Park O K, Ramirez V D
Department of Physiology and Biophysics, University of Illinois, Urbana.
Neuroendocrinology. 1989 Jul;50(1):66-72. doi: 10.1159/000125203.
In the present study, we examined the in vivo release profiles of luteinizing hormone-releasing hormone (LHRH) during the rat estrous cycle by utilizing repetitive push-pull perfusions of the anterior pituitary in the same freely behaving animal. Throughout the estrous cycle, LHRH levels were higher than those reported from previous work using a push-pull cannula placed in the mediobasal hypothalamus. A significant increase in LHRH input to the anterior pituitary was obtained in proestrus (Pro), though the magnitude of increment was different among animals. This LHRH increment in Pro was attributable to a significant increase in the amplitude of LHRH pulses. Interestingly, no changes were observed in the frequency of LHRH pulses (about 1 pulse/50 min) throughout the estrous cycle. The data demonstrate that the anterior pituitary of female rats receives an increased amount of LHRH during Pro due to changes in the amplitude of the LHRH signal without changes in the frequency.
在本研究中，我们通过对同一自由活动的动物进行垂体前叶的重复推挽灌注，研究了大鼠发情周期中促黄体生成激素释放激素（LHRH）的体内释放情况。在整个发情周期中，LHRH水平高于先前使用置于下丘脑中间基底部的推挽插管所报道的水平。在发情前期（Pro），垂体前叶的LHRH输入量显著增加，尽管不同动物的增加幅度有所不同。发情前期LHRH的增加归因于LHRH脉冲幅度的显著增加。有趣的是，在整个发情周期中，LHRH脉冲频率（约1次脉冲/50分钟）未观察到变化。数据表明，由于LHRH信号幅度的变化而频率不变，雌性大鼠垂体前叶在发情前期接受的LHRH量增加。
