Expression Of Leptin In Liver Of The Hepatic Fibrosis Rats And Preventive Effect Of Propylgallate On Hepatic Fibrosis

[Objective]①To investigate the expression of leptin in rat liver with hepatic fibrosis and explore the connection of leptin and the pathogenesis of hepatic fibrosis.②To explore the preventive effects of propylgallate on experimental hepatic fibrosis.[Methods] The fibrotic model of rats was induced by subcutaneous injection of carbon tetrachloride (CCl4). Forty-five female Wistar rat (240±20g) were randomly divide into the normal control group, hepatic fibrisis model group and propylgallate group. The latter two groups were then randomly divide into three-week group and six-week group. The propylgallate group was administered by subcutaneous injection with propylgallate20mg/(kg-d) while was administered to CCI4. At the end of the experiment, rats were killed under pyrogen-free technics for collection of blood and liver tissue. Paraffin embedded liver sections were stained with hematoxylin and eosin for routine histological analysis; Liver fibrosis was scored by image analysis of stain of srirus red and the content of hydroxyproline(HYP); The ALT of plasma was measured with Reitman-Frankel method; The content of malondialdehyde(MDA) in liver tissue was determined by means of TBA method; Endotoxin was measured with a Limulus Amebocyte Lysate test kit; The liver localization of leptin protein was studied by immunohistochemistry; The quantity of leptin in liver tissues was assessed by western-blot analysis.[Results] Compared fibrosis model group with normal control group during hepatic fibrosis:①the content of collagen and hydroxyproline in liver tissues gradually advanced go with the leveles of plasma endotoxin ascended.②As the result of immunohistochemistry and western-blot:just a small amount of leptin was expressed in normal rats, but significantly increased during hepatic fibrosis. Propylgallate group compared with the hepatic fibrosis model group:①The damnified changes of the liver ameliorated, content of HYP. MDA in lives tissue and FI reduced as well.②Endotoxin and ALT in plasa reduced.③The expression of leptin in liver tissue decreased.[Conclusions]①As the content of endotoxin of plasma increased, the expression of leptin in liver tissue raised in hepatic fibrosis induced by CCl4in rats.②Propylgallate can alleviate CCl4induced liver injury and hepatic fibrosis.③The preventive effece of propylgallate on hepatic fibrosis may due to decreasing the level of endotoxin in plasma and lipid peroxidation in liver, and down regulation the expression of leptin in liver tissue.