...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Reproductive toxicology >2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) blocks ovulation by a direct action on the ovary without alteration of ovarian steroidogenesis: lack of a direct effect on ovarian granulosa and thecal-interstitial cell steroidogenesis in vitro.
【24h】

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) blocks ovulation by a direct action on the ovary without alteration of ovarian steroidogenesis: lack of a direct effect on ovarian granulosa and thecal-interstitial cell steroidogenesis in vitro.

机译：2,3,7,8-四氯二苯并-对-二恶英（TCDD）通过直接作用于卵巢而不会改变卵巢类固醇生成来阻止排卵：在体外对卵巢颗粒和鞘间质细胞类固醇生成没有直接作用。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The main purpose of this study was to investigate the direct effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on ovarian function including ovulation and steroidogenesis. In vivo effects of TCDD were investigated on ovulation and alteration of circulating and ovarian steroid hormones in immature hypophysectomized rats (IHR) primed with equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG). In addition, in vitro effects of TCDD on the steroidogenesis of granulosa cells (GC), theca-interstitial cells (TIC), and whole ovarian dispersates derived from the ovary of IHR were investigated. In the ovulation model, rats were hypophysectomized on Day 23 of age. On Day 26, the IHR were given 20 microg TCDD/kg by gavage. The next day eCG (10 IU) was injected sc to stimulate follicular development. Fifty-two hours after eCG, 10 IU hCG was given to induce ovulation. TCDD (20 microg/kg) blocked ovulation and reduced ovarian weight in IHR. Concentrations of progesterone (P4), androstenedione (A4), and estradiol (E2) in sera and ovaries were not altered by TCDD at 12, 24, 48, and 72 h after eCG. except for a two-fold increase in ovarian concentration of A4 at 48 h after TCDD. However, this higher concentration of A4 at 48 h after TCDD did not reflect that of A4 in sera and did not correlate with E2 in either sera or ovaries. In isolated GC from untreated IHR, TCDD (0.1 to 100 nM) had no significant effect on P4 and E2 after stimulation by LH or FSH. In TIC and whole ovarian dispersates containing GC, TIC, and other ovarian cells, TCDD (0.1 to 800 nM) had no effect on A4 and P4 secretion stimulated by LH. Using RT-PCR, AhR mRNA was shown to be expressed constitutively in the whole ovary of IHR with maximum down-regulation at 6 h after TCDD (20 microg/kg). Ovarian CYP1A1 was induced maximally at 6 h after TCDD, whereas CYP1B1 could not be detected. The induction of AhR related genes by TCDD in the ovary implies the existence of AhR-mediated signal transduction pathways. In summary, these results indicate that TCDD does not affect ovulation in IHR by altering ovarian steroidogenesis. It seems that inhibition of ovulation by TCDD is due to processes related to follicular rupture.
机译：这项研究的主要目的是研究2,3,7,8-四氯二苯并-对-二恶英（TCDD）对卵巢功能（包括排卵和类固醇生成）的直接作用。研究了TCDD的体内作用，该反应在未成熟的经水电切除的大鼠（IHR）中以马绒毛膜促性腺激素（eCG）和人绒毛膜促性腺激素（hCG）促排卵和改变了循环和卵巢类固醇激素。此外，还研究了TCDD对颗粒细胞（GC），卵泡间质细胞（TIC）和源自IHR卵巢的整个卵巢分散液的类固醇生成的体外作用。在排卵模型中，在年龄的第23天对大鼠进行垂体切除术。在第26天，通过管饲法向IHR给予20微克TCDD / kg。第二天，皮下注射eCG（10 IU）以刺激卵泡发育。 eCG后52小时，给予10 IU hCG诱导排卵。 TCDD（20 microg / kg）阻止了排卵并降低了IHR中的卵巢重量。在eCG后12、24、48和72小时，TCDD不会改变血清和卵巢中孕酮（P4），雄烯二酮（A4）和雌二醇（E2）的浓度。 TCDD后48小时，卵巢中A4浓度增加了两倍。但是，TCDD后48 h较高的A4浓度不能反映血清中A4的浓度，并且与血清或卵巢中的E2均不相关。在未经处理的IHR中分离出的GC中，TCD（0.1至100 nM）在LH或FSH刺激后对P4和E2没有明显影响。在TIC和含有GC，TIC和其他卵巢细胞的整个卵巢分散液中，TCDD（0.1至800 nM）对LH刺激的A4和P4分泌没有影响。使用RT-PCR，显示AhR mRNA在IHR的整个卵巢中组成性表达，在TCDD后6 h（20 microg / kg）最大下调。 TCDD后6 h最大程度诱导卵巢CYP1A1，而未检测到CYP1B1。 TCDD在卵巢中诱导与AhR相关的基因暗示了AhR介导的信号转导途径的存在。总之，这些结果表明，TCDD不会通过改变卵巢类固醇生成而影响IHR的排卵。 TCDD抑制排卵似乎是由于与卵泡破裂有关的过程。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号