洛美利嗪对大鼠脑微血管内皮细胞上P-糖蛋白活力的影响与P-gp及mdr1基因mRNA表达无关

目的：研究洛美利嗪对原代培养的大鼠脑微血管内皮细胞（RBMECs）上P-糖蛋白（P-gP）功能和表达的影响。方法：使用流式细胞术分析洛美利嗪对P-gp底物-罗丹明123（rhodaminel23，Rh123）在RBMECs中外排的影响，使用流式细胞术分析了洛美利嗪对RBMECs上P-gp表达的影响，应用RT-PCR技术分析了洛美利嗪对RBMECs mdr1基因mRNA水平表达的影响，还使用Transwell模型研究了洛美利嗪对Rh123通透RBMECs单层细胞转运的影响。结果：洛美利嗪通过抑制了RBMECs胞内Rh123的外排；洛美利嗪对P—gP功能的影响与RBMECs上P-gp及mdr1基因mRNA表达无关；在Transwell模型中，洛美利嗪还能显著增加Rh123跨RBMECs单层细胞膜的、经上室至下室的转运，并抑制相反方向的Rh123的转运。结论：洛美利嗪能显著地抑制RBMECs上P-gp的活性，并对P-gp底物的跨细胞转运产生影响。

Lomerizine inhibited the function of P-glycoprotein(P-gp) without decreasing the expression of mdr1 gene and P-gp in primarily cultured rat brain microvessel endothelial cells

AIM: To study the effect of Lomerizine on the activity of P-glycorprotein (P-gp) in primary cultured rat brain microvessel endothelial cells (RBMECs). METHODS: Flow cytometry was used to study the efflux of rhodamine123 (Rh123) and expression of P-gp in RBMECs. RT-PCR was used to measure the expression in mRNA level of mdr1 gene in RBMECs. Transwell model was used to detect the influence of Lomerizine on the transport of Rh123 through RBMECs monolayer. RESULTS: Lomerizine inhibited the efflux of Rh123 in RBMECs. No changes of P-gp and mdr1 gene mRNA expression were detected in RBMECs after the treatment with 30 μmol·L-1 Lomerizine for 72 h. In the study of Transwell model, Lomerizine increased significantly the transport of Rh123 through RBMECs monolayer from upper compartments to lower compartments, and inhibited obviously the transport in reverse direction. CONCLUTION: The effect of Lomerizine on the activity of P-gp was mainly via its direct inhibitory effect on the function of P-gp in RBMECs and the transport of P-gp substrates in BBB may be affected by lomerizine.