Preconditioning with L-alanyl-glutamine reduces hepatic ischemia-reperfusion injury in rats

Abstract

PURPOSE: To evaluate the effects of pre-conditioning with L-alanyl- glutamine (L-Ala-Gln) in rats subjected to total hepatic ischemia. METHODS: Thirty Wistar rats, average weight 300g, were randomly assigned to 3 groups (n=10): G-1 - Saline, G-2- L-Ala-Gln, G-3-control (Sham). G-1 and G-3 groups were treated with saline 2.0 ml or L-Ala-Gln (0.75mg/Kg) intraperitoneally (ip) respectively, 2 hours before laparotomy. Anesthetized rats were subjected to laparotomy and total hepatic ischemia (30 minutes) induced by by clamping of portal triad. Control group underwent peritoneal puncture, two hours before the sham operation (laparotomy only). At the end of ischemia (G1 and G2), the liver was reperfused for 60 minutes. Following reperfusion blood samples were collected for evaluation of alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels. Liver (medium lobe) was removed for immunohistochemistry study with antibody for Caspase-3. RESULTS: It was found a significant decrease (p<0.05) of ALT levels (270.6 +40.8 vs 83.3 +5.5 - p <0.05), LDH (2079.0 +262.4 vs. 206.6 +16.2 - p <0.05) and Caspase-3 expression (6.72 +1.35 vs. 2.19 +1.14, p <0.05) in rats subjected to I / R, comparing the group treated with L-Ala -Gln with G-2. Also, the ALT level was significantly lower (P<0.05) in G-1 and G-2 groups than in G-3 (control group). CONCLUSION: L-Ala-Gln preconditioning in rats submitted to hepatic I/R significantly reduces ALT, LDH and Caspase-3 expression, suggesting hepatic protection.