Effects on Spermatozoa Capability of PCB77, 132, and 149 in Male Offspring of Rats Exposed during Pregnancy (II)

[[abstract]]本研究目的針對多氯聯苯(Polychlorinated biphenyls, PCBs) 化 合 物 2,2',3,3',4,6'-Hexachlorobiphenyls (CB 132) 、 2,2',3,4',5',6-Hexachlorobiphenyls (CB 149)與雌二醇(17β-estradiol, E2)進行基因轉殖酵母菌(PL3 and Y253 Gene type yeast)的雌性素受體試驗(Estrogen receptor)。研究前題著重以篩檢具干擾雌性激素活性之多氯聯苯化合物為考量，利用酵母菌雌性激素篩檢法(Yeast Estrogen Screen, YES)，透過雌性激素與受體鍵結之模式，以雌性激素受體所調控之指標基因轉錄後，評估此類化學物質是否具有雌性激素之干擾效應。研究發現以雌二醇為陽性控制組具有良好效果，Y253/YEp90HEGO/PYER1可分析出Estradiol 之濃 度-指標基因轉錄效應關係曲線。由此曲線推估CB132與149樣本所產生雌性激素干擾效應，大約相當於多少濃度之 E2。以最終濃度分別為 1、10、 100與500 nM之CB132與149 進行雌性激素受體實驗發現在 PL3 與 Y253之表現皆為陰性，結果顯示CB132 與CB149不具干擾雌性激素活性特性。[[abstract]]The aim of this study is to determine short-term estrogenicity of PCB congeners, 2,2',3,3',4,6'-hexachlorobiphenyls (CB 132) and 2,2',3,4',5',6-hexachlorobiphenyls (CB 149. Also included in the test panel were 17？]-estradiol (E2) as a positive control and ethanol as solvent control. Estrogenicity was first defined as a physiologic response to a compound that induced estrus in vivo. The estrogenicity activity of CB 132 and 149 were assessed with a ？]-galactosidase assay with the yeast strain Y253. A complementary growth-based assay used yeast stain PL3 in which carried a URA3 gene that is under the control of the estrogen-response element. The E2 caused a dose-dependent increase in ？]-galactosidase activity. E2 supported growth of the yeast at minimal concentration of 1x10-5 nM. There were negative results for CB 132, CB 149, and ethanol-treated batches with the concentrations of 1, 10, 100, and 500 nM. The results demonstrated that non-dioxin-like PCBs congeners, CB 132 and 149 did not induce the estrogenicity using yeast estrogen screen.[[note]]NSC90-2320-B327-00