摘要
目的研究大鼠延髓尾端加压区对肾血管紧张性和心率的影响。方法采用电刺激和微量注射法对大鼠延髓尾端加压区进行机能定位，以整体灌流肾为模型，观察该区兴奋对肾血管灌注压和心率的影响。结果（１）以电刺激（０．５ｍｓ，８０～１００Ｈｚ，１００μＡ，１０ｓ）并经Ｌ－谷氨酸（Ｌ－ｇｌｕ）检测性验证，提示大鼠延髓尾端升压区位于Ⅻ对脑神经根部联线下方０．８～１．５ｍｍ，中线旁开１．２～１．８ｍｍ的范围。（２）Ｌ－ｇｌｕ微量注射该区，可见心率加快，左肾血管灌流压上升，分别为基础值的２８．４５％和１７．０４％，动脉血压上升。（３）用神经元兴奋毒素红藻氨酸毁损该区可引起动脉血压下降至基础值的５１．７７％。（４）在延髓头端加压区微量注射普萘洛尔和酚妥拉明，可衰减尾端升压区的升压作用，但衰减后的升压作用仍有显著的统计学意义。结论在大鼠延髓尾端有一与心血管活动有关的区域，该区兴奋时通过心率加快和外周血管收缩引起升压效应，说明该区对维持血管运动张力的基础水平和动脉血压的稳定方面有一定的作用。
Objective\ To study the effects of caudal pressor area of ventral surface of medulla oblongata(CPA) on vasotonicity of renal vessels and heart rate.\ Methods\ The caudal edge of ventrolateral medulla was explored to localize sites where microinjections of L glutamate(L glu) produced pressor response in SD rats. The renal perfusion pressure and heart rate were recorded to study the effects of microinjection of L glu in to CPA.\ Results\ The caudal pressor area was limited in following regions:0.8～1 5 mm caudal to median roots of ■ cranial nerve and 1 2～1 8 mm lateral to medline. Microinjection of L glu into CPA induced a significant rising of artery pressure(25 91%,P<0 001). Heart rate 28 45% (P<0 001) and perfusion pressure of kidney(17 04%,P<0 001). Injection of phentolamine and propranolol into bilateral rostral ventrolateral medullary pressor area reduced the pressor effect of L glu injection into CPA.\ Conclsion\ The cells in the caudal most ventrolateral medulla exert atonic pressor activity that contributes to maintenance of basal levels of vasomotor tone and arterial blood pressure.
出处
《福建医科大学学报》
1997年第3期266-270,共5页
Journal of Fujian Medical University
基金
福建省自然科学基金
福建省教委资助
关键词
延髓尾端升压区
肾血管阻抗
血压
心率
caudal pressor area on ventral surface of medulla oblongata
renal vascular resistance
blood pressure
heart rate
