Wójtowicz A K, Gregoraszczuk E L, Lyche J L, Ropstad E
Department of Animal Physiology, Institute of Zoology, Jagiellonian University, Kraków, Poland.
J Physiol Pharmacol. 2000 Sep;51(3):555-68.
To characterize PCB action on follicular cell steroidogenesis two PCB congeners were selected as model substances. PCB 126 because of its dioxin-like configuration and high toxicity and PCB 153 because it is one of the most commonly detected PCB congeners in breast milk. The direct effect of PCBs was investigated using a culture system of porcine theca and granulosa cells collected from porcine preovulatory follicles. Granulosa and theca cells were cultured in M199 medium supplemented with 1, 10 or 100 pg/ml of PCB 126 or 1, 10 and 100 ng/ml of PCB 153. The media were changed after 48, 96 and 144 h and frozen until further estradiol (E2) analysis. Additionally, progesterone (P4) was measured in the granulosa cells culture medium and testosterone (T) in theca cells culture medium. Decrease of testosterone concentration in the theca cells culture medium was found after 96 and 144 hours in culture by both investigated PCB congeners. A decrease in E2 concentration was found after exposure to PCB 153. These findings suggest different actions of two congeners on the steroid synthesis in theca cells. The lack of an increase in E2 secretion after the exposure to PCB 126 could be due to depletion of androgen precursor. In granulosa cell culture PCB153 decreased E2 secretion and increased P4 secretion suggesting luteinization and disruption of aromatization process. PCB 126 in a doses from 1 to 10 pg had no effect on granulosa cells steroidogenesis. However, the highest dose (100 pg) increased concentration of both E2 and P4. This observation suggest that PCB 126 in a pharmacological doses may affect cell membrane permeability, thereby increasing steroid outflow into the medium. These results suggest time dependent and cell-specific differences in PCB 153 and 126 action on follicular cells steroidogenesis. Further studies are required to elucidate the mechanism of PCBs action on ovarian steroidogenesis.
为了表征多氯联苯对卵泡细胞类固醇生成的作用，选择了两种多氯联苯同系物作为模型物质。多氯联苯126因其二噁英样结构和高毒性，多氯联苯153则因其是母乳中最常检测到的多氯联苯同系物之一。使用从猪排卵前卵泡收集的猪卵泡膜细胞和颗粒细胞培养系统研究了多氯联苯的直接作用。颗粒细胞和卵泡膜细胞在补充有1、10或100 pg/ml多氯联苯126或1、10和100 ng/ml多氯联苯153的M199培养基中培养。48、96和144小时后更换培养基并冷冻，直至进一步进行雌二醇（E2）分析。此外，在颗粒细胞培养基中测量孕酮（P4），在卵泡膜细胞培养基中测量睾酮（T）。两种研究的多氯联苯同系物在培养96和144小时后，卵泡膜细胞培养基中的睾酮浓度均降低。暴露于多氯联苯153后，E2浓度降低。这些发现表明两种同系物对卵泡膜细胞类固醇合成有不同作用。暴露于多氯联苯126后E2分泌未增加可能是由于雄激素前体耗竭。在颗粒细胞培养中，多氯联苯153降低了E2分泌并增加了P4分泌，表明黄体化和芳香化过程受到破坏。1至10 pg剂量的多氯联苯126对颗粒细胞类固醇生成没有影响。然而，最高剂量（100 pg）增加了E2和P4的浓度。这一观察结果表明，药理剂量的多氯联苯126可能会影响细胞膜通透性，从而增加类固醇向培养基中的流出。这些结果表明多氯联苯153和126对卵泡细胞类固醇生成的作用存在时间依赖性和细胞特异性差异。需要进一步研究以阐明多氯联苯对卵巢类固醇生成作用的机制。
