L-Alanyl-Glutamine Preoperative Infusion in Patients with Critical Limb Ischemia Subjected to Distal Revascularization Reduces Tissue Damage and Protects from Oxidative Stress

Background: Critical limb ischemia (CLI) is the most severe form of peripheral vascular disease where there is inadequate blood flow to a limb. Our aim was to examine the effects of preoperative infusion of L-alanyl-glutamine (L-Ala-Gln) during the ischemic period and during the first 30 minutes following blood reflow in patients with CLI who are undergoing distal femoral artery bypass surgery. Methods: Thirty-two patients with CLI were alternately allocated to group 1 (saline) or group 2 (L-Ala-Gln). Saline (1000 mL) or L-Ala-Gln 250 mL plus 750 mL of saline were infused intravenously over a 3-hour period prior to surgery. Samples (muscle and blood) were collected at the beginning of the surgical procedure, at the end of ischemia, and at 15 and 30 minutes after reperfusion. Results: L-Ala-Gln induced elevation in glutathione (GSH) muscle concentrations while promoting reduction in thiobarbituric acid reactive substance concentrations, demonstrating enhancement of antioxidant capacity and protection from lipid peroxidation. Decreases in LDH, lactate, and glucose blood concentrations in L-Ala-Gln-treated patients suggest increased glucose utilization by muscle and peripheral tissues. Reduction in creatine phosphokinase blood concentrations may reflect smaller muscle cell damage in L-Ala-Gln-treated patients. Conclusion: L-Ala-Gln pretreatment reduces muscle cell damage and enhances antioxidant capacity in patients with CLI.