尾加压素Ⅱ对大鼠肠系膜微循环的影响

目的: 探讨尾加压素(UII)对于大鼠肠系膜微循环的影响。方法: 采用活体微循环观测技术观察UII对于SD大鼠肠系膜微血管内径、血流速度的作用,采用激光多普勒血流量仪测定肠壁血流量的变化。结果: 正常对照组肠系膜细动脉和细静脉血管内径分别为(21.4±2.3) μm和(38.1±3.6) μm,UII组于滴加UII(10^-7mol/L)后即刻细动脉和细静脉出现收缩,1 min时细动脉和细静脉收缩达到高峰,血管内径分别为(14.1±1.4) μm和(22.2±5.2) μm(与正常对照组比较,P<0.05);细动、静脉内血流速度无明显变化(与正常对照组比较P>0.05);肠壁血流量于滴加UII(10^-7 mol/L)后1 min开始升高,5 min达到高峰 。结论: UII可以使大鼠肠系膜微血管收缩,血流量增加。

Effects of human urotension Ⅱ on in vivo mesenteric microcirculation in rats

AIM: To investigate the effects of human urotensin Ⅱ (hUII) on in vivo mesenteric microcirculation in rats. METHODS: For recording of microcirculation images in the mesentery, the intestinal loop was mounted on the stage of an intravital microscope equipped with a TV camera. Video images of microcirculation were stored by a video cassette recorder. Temporal changes in internal diameter and microcirculatory velocity of microvesseles were measured by computer using the ImagePro software. The blood flow in intestinal wall was measured with PIMII laser Doppler perfusion Imager (Lisca Sweden). RESULTS: The internal diameters of arterioles and venules in control group were (21.4±2.3) μm and (38.1±3.6) μm,respectively. In UII group, the arterioles and venules contracted immediately after treated with UII and up to the peak at 1 min . Both microcirculatory velocity of arterioles and venules showed no significant changes in UII group (compared with control, P＞0.05). The blood flow in intestinal wall increased 1 min after treated with UII and up to high peak at 5 min(6.4±1.1 perfusion unit vs control 4.2±0.9,P＜0.05). CONCLUSION: hUII contracted mesenteric microvesseles in rats and increased microcirculatory blood perfusion in intestinal wall.