前列地尔预处理对犬失血性休克肺损伤的影响

Protective effects of alprostadil pretreatment on lung injury in dogs with hemorrhagic shock

目的通过观察前列地尔对犬失血性休克致肺损伤肺组织前B细胞集落增强因子(pre-B-cell colony-enhancing factor,PBEF)以及血清细胞因子的影响来探讨前列地尔肺保护的机制。方法实验用杂种犬24只,随机均分为四组:对照组(C组)、失血性休克组(S组)、前列地尔30ng组(P1组)、前列地尔60ng组(P2组)。C组仅行动静脉插管不放血,S组股动脉放血,MAP降至(40±5)mm Hg,制备失血性休克急性肺损伤(ALI)模型,间断回输或放血维持此MAP 90min,然后股静脉回输全部失血,维持MAP休克前水平。P1、P2组分别股静脉持续泵注前列地尔30ng·kg^(-1)·min^(-1)(P1组)、60ng·kg^(-1)·min^(-1)(P2组)维持30 min,预处理1h后建立失血性休克ALI模型。分别于休克前(T_0)、休克90min(T_1)、复苏4h(T_4)取动脉血,行动脉血气分析计算氧合指数(OI),取肺组织采用RT_-PCR技术检测PBEF mRNA表达情况;并于T_0、T_1、复苏1h(T_2)、复苏2h(T_3)、T_4时取2ml静脉血通过ELISA法检测T_NF-α、IL^(-1)β、IL^(-1)0、PBEF的浓度。结果与C组比较,T_1、T_4时S、P_1和P_2组OI明显降低,IL^(-1)β、T_NF-a、IL^(-1)0、PBEF浓度和PBEF mRNA表达明显升高(P<0.05);与S组比较,T_1、T_4时P1和P2组OI明显升高,IL^(-1)β、T_NF-α、IL^(-1)0、PBEF浓度和PBEF mRNA表达明显降低(P<0.05)。结论前列地尔可能通过下调PBEF的基因表达,抑制炎症因子IL^(-1)β、T_NF-α、IL^(-1)0的释放,从而减轻失血性休克肺损伤。

Objective To explore the protective mechanism of alprostadil pretreatment in dogs with hemorrhagic shock by observing the variations of pre-B-cell colony-enhancing factor（PBEF）in lung tissue and serum cytokines of the animal.Methods Twenty-four dogs were randomly divided into four groups（n=6）,control group（group C）,hemorrhagic shock group（group S）,group P1 and group P2 received alprostadil 30ng·kg^（-1）·min^（-1）and 60ng·kg^（-1）·min^（-1） respectively.In group C,an indwelling catheter were placed in femoral artery and vein of the dog,but no blood was removed from the catheter.Acute lung injury model of hemorrhagic shock was built in group S by removing blood from the femoral artery,and the MAP was maintained at（40±5）mm Hg for 90 min by removing or transfusing blood.MAP was maintained to preoperative level by blood reinfusion through femoral vein.Alprostadil was continuously infused at the rate of 30 ng· kg^（-1）· min^（-1） and 60ng·kg^（-1）·min^（-1） in groups P_1 and P_2 respectively for 30 min before hemorrhagic shock.Samples of arterial blood and lung tissue were obtained before shock（T_0）,90 min after shock（T_1）,and 4hafter recovery（T_4）.Oxygenation index（OI）was calculated in samples of arterial blood.The histopathological change was observed by light microscope,and the PBEF mRNA level was detected by real-time PCR in lung tissue.Samples of venous blood were taken at T_0,T-1,T_2（1hour after recovery）,T_3（2hour after recovery）,T_4.The concentration of TNF-α,IL^（-1）β,IL^（-1）0 and PBEF were measured by ELISA in these samples.Results Compared with group C,OI was significantly decreased at T_1,T_4,the serum concentrations of IL^（-1）β,TNF-α,IL^（-1）0,PBEF and the level of PBEF mRNA expression were significantly increased at T_1,T_4 in groups S,P_1 and P_2（P〈0.05）;Compared with group S,OI was significantly increased at T_1,T_4,the serum concentrations of IL^（-1）β,TNF-a,IL^（-1）0,PBEF and the level of PBEF mRNA expression were significantly decreased at T_1,T_4 in groups P_1 and P_2（P〈0.05）.Conclusion Alprostadil may reduce lung injury of hemorrhagic shock by decreasing PBEF gene expression and by restraining the release of IL-1β,TNF-αand IL-10.