Castration of male rats reduces the capacity of granules isolated from the median eminence to secrete luteinizing hormone-releasing hormone in response to copper.
Castration of male rats reduces the capacity of granules isolated from the median eminence to secrete luteinizing hormone-releasing hormone in response to copper.
复制标题
雄性大鼠的去势降低了从正中隆起分离出的颗粒响应铜而分泌黄体生成素释放激素的能力。
DOI：
10.1159/000124169
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发表时间：
1985
影响因子：
4.1
通讯作者：
Cho,G
中科院分区：
文献类型：
--
作者：
Barnea,A;Cho,G
以铜为试验物质，研究了雄性大鼠去势对含有黄体生成素释放激素（LHRH）的正中隆起区（MEA）颗粒分泌功能的影响。术后 1、2 或 12 周从假手术或去势大鼠的 MEA 中分离出 LHRH 颗粒，与不同浓度的组氨酸铜复合物 (CuHis) 一起孵育，并估计 LHRH 释放的动力学常数。发现 CuHis 刺激的 LHRH 释放是 CuHis 浓度的饱和函数。去势并没有改变 CuHis 刺激的 LHRH 释放的表观 Km；对于从 1 -2 周和 12 周假手术大鼠获得的颗粒，Km 分别为 3 和 16.9 µM 铜，对于去势大鼠的颗粒，Km 分别为 3.7-5.6 和 10.2 µM 铜。此外，去势并没有改变响应 CuHis 释放的 LHRH 的分数。相比之下，去势显着减少了响应 CuHis 释放的 LHRH 的实际量；假手术大鼠1-2周和12周的Vmax分别为1,933和2,942 pg LHRH释放/6分钟/MEA，而去势大鼠分别为782和757 pg。同样，去势大鼠 MEA 中 LHRH 含量低于假手术大鼠。这些结果表明，去势降低了 MEA 颗粒响应铜等分泌刺激物释放 LHRH 的能力，这不是由于释放过程本身的生化参数发生变化，而是由于可释放的 MEA LHRH 水平降低。
The effect of castration of male rats on the secretory function of median eminence area (MEA) granules containing luteinizing hormone-releasing hormone (LHRH) was examined, using copper as a test substance. LHRH granules, isolated from MEA of sham or castrated rats 1, 2, or 12 weeks postoperatively, were incubated with various concentrations of copper complexed to histidine (CuHis) and the kinetic constants of LHRH release estimated. CuHis-stimulated release of LHRH was found to be a saturable function of the concentration of CuHis. Castration did not alter the apparent Km for CuHis-stimulated release of LHRH; the Kmbeing 3 and 16.9 µM copper for granules obtained from 1 -2 weeks and 12 weeks sham-operated rats, respectively, and 3.7–5.6 and 10.2 µM copper for the granules of castrated rats, respectively. Moreover, castration did not alter the fractional amount of LHRH released in response to CuHis. In contrast, castration markedly reduced the actual amount of LHRH released in response to CuHis; the Vmaxbeing 1,933 and 2,942 pg LHRH released/6 min/MEA for 1–2 weeks and 12 weeks sham-operated rats, respectively, and 782 and 757 pg for the castrated rats, respectively. Similarly, the LHRH content of the MEA of castrated rats was lower than that of the shams. These results are suggestive that castration reduces the capacity of the MEA granules to release LHRH in response to a secretion stimulus such as copper and that this is due not to alterations in the biochemical parameters underlying the release process itself but to a reduced level of MEA LHRH available for release.