Protective effects of different agents on smoke inhalation injury in rats model

Objective To evaluate the protective effect of ulinastatin,dexamethasone and ambroxol on smoke inhalation ingury using rat model.Methods Fifty rats were randomly divided into five groups.The rats in control group(group C)were not exposed to smoke.The remaining four groups were labeled group A,group D,group U and group M and then treated with ambrioxl,dexamethasone,ulinastatin,and normal saline respectively.These four groups were treated after half an hour from the onset of smoke inhalation injury and all rats were sacrificed after a period of six hours.Arterial blood was collected from the rats and then the levels of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)were determined.Lung homogenate was checked for Superoxide dismutase(SOD),malondialdehyde(MDA),nitric oxide(NO)and inducible nitric oxide synthase(iNOS).The pathological changes in lungs were also examined under an optical microscope.Results Under the microscope,group C and group M were compared.The lungs of rats in group M were observed to have infiltrating inflammatory granulocytes,diffused alveolar septum thickening and spotty hemorrhage.The histopathological change in group U and D was minimal in comparison to group M.When compared with group U,the levels of TNF-α,IL-6 and MDA were found to be significantly higher in group M(P0.05).The levels of TNF-α and MDA were also higher in group M than in group D(P0.01).Compared with group C,the levels of NO,iNOS and SOD activity in lung homogenate were higher in group A(P0.05).There was no significant improvement of iNOS in group D and group U(P0.05).Conclusions Dexamethasone and ulinastatin may have the similar anti-inflammatory effect and provide some degree of protection against smoke inhalation injury in rats.The effect of anti-oxygen free radicals and anti-inflammatory are not obvious by treating ambroxol.