Effects of cupric acetate on hypothalamic gonadotropin-releasing hormone release in intact and ovariectomized rabbits.
Effects of cupric acetate on hypothalamic gonadotropin-releasing hormone release in intact and ovariectomized rabbits.
复制标题
醋酸铜对完整兔和卵巢切除兔下丘脑促性腺激素释放激素释放的影响。
DOI：
10.1159/000124528
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发表时间：
1986
影响因子：
4.1
通讯作者：
Spies,HG
中科院分区：
文献类型：
--
作者：
Pau,KY;Spies,HG
本文探讨了静脉注射醋酸铜（CuAc）对清醒、卵巢完整和切除卵巢（OVEX）的小鼠下丘脑促性腺激素释放激素（GnRH）、垂体促黄体生成素（LH）、促卵泡激素（FSH）和催乳素（PRL）释放的影响，这些小鼠皮下植入空白硅胶胶囊或含有结晶雌二醇-17β (E2)的硅胶胶囊。动物后正中隆起推拉灌注6 h，推拉灌注第2 h结束时静脉注射CuAc （2.5 mg/kg体重）。连续收集灌注液样品，每隔10分钟收集一次。每隔10 ~ 30分钟采集外周血样本。采用特异性放射免疫法测定推拉灌注液中GnRH和血浆中LH、FSH、PRL的水平。在未受影响的大鼠（n = 4）中，静脉注射CuAc刺激下丘脑GnRH和垂体LH、FSH和PRL的释放。注射CuAc后下丘脑GnRH的初始升高和随后的降低先于血浆LH、FSH和PRL。将生理盐水注射到完整的小鼠（n = 4）中，对这些激素水平没有任何影响。在接受空白硅橡胶胶囊（n = 4）的OVEX组中，CuAc未能刺激下丘脑GnRH释放或垂体LH、FSH和PRL释放。相比之下，CuAc刺激了接受含有e2硅橡胶胶囊的OVEX小鼠中所有四种激素的释放（n = 3）。这些结果表明，下丘脑GnRH释放的增加先于铜诱导的排卵前促性腺激素释放的增加，并支持神经肽GnRH介导促性腺激素释放的假设。这些数据也令人信服地证明，CuAc的作用需要卵巢的存在。E2可能是卵巢神经内分泌过程中的一种成分。
The effects of intravenous injection of cupric acetate (CuAc) on release of hypothalamic gonadotropin-releasing hormone (GnRH) and pituitary luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin (PRL) were explored in conscious, ovarian intact does and in ovariectomized (OVEX) does that received subcutaneous implants, either blank Silastic capsules or Silastic capsules containing crystalline estradiol-17β (E2). Animals were subjected to push-pull perfusion of the posterior median eminence for 6 h, and CuAc was intravenously injected (2.5 mg/kg body weight) at the end of the 2nd h of push-pull perfusion. Perfusate samples were collected continuously and pooled for assay at 10-min intervals. Peripheral blood samples were obtained at 10- to 30-min intervals. Levels of GnRH in push-pull perfusate and LH, FSH, and PRL in plasma were measured by specific radioimmunoassays. In intact does (n = 4), intravenous injection of CuAc stimulated the release of hypothalamic GnRH and pituitary LH, FSH, and PRL. The initial increase and subsequent decrease in hypothalamic GnRH after CuAc injection preceded those in plasma LH, FSH, and PRL. Injection of saline into intact does (n = 4) had no effect on any of these hormone levels. In OVEX does that received blank Silastic capsules (n = 4), CuAc failed to stimulate either hypothalamic GnRH release or pituitary LH, FSH, and PRL release. In contrast, CuAc stimulated the release of all four hormones in OVEX does that received E2containing Silastic capsules (n = 3). These results show that an increase in hypothalamic GnRH release precedes the increase in copper-induced preovulatory gonadotropin release and support the hypothesis that the neuropeptide GnRH mediates this gonadotropin release. The data also are compelling evidence that the action of CuAc requires the presence of the ovaries. One ovarian component in this neuroendocrine process probably is E2.