Abstract
INTRODUCTION: Pulmonary contusion leads to alveolar damage and inflammation, which can progress to acute lung injury and acute respiratory distress syndrome. Glutamine and L-arginine play critical roles in immune regulation and inflammation control, showing potential protective effects in lung injury models. AIM: This study aimed to investigate the effects of glutamine and/or arginine, which play significant roles in the immuno-inflammatory response, on mitigating inflammation in an experimentally induced pulmonary contusion model. MATERIAL AND METHODS: Thirty male Wistar Albino rats from the same colony were randomly divided into five groups (n = 6 per group). Group I (sham) received no trauma or treatment. Bilateral pulmonary contusion was induced in Groups II-V. Group II received 0.9% saline; Group III received 200 mg/kg/day intraperitoneal glutamine; Group IV received 200 mg/kg/day intraperitoneal arginine; and Group V received both glutamine (200 mg/kg/day) and arginine (150 mg/kg/day). All treatments were administered for 3 consecutive days. Rats were sacrificed three days after the procedure, and histopathologic evaluation was performed afterwards. Three different parameters were scored: inflammation intensity, intraalveolar hemorrhage, and alveolar congestion. Statistical analysis was performed using the Mann-Whitney U test. RESULTS: Compared to the untreated trauma group, all treatment groups showed significant histopathological improvement (p < 0.05). The arginine-only group demonstrated greater effectiveness across all parameters compared to the combined treatment group (p < 0.05). No significant difference was observed between the glutamine-only and arginine-only groups (p > 0.05). CONCLUSIONS: Both glutamine and arginine treatments were effective in reducing inflammation following pulmonary contusion. However, combined treatment was less effective than arginine alone.