Menger M D, Marzi I, Messmer K
Institute for Surgical Research, University of Munich, FRG.
Eur Surg Res. 1991;23(3-4):158-69. doi: 10.1159/000129148.
Using intravital fluorescence microscopy and epi-illumination, the hepatic microcirculatory system of Syrian golden hamsters was analyzed, and the morphology and microhemodynamics were compared to those of rats. After contrast enhancement with 1 mumol/kg acridine orange i.v., the epi-illumination technique allows for visualization of capillary sinusoids and postsinusoidal venules, which are running in parallel with the liver surface, while afferent microvessels could be visualized in only few of the liver lobules investigated. In rat livers, the capillary sinusoids showed morphology similar to that of hamsters, however, postsinusoidal venules could frequently not be observed when applying epi-illumination, since these microvessels are piercing perpendicularly into the depth of the liver tissue. Microhemodynamic analysis, including the sinusoidal perfusion rate, sinusoidal red blood cell velocity and diameters, microvascular white blood cell (WBC) count and the phenomenon of WBC-endothelium interaction, as well as the hepatocellular uptake of the fluorescent compound acridine orange were found to be similar in hamsters as compared to rats. Although transillumination for in vivo microscopy may have the potential to visualize the complete hepatic microcirculatory system due to an increased focus depth, the epi-illumination technique has the advantage for quantitative assessment not only of the morphology of the hepatic microcirculatory system and microvascular blood perfusion, but also allows for evaluation of cellular phenomena within the hepatic microvessels, such as WBC accumulation, WBC-endothelium interaction, phagocytotic activity of Kupffer cells, and hepatocellular transport of fluorescent compounds. Hepatic microcircular disturbances, including accumulation of WBCs and WBC-endothelium interaction are causative in the development of organ failure in conditions such as hemorrhagic and septic shock, and, in particular, postischemic reperfusion injury following liver surgery and liver transplantation. Since accumulation of WBCs and their interaction with the microvascular endothelium are primarily found in postsinusoidal venules, in vivo microscopy of the hamster liver represents a favorable model for studies on cellular phenomena within the hepatic microcirculation.
利用活体荧光显微镜和落射照明技术，对叙利亚金黄地鼠的肝微循环系统进行了分析，并将其形态和微观血流动力学与大鼠的进行了比较。静脉注射1 μmol/kg吖啶橙进行对比增强后，落射照明技术可使与肝表面平行的毛细血管窦和窦后小静脉可视化，而在所研究的少数肝小叶中仅能观察到传入微血管。在大鼠肝脏中，毛细血管窦的形态与地鼠相似，然而，应用落射照明时，窦后小静脉常常无法观察到，因为这些微血管垂直穿入肝组织深部。微观血流动力学分析包括窦灌注率、窦红细胞速度和直径、微血管白细胞计数以及白细胞与内皮细胞相互作用现象，以及荧光化合物吖啶橙的肝细胞摄取，结果发现地鼠与大鼠相似。尽管由于聚焦深度增加，体内显微镜的透照法可能有潜力使整个肝微循环系统可视化，但落射照明技术不仅在定量评估肝微循环系统的形态和微血管血流灌注方面具有优势，而且还能评估肝微血管内的细胞现象，如白细胞聚集、白细胞与内皮细胞相互作用、库普弗细胞的吞噬活性以及荧光化合物的肝细胞转运。包括白细胞聚集和白细胞与内皮细胞相互作用在内的肝微循环紊乱是出血性和感染性休克等情况下器官衰竭发展的原因，特别是肝手术和肝移植后的缺血再灌注损伤。由于白细胞聚集及其与微血管内皮细胞的相互作用主要发生在窦后小静脉，地鼠肝脏的体内显微镜检查是研究肝微循环内细胞现象的良好模型。
