吗啡孵育诱导大鼠脑片P糖蛋白表达增加

Increased expression of p-glycoprotein in rat brain slices induced by morphine incubation

目的观察吗啡孵育诱导新皮质和海马脑片后P糖蛋白(Pgp)表达的变化。方法将大鼠脑新皮质和海马部分切成400μm脑片,并随机分配到正常孵育组、吗啡孵育3h组和吗啡孵育6h组。新皮质和海马吗啡孵育3h组在吗啡孵育6h组之后于孵育液中加入吗啡。所有脑片人工脑脊液(含或不含10μmol/L吗啡)内孵育6h后,采用Westernblot检测Pgp表达量。结果正常孵育大鼠新皮质脑片Pgp表达量显著高于海马脑片(P<0.05),新皮质脑片Pgp表达量是海马脑片的(2.51±0.42)倍。大鼠新皮质脑片采用吗啡孵育3,6h后Pgp表达显著升高;海马脑片吗啡孵育3h后Pgp表达有所升高,但差异无显著性(P>0.05),新皮质和海马脑片吗啡孵育6h后Pgp表达明显增加(P<0.05)。结论吗啡孵育大鼠离体新皮质和海马脑片可时间依赖性地诱导Pgp表达增加,而且此增加呈现一定的脑区差异性;脑片可以作为研究调控Pgp表达防治吗啡耐受的理想工具。

Objective To investigate the expression of P - glycoprotein in brain slices of neocortical and hippocampus induced by morphine incubation. Methods 400 μmol/L neocortical and hippocampus brain slices of rat were randomly allocated into groups of normal incubation, morphine 3 h incubation and morphine 6 h incubation. Morphine was added into the incubation fluid 3 h later in group of 3 h morphine incubation than the group of 6 h morphine incubation. P - glycoprotein expression in all brain slices was detected by Western blot after 6 h incubation in artificial cerebral spinal fluid （with or without 10 μmol/L morphine）. Results Pgp expression in neocortical brain slices under normal incubation is significantly higher than that in hippocampus brain slices under normal incubation （ P 〈 0. 05 ）. After 3 h or 6 h incubation with morphine, P - glycoprotein expressions in neocortial brain slices were significantly elevated. No significant increase of P - glycoprotein expression was found in hippocampus brain slices after 3 h incubation with morphine （P 〉 0. 05 ）. After 6 h incubation with morphine, there was statistical increase of P - glycoprotein expressions in hippocampus brain slices （ P 〈 0. 05 ）. Conclusion Morphine incubation induces increased P - glycoprotein expression in neocortieal and hippocampus brain slices of rat in a time - dependent manner with great variability in different brain zones. Brain slices can be used as a ideal tool for prevention or treatment of morphine tolerance with P - glycoprotein modulation.