硅胶管包裹大鼠颈动脉对血管收缩功能的影响

Effect of the Collar-induced Adventitia Injury on Vasoconstriction of Rat Carotid Artery

目的观察硅胶管包裹所致的血管外膜损伤对大鼠颈动脉收缩功能的影响。方法用硅胶管经血管外膜包裹大鼠颈动脉,分别于术后3 d、1周、2周测量大鼠双侧颈动脉血流量,观察血管对局部应用5-羟色胺(5-HT)的反应,光镜下观察血管形态学变化。结果与对照侧比较,硅胶管包裹大鼠颈动脉的早期阶段,包管侧颈动脉呈血管慢性收缩的组织学改变,表现为血管腔缩小[包管3 d缩小(12.15±2.29)%(P=0.003);包管1周缩小(45.17±3.84)%(P<0.001)]。内弹力板弯曲、中膜增厚[包管3 d增厚(23.04±5.96)%(P=0.009);包管1周增厚(61.65±10.32)%(P<0.001)],伴颈动脉血流量降低及血管对5-HT的收缩反应增强。硅胶管包裹2周,包管侧颈动脉管壁重塑,表现为中膜增厚[增厚(31.52±4.56)%(P=0.012)]及弥漫性血管内膜增生[新生内膜面积平均(0.19±0.05)mm2],伴血管腔面积缩小[减少(37.17±4.57)%(P<0.001)]及颈动脉血流量降低,血管对5-HT的收缩反应恢复至对照侧水平。结论血管外膜损伤能引起血管收缩功能增强及新生内膜形成,血管收缩功能的改变出现在内膜增生性病变之前。

Objective To observe the effects of the chronic adventitia injury on the vasoconstriction of the rat carotid artery. Methods A non-occlusive silicone collar was positioned around the right carotid artery of rats. Blood flow and vascular reactivity to 5-HT were examined, and both carotids were harvested for morphometry at day 3,7 and 14 after operation. Results In the early stage of advenfitia injury induced by positioning a silicone collar around file rat carotid artery, there appeared the characteristic histological changes of chronic vasospasm in collared artery, such as the reduction of the luminal area for （12.15±2.29）% at day 3 after operation （P =0.003 ） and （45.17±3.84）% at day 7 （P 〈 0.001 ）] ,corrugation of the internal elastic lamina,medial thickening up to [ （23.04±5.96）% at day 3 （P =0.009）, （61.65±10.32）% for day 7 （P 〈 0.001 ）] ,the reduction of the blood flow and the increase of vascular reactivity to 5-HT when compared to con- tralateral arteries. Two weeks after collar placement, the vascular wall remodeling was observed in injured artery, such as the medial thickening for [（31.52±4.56） %,P =0.012] and a diffuse intimal hyperplasia,the reduction of the lunfinal area [（37.17±4.57）% （P 〈 0.001）] and the carotid artery blood flow. The average neointima area was （0.19±0.05） rom2 in collared arteries. The vascular reactivity to 5-HT came back to the normal level. Conclusions Collar-induced advenfitia injury caused the enhancement of vascular contractility and the neointima formation. The change of vascular contractility appeared before the formation of neointima.