The Mechanism Of Pulmonary Edema In Acute Spinal Cord Injured Rats And The Protection Ability Of Astragalin To Pulmonary Edema

The purpose of this study was to observe the changes of the pulmonary edema and pulmonary histopathology at different time point in acute spinal cord injured rats, to investigate the relationship between pulmonary edema and the changes of substance P and CD44 in serum and bronchoalveolar lavage fluid(BALF). And to investigate the relationship between astragalin and pulmonary edema, substance P and CD44. The spinal cord injury(SCI) models were induced at the level of seven cervical vertebrae(C7) by dropping a weight of lOg from the height of 25mm(Allen's model). To observe the change of the pulmonary pathology and lung wet/dry weight ratios(W/D). The content of substance P and protein concentration in serum and BALF were measured. Then the lung permeability index(LPI) was calculated. To install control group to observe the effect of astragalin with different concentration on pulmonary pathology, lung wet/dry weight ratios, substance P and CD44. Pulmonary edema and hemorrhage were noted in SCI rats, which reach pea at 3d after injury, and relieve at 1 week. The degree of pulmonary edema was positive correlation with the change of substance P in serum and BALF, and was negative correlation with the change of CD44 in serum. Astragalin with defferent density affected the pulmonary pathology and edema and the change of substance P and CD44 in serum and BALF in SCI rats. In rats with spinal cord injury, sympathetic nerve may be over excitation, which may stimulate the release of substance P to take part in the development of neurogenic pulmonary edema. Furthermore, alveolar epithelial cell damaged after pulmonary injury, which decreased CD44 expression, so reconditioning ability decreased. Astragalin can lessen the degree of pulmonary edema in SCI rats.