Study On The Change Of Expression Of Angiotensin â…¡ Type 1 Receptor In The Formation Of Liver Fibrosis

Background/ PurposeLiver fibrosis is a common pathological change appearing in the occurrence and development of various kinds of chronic liver diseases, and its research is increasingly paid more attention to by people. Recently, series studies on the renin angiotensin aldosterone system(RAAS) of local tissue in the liver fibrosis have been performed, and firstly found that: the expression of aldosterone synthetase gene-CYP1B2mRNA in hepatic stellate cell(HSC) strengthens in the formation of liver fibrosis. Antisterone can inhibit liver fibrosis of earlier stage. Angiotensin II type 1 Receptor(AT1R) exists in the rat HSC. But the study on AT1R in human liver tissue has not been reported. This study is to detect the change of ATIR expression and its role in the occurrence and development in the every stage of the formation of live fibrosis . Methods1. Histochemical stain( HE and MASSON) was used to check and define the pathological stage of fibrosis of the specimen tissue, and observe the distribution of collagen under the light microscope.2. The immunohistochemical method-SABC was used to detect the type I collagen, and utilize the medical image analysis system to make the quantitative analysis of collagen area.3. The transmission electromicroscopy was applied to observe HSC and collagen fiber in the hepatic sinus and tube converge area.4. The indirect immunofluorescopy was used to examine AT1R, and observe the result under the fluorescent microscope, and according to the number of positive cells per high-times visual field, perform the half-quantitative analysis.5. Reverse transcription polymerase chain reaction was used to detect the AT1RmRNA, and reversely transcript the stable internal standard segementGAPDH at the same time, then the ratio of two area light degree (IA) was usedas the relative expression of mRNA of the receptor.Results1. Project Electromicroscopy shows that the fiber tissue in the fibrotic liver increases significantly than that hi the normal liver, and its density gets thicker. The static HSC appears as star polygon, and has many processes, lip drops can be observed in the cytoplasm. The appearance of activating HSC is like long oval, lip drops in the cytoplasm decrease or disappear, replaced by the increasing rough surface endoplasmic reticulum.2. As the increasing of liver fibrosis, the area of collagen enlarges gradually. The cell number of ATIR positive expression in the fibrotic liver tissue is significantly increased than that in the normal liver (P<0.001).The increase of positive cell number is positively related to the enlargement of the collagen area.3. The expression of AT1RmRNA in the fibrotic live tissue increases significantly than that in the normal liver , and both have obvious difference(P<0.01).ConclusionThrough examination of AT1R and ATlRmRNA in the fibrotic liver and normal liver, this study confirms that as the increasing of fibrosis of liver tissue, the expression of AT1R and AT1RmRNA increase obviously. Therefore, It is thought that the Angiotensin II and its AT1R play an important role in the activating, transformation of HSC and the occurrence and development of liver fibrosis. Advancement of this study may possibly provide a new ways for the prevention and therapy of liver fibrosis.