Transport characteristics of hydrochlorothiazide in the human intestinal cell line Caco-2

A human intestinal epithelial cell Caco-2 model in vitro cultured had been applied to study the effects of hydrochlorothiazide concentrations,conveying times,P-glyprotein(P-gp) inhibitor verapamil and conveying Liq pHs on the transport of hydrochlorothiazide.In the Caco-2 monolayer model,the apparent permeability coefficients(Papp) of hydrochlorothiazide transport from Basolateral(B) to Apical(A) was larger than that of the opposite direction.In the presence of verapamil,a P-glycoprotein inhibitor,the ratio of Papp B→A and Papp A→B was significantlly decreased from 2.87 to 0.67(P0.01).Meanwhile,the ratio of Papp B→A and Papp A→B in pH 6.0 was significantlly less than that in pH7.4(ratio 0.38 versus 2.81,respectively,P0.01).Results showed that the Absorption of hydrochlorothiazide in Caco-2 cell model should be an active transport mediated by transporter,along with excretion action mediated by P-glycoprotein.