Ward B J, Firth J A
Department of Anatomy and Cell Biology, St. Mary's Hospital Medical School, London, UK.
J Mol Cell Cardiol. 1989 Dec;21(12):1337-47. doi: 10.1016/0022-2828(89)90679-2.
Isolated perfused rat hearts were used to assess the effect of 30 or 60 mins of hypoxia on the ultrastructure of the capillary endothelium and particularly on the interendothelial junctions. Perfusions were carried out both in the presence and absence of albumin. Albumin had no effect on ultrastructure or membrane spacing in the interendothelial clefts, neither in oxygenated controls nor in hypoxic hearts. After 30 and 60 mins of hypoxia some capillaries showed endothelial swelling while after 60 mins the endothelium of others was attenuated. The wide regions of the intercellular cleft were not affected by hypoxia but the "narrow zone" gap between membranes became significantly smaller. We conclude that factors within the clefts other than the "tightness" of the narrow zones are responsible for changes in permeability in hypoxia and with albumin.
采用离体灌注大鼠心脏来评估30或60分钟缺氧对毛细血管内皮超微结构，尤其是内皮间连接的影响。灌注实验分别在有白蛋白和无白蛋白的情况下进行。白蛋白对内皮间裂隙的超微结构或膜间距均无影响，无论是在氧合对照组还是缺氧心脏中。缺氧30分钟和60分钟后，一些毛细血管出现内皮肿胀，而60分钟后，其他毛细血管的内皮变薄。细胞间裂隙的宽阔区域不受缺氧影响，但膜间的“狭窄区”间隙显著变小。我们得出结论，除狭窄区的“紧密性”外，裂隙内的其他因素是缺氧及白蛋白存在时通透性变化的原因。
