丙酮酸乙酯对烫伤延迟复苏大鼠多器官功能及死亡率的影响

目的观察丙酮酸乙酯（EP）对烫伤延迟复苏动物多器官功能及死亡率的影响，探讨其保护作用的机制。方法采用雄性Wistar大鼠30％总体表面积Ⅲ度烫伤模型。实验分为两部分进行：①死亡率观察：130只大鼠按照随机数字表法分为假烫伤组（n=10）、烫伤组（n=60。伤后6h腹腔注射生理盐水40ml／kg进行复苏，然后按照不同时间点腹腔注射等量生理盐水）和EP组（n=60。伤后6h腹腔注射生理盐水40ml／kg进行复苏，按不同时间点腹腔注射EP液40mg／kg。每日2次．间隔12h。给药3d）。除假烫伤组外，各组又分为伤前2h（n=20）、伤后2h（n=20）和伤后12h（n=20）给药3个亚组。观察不同时间点各组动物7d死亡率。②器官功能观察：70只大鼠随机分为假烫伤组（n=10）、烫伤组（n=30）和EP组（n=30，伤后2h给药），并分别于伤后12、24和72h活杀，检测器官功能指标改变。结果与烫伤组相比，伤后12hEP组动物死亡率显著降低（35．0％比75．0％，P〈0．05）。伤后2hEP组血清丙氨酸转氨酶、天冬氨酸转氨酶、尿素氯、肌酐、肌酸激酶水平及肺组织髓过氧化物酶活性均明显下降（P〈0．05或P〈0．01）。结论EP能明显改善严重烫伤延迟复苏大鼠的预后，并对重要器官功能具有显著保护作用。

Effect of treatment with ethyl pyruvate on multiple organ dysfunction and mortality following delayed resuscitation after burn injury in rat

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.