ENVIRONMENTAL EPOXIDES--MECHANISMS OF OVOTOXICITY

环境化学品4-乙烯基环己烯(VCH)是在 生产橡胶轮胎、阻燃剂、杀虫剂、 增塑剂和抗氧化剂。双环氧化物给药(30d) 代谢物4-乙烯基环己烯二环氧化物(VCD)破坏大部分 小鼠卵巢腔前(原始)小卵泡的数量 老鼠。女性出生时只有有限数量的原始卵泡 不能再生的；因此，破坏卵母细胞的化学物质 这些卵泡中含有的卵泡会导致卵巢早衰。 妇女暴露于已知的卵毒物质，如香烟烟雾和 化疗药物与早期绝经有关，因此， 在工业环境中可能接触到其他卵毒化学品 是值得关注的。以前对大鼠注射VCD(80 mg/kg)的研究表明， 破坏小卵泡需要每天给药(10天)，是通过 生理性细胞死亡(细胞凋亡)，并伴随着改变 细胞凋亡(Bax)、氧化应激相关基因的表达 (超氧化物歧化酶)和解毒(环氧化物水解酶)。这个 这里提出的研究将描述氧化应激的作用 VCD诱导的细胞凋亡中的卵泡代谢。实验性的 方法将涉及利用对VCD的响应转变 我们在小卵泡中观察到的剂量具有保护作用(1 剂量)，对细胞凋亡的影响(每天10次和15次)。另外， 这些研究将使用我们已有的分离的小卵泡系统 与共焦显微镜联合开发以定位事件 在特定的细胞内。需要检验的假设是：VCD 在小腔前卵泡中启动氧化应激反应 在重复给药后改变，以触发Bax的发作- 介导的细胞凋亡。具体目标是1)描述 Bax介导的细胞凋亡中的氧化应激反应，2)与VCD相关 小卵泡的代谢与氧化应激，以及3)评估 通向细胞凋亡的应激激活途径。这些研究将使用一种 综合形态、生化和分子方法提供 更好地了解沙门氏菌引起卵子毒性的机制 职业性的，环氧化物。这些研究的结果将提供 对暴露于卵毒环境的影响有更深入的了解 化学品对妇女生殖健康的影响。

The environmental chemical, 4-Vinylcyclohexene (VCH) is produced in the manufacture of rubber tires, flame retardants, insecticides, plasticizers, and antioxidants. Dosing (30 d) with the diepoxide metabolite, 4- vinylcyclohexene diepoxide (VCD) destroys the majority of small pre-antral (primordial) follicles in the ovaries of mice and rats. Females are born with a finite number of primordial follicles that cannot be regenerated; thus, chemicals that destroy oocytes contained in these follicles can produce premature ovarian failure. Exposure of women to known ovotoxicants such as cigarette smoke and chemotherapeutic agents has been associated with early menopause, thus, potential exposure to other ovotoxic chemicals in the industrial setting is of concern. Previous studies with VCD (80mg/kg) in rats showed that destruction of small follicles requires daily dosing (10 days), is via physiological cell death (apoptosis), and is accompanied by altered expression of genes associated with apoptosis (bax), oxidative stress (superoxide dismutase, and detoxification (epoxide hydrolase). The studies, proposed here will characterize the role of oxidative stress and follicular metabolism in VCD-induced apoptosis. The experimental approach will involve exploiting the shift in responsiveness to VCD dosing we have observed in small follicles from a protective effect (1 dose), to an apoptotic effect (10 and 15 daily doses). Additionally, these studies will use the isolated small follicle system we have developed in conjunction with confocal microscopy to localize events within specific cells. The hypothesis to be tested is that: VCD initiates an oxidative stress response in small pre-antral follicles that is altered after repeated dosing to trigger the onset of bax- mediated apoptosis. The Specific Aims are 1) to characterize the oxidative stress response in bax-mediated apoptosis, 2) to relate VCD metabolism with oxidative stress in small follicles, and 3) to evaluate the stress-activated pathway to apoptosis. The studies will use an integrated morphological, biochemical and molecular approach to provide a greater understanding of the mechanisms of ovotoxicity caused by occupational, epoxides. The results of these studies will provide greater insight as to the impact of exposure to ovotoxic environmental chemicals on reproductive health in women.