In vivo observation of intrarenal microvessels and evaluation of the effect of exgenous high dose Angiotensin II forrenal microcirculation by a needle probe video microscope with a CCD camera.

我们通过带CCD摄像机的针型视频显微镜（放大倍数=400）观察肾内微血管。在5只麻醉犬中，针形探头（O.D.= 3.5 mm，长度= 6.5mm）从肾侧缘通过肾包膜引入肾皮质或髓质。当发生肾内出血时，停止显微镜观察（通过图像退化识别）。血管紧张素II经动脉灌注后，体循环压力和肾血流量显著改变。血管紧张素Ⅱ可使MAP升高（18 ± 0.05）%，与对照组比较，差异有统计学意义（P < 0.05）。20秒后达到4%，并保持高压3分钟。其中RBF下降25（±）SY。血管紧张素Ⅱ 20 μ g动脉内灌注20秒时，血管紧张素Ⅱ的抑制率为5%（P < 0.05），与对照组相比，差异有显著性意义（P < 0.05），120秒时恢复到基础水平。同时，在体可视化单个肾单位中，输入和输出小动脉开始收缩， ...更多信息 ctly。血管紧张素Ⅱ注射后，第一时间传入小动脉出现震颤，另一方面也出现强烈的血管舒缩，肾小球也随之震颤。震颤后10秒，传入小动脉开始明显收缩。60秒后，输入小动脉内径由14.8 ± 1.5mm缩小34%。[）4.5 mm，并在150秒内恢复到基底直径。20 μ g AII也能使传出小动脉收缩，但与传入小动脉相比，震颤或血管舒缩受到血管紧张素II的抑制。在相同时程下，传出动脉相应地由13.9 ± 0.5SY收缩36%。（）40 mm，差异有显著性，150 s后恢复。与输入A缩窄和输出A缩窄相对应，这些动脉几乎同时缩窄至最小直径。在最小直径/最大直径的收缩百分比下，输入小动脉比输出小动脉有更强的收缩趋势。两组经t检验无显著性差异。外源性高剂量血管紧张素Ⅱ在体内对传入小动脉和远侧小动脉均有收缩作用。少

We visualized intrarenal microvessels by a needle-type video-microscope with a CCD camera (magnification =400). In 5 anesthetized dogs, the needle probe (O.D.=3.5 mm, length =6.5 mm) was introduced into the renal cortex or medulla through the renal capsule from the lateral renal border. Microscopic observation was discontinued when intrarenal bleeding occured (this was recognized by degradation of the image). Systemic Pressure and Renal blood flow after intraarterial infusion of angiotensin II changed significantly. MAP was elevated by angotensin II infusion from (incresed rate 18 (]SY.+-。[) 4 %) after 20 second later and remained high pressure for 3 minutes. Wheres RBF was decreased 25 (]SY.+-。[) 5 % significantly at 20 second which were significant difference, by intra-arterial infusion of 20ug angiotensin II,and returned to the basal level by 120 second. At the same time courese, in the visualized single nephron in vivo, Afferent and efferent arteriole began to be constricted distin … More ctly. At the first time afferent arteriole paticuraly seemmed to be trembled after boulas injection of angiotensin II,on the other hand it appeared vasomotion vigorously too, and the glomerus was shaked accordinaly. After trembling, afferent arteriole began to be constricted apparently at 10 second. The 60 second later, the diameter of afferent arteriole decresed 34% from 14.8 (]SY.+-。[) 4.5 mm, and returend to the basal diameter by 150 seconds. Wheres efferent arteriole was also constricted after 20ug AII infusion, but compeard with afferent arteriole, trembling or vasomotion was very restraind from angiotensin II effect. With the same time course, efferent artry was accordinaly constricted 36% from 13.9 (]SY.+-。[) 40mm, which had significant difference, and recovered by 150 seconds. Compered with affrent A constriction and efferent A constriction, These Arteries were constricted to minimam diameter at the almost same time. At the constricted diameter percentage, which was minimam diameter/maximum diameter at a mesured vessels, afferent Arteriole has a tendency, which was more constricted strongly than efferent arteriole. But two groups had no significant difference of T-test. Exgenous high dose Angiotensin II constricts both afferent arteriole and effernt arteriole in vivo. Less