目的研究洛美利嗪对血脑屏障上P-糖蛋白功能活性的影响,寻找新型高效的P-糖蛋白抑制剂。方法使用罗丹明123荧光指示剂研究脑微血管内皮细胞上P-糖蛋白的活性,应用RT-PCR技术分析洛美利嗪对mdr基因mRNA的影响。结果洛美利嗪能够浓度依赖性地增加RBMECs中的罗丹明123水平,对RBMECs上mdr基因mRNA表达无影响。结论洛美利嗪通过抑制P-糖蛋白功能活性而逆转血脑屏障上的多药耐药。 Objective To investigate the effect of lomerizine on the functional activity of P-glycoprotein on the blood-brain barrier and to find novel and effective inhibitors of P-glycoprotein. Methods Rhodamine 123 fluorescent indicator was used to study the activity of P-glycoprotein on cerebral microvascular endothelial cells. The effect of Lomerizine on mRNA expression of mdr gene was analyzed by RT-PCR. Results Lomerizine increased the concentration of rhodamine-123 in RBMECs in a concentration-dependent manner and had no effect on the expression of mdr mRNA in RBMECs. Conclusions Lomerizine reverses multidrug resistance on the blood-brain barrier by inhibiting the functional activity of P-glycoprotein.