摘要目的 比较不同液体复苏时辛二酰苯胺异羟肟酸对初进高原失血性休克大鼠的肺保护作用.方法 雄性Wistar大鼠48只,1.5～2.0月龄,体重250～300 g,从海拔2 800 m养殖地运输到海拔3 780 m实验地.采用随机数字表法分为4组(n=12):假手术组(Sham组)、失血性休克组(HS组)、乳酸钠林格氏液复苏+辛二酰苯胺异羟肟酸组(LR+SAHA组)和高渗氯化钠羟乙基淀粉40注射液复苏+辛二酰苯胺异羟肟酸组(HSH+ SAHA组).采用容量控制法建立失血性休克模型,在1 5 min内匀速放出45％ ～ 55％血容量,使MAP降至30 ～ 40 mmHg,通过放血或自体血回输维持该水＜90 min.Sham组只置管,不进行放血和复苏,观察3h时腹主动脉取血样后处死;HS组制备失血性休克模型,造模成功即刻,腹主动脉取血样后处死;LR+SAHA组失血性休克模型制备成功后,于20 min内输注1.5倍失血量的乳酸钠林格氏液,然后于5 min内输注二酰苯胺异羟肟酸7.5 mg/kg(溶于0.25 ml生理盐水);HSH +SAHA组失血性休克模型制备成功后,于5 min内输注高渗氯化钠羟乙基淀粉40注射液4 ml/kg,然后于5 min内输注二酰苯胺异羟肟酸7.5 mg/kg(溶于0.25 ml生理盐水).LR+SAHA组和HSH+SAHA组复苏后3h时腹主动脉取血样后处死大鼠.取腹主动脉血样,进行血气分析,计算氧合指数,记录急性肺损伤(氧合指数≤300 mmHg)的发生情况.取肺组织,HE染色后,光镜下观察病理学结果,并进行肺损伤评分,透射电镜下观察超微结构,测定肺组织湿重/干重(W/D)比值,采用Western blot法检测肺组织claudin-3和claudin-4的表达水平.结果 HS组急性肺损伤的发生率为70％,Sham组、LR+SAHA组和HSH+SAHA组均未发生急性肺损伤.与Sham组比较,HS组、LR+SAHA组、HSH+SAHA组肺损伤评分和肺组织W/D比值升高,肺组织claudin-3和claudin-4表达下调(P＜0.05);与HS组比较,LR+SAHA组和HSH+SAHA组肺损伤评分和肺组织W/D比值降低,肺组织claudin-3和claudin-4表达上调(P＜0.05),病理学损伤减轻;与LR+SAHA组比较,HSH+SAHA组肺损伤评分和肺组织W/D比值降低,肺组织claudin-3和claudin-4表达上调(P＜0.05),病理学损伤减轻.结论 高渗氯化钠羟乙基淀粉40注射液复苏时辛二酰苯胺异羟肟酸对初进高原失血性休克大鼠的肺保护作用优于乳酸钠林格氏液复苏时.

abstractsObjective To compare the lung protection provided by suberoylanilide hydroxamic acid (SAHA) in a rat model of hemorrhagic shock after entering high altitude for the first time during resuscitation with different fluids.Methods Forty-eight male Wistar rats,aged 1.5-2.0 months,weighing 250-300 g,were transported from the breeding area at altitude 2 800 m to the experimental area at altitude 3 780 m.The rats were randomized into 4 groups (n =12 each) using a random number table:sham operation group (group Sham),hemorrhagic shock group (group HS),resuscitation with lactated Ringer's solution combined with SAHA group (group LR + SAHA),and resuscitation with hypertonic sodium chloride hydroxyethyl starch 40 solution (HSH40) combined with SAHA group (group HSH+SAHA).Hemorrhagic shock was induced by removing 45％-55％ of blood volume from the left femoral artery at a constant speed within 15 min until mean arterial pressure was reduced to 30-40 mmHg and maintained at this level for 90 min through blood-letting or reinfusion of the shed blood.In group Sham,only cannulation was performed,the rats received no blood-letting or resuscitation,blood samples were collected from the abdominal aorta at 3 h of observation,and then the rats were sacrificed.In group HS,hemorrhagic shock was induced,blood samples were collected from the abdominal aorta immediately after successful establishment of the model,and then the rats were sacrificed.In group LR+SAHA,after successful establishment of the model,lactated Ringer's solution (1.5 times the volume of blood loss) was infused over 20 min,and then SAHA 7.5 mg/kg (in 0.25 ml of normal saline) was infused over 5 min for resuscitation.In group HSH+ SAHA,after successful establishment of the model,HSH40 4 ml/kg was infused over 5 min,and then SAHA 7.5 mg/kg (in 0.25 ml of normal saline) was infused over 5 min for resuscitation.In LR+SAHA and HSH+SAHA groups,the animals were sacrificed after blood samples were collected from the abdominal aorta at 3 h after resuscitation.Blood samples from the abdominal aorta were obtained for blood gas analysis,the oxygenation index was calculated,and the occurrence of acute lung injury (oxygenation index ≤ 300 mmHg) was recorded.Lungs were removed for examination of the pathologic changes (with light microscope) and ultrastructure (with transmission electronic microscope) and for determination of wet to dry weight ratio (W/D ratio) and expression of claudin-3 and claudin-4 in lung tissues (by Western blot).The lung injury was scored.Results The incidence of acute lung injury was 70％ in group HS,and no acute lung injury was found in Sham,LR+SAHA and HSH+SAHA groups.Compared with group Sham,the lung injury score and W/D ratio in lung tissues were significantly increased,and the expression of claudin-3 and claudin-4 in lung tissues was significantly down-regulated in HS,LR+SAHA and HSH+SAHA groups (P＜ 0.05).Compared with group HS,the lung injury score and W/D ratio in lung tissues were significantly decreased,the expression of claudin-3 and claudin-4 in lung tissues was significantly up-regulated (P＜ 0.05),and the pathologic changes were significantly attenuated in LR +SAHA and HSH +SAHA groups.Compared with group LR+SAHA,the lung injury score and W/D ratio in lung tissues were significantly decreased,the expression of claudin-3 and claudin-4 in lung tissues was significantly up-regulated (P ＜ 0.05),and the pathologic changes were significantly attenuated in group HSH+SAHA.Conclusion SAHA provides better lung protection when resuscitation is performed with HSH40 than with lactated Ringer's solution in a rat model of hemorrhagic shock after entering high altitude for the first time.