抑肽酶对全氟异丁烯诱导大鼠急性肺损伤的影响及其机制

Effect and mechanism of aprotinin on acute lung injury in rats induced by perfluoroisobutylene

目的探讨蛋白酶抑制剂抑肽酶对全氟异丁烯(PFIB)诱导大鼠急性肺损伤(ALI)的影响及其机制。方法PFIB诱导建立大鼠ALI动物模型。将成年雄性SD大鼠40只按体重排序,以体重为区组因素随机分成5组:对照组(N组)、ALI组(I组)、5 mg/kg抑肽酶组(L组)、15 mg/kg抑肽酶组(M组)、30 mg/kg抑肽酶组(H组)。PFIB吸入30min后,I组经腹腔注射生理盐水,抑肽酶治疗组则经腹腔注射不同剂量(5、15、30 mg/kg)的抑肽酶溶液。24 h后收集各组支气管肺泡灌洗液(BALF)和血液,并测定各组的动脉血气值及肺湿/干质量比值,用BCA法测定支气管BALF总蛋白含量,ELISA法测定血清肿瘤坏死因子-α(TNF-α)和白介素-6(IL-6)的量,并在光镜下进行肺组织病理检查。结果 I组肺湿干重比、BALF总蛋白含量、IL-6、TNF-α水平较N组均明显升高(P<0.05)。经抑肽酶治疗后,L组湿干重比、总蛋白含量水平与I组比较,差异无统计学意义(P>0.05),IL-6、TNF-α水平有明显降低(P<0.05)。H组湿干重比、总蛋白含量、IL-6、TNF-α水平均明显低于I组(P<0.05),与L组、M组比较也有明显降低(P<0.05)。染毒后大鼠pH值及氧分压明显下降,二氧化碳分压升高,经抑肽酶治疗后,pH值及氧分压有所提高,二氧化碳分压有所下降,以高剂量时改变最明显。肺组织病理组织学结果显示,抑肽酶能明显改善肺组织病理损伤,以高剂量最有效。结论抑肽酶能通过抑制细胞因子和炎症介质的释放来减轻大鼠ALI的肺部炎症反应。

Objective To research the effect and mechanism of aprotinin on acute lung injury in rats induced by perfluoroisobutylene （PFIB）. Methods The model of acute lung injury in rats was induced by PFIB. Forty adult male Sprague-Dawley rats were averagely and randomly divided into saline control group （N group） , ALl group （I group） and aprotinin groups（5,15 g,30 mg/kg, L/M/H group）. The rats in I group were intravenously injected with normal saline and the rats in aprotinin groups were intravenously injected with aprotinin （5,15,30 mg/kg） thirty minutes after PFIB was inhalated. The brochoalveolar lavage fluid （BALF） and blood were collected in rats of each group 24 hours later. The arterial blood gas was observed. The wet to dry weight ratios （W/D） were deter- mined. The total protein in bronchoalveolar lavage fluid was evaluated by BCA method. The tumor necrosis factor-or （TNF -α）and the interleukin-6 （IL-6） were determined by ELISA method. The pathological changes in lung tis- sues were also observed under the microscope. Results The levels of lung wet-dry weight ratio, total protein con- tent in BALF, IL-6, TNF-α were significantly higher （ P 〈 0. 05） than the group N. With the treatment of aprotin- in, the levels of wet to dry weight ratio, total protein content in L group were not significantly different （P 〉 0. 05） ,compared to group I. But the values of IL-6, TNF-α were lower （ P 〈 0. 05 ）. The levels of wet to dry weight ratio , total protein , IL-6 and TNF-α in group H were significantly lower than that in group I （P 〈 0. 05） group L and group M （P 〈 0. 05 ）. After the rats exposed to PFIB, the values of PH and partial pressure of oxygen were decreasing, and the values of carbon dioxide partial pressure were improving. With the treatment of aprotinin, all the values could improve towards a good situation. Histopathology of lung tissue showed that aprotinin could sig- nificantly improve lung tissue damage, with high doses of the most. Lung tissue histopathology showed aprotinin could significantly reduce lung tissue damage,and high-dose aprotinin was most effective. Conclusion Aprotinin, the protease inhibitor, could relieve inflammation in the lungs of rats with ALI induced by PFIB though blocking the excess release of cytokines and inflammatory mediators.