Structural and hemodynamic analysis of the mouse retinal microcirculation
Structural and hemodynamic analysis of the mouse retinal microcirculation
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DOI：
10.1167/iovs.02-0738
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发表时间：
2003-11-01
影响因子：
4.4
通讯作者：
Vicaut, E
中科院分区：
文献类型：
--
作者：
Paques, M;Tadayoni, R;Vicaut, E
目的。在holangiotic视网膜中，人们对微血管层之间的联系和微血管层内的循环知之甚少。本研究旨在探讨小鼠视网膜微血管的三维排列和血流动力学。在荧光素葡聚糖填充的视网膜平板上进行共聚焦显微镜观察。用荧光活体显微镜测定深层毛细血管流速。观察视网膜分支静脉闭塞后各参数的变化。浅层和中间层都是毛细血管血流的不对称十字路口，大约70%的毛细血管连接将小动脉的血流引导到深层。深层的静脉流动通过横小静脉与浅层的大静脉相连，表明大静脉与深层直接相连。深层红细胞速度+/- SD分别为1.26 +/- 0.34和0.8 +/- 0.32 mm/sec。支静脉闭塞后，深层小静脉扩张，流速降低。在小鼠视网膜中，我们建立了视网膜微循环的三维模型，显示小动脉侧大多数微血管连接引导血流从浅层流向深层，小静脉侧反之。然而，浅层的直接动静脉连接和深层较长的血管长度提供了主动调节视网膜内流动的可能性。与其他毛细血管床相比，毛细血管流速和微红细胞压积都很高，有利于营养物质向视网膜内输送。
PURPOSE. In the holangiotic retina, little is known about the connections between and the circulation within microvessel layers. The goal of the present study was to explore the three-dimensional arrangement and hemodynamics of mouse retinal microvessels.METHODS. Confocal microscopy was performed on fluorescein dextran-filled retinal flatmounts. Capillary velocity in the deep layer was measured by epifluorescence intravital microscopy. The changes in the studied parameters after branch retinal vein occlusion were evaluated.RESULTS. The superficial and intermediate layers are both asymmetric crossroads for capillary blood flow, with approximately 70% of the capillary connections directing the flow from the arterioles into the deep layer. The venous flow from the deep layer joins the major veins in the superficial layer through transverse venules, indicating that major veins are directly connected to the deep layer. Red and white blood cell velocities +/- SD in the deep layer were 1.26 +/- 0.34 and 0.8 +/- 0.32 mm/sec respectively. After branch vein occlusion, venule dilation and decreased velocity were observed in the deep layer.CONCLUSIONS. In the mouse retina, a tridimensional model of retinal microcirculation was established, showing that most microvessel connections on the arteriolar side direct the flow from the superficial to the deep layer, and vice versa on the venular side. However, the presence of direct arteriovenous connections in the superficial layer and the longer vessel length in the deep layer offer the possibility of actively modulating intraretinal flow. Compared with other capillary beds, both the capillary velocity and microhematocrit are high, a situation that favors nutrient delivery to the inner retina.