞发生率的差异（根据实验组不同，分别小于5%与16 - 47%）。
