Effects of L-arginine and L-NAME on ischemia-reperfusion in rat liver

ABSTRACT

PURPOSE: To evaluated the effects of L-arginine (a NO donor) and L-NAME (Nw-nitro-L-arginine methyl ester - a NOS inhibitor) on ischemia-reperfusion in rat livers. METHODS: One hundred fifty two male Wistar rats were divided into four groups control (simulated surgery); hepatic IR; pretreatment with L-arginine plus hepatic IR; and L-NAME plus hepatic IR. The hepatocellular damage was evaluated at the first, third and seventh days after the procedures through the alanine-aminotransferase (ALT) and aspartate-aminotransaminase (AST) levels, as well as histopathological features vascular congestion (VC); steatosis (STE); necrosis (NEC); and inflammatory infiltration (INF). The mortality rate was also evaluated. RESULTS: The pretreatment with L-NAME significantly worsened the AST levels after hepatic IR (p<0.05) at first day and L-arginine demonstrated an attenuating effect on ALT levels at seventh day (p<0.05). Furthermore, the administration of L-arginine was able to reduce the VC and STE in the seventh day after hepatic IR (p<0.05). The analysis of the mortality rates did not demonstrate any difference between the groups. Nevertheless, there was not effect of L-arginine and L-NAME on the mortality of the animals. CONCLUSION: L-arginine/NO pathway has a role in the hepatic IR because the pretreatment with L-arginine partially had attenuated the hepatocellular damage induced by hepatic IR in rats. .