目的 探讨急性百草枯(PQ)中毒鼠肺组织病理损伤和肺组织血红素氧合酶-1(HO-1)的表达及三七总皂甙(PNS)的保护作用。 方法 150只SD雄性鼠分为正常对照组(C组)30只、PQ中毒组(PQ组)60只及PNS组60只。PQ组和PNS组一次性灌胃PQ 25 mg/kg染毒,C组给予等体积生理盐水灌胃。其中PNS组于染毒前15 min以PNS 50 mg/kg阴茎静脉注射保护,以后1次/d给药直至处死前;PQ组、C组分别在同时间点给予等体积生理盐水。观察各组大鼠在中毒后6、12 h,1、3、5、7 d肺组织病理改变,采用蛋白质印迹法分析肺组织HO-1蛋白表达和反转录-聚合酶链反应方法测定鼠肺组织HO-1 mRNA的表达。 结果 C组HO-1蛋白和HO-1 mRNA绝大多数标本有弱表达,个别标本不表达;与C组相比PQ组及PNS组HO-1蛋白和HO-1 mRNA表达增强,差异有统计学意义(P<0.05);PQ组HO-1蛋白和HO-1 mRNA的表达在1 d达高峰之后下降,第3天基本恢复到C组水平;PNS组与PQ组相似,但在6 h、12 h、1 d及3 d高于PQ组,差异有统计学意义(P<0.05),至第5天和第7天二者相比差异无统计学意义(P<0.05)。PQ组肺组织病理损伤评分在6、12 h,1、3 、5、7 d各亚组均高于PNS相应组,差异有统计学意义(P<0.05),C组肺组织病理大致正常,与PQ组及PNS组相比,差异有统计学意义(P<0.001)。 结论 HO-1参与PQ中毒所致急性肺损伤,PNS对PQ中毒所致急性肺损伤有保护作用。
Objective To investigate the expression pattern of hypoxia-inducible factor 1α (HIF-1α) in experimental secondary spinal cord injury (SSCI) in rats and its potential effects on SSCI. Methods A total of 66 SD rats (female or male) with weight (250 ± 20) g were randomly divided into 3 groups: normal control group (group A, n=6), pseudo injury group (group B, n=6), and spinal cord injury (SCI) group (group C, n=54). In group A, no treatment was given as normal control. In groupB, only laminectomy was appl ied. In group C, laminectomy was appl ied and static compression model of SCI was built at T10 level. The expression of HIF-1α was measured with HE and immunohistochemical staining in groups A, B (1 hour after pseudo injury), and C (1, 3, 6, 12 hours and 1, 2, 3, 7, 14 days after SCI). Results All rats survived to the end of the experiment. HE staining showed that the spinal tissue of groups A and B were dense and the nucleus were round and big with l ight staining and clear nucleolus. The injured neuron at 1-12 hours after SCI of group C presented pyknosis and deep eosin staining. The swelling axon with bubbles and the disintegrated and disorganized medullary sheath in white matter appeared at 1-3 days after SCI. The hyperplasia of gl ial cells were obvious and gray matter cells were broken and apoptosis with cavities in injured spinal segment was observed at 7 and 14 days after SCI. Immunohistochemical staining showed that HIF-1α was poorly expressed in group A and increased a l ittle in group B. The positive expression in group C increased at 3 hours after SCI, which was found in spinal cord anterior horn neurons and a small amount of gangl ion cells. It reached peak at 1 day, maintained at a high level during 1-3 days and then decl ined. At 14 days, it appeared only in a small amount of gangl ion cells of white matter. There was no significant difference in the number of HIF-1α positive cells between groups A and B (t=1.325, P=0.137). The number of HIF-1α positive cells at each time point in group C was more than those in groups A and B (P lt; 0.05), and there were significant differences between all time points in group C (P lt; 0.05). Conclusion The expression of HIF-1α increases after SCI, it is related to the ischemia hypoxia after SSCI, and the expression pattern was correlated with the injury time.