室旁核内部分氨基酸类神经递质在压力感受性反射过程中的变化

目的阐明下丘脑室旁核对压力感受性反射的中枢调节过程中部分氨基酸类神经递质的作用。方法以脑部微量透析法和高效液相色谱法观察清醒大鼠下丘脑室旁核(paraventricular nucleus,PVN)细胞外液中的五种氨基酸类神经递质在诱发压力感受性反射时的动态变化。结果静脉注射苯肾上腺素时,丙氨酸(ala-nine,Ala)和牛磺酸(taurine Tau)没有明显变化,而天冬氨酸(asparate,Asp),谷氨酸(glutamate,Glu)和甘氨酸(glycine,Gly)含量逐渐明显增加,3者均在引起血压变化后10min时达到高峰(P<0.05);静脉注射硝普钠时,Gly和Asp含量迅速明显增加(P<0.05)。结论Asp,Glu和Gly可能参与下丘脑室旁核对压力感受性反射的中枢调节过程。

Change in extracellular amino acids in hypothalamic paraventricular nucleus during baroreflex

[Obsjective] To investigate whether some special amino acids in the hypothalamic paraventricular nucleus (PVN) are involved in the regulation of baroreflex induced by intravenous injection of phenylephrine or sodium nitroprusside(SNP). [Methods] The microdialysis technique and high-performance liquid chromatography was used to quantify the extracellular concentrations of asparate(Asp), glutamate(Glu), glycine(Gly), alanine (Ala) and taurine (Tau) During inducing baroreflex in the PVN on the conscious rat. [Results] The concentrations of Asp, Glu and Gly were significantly increased (P <0.05) by injection of phenylephrine, and the peak appeared at 10 min after the pressor reflex. During injection of SNP, the concentrations of Gly and Asp quickly increased (P <0.05). [Conclusion] The results suggest that Asp, Glu and Gly in the PVN are involved in the central regulation of baroreflex.