论文部分内容阅读
目的:进一步探讨P-糖蛋白(P-gp)与其多种耐药逆转剂间ATP依赖性相互作用的机制.方法:从牛脑灰质中分离得到微血管内皮细胞(BCEC),制成细胞膜,定磷法测定BCEC膜上P-gp ATPase活性.结果:维拉帕米(Ver)、长春新碱(VCR)、阿霉素(Dox)、粉防己碱(Tet)、蝙蝠葛碱(DRC)、小檗胺(BBM)以及蝙蝠葛苏林碱(DRS)增加基础P-gpATPase活性,其Km值分别约为17、5.9、41、2.3、11、23和22μmol/L.小檗碱(BBR)仅有轻微的激活作用,延胡索乙素(dl-THP)和左旋四氢巴马汀(l-THP)不改变基础P-gp ATPase活性.环孢素A(CsA)抑制基础P-gp ATPase活性;竞争性抑制Ver或VCR激活的P-gp ATPase活性;非竞争性抑制Dox或Tet激活的P-gp ATPase活性.Dox非竞争性抑制Tet-激活的P-gp ATPase活性.结论:各种多药耐药逆转剂与P-gp相互作用的机制及其对P-gp ATPase活性的影响各不相同.CsA、Ver和VCR在血脑屏障P-gp上的结合部位可能是重叠的或者是有相互联系的,而CsA、Dox和Tet与P-gp的结合是相互独立的,并存在各自不同的结合部位.
OBJECTIVE: To further explore the mechanism of ATP-dependent interaction between P-glycoprotein (P-gp) and its multidrug resistance reversal agents.Methods: Microvascular endothelial cells (BCECs) were isolated from bovine cerebral gray matter P-gp ATPase activity on BCEC membrane was determined by phosphorus method.RESULTS: The VCR, Dox, Tet, DRC, Berberine (BBM) and dauricine (DRS) increased basal P-gpATPase activity with Km values of 17,5.9,41,2.3,11,23 and 22 μmol / L, respectively. Berberine (BBR) Slight activation, d-THP and l-THP did not alter basal P-gp ATPase activity.Cycosporine A (CsA) inhibited basal P-gp ATPase activity; competition Inhibit V- or VCR-activated P-gp ATPase activity noncompetitively inhibit Dox or Tet-activated P-gp ATPase activity.Dox non-competitively inhibits Tet-activated P-gp ATPase activity.Conclusion: Various multi-drug resistance The mechanism of the interaction between drug reversal agent and P-gp and its effect on the activity of P-gp ATPase are different. The binding sites of CsA, Ver and VCR on the blood-brain barrier P-gp may overlap or be interrelated , While the binding of CsA, Dox and Tet to P-gp is independent of each other, and there are different binding sites for each.