Objective: To observe the effects of ethyl pyruvate (EP) treatment on multiple organ dysfunction and mortality following delayed resuscitation after burn injury in rat, and investigate the mechanisms of its protective effect.
Methods: Male Wistar rats were subjected to 30% full-thickness scald injury followed with delayed resuscitation (6 hours postburn). (1) One hundred and thirty male Wistar rats were randomly divided into sham scald group (n=10), scald group (n=60) and EP-treatment group (n=60). In the scald group, 40 ml/kg normal saline was injected intraperitoneally 6 hours after scald injury for resuscitation, and it was repeated periodically. Following delayed resuscitation after burn injury, EP was injected at a dose of 40 mg/kg every 12 hours in EP-treatment group for 3 days. According to the interventional time points, rats of scald and EP-treatment groups were respectively divided in three subgroups: 2 hours prior to scald (n=20), 2 hours after scald (n=20), and 12 hours after scald (n=20). The mortality of animals was observed with 7 days as the cut point. (2) Seventy male rats were randomly divided into sham scald group (n=10), scald group (n=30), and EP-treatment group (n=30). In EP-treatment group, 40 mg/kg EP was injected intraperitoneally 2 hours after scald. Animals were sacrificed at 12, 24, and 72 hours postburn, and serum samples were collected to determine the organ functional parameters, and lung tissue was obtained for measurement of myeloperoxidase (MPO) activity.
Result: The 7-day mortality in scald and EP-treatment groups (EP given 12 hours postburn) was 75.0% and 35.0% respectively (P<0.05). Compared with scald group, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatinine (Cr) and creatine kinase (CK) levels were markedly decreased in EP-treatment group at 12 to 24 hours postburn (P<0.05 or P<0.01), and pulmonary MPO activities were also significantly declined at 12 to 72 hours following burns (P<0.05 or P<0.01).
Conclusion: EP can obviously improve the outcome in rats with delayed resuscitation after burn injury, and prevent the development of multiple organ dysfunction secondary to major burns.