Bicuculline Infusions Advance the Timing of Luteinizing Hormone Surge in Proestrous Rats: Comparisons with Naloxone Effects
Bicuculline Infusions Advance the Timing of Luteinizing Hormone Surge in Proestrous Rats: Comparisons with Naloxone Effects
复制标题
荷包牡丹碱输注提前了发情前大鼠黄体生成激素激增的时间：与纳洛酮效应的比较
DOI：
10.1006/hbeh.1994.1039
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发表时间：
1994
影响因子：
3.5
通讯作者：
K. Jinnai
中科院分区：
文献类型：
--
作者：
F. Kimura;K. Jinnai
通过在LH峰前注入GABA_A受体拮抗剂荷包牡丹碱（BIC）是否能提前大鼠动情前期LH峰的时间，研究GABA神经元在LH分泌峰控制中的作用。阿片受体拮抗剂纳洛酮（NAL）的效果也进行了比较。在发情前期的雌性大鼠静脉输注NAL（2或5 mg/hr）或BIC（50 mg/kg/hr）3小时（1000-1300小时），在此期间通过自由活动大鼠的心房内插管以6分钟的间隔采集血样。接受输注的动物在7小时内（1400-2000小时）以1小时间隔再次流血的。NAL输注在2毫克/小时诱导脉冲LH分泌的增加，但不影响的时间，幅度和LH峰的持续时间。NAL输注在5毫克/小时，不仅诱导了更大的增加脉动LH分泌，但也导致了一个明显的LH峰过早。相反，在BIC输注期间，直到1200小时才观察到LH分泌的显著变化，但随后LH分泌迅速急剧上升，表明LH过早激增。这些结果是一致的假设，紧张性LH分泌是敏感的NAL，但不BIC，而LH分泌的激增是敏感的巴比妥类药物已被称为GABAA受体复合物的激活剂。因此，我们认为，有一个LHRH浪涌发生器，不同于脉冲发生器，在大脑中，它的电路中有GABA神经元。
The role of GABA neurons in the control of the surge of LH secretion was investigated by examining whether GABAA receptor antagonist bicuculline (BIC) infusion prior to the LH surge could advance the timing of the proestrous surge in the rat. The effect of the opioid receptor antagonist naloxone (NAL) was also examined for comparison. Female rats in proestrus were iv infused with NAL (2 or 5 mg/hr) or BIC (50 mg/kg/hr) for a 3-hr (1000-1300 hr) period during which blood samples were collected at 6-min intervals through an intraatrial cannula in freely moving rats. The animals that received infusion were bled again over a 7-hr period (1400-2000 hr) at 1-hr intervals. NAL infusions at 2 mg/hr induced an increase in pulsatile LH secretion, but did not affect the timing, magnitude, and duration of the LH surge. NAL infusions at 5 mg/hr not only induced a greater increase in pulsatile LH secretion but also resulted in a pronounced LH surge prematurely. In contrast, during BIC infusion, no significant changes in LH secretion were seen until 1200 hr, but afterward a rapid and sharp rise in LH secretion occurred, suggesting the premature LH surge. These results are consistent with the hypothesis that the tonic LH secretion is sensitive to NAL, but not to BIC, whereas the surge of LH secretion is sensitive to barbiturates that have been known as the activator of GABAA receptor complex. Therefore, we suggest that there is a LHRH surge generator, distinct from the pulse generator, in the brain, and it has GABA neurons in its circuitry.