Luteinizing hormone-releasing hormone in peripheral plasma and hypothalamus of normal and ovariectomized rats.
Luteinizing hormone-releasing hormone in peripheral plasma and hypothalamus of normal and ovariectomized rats.
复制标题
正常和卵巢切除大鼠的外周血浆和下丘脑中的黄体生成素释放激素。
DOI：
10.1159/000122496
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发表时间：
1976
影响因子：
4.1
通讯作者：
S. Mccann
中科院分区：
文献类型：
--
作者：
J. E. Wheaton;S. Mccann
采用特异性放射免疫法测定未切除卵巢和未切除卵巢大鼠血浆和下丘脑LHRH，其值与外周血血浆FSH和LH滴度相关。在发情周期的大多数阶段，血浆LHRH要么检测不到，要么存在非常小的值。部分动物在发情前13.00 ~ 20.00 h， PP - LHRH浓度升高。斩首采血大鼠LHRH平均升高幅度最大；当从乙醚化大鼠身上取样本时，升高幅度略小，而从颈静脉留置管大鼠身上取样本时，升高幅度最小。在切除卵巢的动物中，大约一半的LHRH升高；每隔15分钟从颈内插管中抽取重复样本。在LHRH升高的动物中，LHRH是高度可变的，这表明它以脉动的方式释放。去卵巢动物血浆LHRH和LH滴度有相关性。LHRH和LH之间的相关性相对较低，这可能是因为LHRH脉冲可以在相当长的时间内引起LH释放；此外，LHRH从循环中被清除的速度比LH快得多，这可以从外源性LHRH通过注射消失的时间过程中看出。在正常大鼠中，下丘脑LHRH含量在染病第1天10.00 h时略低于其他时间。卵巢切除术后4周，LHRH明显低于正常大鼠任何时间的水平。在切除卵巢的大鼠中，LHRH的再合成似乎跟不上其释放的步伐，导致下丘脑储存的下降。
Plasma and hypothalamic LHRH was measured by specific radioimmuno-assay in intact and ovariectomized rats, and the values were correlated with peripheral plasma (PP) FSH and LH titers. At most stages of the estrous cycle, plasma LHRH was either undetectable or present at very minimal values. An increase in PP LHRH concentration was observed in some animals between 13.00 and 20.00 h on proestrus. The mean elevation in LHRH was greatest in rats when blood samples were taken by decapitation; elevation was somewhat less when samples were taken from etherized rats and minimal when taken from rats bearing indwelling jugular cannulae. LHRH was elevated in approximately half the ovariectomized animals; repeated samples were drawn at 15-min intervals from intrajugular cannulae. In animals with LHRH elevations, LHRH was highly variable, which indicates that it is released in pulsatile fashion. Plasma LHRH and LH titers were correlated in ovariectomized animals. The relatively low correlation between LHRH and LH may be explained by the fact that a pulse of LHRH can elicit LH release over a considerable time span; also, LHRH is cleared much more rapidly from the circulation than is LH, as revealed by the time course of disappearance of exogenous LHRH given by bolus injection. In intact rats, hypothalamic LHRH content was slightly lower at 10.00 h on diestrus day 1 than at other sample times. LHRH was significantly lower 4 weeks following ovariectomy compared to levels in intact rats at any sample time. It would appear that LHRH's resynthesis does not keep pace with its release in ovariectomized rats, resulting in a decline in hypothalamic stores.