目的研究呋塞米口服的吸收机制。方法首先通过MTT法考察呋塞米对细胞活性和增殖的影响情况,其次采用Caco-2细胞单层模型研究呋塞米的跨膜转运机制。结果呋塞米浓度≤100μmol/L对Caco-2细胞活性和增殖无影响;25,50,100μmol/L的呋塞米从AP侧到BL侧转运的表观渗透系数分别为0.364,0.347,0.345×10-6cm/s,外排率Pratio分别为1.74,1.7和1.67;加入维拉帕米前后的外排率Pratio分别为1.78和1.13,有显著性差异。结论呋塞米以被动扩散为主要的转运方式,存在可能由P-糖蛋白介导的主动转运。 Objective To study the oral absorption mechanism of furosemide. Methods The effect of furosemide on cell viability and proliferation was investigated by MTT assay. The transmembrane transport mechanism of furosemide was studied by Caco-2 cell monolayer model. Results Furosemide concentration of ≤100μmol / L had no effect on the activity and proliferation of Caco-2 cells. The apparent permeability coefficients of 25, 50 and 100μmol / L furosemide transiting from AP side to BL side were 0.364, 0.347 and 0.345 × 10-6cm / s, efflux rate Pratio were 1.74,1.7 and 1.67; Verapamil before and after the discharge rate Pratio were 1.78 and 1.13, a significant difference. Conclusions Furosemide is mainly transported by passive diffusion, and P-glycoprotein may mediate the active transport.