Release of glutamate and aspartate from the preoptic area during the progesterone-induced LH surge: in vivo microdialysis studies.
Release of glutamate and aspartate from the preoptic area during the progesterone-induced LH surge: in vivo microdialysis studies.
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黄体酮诱导的 LH 激增期间视前区谷氨酸和天冬氨酸的释放：体内微透析研究。
DOI：
10.1159/000126673
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发表时间：
1994
影响因子：
4.1
通讯作者：
Brann,DW
中科院分区：
文献类型：
--
作者：
Ping,L;Mahesh,VB;Wiedmeier,VT;Brann,DW
为了研究兴奋性氨基酸神经递质在雌二醇和孕酮治疗的卵巢切除（ovx）成年大鼠中LH和FSH分泌调节中的作用，我们测量了兴奋性氨基酸神经递质谷氨酸和天冬氨酸的释放速率，以及在30- 40 ℃收集的下丘脑视前区（POA）微透析灌注液样品中的神经活性氨基酸丝氨酸。在孕酮诱导的LH峰期间，通过使用邻苯二甲醛预衍生化，然后通过HPLC结合荧光检测的测定来测量氨基酸的浓度。与雌激素对照组相比，孕酮处理的雌激素致敏的ovx大鼠POA中谷氨酸的释放速率在15：30和16：00 h增加。与雌激素对照组相比，经炔雌醇处理的雌激素致敏OVX大鼠POA中天冬氨酸的释放率在12：00、12：30、15：00和16：00 h增加。孕酮处理的大鼠中谷氨酸和天冬氨酸的POA释放速率的增加发生在孕酮诱导的血清LH水平达到峰值之前。POA释放率的增加谷氨酸和天冬氨酸的特异性证明了这一发现，即视前释放的神经失活的神经递质丝氨酸是不变的类固醇治疗。与卵巢切除对照组相比，单独给予雌二醇对谷氨酸、天冬氨酸或丝氨酸的POA释放速率没有显著影响。总之，本研究表明，POA释放率的谷氨酸和天冬氨酸增加之前立即在雌激素引发的成年OVX大鼠的孕酮诱导的LH峰。这一发现进一步证明了兴奋性氨基酸神经传递可能是雌性大鼠中介导促性腺激素峰表达的神经传递线的重要组成部分。
To examine the role of excitatory amino acid neurotransmitters in the regulation of LH and FSH secretion in ovariectomized (ovx) adult rats treated with estradiol and progesterone, we measured the release rates of the excitatory amino acid neurotransmitters, glutamate and aspartate, as well as the neurally inactive amino acid serine in microdialysis perfusate samples of the preoptic area (POA) of the hypothalamus collected at 30-min intervals during the LH surge induced by progesterone. The concentrations of the amino acids were measured by assay using orthophthalaldehyde prederivatization followed by HPLC coupled with fiuorometric detection. The release rates of glutamate in the POA increased at 15:30 and 16:00 h in the progesterone-treated estrogen-primed ovx rat as compared to estrogen controls. Release rates of aspartate in the POA were increased at 12:00, 12:30, 15:00 and 16:00 h in the progesterone-treated estrogen-primed ovx rat as compared to estrogen controls. The increase in POA release rates of glutamate and aspartate in the progesterone-treated rats occured immediately prior to peak serum LH levels induced by progesterone. The specificity of the increase in POA release rates of glutamate and aspartate was evidenced by the finding that the preoptic release of neurally inactive neurotransmitter serine was unchanged by steroid treatment. Estradiol alone had no significant effect on the POA release rates of glutamate, aspartate or serine as compared to ovariectomized controls. In conclusion, the present study demonstrates that the POA release rates of glutamate and aspartate are increased immediately preceding the peak of the progesterone-induced LH surge in the estrogen-primed adult ovx rat. This finding adds further evidence that excitatory amino acid neurotransmission may be an important component in the neurotransmission line mediating gonadotropin surge expression in the female rat.