摘要：
Objective To investigate the protective effect of thalidomide on acute lung injury (ALI) induced by paraquat (PQ) poisoning in rats and its possible mechanism. Methods Sixty SPF Wistar rats were randomly divided into six groups with 10 rats in each group. The rat model of PQ poisoning was reproduced by intraperitoneal injection of PQ solution 20 mg/kg (PQ model group), and the rats were treated by intraperitoneal injection of gradient thalidomide (50, 100, 200 mg/kg treatment groups) 30 minutes later continuously for 3 days. The normal saline (NS) control group and thalidomide control group (thalidomide 200 mg/kg) were established. After 3 days, the abdominal aorta blood was collected, and the superoxide dismutase (SOD) activity was determined by hydroxylamine method, serum malondialdehyde (MDA) content was determined by thiobarbituric acid method. The rats were sacrificed for lung tissue, the levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined by enzyme-linked immunosorbent assay (ELISA). The phosphorylation levels of p65 and inhibitor-α of nuclear factor-κB (NF-κB) (IκB-α), which were the NF-κB signaling pathway proteins, were determined by Western Blot. The pathological changes in lung tissue were observed under light microscope by hematoxylin-eosin (HE) staining. Results Under microscope, obvious congestion of pulmonary interstitial and alveolar septum, a large number of inflammatory cells infiltration and thickened alveolar wall were observed after 3 days of PQ poisoning, and the congestion of pulmonary interstitial and alveolar septum, edema and inflammatory cells infiltration in the lung tissue were significantly reduced after treatment of 50, 100, 200 mg/kg thalidomide, but compared with NS control group, there was still a small amount of edema fluid, inflammatory cells and erythrocytes in the lungs tissue. Compared with the NS control group, serum MDA content and the levels of TNF-α and IL-6, and the phosphorylation of p65 and IκB-α in lung tissue were significantly increased after PQ exposure, and the activity of serum SOD was significantly decreased. Treatment with 50, 100, 200 mg/kg thalidomide could significantly reduce the levels of MDA, TNF-α, IL-6, and phosphorylation of IκB-α and p65, and increase SOD activity, in a dose-dependent manner, and the levels were significantly different from PQ model group [MDA (mmol/L): 8.26±1.20, 6.72±1.18, 5.51±1.44 vs. 9.02±1.03, TNF-α (ng/mg): 3.00±0.14, 1.84±0.18, 1.58±0.11 vs. 3.30±0.14, IL-6 (ng/mg): 1.26±0.04, 1.06±0.04, 0.97±0.08 vs. 1.97±0.07, p-p65/p65: 6.01±0.35, 3.64±0.15, 2.89±0.18 vs. 6.34±0.23, p-IκB-α/IκB-α: 2.27±0.13, 2.14±0.22, 1.52±0.14 vs. 2.96±0.20, SOD (kU/L): 195.7±19.3, 207.1±25.6, 225.8±23.1 vs. 188.2±26.6, all P < 0.05]. There was no significant effect on lung by 200 mg/kg thalidomide alone. Conclusion Thalidomide has a protective effect on ALI induced by PQ poisoning in rats in a dose-dependent manner, the mechanism may be achieved by reducing the level of oxygen free radicals, reducing the inflammatory factor and inhibiting the IκB-α/NF-κB signal pathway activation.%目的 探讨沙利度胺对百草枯(PQ)中毒急性肺损伤(ALI)大鼠的保护作用及其可能机制.方法 将60 只SPF级Wistar大鼠按随机数字表法分为6组,每组10只.采用腹腔注射PQ溶液20 mg/kg建立大鼠PQ中毒模型(PQ模型组),30 min后腹腔注射梯度沙利度胺进行干预(50、100、200 mg/kg干预组),连续3 d;并设立生理盐水(NS)对照组和沙利度胺对照组(给予200 mg/kg).分别于3 d后取大鼠腹主动脉血,采用羟胺测定法检测血清超氧化物歧化酶(SOD)活性,采用硫代巴比妥酸测定法检测血清丙二醛(MDA)含量.处死大鼠取肺组织,采用酶联免疫吸附试验(ELISA)检测肿瘤坏死因子-α(TNF-α)和白细胞介素-6(IL-6)含量;采用蛋白质免疫印迹试验(Western Blot)检测核转录因子-κB(NF-κB)信号通路蛋白p65和NF-κB抑制蛋白-α(IκB-α)的磷酸化水平;经苏木素-伊红(HE)染色后,光镜下观察肺组织病理学改变.结果 PQ染毒3 d后可见大鼠肺间质及肺泡间隔明显充血,有大量炎性细胞浸润,肺泡壁增厚;而给予50、100、200 mg/kg沙利度胺干预后,大鼠肺间质和肺泡间隔充血、水肿及炎性细胞浸润明显减轻,但仍可见少量水肿液、炎性细胞及红细胞.与NS对照组比较,PQ染毒后血清MDA含量以及肺组织TNF-α、IL-6水平和p65、IκB-α蛋白磷酸化水平均明显升高,血清SOD活性明显降低;而给予50、100、200 mg/kg沙利度胺干预后,可呈剂量依赖性地抑制PQ染毒诱导的MDA、TNF-α、IL-6含量及p65、IκB-α蛋白磷酸化水平升高,并提高SOD活性,与PQ模型组比较差异有统计学意义〔MDA(mmol/L):8.26±1.20、6.72±1.18、5.51±1.44比9.02±1.03,TNF-α (ng/mg)为3.00±0.14、1.84±0.18、1.58±0.11比3.30±0.14,IL-6(ng/mg):1.26±0.04、1.06±0.04、0.97±0.08比1.97±0.07, p-p65/p65:6.01±0.35、3.64±0.15、2.89±0.18比6.34±0.23,p-IκB-α/IκB-α:2.27±0.13、2.14±0.22、1.52±0.14比2.96±0.20,SOD(kU/L):195.7±19.3、207.1±25.6、225.8±23.1比188.2±26.6,均P<0.05〕.单纯给予200 mg/kg沙利度胺对肺脏则无明显影响.结论 沙利度胺对PQ中毒ALI大鼠具有保护作用,并呈一定剂量依赖性,其机制可能与降低氧自由基和炎性因子水平,以及抑制IκB-α/NF-κB信号通路活化有关.
