Ketamine alleviates LPS induced lung injury by inhibiting HMGB1-RAGE level

Inflammatory cytokines secretion is an important reason to promote lung tissue inflammation in acute lung injury (ALI). High mobility group box 1 (HMGB-1) and its receptor for advanced glycation end products (RAGEs) play a role in ALI. Ketamine can significantly alleviate ALI, whereas its specific mechanism has not been fully elucidated.

A total of 60 male Wistar rats were equally randomly divided into three groups, including ALI group which was established by 10 mg/kg LPS femoral vein injection, ketamine group which was constructed by 50 mg/kg ketamine femoral vein injection based on ALI model, and control group. Blood gas analysis was applied to detect arterial blood oxygen partial pressure (PaO2) and pH. Lung tissue wet/dry weight ratio (W/D), myeloperoxidase (MPO) and superoxide dismutase (SOD) activity were detected. Real-time PCR and ELISA were used to test HMGB-1 expression in lung tissue and serum. RAGE and NF-κB changes were determined by Real-time PCR and Western blot.

Compared with control, ALI group presented decreased PaO2 and PH, elevated W/D, enhanced MPO activity, declined SOD activity, upregulated HMGB-1 mRNA, increased HMGB-1 secretion, and increased RAGE and NF-κB mRNA and protein (p < 0.05). Ketamine treatment significantly elevated PaO2 and PH, reduced W/D, declined MPO activity, enhanced SOD activity, inhibited HMGB-1 mRNA and secretion, and downregulated RAGE and NF-κB mRNA and protein (p < 0.05).

Ketamine can alleviate LPS induced lung injury through inhibiting HMGB1-RAGE level. It could be treated as a new choice for ALI treatment.