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.