Studies on the effects of dioxin/dioxin-like congeners on the ovarian function and morphology in the progeny.

结果如下：1)雌性大鼠在交配前2周至断奶前通过自然分娩口服PCB126对子代卵巢的生长和基因表达产生直接的不良影响。2)妊娠15天单次口服PCB126可减少子代第一次排卵时排出的卵母细胞数。提示PCB126对子代卵巢的毒性临界点可能在孕15天以后。3)孕15天单次经口接触PCB126可导致雌性大鼠卵巢腔前和/或腔前卵泡数量减少，与类固醇生成相关的基因表达减弱，子代血液中抑制素和雌二醇水平降低，FSH水平升高，提示PCB126干扰了子代卵泡的生长和卵巢中类固醇的产生。子宫或哺乳期暴露于多氯联苯126可抑制卵泡的生长，减少首次排卵时排出的卵母细胞数，但这种不良反应在乳汁暴露的子代中更为明显。5)24日龄大鼠一次性口服多氯联苯126对大卵泡的生长和首次排卵没有任何不利影响，表明该年龄段的卵巢对多氯联苯126.6的敏感性较低)证实了激光显微切割技术对于卵巢特定部位基因表达的采样和分析非常有用，以寻找多氯联苯126的靶细胞。

Next results were obtained by this study.1) Dairy oral exposure of female rats to PCB126 from 2weeks before mating until weaning through spontaneous delivery induced direct adverse effects on the growth and gene expression in the ovary of their progeny.2) Single oral exposure of female rats to PCB126 at gestational day 15 decreased the number of oocytes shed at the first ovulation in the progeny, suggesting that the critical point of PCB126 toxicity on the ovary of the progeny might be after gestational day 15 in the rats.3) Single oral exposure of female rats to PCB 126 at gestational day 15 induced decreasing the number of pre-antral and/or antral follicles and impaired expression of the genes associated with steroid-genesis in the ovary, decreasing blood level of inhibin and estradiol, and increasing blood level of FSH in the progeny, suggesting that PCB 126 disturbed follicular growth and steroid production in the ovary of the progeny.4) From the fostering study, either in utero or lactational exposure to PCB 126 induced growth inhibition of the ovarian follicles and decreasing the number of oocytes shed at the first ovulation, but such adverse effects were much more obvious in the lactationally-exposed progeny.5) Single oral exposure to PCB 126 in 24-day-old rats had not any adverse effects on the growth of the large ovarian follicles and the first ovulation, indicating low sensitivity of the ovary at this age to PCB 126.6) It was confirmed that a laser microdissection technique was very useful for sampling and analysis of gene expression of the particular sites in the ovary for searching the target cells of PCB 126.