The Effects Of Ulinastatin On The ALI Rabbits Induced By Underwater Explosion

Objective To investigate the effects of Ulinastatin on rabbits ALI induced by underwater shock wave,the ALI rabbits models were established by underwater explosion device.Methods To establish the rabbit ALI model induced by underwater explosion,A（1.5m）,B（1.8m）and control（N）were set up,respectively.ALI model of rabbits induced by underwater explosion was preliminarily estimated by comparing the mortality,lung tissue moisture content and lung tissue pathology of the three groups at0h,4h,12h,24h after injury.To study the effect of Ulinastatin on rabbits with ALI induced by underwater explosion were based on the establishment of early rabbit ALI model.Two groups were set up in this experiment,namely Ulinastatin group（U）and injury group（I）.In the U group,Ulinastatin was given immediately after injury,and the serum levels of matrix metalloproteinase 9（MMP-9）,tumor necrosis factor alpha（TNF-α）and nuclear transcription factor B（NF-κB）were collected at 4h,12h and 24h after injury.Western Blot was used to measure the expression of MMP-9 in the lung tissues of the two groups.And the moisture content in the lung tissues was measured and the pathological results were observed under the microscope by two veteran pathologists.Results1.Above all,compared with group N,experimental rabbits in group A had higher mortality（70%）,hypoxemia（75.34±4.34）mmHg,and higher lung tissue moisture content（86.58±4.07）%（P<0.05）.There was no statistically significant difference in mortality between group B（20%）and group N（P>0.05）.The PaO₂ in group B （76.68±4.48）mmHg was significantly inferior to group B,and the lung moisture content of group B higher than that of group N.Meanwhile,the pathological results of the lung tissue showed that the alveoli of the experimental rabbits in group A were different in size,and the alveolar cavity was filled with red blood cells and a large number of neutrophils were infiltrated.The alveoli of the experimental rabbits in group B varied in size,with partial alveolar rupture and fusion,and a small amount of red blood cells exuded in the alveolar cavity and lung stroma.2.The levels of TNF-αin serum were significantly lower at 12h after injury in the W group than that of in the I group（P<0.05）.And MMP-9,TNF-αand NF-κB levels in serum were significantly lower at 24h after injury than that of in the I group （P<0.05）.MMP-9 was highly expressed in lung tissue of group I,while it was low in lung tissue of group U by WB method.The lung tissue moisture content in group W was significantly lower than that in group I（P<0.05）.Conclusion1.The 1.8m detonation distance was suitable forestablishing the experimental animal model of rabbit ALI induced by underwater explosion.Suchmodel had the characteristics of low mortality,good repeatability,and moderate lung injury and can be treated,which can provide a reliable animal model of rabbit ALI induced by underwater shock wave for subsequent experimental studies.2.Ulinastatin can significantly reduce the expression levels of MMP-9,TNF-αand NF-κB inflammatory factors in the serum of experimental rabbits,reduce pulmonary edema,and reduce the expression of MMP-9 in the lung tissue,thus may play important role in ALI induced by underwater shock wave in rabbits.