Gatti P J, Dias Souza J, Gillis R A
Department of Pharmacology, Georgetown University, School of Medicine and Dentistry, Washington, DC 20007.
Brain Res. 1988 May 17;448(2):313-9. doi: 10.1016/0006-8993(88)91269-3.
Recently, Somberg, in a preliminary report (1983), noted that electrical stimulation of the area postrema causes an increase in coronary vascular resistance. The increase in resistance was mediate by an increase in sympathetic activity as it was counteracted by alpha-adrenergic receptor blockade. The purpose of our study was to confirm the findings of Somberg by using the method of chemical-induced activation of cell bodies in the area postrema. This was done by bilateral topical application of kainic acid to the area postrema of cats while monitoring coronary blood flow, heart rate, arterial blood pressure and the ECG. Topical application of kainic acid produced an increase in coronary vascular resistance (43 +/- 13%, P less than 0.05), S-T segment changes, increases in heart rate (60 +/- 10, P less than 0.05) and arterial blood pressure (88 +/- 20, P less than 0.05) and ventricular tachyarrhythmias. All of these effects were prevented by pretreating animals with the alpha-adrenoceptor blocking agent, phentolamine. These results suggest that chemical excitation of area postrema neurons produces coronary constriction that is mediated by the sympathetic nervous system and alpha-adrenoceptors on coronary vessels.
最近，索姆伯格在一份初步报告（1983年）中指出，对最后区进行电刺激会导致冠状动脉血管阻力增加。阻力的增加是由交感神经活动增强介导的，因为它可被α-肾上腺素能受体阻断所抵消。我们研究的目的是通过使用化学诱导激活最后区细胞体的方法来证实索姆伯格的研究结果。这是通过在监测冠状动脉血流量、心率、动脉血压和心电图的同时，对猫的最后区双侧局部应用 kainic 酸来实现的。局部应用 kainic 酸会导致冠状动脉血管阻力增加（43±13%，P＜0.05）、ST 段改变、心率增加（60±10，P＜0.05）、动脉血压增加（88±20，P＜0.05）以及室性快速心律失常。所有这些效应都可通过用α-肾上腺素能受体阻断剂酚妥拉明预处理动物来预防。这些结果表明，最后区神经元的化学兴奋会产生由交感神经系统和冠状动脉血管上的α-肾上腺素能受体介导的冠状动脉收缩。
