基于P-糖蛋白的肠吸收在体单向肠灌流模型验证

对基于P-糖蛋白(P-gp)肠吸收单灌流模型进行验证。首先,通过酚红灌流,采用质量法进行水分校正,通过高效液相色谱法对灌流前后酚红水平进行检测,以验证肠上皮细胞的紧密连接结构正常,且肠上皮的完整性保持良好;其次,采用FDA指定阳性药地高辛对模型进行验证,给予大鼠不同质量浓度维拉帕米后,对大鼠回肠段地高辛吸收参数进行观察对比。酚红在大鼠体内回肠段存在吸收,吸收参数有效渗透系数Peff为(1.09±0.62)×10~(-6)cm·s~(-1),结果表明肠上皮细胞的紧密连接结构正常,且肠上皮的完整性保持良好,地高辛灌流不给予维拉帕米时,地高辛在回肠段存在一定程度的吸收,吸收参数有效渗透系数Peff为(1.07±0.59)×10~(-5)cm·s~(-1),给予大鼠0.01,0.1 mmol·L~(-1)浓度的维拉帕米后,地高辛在大鼠回肠的吸收呈上升趋势,吸收参数有效渗透系数Peff分别为(1.58±0.69)×10~(-5),(3.28±0.95)×10-5cm·s~(-1),高浓度时,数据差异具有统计学意义(P0.05)。地高辛灌流实验验证了小肠上皮P-gp表达完整,可以用于P-gp外排转运体的研究。

Validation of in situ single pass perfusion model based on P-gp

To validate in situ rats intestinal single pass perfusion model based on P-glycoprotein (P-gp). Firstly, phenol red perfusion was carried out to verify the close connection structure of intestinal epithelial cells, and the integrity of the intestinal epithelium, with a gravimetric method for correcting water flux. The level of phenol red was determined by high performance liquid chromatography (HPLC) both before and after perfusion. Secondly, the positive drug digoxin specified by FDA was used to validate the model. After different mass concentrations of verapamil were given in the rats, the absorption parameters of digoxin in ileum of rats were observed and compared. The results showed that the phenol red was absorbed in rats ileum segment, with an effective permeability coefficient of (1.09±0.62)×10^-6 cm·s^-1. The experiment results indicated that the close connection structure of intestinal epithelial cells was normal, and the integrity of the intestinal epithelium was maintained well. In digoxin perfusion experiment, in case no verapamil was given, digoxin showed certain degree of absorption in rat ileum, with an effective permeability coefficient (P_eff) of (1.07±0.59)×10^-5 cm·s^-1; after mass concentrations of 0.01,0.1 mmol·L^-1 verapamil were given, the absorption of digoxin was on the rise in rat ileum, with an effective permeability coefficient P_eff of (1.58±0.69)×10^-5, (3.28±0.95)×10^-5 cm·s^-1 respectively (P<0.05). Digoxin perfusion experiment verified that P-gp expression in small intestine epithelium was intact and can be used in the research of P-gp efflux transporter.