兴奋下丘脑弓状核神经元降低大鼠血浆唾液酸水平的作用

EXCITATION OF HYPOTHALAMIC NUCLEUS ARCUATUS NEURON INDUCED DECREASE OF PLASMASIALIC ACID LEVEL IN RATS

实验采用下丘脑弓状核（ＡＲＣ）区微量注射和紫外分光光度测定法，研究ＡＲＣ区注射不同浓度谷氨酸钠（ＧｌＵ）对大鼠血浆唾液酸（ＳＡ）水平的影响。结果表明：（１）ＡＲＣ区注射Ｇｌｕ后，血浆ＳＡ水平较对照组明显降低（Ｐ＜０．０１），而且随Ｇｌｕ浓度的增加，血浆ＳＡ水平降低所需的时间逐渐缩短；（２）例脑室注射阿朴吗啡后，ＡＲＣ区注射测射Ｇｌｕ，血浆ＳＡ水平明显降低（Ｐ＜０．０１），而且降低发生时间较对照组提前；（３）例脑室注射螺哌啶酮后，ＡＲＣ区注射Ｇｌｕ，血浆ＳＡ水平无明显变化（Ｐ＞０．０５）。这提示下丘脑ＡＲＣ区神经元兴奋导致血浆ＳＡ水平降低可能与下丘脑ＡＲＣ区的多巴胺能神经元兴奋释放多巴胺（ＤＡ）有关，且通过ＤＡ－Ｄ２受体起作用。

The effect of sodium glutamate (Gln) on plasma static acid (SA) level was studied by means of microinjection into the nucleus arcuatus (ARC) and ultroviolet spectrophotometry.The results indicate: (1 ) The plasma SA level was significantly decreased after microinjection of Gin into the ARC (P<0. 01 ). With increasing Glu concentration,the onset of the decrease occurred earlier. (2) When Glu was microinjected into ARC after intraventricular injection of apomorphine, the plasma SA level was significantly decreased (P<0. 01 ) and the time required to cause the decrease was shortened.(3)When Gin was microinjected into ARC after intraventricular injection of spiperone,no change was found in the plasma SA level (P>0. 05). The above results suggest that the mechanism underlying the decrease of plasma SA level is probably related to modulated dopamine (DA) release of hypothalamic dopaminergic neurons by DA-D2 recedetor.