Estrogenic activity of by-products produced by the reaction of estrogens with hypochlorous acid.

来自人类和动物的雌激素被认为是环境中内分泌干扰物的一个因素。我们研究了它们的卤代衍生物，这可能是由氯处理在污水处理厂。在有机溶剂中与次氯酸反应生成雌酮（E1）、17 β-雌二醇（E2）、雌三醇（E3）和17 α-乙炔基雌二醇（EE 2）的氯代衍生物，当溴离子存在时也生成溴代衍生物。用酵母双杂交法测定了卤代衍生物的雌激素活性，并与人雌激素受体a（hERα）和青鳉鱼雌激素受体a（medERα）进行了比较。虽然4-CIE 1和10-氯-1，4-雌二烯-3，17-二酮的活性与El相似，但在hERα激动剂测定中，2-C1 E1和2，4-diCIE 1的活性分别约为El的4/5和1/50。在2，4，16，16-tetraClE 1中未检测到活性。E_2、E_3和EE_2的氯代衍生物的雌激素活性与E_1相似。溴代衍生物的活性略弱于相应的氯化衍生物。在人乳腺癌MCF 7细胞中设计的GFP表达系统及其细胞增殖测定中获得了类似的结果。事实上，在位于日本静冈县的城市污水处理厂的流出物中检测到El、2-ClE 1、4-C1 E1和2，4-diClE 1的氯化衍生物。通过实时定量PCR分析E1和E2的氯化衍生物对MCF 7细胞中基因表达水平的影响。两个充分研究的雌激素反应基因，pS2和PgR，相应的氯代衍生物的雌激素活性的水平增加。另一方面，AhR taeget基因、Cyplal水平降低。

Estrogens that originate from humans and animals are thought of as a factor of endocrine disruptors in the environment. We investigated their halogenated derivatives, which could be produced by chlorine treatment at a sewage treatment plant. The chlorinated derivatives of estrone (El), 17p-estradiol (E2), estriol (E3), and 17a-ethynylestradiol (EE2) were produced by the reaction with hypochlorous acid in organic solvents and also brominated derivatives when bromide ions were present. The estrogenic activities of the halogenated derivatives were measured by yeast two-hybrid assays incorporating the human estrogen receptor a (hERα) or medaka fish (Oryzias latipes) estrogen receptor a (medERα). Although the activities of 4-CIE1 and 10-chloro-l,4-estradiene-3,17-dione were similar to those of El, the activities of 2-C1E1 and 2,4-diCIE1 were approximately 4/5 and 1/50 that of El, respectively, in an agonist assay for hERα. No activity was detected in 2,4,16,16-tetraClE1. The estrogenicities of chlorinated derivatives of E2, E3, and EE2 showed a similar tendency to that of El. The brominated derivatives showed slightly weaker activity than the corresponding chlorinated derivatives. Similar results were obtained in a devised GFP expression system in human breast carcinoma MCF7 cells and in their cell proliferation assay. In fact, chlorinated derivatives of El, 2-ClE1, 4-C1E1 and 2,4-diClE1 in the effluent of a municipal sewage treatment plant located in Shizuoka prefecture, Japan were detected. The effects of chlorinated derivatives of El and E2 on the gene expression levels in MCF7 cells were analyzed by real-time quantitative PCR. The levels of two well-studied estrogen-responsive genes, pS2 and PgR, increased corresponding to the estrogenicity of chlorinated derivatives. On the other hand, AhR taeget gene, Cyplal levels were decreased.