【摘要】 目的探讨高碳酸血症对急性肺损伤模型的保护作用及可能的机制。方法 24只新西兰兔按随机数字表法分为对照组、治疗组、预防组,每组8只。采用脂多糖静脉注射复制肺损伤模型,观察3组兔血流动力学、血气指标的变化;检测肺组织湿/干重（W/D）比、光镜、肺损伤组织学定量评价指标（IQA）来评估肺脏的损伤程度。通过对肺组织中髓过氧化物酶（MPO）、丙二醛（MDA）及血清和支气管肺泡灌洗液（BALF）中白细胞介素-8（IL-8）、肿瘤坏死因子-α（TNF-α）浓度及中性粒细胞凋亡率的测定,阐明高碳酸血症对肺损伤保护的可能机制。结果 （1）治疗组、预防组在模型形成后平均动脉压、心率、动脉血二氧化碳分压（PaCO₂）、动脉血氧分压/吸入气氧浓度（PaO₂/FiO₂）分别为（79±6）mm Hg（1 mm Hg=0.133 kPa）、（180±10）次/min、（99±13）mm Hg、250±26,（80±9）mm Hg、（181±12）次/min、（95±11）mm Hg、241±56,与对照组[（66±10）mm Hg、（139±13）次/min、（31±4）mm Hg、182±35]比较差异有统计学意义（t 值分别为4.05、26.32、5.36、28.15、12.54、11.07、16.13、12.36,P 均分别<0.05、0.01）;（2）治疗组、预防组 W/D、MPO、MDA 分别为1.98±0.28、1.87±0.30、（6.1±1.6）U/g、（5.8±1.5）U/g、（20±5）mg/L、（19±4）mg/L,与对照组[2.43±0.26、（9.0±1.3）U/g、（36±8）mg/L]比较差异有统计学意义（t 值分别为11.07、24.46、2.35、9.63,12.34、25.32,P 分别<0.05、0.01）;（3）治疗组、预防组血清和 BALF 中 IL-8、TNF-α、中性粒细胞凋亡率分别为（50±8）ng/ml、（103±49）ng/ml、（94±16）ng/ml、（44±9）ng/ml、（38±9）%、（56±5）%、（49±7）ng/ml、（96±50）ng/ml、（91±14）ng/ml、（39±6）ng/ml、（39±10）%、（55±10）%,与对照组[（91±43）ng/ml、（177±60）ng/ml、（162±15）ng/ml、（67±7）ng/ml、（19±7）%、（43±7）%]比较差异有统计学意义（t 值分别为7.12、5.55、7.30、3.93、13.08、8.00,P 分别<0.05、0.01）;（4）各组血清及 BALF 中 IL-8、TNF-α与中性粒细胞凋亡率呈负相关（r 值分别为-0.73、-0.72、-0.52、-0.64、-0.73、-0.56、-0.57、-0.78、-0.69、-0.75、-0.82、-0.84,P 均<0.05）。结论高碳酸血症对急性肺损伤具有保护作用,对血流动力学无明显影响。更多还原

【Abstract】 Objective To explore the protective effects of hypercapnia on acute lung injury（ALI） and the possible mechanisms.Methods Twenty-four healthy New Zealand white rabbits were involved in this study,and randomly divided to three groups,a control group,a therapeutic group,and a prophylactic group（n=8,each）.Lipopolysaccharide（1 mg/kg）was injected intravenously to establish the ALI model. Blood gas analysis and artery pressure were monitored.IL-8 and TNF-α in the serum and bronchoalveolar lavage fluid（BALF）,wet weight/dry weigh（W/D）,index of quantitative assessment of histological lung injury（IQA）,myeloperoxidase（MPO）and malondialdehyde（MDA）activity in the lung tissue were measured.Apoptosis index of neutrophils were determined.Results（1）The mean artery pressure,heart rate,PaCO₂,and PaO₂/FiO₂ changed in the ALI model of the therapeutic group and the prophylactic group [（79±6）mmHg（1 mm Hg=0.133 kPa）,（180±10）/min,（99±13）mm Hg,250±26,（80±9） mm Hg,（181±12）/min,（95±11）mm Hg,241±256,respectively].In the control group,they were （66±10）mm Hg,（139±13）/min,（31±4）mm Hg,182±35,respectively.The differences were significant compared with the control group（t=4.05,26.32,5.36,28.15,12.54,11.07,16.13,12.36,P< 0.05,0.01）.（2）The levels of W/D,MPO,and MDA in the therapeutic group and the prophylactic group were 1.98±0.28,1.87±0.30,（6.1±1.6）U/g,（5.8±1.5）U/g,（20±5）mg/L,（19±4）mg/L; while in the control group,they were[2.43 + 0.26,（9.0±1.3）U/g,（36±8）mg/L]respectively.The difference was significant（t=11.07,24.46,2.35,9.63,12.34,25.32,P<0.05,0.01）.（3）The levels of IL-8 and TNF-α in the serum and BALF and the apoptosis index in the three groups were（50±8）ng/ml, （103±49）ng/ml,（94±16）ng/ml,（44±9）ng/ml,（38±9）%,（56±5）%,（49±7）ng/ml, （96±50）ng/ml,（91±14）ng/ml,（39±6）ng/ml,（39±10）%,（55±10）%,（91±43）ng/ml, （177±60）ng/ml,（162±15）ng/ml,（67±7）ng/ml,（19±7）%,（43±7）%,respectively.The difference was significant among the three groups（t=7.12,5.55,7.30,3.93,13.08,8.00,P<0.05,0.01 respectively）.（4）The apoptosis index of neutrophils was negatively correlated with the levels of IL-8 in the serum and BALF（r=-0.73,-0.72,-0.52,-0.64,-0.73,-0.56,all P<0.05）,and the levels of TNF-α in the serum and BALF（r=-0.57,-0.78,-0.69,-0.75,-0.82,-0.84,all P<0.05）. Conclusion Hypercapnia does not affect hemodynamies and has protective effects on ALl.更多还原