In addition to the transfer across the placenta, placenta displays hormonal and xenobiotic metabolism, as well as enzymatic defense against oxidative stress. We analyzed aromatase (CYP19A1), uridine 5'-diphospho-glucuronyltransferase (UGT), glutathione-S-transferase (GST) and catalase (CAT) activitiesin over 70 placentas from nonsmokers stored at -80 °C from former perfusion studies. A wide interindividual variation in all activities was found. Longterm storage at -80 °C did not affect the activities. Ethoxyresorufin-O-deethylase (EROD, CYP1A1) was not detected in any of the studied placentas perfused with chemicals. Several compounds in placental perfusion changed statistically significantly the enzyme activities in placental tissue. Melamine and nicotine increased CYP19A1, melamine increased UGT and GST, PhIP with ethanol decreased CYP19A1 and increased GST, and PhIP with buprenorphine decreased CAT. Antipyrine in 100 µg/ml also changed the studied enzyme activities, but not statistically significantly. Because antipyrine is a reference compound in placental perfusions, its potential effects must be taken into account in human placental perfusion. Enzyme activities deserve further studies as biomarkers of placental toxicity. Finally, enzyme activities deserve further studies as biomarkers of placental toxicity.

中文翻译：

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人胎盘中酶的代谢活性

除了跨胎盘转移外，胎盘还表现出激素和异生物代谢，以及针对氧化应激的酶防御。我们分析了 70 多个来自非吸烟者的胎盘中的芳香酶 (CYP19A1)、尿苷 5'-二磷酸-葡萄糖醛酸转移酶 (UGT)、谷胱甘肽-S-转移酶 (GST) 和过氧化氢酶 (CAT) 的活性，这些胎盘来自之前的灌注研究，这些胎盘来自于 -80 °C 的储存。在所有活动中发现了广泛的个体间差异。-80 °C 长期储存不影响活性。在所研究的任何灌注化学物质的胎盘中均未检测到乙氧基试卤灵-O-脱乙基酶（EROD、CYP1A1）。胎盘灌注中的几种化合物显着改变胎盘组织中的酶活性。三聚氰胺和尼古丁增加CYP19A1，三聚氰胺增加UGT和GST，含乙醇的 PhIP 降低 CYP19A1 并增加 GST，含丁丙诺啡的 PhIP 降低 CAT。100 µg/ml 的安替比林也改变了研究的酶活性，但没有统计学意义。由于安替比林是胎盘灌注中的参考化合物，因此必须考虑其在人胎盘灌注中的潜在影响。酶活性作为胎盘毒性的生物标志物值得进一步研究。最后，酶活性作为胎盘毒性的生物标志物值得进一步研究。酶活性作为胎盘毒性的生物标志物值得进一步研究。最后，酶活性作为胎盘毒性的生物标志物值得进一步研究。酶活性作为胎盘毒性的生物标志物值得进一步研究。最后，酶活性作为胎盘毒性的生物标志物值得进一步研究。