Role of substance P in developing pulmonary edema after acute cervical spinal cord injury in rats

English Keywords:Spinal cord injury  Pulmonary edema  Substance P  Rat

English Abstract:

  【Abstract】 Objective：To investigate the relationship between pulmonary edema and substance P in rats suffering ｆｒｏｍ　acute cervical spinal cord injury.Method：40 Wistar rats with 240-250g in weight，were randomly divided into two groups：control group（n=20） and injury group（n=20），and the latter ｗａｓ subdivided into groups of 24h，3d，1 week，2 weeks after injury respectively.The spinal cord injury（SCI） models were induced at the level of C7 vertebra by dropping a weight of 10g from the height of 25mm （Allen′s model）.While in control group，laminas were removed only，leaving spinal cord at the same level intact.All the animals were sacrificed at each time point ranging from 24h to 2 weeks（24h，3d，1 week，2 weeks）.Substance P and protein concentration in serum and bronchoalveolar lavage fluid（BALF） were measured.The lung permeability index（LPI） and change of the pulmonary pathology were calculated.Result：In injury group，lung slices showed pulmonary capillaries congestion at 24ｈ after injury，ａｎｄ　the pulmonary alveoli were filled with erythrocytes and serous extravagated，which peaked at 3d，and began ease at 1 week.The content of substance P in serum and BALF began increasing at 24h，reached peak at 3d，declined at 1 week，and declined obviously at 2 weekｓ.There was statistical significance with respect to the content of substance P in serum between control group and injury group at 24h，3d and 1 week（P<0.05），and the deviation of LPI was similar to that of substance P.Conclusion：The deviation of substance P in serum and BALF is consistent with the degree of pulmonary edema in acute cervical spinal cord injury in rats.Substance P may take part in the development of pulmonary edema in SCI rats.