猫延髓头侧腹外侧区注射内皮素—1对猫心血管活动的影响

研究内皮素－１在猫延髓头侧腹外侧区对心血管活动的影响。方法：采用脑立体定向和脑内微量注射技术。结果：ｒＶＬＭ内微量注射ＥＴ－１后，平均动脉压升高（３．７±１．３）ｋＰａ、心率增加（２９±７）ｂｅａｔｓ．ｍｉｎ＾－１，肾神经活动增加４５％±１０％，量效呈正相关。

Effect of endothelin-1 injected into rostral ventrolateral medulla on cardiovascular responses in cats]

AIM: To study the effect of endothelin-1 (ET-1) in the rostral ventrolateral medulla (rVLM) on cardiovascular responses in cats. METHODS: The stereotatic technique and microinjection method were used. RESULTS: ET-1 (4 mumol.L-1 0.5 microL) microinjected into rVLM induced mean arterial pressure (MAP) increasing (3.7 +/- 1.3) kPa, heart rate (HR) accelerating (29 +/- 7) beats.min-1, and renal nerve activity (RNA) intensifying 45% +/- 10%. The effects were dose-dependent. Before and after bilateral vagotomy, there was no significant difference in the reaction of MAP, HR, and RNA. After intravenous injection with phentolamine (5 mg.kg-1, alpha-blocker), ET-1 did not induce significant change of MAP. ET-1 raised the content of peripheral plasma argipressin (Arg) from (12.4 +/- 6.5) to (70.3 +/- 24.2) ng.L-1 with radioimmunoassay, and showed a correlation with MAP changes. ET-1 induced heart rhythm disorder (HRhD) in acute myocardiac ischemia, the occur time of HRhD was (4.8 +/- 2.9) min, and the score was 4.4 +/- 1.6, and it was significantly different from control. CONCLUSION: ET-1 microinjected into rVLM could involve with control regulation of cardiovascular and sympathetic nerve activity.