Pulmonary contusion induced by blunt chest trauma can result in respiratory dysfunction and secondary inflammatory reaction, which can take part in the occurrence of systemic inflammatory response syndrome and multiple-organ dysfunction syndrome. However, the reason and mechanism of pulmonary contusion is urgently for clarity.OBJECTIVE:
To investigate the protective effect and mechanism of ligustrazine on cell apoptosis in the acute stage of pulmonary contusion induced by blunt chest trauma in rats.METHODS:
Healthy male Sprague-Dawley rats were divided equally and randomly into three groups: control group, model group and ligustrazine group. Blunt chest trauma models were prepared in the latter two groups. Rats in the ligustrazine group were intraperitoneally injected with 80 mg/kg ligustrazine immediately after blunt chest trauma. Lung tissues were collected at 1, 2 and 3 hours after blunt chest trauma to observe pathomorphological changes. The apoptotic index, pulmonary microvascular permeability and severity of pulmonary edema were detected to assess the lung function. Expressions of Caspase-3, Bax and Bcl-2 were detected by immunohistochemical staining, and blood tumor necrosis factor alpha was also detected.RESULTS AND CONCLUSION:
In the model group, tumor necrosis factor alpha increased at 1 hour and increased sharply in 2 and 3 hours after blunt chest trauma (P < 0.05); the apoptotic index and the degree of lung injury increased significantly at 2 and 3 hours after blunt chest trauma (P < 0.05); pulmonary microvascular permeability and degree of pulmonary edema were increased (P < 0.05); the expression of Caspase-3 increase significantly (P < 0.05) with the decrease of the ratio of Bcl-2 to Bax (P < 0.05). In the ligustrazine group, tumor necrosis factor alpha decreased notably (P < 0.05); the apoptotic index and the degree of lung injury decreased significantly after blunt chest trauma (P < 0.05); pulmonary microvascular permeability and the degree of pulmonary edema were relieved (P < 0.05); the expression of Caspase-3 decreased significantly (P < 0.05) with the increase of the ratio of Bcl-2 to Bax after treated with ligustrazine (P < 0.01). These findings indicate that ligustrazine can alleviate cell apoptosis in the acute stage of pulmonary contusion induced by blunt chest trauma by inhibiting the tumor necrosis factor alpha, down-regulating the expression of Caspase-3 and enhancing the ratio of Bcl-2/Bax.