ABSTRACT
[ABSTRACT]AIM:Toexplorethedevelopmentofhepaticsinusoidalcapillarizationintheearlystageofliverfi-brosis induced by carbon tetrachloride (CCl4) in rats.METHODS:Clean SD rats were randomly divided into normal con-trol group (group N, n=6) and liver fibrotic model group (group M, n=32).The rats in group N were intraperitoneal in-jected with saline and the rats in group M were intraperitoneal injected with CCl 4(2 mL/kg, twice a week for 4 weeks).At the end of the 3rd day and the 1st, 2nd and 4th weeks, all rats were killed and then the samples were collected .The patho-logical changes in the livers were observed by HE staining and Masson straining .The development of hepatic sinusoidal capillarization was observed by transmission electron microscopy (TEM) and immunohistochemical staining .The cell sur-face expression of vascular endothelium-associated marker CD31, collagen type Ⅳ(Col IV) and laminin (LN) was deter-mined.RESULTS:HE and Masson staining showed the formation of liver fibrosis after treatment with CCl 4 for 4 weeks. TEM showed that the fenestrate diameter of liver sinusoidal endothelial cells (LSECs) grew down, the fenestrate numbers of LSECs were decreased along with the development of liver fibrosis , and the consecutive basement membrane was formed at the end of the experiment .The expression of CD31 was significantly increased along with the development of defenestration , and the expression of Col IV and LN was significantly increased after the treatment with CCl 4 for 2 weeks and 4 weeks , re-spectively .CONCLUSION:The typical hepatic sinusoidal capillarization was detected in the early stage of liver fibrosis , and the deposition of LN in the liver sinusoidal walls was the mainly factor of formation of the consecutive basement mem -brane .