【摘要】 电刺激下丘脑室旁核观察了14只大鼠盲肠系膜微循环的变化。在0.2～0.6mA的刺激强度下,盲肠系膜各级微动脉及毛细血管括约肌（A₁26～66μm、A₂18～26μm、A₃6.6～18μm）均发生明显的收缩,A₁～A₃管径平均变化分别为9.9±2.8％、19.3±5.6％、46.1±7.1％,在收缩程度上存在A₃>A₂>A₁的现象。并且在A₃微血管的收缩过程中伴有血管运动增强。但微静脉未见收缩反应。刺激后与管径变化相应,微循环血流出现明显减慢,甚至出现停滞或倒流。电刺激后动脉血压平均上升4.9kpa,并呈双相性变化:第一峰波在刺激开始后0.5～2秒出现;第二峰波在刺激停止后6～7秒出现并持续1～5分钟然后缓慢下降。更多还原

【Abstract】 Electric stimuli ( 0.2-0.6mA ) were applied to the paraventricular nucleus of hypothalamus(PVN)to observe the changes in the microciculation of mesoappendix in 14 rats. All of the consecutive segments of the mesoappe-ndix arterioles and precapillary sphincters ( orders of diameter A1=26-66 μm, A2 = 18-26 μm and A3=6.6-18μm ) showed obvious constriction, the mean percentage of constriction for A1, A2 and A3 were 9.9± 2.8%, 19.3 ± 5.6% and 46.1 ±7.1% respectively, suggesting that the smaller the caliber, the greater the degree of vasoconstriction. The vasoconstriction was accompanied by the increase of rhythmic vasomotion in A3 arterioles. No contractive responses were observed in the venules. Along with the changes in lumen diameters after stimulation, the blood flow in mesoappendix microvasculature slowed down, with arrest and even reverse of blood flow seen in extreme cases. After electric stimulation, the systemic arterial blood pressure was elevated by a mean value of 4.9 kpa, showing 2 upswings: the first one occurred soon after the beginning of stimulation, the second one occurred 6-7 sec after the stop of stimulation, persisted for 1-5 min and then became flat gradually.更多还原