谷氨酸钠刺激下丘脑弓状核区对大鼠血浆唾液酸水平的影响

EFFECT OF HYPOTHALAMIC NUCLEAUS ARCUATUS ON RAT SIALIC ACID LEVEL UNDER SODIUM GLUTAMATE STIMULATION

①目的探讨弓状核（ＡＲＣ）区神经元兴奋对大鼠血浆唾液酸（ＳＡ）水平的影响。②方法紫外分光光度法，测定ＡＲＣ区注射不同浓度谷氨酸钠（Ｇｌｕ）对大鼠血浆ＳＡ水平的影响，并与对照组进行比较。③结果ＡＲＣ区注射Ｇｌｕ后，血浆ＳＡ水平较对照组明显降低（ｔ＝２．７１７～５．２０８，Ｐ均＜０．０５），且呈明显的量效依赖关系，此效应可被静脉注射多巴胺受体阻断剂（螺哌啶酮）阻断。④结论下丘脑ＡＲＣ区神经元兴奋导致血浆ＳＡ水平降低，可能与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。

Objective To study the effect of nucleus arcuatus excitaton on plasma sialic acid(SA) level in rats. Methods Different concentrations of sodium glutamate(Glu) were injected into nucleus arcuatus(ARC) and ultraviolet spectrophotometry was used to detect the plasma SA level. Results The plasma SA level of rats was significantly decreased after the microinjection of Glu into ARC( t=2.717￣5.208, P<0 .05). The decrement was in a dose dependent manner. This effect could be blocked by intravenous injection of spiperone. Conclusion The mechanism which causes the decrease of plasma SA level is possibly related to the release of dopamine(DA) by the hypothalamic dopaminergic neurons and modulated by the DA D 2 receptor.