The Protective Effect Of NAC Against Experimental Model Of Injury Liver

Aim: To select the SD rat to establish D-gal(D-galactopyranoside) induced hepatic injury model. To study the protective effect of NAC (N-Acetylcysteine) against the hepatic injury. The mechanisms of the protect activities were investigated by compare the GSH and NO (nitric oxide) level in serum and liver tissue of each rat group. Additional, to investigate the activities of two types of NOS(nitric oxide synthase) in rat's liver to elucidate the changes of NO level with NAC treatment.Method:1. The hepatoprotective effect of NAC in D-gal induced hepatic injury model of SD ratThe acute liver injury model were induced by D-gal. All the rats in NAC treat group were intraperitoneal injected with NAC at 6 hours after that D-gal were given. Each NAC treat group was given NAC 0.1mmol/kg or 0.19mmol/kg three times every 6 hours. Collecting the serum, plasma and liver tissue of these rats at 24 hours after the D-gal was given. The ALT(alanine aminotransferase), AS T(aspartate aminotransferase), TBiL (total bilirubin) level and PT(Prothrombin time) were assayed. And, the pathologic changes of each group were observed. 2. To study the mechanisms of the hepatoprotective activities of NAC2.1. To detect the GSH level in serum and liver tissue of each groupThe GSH concentration were mensurated by HPLC (High Performance Liquid Chromatography). Comparing the GSH level in serum and liver tissues of each group.2.2. To detect the NO level of in serum and liver tissue after NAC or GSH were given. And to detect two type of NOS activities in liver tissue:The NO concentration were determined by the Nitric Oxide quantitation Kit from Nanjing Jiancheng Bioengineering Institute. The activities of iNOS and cNOS in the liver tissue were detected by monitoring the conversion of 3H-Arginine.Result:1. The ALT, AST and TBil level in serum were markedly decreased and it showed a shortened prothrombin time in the two NAC treated groups.7The morphological findings of hepatic tissue from acute liver injured rats were significantly improved with NAC treatment.2. The GSH level in serum and liver tissue was significantly increased in the NAC treatment group. It showed a significant increase of the GSH concentration in liver tissue of which treated with higher dose group of NAC than that lower dose group.3. The hepatic NO concentration of acute liver injured rat group was significant decreased in the NAC treatment group. Whereas the serum NO concentration was significant increased in the same group. That conclusion may also be proved by detect the two types of NOS activities in liver tissue. It shown that the iNOS were inhibited but the cNOS were activated with NAC treatment.Conclusion:1. Treat with NAC intraperitoneal injection can protect hepatocyte from morphological and functional destruction of the hepatic injured rats induced by D-gal.2. The effect of liver injured rats treatment with NAC may probably interpret by the mechanisms as follows: (1). The GSH level in liver tissue and serum of D-gal induced hepatic injured rats was significant increase with NAC treatment. (2). The NO concentration in serum is also increase with NAC treatment, and that makes the liver perfusion increased. But the NO concentration in liver tissue is decreased in NAC treated group. It cutdown the liver injury induced by high concentration of NO in liver tissue. This conclusion was also been demonstrated by detect the iNOS and cNOS activities in liver tissue.