延髓头端腹外侧区在大鼠外侧下丘脑/穹窿周围区升压反应中的作用

Role of the rostral ventrolateral medulla in pressor response of lateral hypothalamus-perifornical region to glutamate in rats

目的探讨延髓头端腹外侧区(RVL)对大鼠外侧下丘脑/穹窿周围区(LH/PF)升压反应的影响和作用机制。方法30只健康Wistar大鼠随机分成4组:酚妥拉明组;心得安组;阿托品组和谷氨酸二乙酯组,每组均用生理盐水作对照。谷氨酸钠微量注入大鼠LH/PF后,观察血压升高和心率加快反应;然后分别将酚妥拉明、心得安、阿托品和谷氨酸二乙酯微量注射到RVL,再观测注射谷氨酸钠后的血压和心率变化。结果谷氨酸钠微量注入LH/PF后大鼠的动脉血压明显升高,心率加快;RVL内分别微量注射酚妥拉明、心得安、甲基阿托品和谷氨酸二乙酯后再注射谷氨酸钠,各组大鼠的升压反应明显降低,与生理盐水对照组之间有非常显著性差异(P<0.01)。结论RVL内的α-、β-、M-和谷氨酸(Glu-)受体介导LH/PF的升压反应。

Objective To investigate the effect and mechanisms of rostral ventrolateral medulla （RVL） on the pressor response of lateral hypothalamus-perifornical region （LH/PF） in rats. Methods 30 healthy Wistar rats were randomly divided into four groups： the phentolamine group; propranolol group; atropine group and glutamate diethyl ester group, saline was as the control in every group. After microinjection of Glu into LH/PF, the blood pressure and heart rate were observed. Then phentolamine, propranolol, atropine and glutamate diethyl ester were microinjected into RVL and the blood pressure and heart rate changes induced by microinjection of Glu were observed again. Results Microin]ection of Glu into LH/PF can cause the blood pressure elevating and heart rate accelerating. The pressor response of Glu to excited LH/PF could be attenuated after response of phentolamine, propranolol, atropine and glutamatediethyl ester microinjected into RVL. The blood pressures of phentolamine group, propranolol group, atropine group and glutamate diethyl ester group reduced significantly different from those in the saline control group （ P〈0.01）. Conclusion The α-,β-,M- and Glu-receptors in the RVL induce the pressor response of LH/PF region.