Protective Effects Of Captopril On Smoke Inhalation Injury In Rat

Objective To investigate the protective effects of captopril and its basic mechanism in rats with smoke inhalation injury. Method48clean level adult male SD rats were randomly divided into three groups,16for each group:control group, injured group and captopril group. The captopril group were administered i.p. captopril after inhalation injury,with the same volume, the injury group were administered i.p. normal saline using the same method. Femoral aortic blood of Injuries and CAP group was collected at2h,5h respectively, then each was executed for8.And do the same to the control group at the same point. Then they were all decapitated and the left lung tissues of each group at5h were collected. Serums were prepared for tumor necrosis factor-α (TNF-α),interleukin-6(IL-6),interleukin-10(IL-10).And Lung homogenates were examined for superoxidedismutase (SOD),malondialdehyde (MDA) and myeloperoxidase (MPO). The pathological changes in lungs were also examined under an optical microscope. Then take the left lobe fixed in formalin, followed by dehydration, embedded in paraffin, sliced, hematoxylin-eosin(HE) staining, and then examined lungs pathological changes under an optical microscope.Results1General conditions after inhalation injury:The rats after smoke inhalation damage onset of wheezing, accelerated heartbeat and the performance generally disappeared after extracting then at indoor empty zone for a while. The control group without smoke inhalation damage breathe smoothly, and have no shortness of breath and breathing difficulties and other symptoms.2The macroscopic observation and pathological section of three groups:The lungs of control group on visual inspection had normal congestion,normal color and no edema. The injury group were found to have severe diffused and passive lung congestion. CAP group which is better than the injury group were less edema and more fresh.The lungs of rats in control group were found no diffused alveolar septum thickening,infiltrating inflammatory granulocyts and spotty hemorrhage. The lungs in the injured group were found heterophil granulocyte, edema and histoleucocyte in lung stroma. The CAP group which is better than the control group were found less same cells.3The results of TNF-a,IL-6and IL-10in the three groups:The data of arterial blood analysis revealed that compared with control group TNF-a and IL-6levels of injury group were increased(p<0.01). While compared with control group the levels of TNF-a,IL-6and IL-10of CAP group at5h which is better than the injury group(p<0.05) were significantly changed (p<0.01).4The results of MDA,MPO and SOD in the three groups:Compared with control group, TNF-a and IL-6levels of the injury group were increased(p<0.01).while the SOD levels were significantly decreased(p<0.01). Compared with control group the levels of MDA,MPO and SOD of CAP group at5h which is better than the injury group(p<0.05) were significantly changed (p<0.01).Conclusions Captopril has some protective effects on smoke inhalation injured rats by decreasing the inflammatory response.