Effects Of Captopril On TNF-α,IL-8 And ICAM-1 In Rats With Acute Lung Injury

Objective:To explore the effects of Captopril on changes of TNF-α, IL-8, ICAM-1, and the lungpathomorphology in rats with smoke inhalation-induced acute lung injury(ALI).Methods:Thirty-six Wistar rats were randomly divided into three groups :control group, ALI group andCAP group (n=12 each). CAP group received Captopril(5mg/kg)by intra-peritoneal injection,Controlgroup and ALI group were given equal amount of 0.9% NaCl solution. The rats were exposed to smoke toset up the model of serious smoke inhalation-induced acute lung injury 15 minutes later. To observe clinicalmanifestations, the arterial blood gases were analyzed, the serum concentration of TNF-αand IL-8 weremeasured by radioimmunoassay, the expression of ICAM-1 were measured by immunohistochemistrialmethod and analyzed by multi-media imagine analysis system,to observe the lung pathomorphologicalchanges.Results:(1) In ALI group, cyanosis was obvious, lots of secretion came out from mouth and nasal cavities.Compared with the ALl group, cyanosis in CAP group was less severe, secretion from mouth and nasalcavities were slightly less.(2) PaO₂,SaO₂ and PaO₂/FiO₂ in ALIgroup decreased continuously during thetrial, there were significant differences between the ALl group and the control group(p＜0.01), and PaO₂/FiO₂ were all less than 300. PaO₂/FiO₂ of CAP group were all less than 300 5 minutes after injury, PaO₂and PaO₂/FiO₂ improved significantly at the end of 5 hours than that of 5 minutes(p＜0.01); PaO₂ wassignificantly more than that in the ALI group (p＜0.01).(3) The serum concentration of IL-8 wassignificantly lower in CAP group than in the ALI group(p＜0.05), there were no significant differencesbetween the ALI group and the CAP group about TNF-α(p＞0.05). (4) The expression of ICAM-1 wassignificantly lower in CAP group than in the ALl group(p＜0.01), and the lung pathomorphologicalchanges were less severe.Conclusions: Captopril may reduce the IL-8 and ICAM-1,reduce lung injury and improve the gasexchange in ALI.Captopri has no significant effect on the serum concentration of TNF-α.