الفهرس 
Contents
Histology of the liverOnly 14 pages are availabe for public view
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Abstract
Liver fibrosis and cirrhosis is a major problem which has serious clinical impacts. As renin-angiotensin system (RAS) plays an important role in hepatic fibrosis. So, AT1 receptors blockade can reduce the activated HSC accumulation and inhibit liver fibrosis. Losartan is an angiotensin II receptor blocker that acts on AT1 receptors and has been found to inhibit the progression of hepatic fibrosis. Assessment of the stage of the liver disease is very important for diagnosis, prognosis and treatment. Liver biopsy is the oldest and most accurate method used to evaluate progression of chronic liver diseases but it has several complications. Recently many non-invasive markers (NIMs) for assessing liver fibrosis have been developed. This study was designed to evaluate CCl4 induced liver fibrosis and the reversibility of liver fibrosis by angiotensin receptor blocker (Losartan) using invasive method (liver biopsy) and non-invasive methods (SGOT, SGPT and serum tissue inhibitor metalloproteinase 1).
Forty-two adult albino rats were randomly divided into three groups: Control group (n =12): Rats received intraperitoneal (i.p.) injections of 1mg/kg corn oil twice daily and were sacrificed after 8,10 and 12 weeks from the start of the experiment. CCl4 treated groub (n = 18): Rats received 1mL/kg CCl4 dissolved in corn oil (1:1) twice a week for 8 weeks Then they were sacrificed either immediately, two weeks or four weeks after last CCl4 injection. Losartan treated group (n=12): Rats received CCl4 for 8 weeks followed by oral treatment of Losartan (10mg/kg/day) by gastric gavage for two weeks or four weeks then animals were sacrificed. At the assigned times, samples of blood were obtained. SGPT and SGOT were assayed by the colorimetric method and serum tissue inhibitor metalloproteinase 1 (Timp1) by Elisa. Livers of rats were processed for histopathological assessment and were stained with H & E for histopathological examination, Masson trichrome and Sirius red for liver fibrosis, and Immunostaining for (Timp1). Image analysis of the area occupied by collagen fibers was estimated in liver sections stained with Sirius red.
The mean data obtained from the invasive and non-invasive methods from all groups were analyzed and compared to each other and to the control. In the Control group, serum levels of GOT, GPT and Timp1 were 25.60 ± 5.41 U/L, 101.34 ± 10.05 U/L and 8.88 ± 2.18 pg/ml respectively. Fine collagen fibers also could be seen surrounding the central vein, portal tract and in the wall of blood sinusoids. Image analysis of the area % occupied by collagen fiber was 1.77 ± .85.