乌司他丁减轻重症中暑大鼠肺的炎症和氧化损伤

The study of Ulinastatin to reduce pulmonary inflammation and oxidative injury in rats with severe heatstroke

目的 观察乌司他丁对重症中暑大鼠肺损伤的作用.方法 48只大鼠随机（随机数字法）分为空白组（HS）、低剂量乌司他丁组（LUTI）、高剂量乌司他丁组（HUTI）和对照组（Sham）4组,每组12只.通过人工气候舱制备重症中暑大鼠模型,监测直肠温度（Tc）、监测心率（HR）和平均动脉压（MAP）,记录Tc＞42℃的时间和重症中暑发生时间,分别于热打击开始后0 min、20 min、40 min和60 min采动脉血检测血氧分压（PaO2）和二氧化碳分压（PaCO2）,并于60 min留取支气管肺泡灌洗液（BALF）并用酶联免疫法检测其中的肿瘤坏死因子-α（TNF-α）、白介素-1 β（IL-1β）和白介-6（IL-6）质量浓度,收集肺组织进行病理分析和诱导性氧化亚氮（iNOS）的Western blot检测.采用PASW Statistics 17.0统计软件行方差分析,生存分析使用Kaplan-Mier曲线和Log Rank检验,以P＜0.05为差异具有统计学意义.结果 LUTI和HUTI组相比HS组在Tc＞42℃的时间（P=0.00）、重症中暑发生时间（P=0.00）和中位生存时间（P=0.00）均延长.热打击后60 min时HS组PaO2较其他三组明显降低（P=0.00）,而LUTI和HUTI组之间差异无统计学意义（P=0.91）.同时,HS组PaCO2较其他三组明显升高（P=0.00）,LUTI和HUTI组之间差异无统计学意义（P=0.79）.LUTI和HUTI组大鼠的BALF中TNF-α、IL-1β和IL-6浓度较HS组低（P=0.00,P=0.00和P=0.00）,而且HUTI组的炎症介质浓度也低于LUTI组（P=0.02,P=0.04和P=0.04）.病理结果显示LUTI和HUTI组大鼠肺损伤较HS组轻（p=0.00）.肺组织iNOS蛋白表达比较中,HS组较LUTI和HUTI组增加（P=0.00）,而LUTI组表达量也高于HUTI组（P=0.03）.结论 乌司他丁具有改善重症中暑大鼠呼吸衰竭和预后的效果,这种作用可能与减轻肺组织的炎症和氧化损伤有关.

Objective To investigate the effect of ulinastatin on acute lung injury in rats with severe heatstroke.Methods Fourty-eight rats were randomly （random number） assigned into control group （HS group,n =12）,low dose Ulinastatin group （LUTI group,n =12）,high dose Ulinastatin group （HUTI group,n =12） and non-thermal group （Sham group,n =12）.Rats were prepared with pre-warm chamber to initiate heatstroke.The change of rectum temperature （Tc）,heat-rate （HR） and mean arterial pressure （MAP） under heat-stress were recorded.The time-point of heatstroke onset and Tc ＞42 ℃ was observed.Arterial blood samples were draw at 0 min,20 min,40 min and 60 min for testing partial pressure of oxygen （PaO2） and partial pressure of carbon dioxide （PaCO2）.Bronchoalveolar lavage fluid （BALF） were collected at 60 min,and the concentrations of tumor necrosis factor-α （TNF-α）,interleukin-1β （IL-l β） and interleukin-6 （IL-6） in BALF were measured with enzyme linked immunosorbent assay kit.Lung tissues were harvested for observing pathological change and measuring the expression of iNOS with Western blot test.Results Compared with HS group,the time-point of Tc ＞ 42℃ （P =0.00）,severe heat-stroke （P =0.00） and the median of survival time （P =0.00） in LUTI and HUTI groups were significantly increased.At 60min after heat-stress,the level of PaO2 in HS group was much lower than those in other groups （P =0.00）.But there were no differences between LUTI and HUTI groups （P =0.91）.The value of PaCO2 in HS group was much higher than those in other groups （P =0.00）.And the differences between LUTI and HUTI groups were no significant （P =0.79）.The concentrations of TNF-α,IL-1β and IL-6 in HS group was the highest in four groups （P =0.00,P =0.04 and P =0.04）,followed by LUTI,HUTI and Sham group.The concentrations of proinflammatory cytokine in LUTI were higher than those in HUTI group （P =0.02,P =0.00,P =0.00）.Compared with HS group,the pathological injuries were alleviated in LUTI and HUTI group （P =0.00）.The expression of iNOS in lung tissue of HS group was strengthened than LUTI and HUTI group （P =0.00）,and there was a significant difference between LUTI and HUTI group （P =0.03）.Conclusion Ulinastatin improves respiratory dysfunction and the prognosis of severe heatstroke rats through reducing the inflammatory and oxidative injury in lung tissue.