【摘要】 目的:探讨谷氨酸钠注入大鼠外侧下丘脑-穹窿周围区后产生的心血管效应,及其静脉注射不同受体阻断剂反应的意义。方法:实验于2004-06/09在北京大学医学部生理学与病理生理学系完成。选用72只健康Wistar大鼠。取18只大鼠谷氨酸钠微量注入外侧下丘脑/穹窿周围区后(n=9),用等容量生理盐水溶液做对照(n=9),观察血压和心率的变化;取54只大鼠分别静脉注射交感缩血管神经阻断剂酚妥拉明(n=9)、心交感神经阻断剂心得安(n=9)、心迷走神经阻断剂阿托品(n=9)预处理后,再观测谷氨酸钠注入外侧下丘脑/穹窿周围区后的血压和心率的变化。3个对照(每组n=9)用等容量生理盐水溶液注射后再谷氨酸钠注入外侧下丘脑/穹窿周围区,同时记录血压和心率的变化。结果:72只大鼠均进入结果分析。①谷氨酸钠微量注入外侧下丘脑/穹窿周围区可使动脉血压明显升高,心率加快,与外侧下丘脑/穹窿周围区内注射生理盐水的相应值比较,血压和心率的变化差异均有显著意义[(2.03±0.32),(0.00±0.09)kPa;(40.9±6.6),(1.1±1.1)次/min,P<0.05]。②静脉注射酚妥拉明使基础血压下降,注射酚妥拉明预处理后,谷氨酸钠兴奋外侧下丘脑/穹窿周围区的升压和增心率反应明显降低,与生理盐水对照组之间有高度差异[(1.1±0.2),(2.5±0.3)kPa,P<0.05;(15.3±2.9),(45.1±8.2)次/min,P<0.05]。③静脉注射心得安本身可使基础心率明显减慢,注射心得安预处理后,谷氨酸钠兴奋外侧下丘脑/穹窿周围区的升压和增心率反应明显降低,与生理盐水对照组之间有高度差异[(0.3±0.1),(2.2±0.2)kPa;(4.7±0.7),(12.6±1.3)次/min,P<0.05]。④静脉注射甲基阿托品预处理可使基础心率明显增加,使谷氨酸钠兴奋外侧下丘脑/穹窿周围区的升压和增心率反应明显降低,与生理盐水对照组之间有高度差异[(1.1±0.1),(2.3±0.1)kPa;(4.4±1.1),(16.4±4.6)次/min,P<0.05]。结论:谷氨酸钠兴奋外侧下丘脑/穹窿周围区使血压升高、心率加快反应有特异性。分别静脉注射酚妥拉明、心得安、阿托品均使兴奋外侧下丘脑/穹窿周围区引起的加压效应衰减,说明应用相应的阻断剂抑制谷氨酸钠心血管效应的作用中,交感缩血管神经、心交感神经和心迷走神经都参与了外侧下丘脑/穹窿周围区的升压反应。更多还原

【Abstract】 AIM:To investigate the cardiovascular effect following the injection of glutamate into the lateral hypothalamus-perifornical region of rats, and discuss the significance of the reaction after venous injection of different receptor blockers. METHODS:The experiment was completed in the Department of Physiology and Pathphysiology, Peking University Health Science Center from June to September 2004. Seventy-two healthy Wistar rats were selected. Trace glutamate (n=9) and saline solution of the same volume (n=9) were injected into the lateral hypothalamus-perifornical region of rats, and then the changes of blood pressure and heart rate were observed; Fifty-four rats were treated with the preconditioning of venous injections of phentolamine (n=9), which was a blocking agent of sympathetic vasoconstrictor nerve, propranolol (n=9), which was a blocking agent of cardiac sympathetic nerve, and atropine (n=9), which was a blocking agent of cardiac vagus nerve, and then the changes of blood pressure and heart rate were observed after glutamate was injected into the lateral hypothalamus-perifornical region. Rats in the 3 control groups (9 rats in each group) were treated with saline solution of the same volume, and then changes of blood pressure and heart rate were recorded after glutamate was injected into the lateral hypothalamus-perifornical region. RESULTS: Totally 72 rats were involved in the analysis of results. ① Injection of trace glutamate into the lateral hypothalamus-perifornical region could obviously increased the arterial pressure and accelerate heart rate, and there were significant differences in the changes of blood pressure and heart rate as compared with those treated with injection of saline into the lateral hypothalamus-perifornical region [(2.03±0.32), (0.00±0.09) kPa; (40.9±6.6), (1.1±1.1) beats per minute, P < 0.05]. ② Venous injection of phentolamine could decrease the basic blood pressure,after preconditioning of phentolamine, the reactions of increased blood pressure and heart rate in the excited lateral hypothalamus-perifornical region were significantly decreased as compared with the saline control group [(1.1±0.2), (2.5±0.3) kPa, P < 0.05; (15.3 ± 2.9), (45.1 ± 8.2) beats per minute, P < 0.05]. ③Venous injection of propranolol could slow down the basic heart rate, after preconditioning of propranolol, the reactions of increased blood pressure and heart rate in the excited lateral hypothalamus-perifornical region were significantly decreased as compared with the saline control group [(0.3±0.1), (2.2±0.2) kPa; (4.7 ± 0.7), (12.6 ± 1.3) beats per minute, P < 0.05]. ④ The preconditioning of venous injection of atropine could obviously increase the basic heart rate, the reactions of increased blood pressure and heart rate in the excited lateral hypothalamus-perifornical region were significantly decreased as compared with the saline control group [(1.1±0.1), (2.3±0.1) kPa; (4.4 ± 1.1), (16.4 ± 4.6) beats per minute, P < 0.05]. CONCLUSION:Injection of glutamate into the excited lateral hypothalamus-perifornical region can specify the increase of blood pressure and acceleration of heart rate. The venous injections of phentolamine, propranolol and atropine respectively can all reduce the increase of blood pressure, it is indicated that all the sympathetic vasoconstrictor nerve, cardiac sympathetic nerve and cardiac vagus nerve were involved in the reaction of increase of blood pressure in the lateral hypothalamus-perifornical region during the role of corresponding blocking agent in inhibiting the cardiovascular effect of glutamate.更多还原