Priming effect of luteinizing hormone releasing factor elicited by preoptic stimulation and by intravenous infusion and multiple injections of the synthetic decapeptide.
Priming effect of luteinizing hormone releasing factor elicited by preoptic stimulation and by intravenous infusion and multiple injections of the synthetic decapeptide.
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视前刺激以及静脉输注和多次注射合成十肽引起黄体生成素释放因子的启动效应。
DOI：
10.1677/joe.0.0690359
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发表时间：
1976
期刊：
影响因子：
--
通讯作者：
M. Aiyer
中科院分区：
文献类型：
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作者：
G. Fink;S. Chiappa;M. Aiyer
我们研究了电刺激内侧视前区或静脉注射是否能引起黄体生成素的启动效应。输液或多次静脉注射。注射合成十肽。所有实验均在戊巴比妥钠麻醉的动物上进行，在发情前期大鼠，对第二次持续15分钟、间隔60分钟的电刺激，黄体生成素的反应显著大于对第一次刺激的反应。恒速输注人工合成的促黄体生成素90min后，血浆促黄体生成素在前45-60min逐渐升高，之后显著升高。在45min或更短的时间内，注入相同总剂量的促黄体生成素，无论是15或75 ng/100g体重的大鼠，这种促黄体生成素的分泌都没有发生。剂量为15 ng/100g体重，分6次静脉注射。注射间隔15分钟后，血浆黄体生成素水平在75分钟后显著升高。视前刺激90min的大鼠血浆平均促黄体生成素浓度与注射促黄体生成素90min的大鼠相似，但刺激后大鼠的反应变化要大得多。这些结果表明，促性腺激素的启动效应既可由内源性的促黄体生成素引起，也可由合成的促黄体生成素引起。无论促黄体生成素是以恒定的速度还是以脉动的方式到达脑垂体，该因子都能显著提高促性腺激素细胞的反应性。这些发现与自发的排卵前黄体生成素高峰的发展的相关性进行了讨论。在间情期大鼠持续输注黄体生成素-RF不能引起启动效应，这支持类固醇激素，特别是雌二醇-17phi决定效应的大小的观点。静脉注射黄体生成素对雄性大鼠的促黄体生成素反应。促黄体生成素输注量明显低于女性。用苯甲酸雌二醇预治疗并没有显著增加反应，这表明这种性别差异不能简单地归因于男性血浆雌激素水平较低。
We have investigated whether the priming effect of LH-RF can be elicited by electrical stimulation of the medial preoptic area, or by i.v. infusion or multiple i.v. injections of the synthetic decapeptide. All experiments were carried out on animals anaesthetized with sodium pentobarbitone at 13.30 h. In pro-oestrous rats, the LH response to the second of two electrical stimuli, 15 min in duration and separated by 60 min, was significantly greater than the response to the first stimulus. When synthetic LH-RF was infused at a constant rate for 90 min, plasma LH increased gradually for the first 45-60 min after which it increased markedly. This enhanced secretion of LH did not occur in rats which were infused with the same total dose of LH-RF, either 15 or 75 ng/100 g body wt, over periods of 45 min or less. When a dose of 15 ng LH-RF/100 g body wt was administered in six divided doses by i.v. injections, each separated by 15 min, there was a marked increase in plasma LH after 75 min. The profile of the mean plasma LH concentration in rats subjected to preoptic stimulation for 90 min was similar to that in rats infused for 90 min with LH-RF, but the variation in response was much greater in the stimulated rats. These results indicate that the priming effect can be elicited by endogenous as well as synthetic LH-RF, and that whether LH-RF reaches the pituitary at a constant rate or in a pulsatile manner the factor is capable of significantly increasing the responsiveness of the gonadotrophs. The relevance of these findings with respect to the development of the spontaneous preovulatory LH surge is discussed. A priming effect could not be elicited by constant LH-RF infusion in dioestrous rats; this supports the view that steroid hormones, especially oestradiol-17phi, determine the magnitude of the effect. The LH response in male rats subjected to i.v. infusion of LH-RF was much lower than in females. Pre-treatment with oestradiol benzoate did not increase the response significantly, suggesting that this sex difference cannot be ascribed simply to low levels of plasma oestrogen in the male.