Centre for Education and Research on Ageing and ANZAC Research Institute, University of Sydney and Concord RG Hospital, Sydney, Australia.
Microcirculation. 2010 Jan;17(1):32-8. doi: 10.1111/j.1549-8719.2009.00004.x.
Fenestrations are pores in the liver sinusoidal endothelium that facilitate the transfer of particulate substrates between the sinusoidal lumen and hepatocytes. Fenestrations express caveolin-1 and have structural similarities to caveolae, therefore might be a form of caveolae and caveolin-1 may be integral to fenestration structure and function. Therefore, fenestrations were studied in the livers of caveolin-1 knockout mice.
Scanning, transmission and immunogold electron microscopic techniques were used to study the liver sinusoidal endothelium and other tissues in caveolin-1 knockout and wild-type mice.
Comparison of fenestrations in wild-type and knockout mice did not reveal any differences on either scanning or transmission electron microscopy. The diameter of the fenestrations was not significantly different (74 +/- 13 nm knockout mice vs 78 +/- 12 nm wild-type mice) nor was the fenestration porosity (6.5 +/- 2.1 knockout vs 7.3 +/- 2.4% wild-type mice). In contrast, adipocytes and blood vessels in other tissues lacked caveolae in the knockout mice. Caveolin-1 immunogold of livers of wild-type mice indicated sparse expression in sinusoidal endothelial cells.
The normal structure of fenestrations in the liver sinusoidal endothelium is not dependent upon caveolin-1 and fenestrations are not a form of caveolae.
肝窦内皮细胞的窗孔有利于将颗粒性底物在窦腔和肝细胞之间进行转移。窗孔表达 caveolin-1，并且具有与小窝类似的结构，因此可能是小窝的一种形式，而 caveolin-1 可能是窗孔结构和功能的组成部分。因此，在 caveolin-1 敲除小鼠的肝脏中研究了窗孔。
使用扫描、透射和免疫胶体金电子显微镜技术研究了 caveolin-1 敲除和野生型小鼠的肝窦内皮细胞和其他组织。
对野生型和敲除型小鼠的窗孔进行比较，在扫描或透射电子显微镜下均未发现任何差异。窗孔的直径没有显著差异（74±13nm 敲除型小鼠与 78±12nm 野生型小鼠），窗孔的孔隙率也没有显著差异（6.5±2.1%敲除型小鼠与 7.3±2.4%野生型小鼠）。相比之下，其他组织中的脂肪细胞和血管在敲除型小鼠中缺乏小窝。野生型小鼠肝脏的 caveolin-1 免疫胶体金显示出窦状内皮细胞中稀疏表达。
肝窦内皮细胞窗孔的正常结构不依赖于 caveolin-1，并且窗孔不是小窝的一种形式。
