合成短肽S247对呼吸机所致肺损伤p38MAPK通路激活的影响

Effects of synthesized peptide S247 on the activation of p38MAPK during ventilator-induced lung injury

目的研究合成短肽S247对大鼠呼吸机所致肺损伤(VILI)p38MAPK通路激活的影响。方法30只健康雄性SD大鼠随机均分成A、B、C三组：A组潮气量(V_T)为8mL/kg,B组V_T为40 ml/kg,C组V_T为40mL/kg。试验前一周每天一次腹腔注射合成短肽S247溶液(100 mg/kg),直至试验前0．5h。各组通气时间均为2h,呼吸频率均为80次/min。试验结束处死大鼠,收集肺灌洗液和组织标本,光镜观察肺病理改变,Western Blot方法检测各组肺组织中p38、磷酸化p38(p-p38)的水平。同时分别检测各组肺灌洗液中总蛋白、白细胞计数、MPO以及MIP-2的水平。结果和A组相比,B组肺病理改变明显,总蛋白、白细胞计数、MPO、MIP-2、p-p38等指标均显著高于A组(P＜0．01)。和B组相比,C组病理改变明显减轻,p-p38和其他各项指标指标均显著低于B组(P＜0．01或P＜0．05)。结论合成短肽S247能显著抑制VILI时p38通路的激活,减轻肺损伤,对VILI具有一定保护作用。

Objective To study the effect of synthesized peptide S247 on the activation of p38MAPK of ventilatorinduced lung injury. Methods Thirty healthy male SD rats were divided into group A, group B, group C, n 10. All rats were performed with mechanical ventilation, group A with tidal volume （VT） 8 ml/kg, breathing rate （p） 80/min; group B with tidal volume （VT） 40 ml/kg, breathing rate （p） = 80/min; group C with tidal volume （VT） 40 ml/kg, breathing rate （p） 80/min. The rats in group C were intraperitoneally injected with synthesized peptide S247 （100 mg/kg） once a day for a week. The time of ventilation in all groups was two hours. Rats were sacrificed after the experiment was finished. The lung lavage liquid and lung tissue were collected and stored with correct methods. The measured indexes included lung pathology change, total protein, WBC, MPO and MIP-2. The expression of p38 and p-p38 were measured by Western Blot in lung tissue. Results Compared with group A, total protein, WBC, MPO, MIP-2 and p-p38 significantly increased in group B; compared with group B, total protein, WBC, MPO, MIP-2 and p-p38 significantly decreased in group C. Conclusion Synthesized peptide S247 significantly inhibited the activation of p38 and relieved the degree of ventilator induced lung injury.