肺表面活性物质携载超氧化物歧化酶向大鼠肺组织转运的实验研究

Empirical study of the transportation of pulmonary surfactant-super oxide dismutase liposome to lung tissue in rats

目的探讨通过建立肺表面活性物质-超氧化物歧化酶(PS-SOD)脂质体携载 SOD 向大鼠肺组织转运的可行性。方法改良旋转蒸发法制备 PS-SOD 脂质体。选用 Wistar 大鼠32只,随机分为4组:生理盐水对照组、PS 组、SOD 组和 PS-SOD 脂质体组,每组8只。各组分别经主气管直接注入生理盐水、PS、SOD、PS-SOD 脂质体。各组再分为2个亚组,每组4只,分别于术后2 h 和24 h 处死。测定肺灌洗液、肺组织匀浆 SOD 活力;进行肺组织 SOD 荧光标记,荧光显微镜和透射电镜观察肺组织细胞中 SOD 的转运效果。结果 PS-SOD 脂质体为单层脂膜圆形小体,各成分的性能稳定。2 h时,PS-SOD 脂质体组和 SOD 组肺灌洗液 SOD 活力(32.87±5.47、33.14土5.61)高于生理盐水组(2.15±0.17,均 P<0.01),但两组之间差异无统计学意义(P>0.05);PS-SOD 脂质体组荧光平均光密度(0.109±0.018)明显低于生理盐水组和 PS 组(0.144±0.052、0.143±0.026,均 P<0.01);PS-SOD 脂质体组与 SOD 组相比,荧光平均光密度的差异无统计学意义(P>0.05)。24 h 时,PS-SOD 脂质体组肺灌洗液 SOD 活力(11.54±1.42)高于生理盐水组(2.10±0.21)和 SOD 组(6.28±1.45,均P<0.01)。PS-SOD 脂质体组荧光平均光密度(0.112±0.018)明显低于其余3组(生理盐水组:0.146±0.034,PS 组:0.147±0.024,SOD 组:0.135±0.018,均 P<0.01)。无论2 h 还是24 h,PS-SOD 脂质体组肺组织匀浆 SOD 活力(16.83±2.69和15.70±2.75)均高于生理盐水组(5.79±0.93和5.84±1.31,均 P<0.01),而 SOD 组与生理盐水组差异无统计学意义(P>0.05),且 PS-SOD脂质体组肺组织匀浆 SOD 活力明显高于 SOD 组(7.07±1.04、6.11±1.06,均 P<0.01)。透射电镜PS-SOD 脂质体组肺泡Ⅱ型上皮细胞内含有大量的脂质体吞噬泡,其形态及大小与 PS-SOD 脂质体相似。结论 PS-SOD 脂质体能有效地增强 SOD 向肺组织细胞转运,并有缓释延长 SOD 抗氧化活性的作用。通过气管内直接给药使 SOD 在肺组织细胞中更充分发挥其抗氧化活性。

Objective To study the feasibility of the transportation of pulmonary surfactant-super oxide dismutase（PS-SOD） liposome to lung tissue in rats. Methods 32 Wistar rats were randomly divided into 4 groups（8 rats in each group） ： normal saline group, PS group, SOD group, PS-SOD liposome group. Each group was further divided into two groups（4 rats in each group）, and the rats were respectively killed 2 and 24 hours after the operation. While the biological activity of SOD in irrigating solution and tissue bomogenate were detected, lung tissue were labeled with fluorescent and then observed under microscope and transmission electron microscope. Results PS-SOD liposome was corps ronds with monolayer lipid with stable surface tension and antioxidative activity. At the point of 2 hours after operation, while the SOD biological activity of irrigating solution in PS-SOD liposome group（32. 87 ± 5.47） and SOD group （33.14 ± 5.61）were obviously higher than that in normal saline group （2. 15 ± 0. 17,P 〈 0.01）, there was no difference between them （ P 〉 0. 05 ）. The mean fluorescence optical density in PS-SOD liposome group （0. 109 ±0. 018）was lower than that in normal saline group（0. 144 ± 0. 052）and PS group（0. 143 ± 0. 026, P 〈 0. 01 ）. 24 hours after operation, the SOD biological activity of irrigating solution in PS-SOD liposome group（ 11.54 ± 1.42） was the highest （P 〈 0. 01 ） and the mean fluorescence optical density in PS-SOD liposome group（0. 112 ± 0.018） was the lowest （P 〈 0.01）. The SOD biological activity of tissue bomogenate in PS-SOD liposome group （2 h： 16. 83 ± 2. 69,24 h： 15.70 ± 2. 75 ） was higher than that in normal saline group （2 h：5.79 ± 0. 93, 24 h： 5.84 ± 1.31 ） and in SOD group （2 h：7.07 ± 1.04, 24 h： 6. 11 ± 1.06, P 〈 0. 01 ） both at the point of 2 and 24 hours after the operation. Lots of PS-SOD liposome was observed in type II alveolar epithelial cells under transmission electron microscope. Conclusion Intracheal administ ration of PS-SOD liposome enhanced the transportation of SOD into lung tissue and its antioxidative activity.