红霉素经环磷酸腺苷途径改善百草枯处理的血管内皮细胞通透性机制研究

The mechanism of alleviation of paraquat induced vascular endothelial permeability by erythromycin through adenosine 3＇5＇-cyclic monophosphate pathway

目的探讨红霉素对百草枯所致血管内皮细胞屏障功能的保护作用及分子机制。方法采用二室弥散装置体外培养人脐静脉内皮细胞，将培养好的细胞按随机数字表法分为百草枯组（P组）、百草枯＋红霉素组（P＋E组）、正常对照组（N组），分别孵育6、12、24、36、48h。采用免疫荧光和放射免疫法分别检测单层血管内皮细胞屏障对大分子物质的通透性变化以及内皮细胞内环磷酸腺苷（cAMP）浓度的变化。结果①N组内皮细胞通透率趋于稳定；P组随时间延长通透率升高，于36h和48h时显著高于N组（P〈0．01和P〈0．05）；P＋E组36h时通透率显著低于P组，但仍高于N组（P均〈0．01），至48h时与N组无明显差异。②N组内皮细胞cAMP浓度在各时间点较为稳定；P组随时间延长cAMP浓度降低，24h起明显低于N组（P均〈0．05）；P＋E组随时间延长cAMP浓度升高，24h起明显高于P组（P〈0．05或P〈0．01），但48h时才显著高于N组（P〈0．01）。P组和P＋E组内皮细胞通透率与cAMP浓度均呈明显负相关（r1=-0．913，r2=-0．648，P均〈0．05）。结论红霉素能改善百草枯中毒所致的血管内皮细胞屏障功能受损程度，其可能机制是通过升高内皮细胞cAMP浓度、降低细胞通透性而实现。

Objective To discuss the effects of erythromycin in protecting against paraquat induced vascular endothelial cell permeability and the possible molecular mechanism of the affect. Methods The transwell was used to culture human umbilical vein endothelial cells （HUVEC） in vitro. The cultured endothelial cells were divided into three groups： control group （N group）, paraquat group （P group）, paraquat＋erythromycin group （P＋E group）. The variables were measured under different conditions at 6, 12, 36 and 48 hours by immunofluorescence and immunoradiometric assay to determine the changes in vascular endothelial permeability to macromolecules and the change in adenosine 3＇5＇-eyelie monophosphate （cAMP） concentration （[cAMP]）. Results （1）Endothelial permeability was steady in N group. The permeability in P group was increased, and it was higher than N group at 36 hours and 48 hours with statistical significance （P〈0.01 and P〈0.05）. The permeability of P＋E group was lower than P group and was higher than N group at 36 hours （both P〈0.01）, and there was no difference between N group and P＋E group at 48 hours. （2） The [cAMP] was stable in N group at different time points; [cAMP] was decreased in P group with statistical significance at 24 hours as compared with N group （P〈0. 05）. [cAMP] was elevated in P＋E group, and it was higher than that of P group after 24 hours （P〈0. 05 or P〈0.01）; moreover, [cAMP] of P＋E group was higher than that of N group at 48 hours （P〈0.01）. Endothelial permeability and [cAMP] was significantly negatively correlated in both P group and P ＋E group （r1=-0. 913, r2 =- 0. 648, both P〈0. 05）. Conclusion Erythromyein could improve the function of damaged vascular endothelial cell barrier after paraquat poisoning, and it was the result of lowering of cellular permeability due to elevation of endothelial cAMP.