Evaluating the regulation of transporter proteins and P-glycoprotein in rats with cholestasis and its implication for digoxin clearance

Figure 1 Effect of bile duct ligation on pharmacokinetics of digoxin in rats. A: Pre-surgery digoxin pharmacokinetic studies was compared and presented as digoxin concentration-versus-time line curves; B: Post-surgery digoxin pharmacokinetic studies were compared and presented as digoxin concentration-versus-time line curves, C: Area under the curve, the area under the digoxin plasma concentration-versus-time. Values are expressed as means ± SD, n = 6; ^aP < 0.05 vs pre-surgery bile duct ligation group, ^bP < 0.05 vs post-surgery sham. BDL: Bile duct ligation; AUC: Area under the curve.

Figure 2 Effect of bile duct ligation on protein expressions of multidrug resistance 1. Multidrug resistance 1 (MDR1) protein assay was performed by quantitative western blot. A: Fluorescence densities of the protein bands were measured and normalized to the relative total protein amount of each sample; B: The representative western blot images for the expression of MDR1 in the liver, kidney, small intestine; C: Representative western blot image for the total protein stain by REVERT™ Total Protein Stain kit. Values are depicted as means ± SD; n = 6; ^aP < 0.05 compared with sham surgery rats. BDL: Bile duct ligation; MDR1: Multidrug resistance 1.

Figure 3 Effect of bile duct ligation on protein expressions of organic anion transporting polypeptides 1A4. Organic anion transporting polypeptides (OATP)1A4 protein assay was performed by quantitative western blot. A: Fluorescence densities of the protein bands were measured and normalized to the relative total protein amount of each sample; B: The representative western blot images for the expression of OATP1A4 protein in the liver, small intestine. OATP1A4 was not detected in the kidney by western blot; C: Representative western blot image for the total protein stain by REVERT™ Total Protein Stain kit. Values are expressed as means ± SD; n = 6; ^aP < 0.05 compared with sham surgery rats. ND: Not detected; BDL: Bile duct ligation; OATP: Organic anion transporting polypeptides.

Figure 4 Effect of bile duct ligation on protein expressions of organic anion transporting polypeptides 4C1 in the kidney. Organic anion transporting polypeptides (OATP)4C1 protein assay was performed by quantitative western blot. A: Fluorescence densities of the protein bands were measured and normalized to the relative total protein amount of each sample; B: The representative western blot images for the expression of OATP4C1 protein in the kidney. Liver sample was loaded with kidney samples as negative control for OATP4C1; C: Representative western blot image for the total protein stain by REVERT™ Total Protein Stain kit. Values are expressed as means ± SD; n = 6; ^aP < 0.05 compared with sham surgery rats. BDL: Bile duct ligation; OATP: Organic anion transporting polypeptides.

Figure 5 Effect of bile duct ligation on mRNA expressions of multidrug resistance 1, organic anion transporting polypeptides1a4 and 4C1. mRNA expression in each sample was standardized to its glyceraldehyde-3-phosphate dehydrogenase level. A: Expressions of multidrug resistance 1 in the liver, kidney, small intestine, and the effect of bile duct ligation (BDL) on the mRNA expressions in each tissue; B: Expression of organic anion transporting polypeptides (OATP)1A4 mRNA in the liver, kidney and small intestine, and the effect of BDL on OATP1A4 mRNA expressions; C: Expression of OATP4C1 mRNA in the kidney and the effect of BDL on its expression. Values are depicted as means ± SD; n = 6; ^aP < 0.05 compared with sham surgery rats. BDL: Bile duct ligation; OATP: Organic anion transporting polypeptides; MDR1: Multidrug resistance 1; GAPDH: Glyceraldehyde-3-phosphate dehydrogenase.