Article Figures & Data
Figures
- Fig. 1.
BOPTA and MEB transport across hepatocyte membranes and concentrations inside liver compartments. BOPTA and MEB distribute into sinusoids and interstitium before entry into normal hepatocytes across Oatps. Once inside hepatocytes, both compounds exit into bile canaliculi across the Mrp2 or back into sinusoids across Mrp3 transporters. CLin (in ml/min)., CLint,bile, and CLef generate concentrations that increase from sinusoids, to hepatocytes and bile canaliculi (illustrated by the number of circles). RIF is a substrate of Oatps and inhibits both Oatps and Mrp2. HV, hepatic vein; PV, portal vein.
- Fig. 2.
Effects of drug perfusion on bile flow rates over the experimental protocol (105 minutes). Livers were perfused with 200 µM BOPTA (white circles), 64 µM MEB (black squares), 200 µM BOPTA and 100 µM RIF (blue circles), and 64 µM MEB and 100 µM RIF (pink squares).
- Fig. 3.
MEB hepatic pharmacokinetics and concentrations. Concentrations in portal vein (Cin) Concentrations in portal vein (Cin, A, black circles), hepatic veins (Cout, A, squares), hepatocytes (B), and bile (C) were used to calculate the hepatic CL (D), the efflux CL back to sinusoids (fL CLef) (E), and the biliary intrinsic CL (fL CLint,bile) (F). In (C, right, y-axis), the bile excretion rates (vbile) are shown for MEB (green squares) and MEB+RIF (purple squares). In sinusoids, the MEB unbound fraction was equal to 1 because no protein was added in the perfusate, whereas the MEB unbound fraction (fL) was unknown in livers. Livers were perfused with 64 µM MEB (black squares) or 64 µM MEB and 100 µM RIF (white squares). To compare the parameters over time, we use a two-way ANOVA with Sidak’s multiple comparison test of mean values at each time point between groups.
- Fig. 4.
BOPTA hepatic pharmacokinetics and concentrations. Concentrations in portal vein (Cin, A, black circles), hepatic veins (Cout, A, squares), hepatocytes (B) and bile (C) were used to calculate the hepatic clearance (CL, D), the efflux clearance back to sinusoids (fL CLef, E) and the biliary intrinsic clearance (fL CLint,bile, F). In C (right Y-axis), the bile excretion rates (vbile) are shown for BOPTA (green squares) and BOPTA+RIF (purple squares). In sinusoids, the BOPTA unbound fraction was equal to 1 because no protein was added in the perfusate, while the BOPTA unbound fraction (fL) was unknow in livers. Livers were perfused with 200 µM BOPTA (black squares) or 200 µM BOPTA and 100 µM RIF (white squares). To compare the parameters over time, we use a two-way ANOVA with the Sidak’s multiple comparison test of mean values at each time-point between groups.
- Fig. 5.
(A) Using the counter placed over the liver, the hepatocyte uptake into hepatocytes (micromoles per minute) was measured by the slope of the relation between hepatocyte concentrations and time over 2 minutes at the very beginning of the drug perfusion to avoid an underestimation of hepatocyte concentrations associated with early excretion into bile canaliculi. A delay of 1 minute (from 45 to 46 minutes) assured a homogeneous drug distribution within the interstitium. (B) Relationship between bile excretion rates and hepatocyte concentrations. Each symbol illustrates one time point, and six symbols were included by liver (every 5 minutes between 50 and 75 minutes); and the slope of the linear regression obtained in each group is the CLint,bile. Livers were perfused with 200 µM BOPTA (white circles), 64 µM MEB (black squares), 200 µM BOPTA and 100 µM RIF (blue circles), and 64 µM MEB and 100 µM RIF (pink squares).
Tables
- TABLE 1
BOPTA and MEB pharmacokinetic parameters and concentrations in the presence of RIF (+RIF) and the absence of RIF (−RIF)
Parameters BOPTA BOPTA+RIF +RIF/−RIF Ratio MEB MEB+RIF +RIF/−RIF Ratio Cin (μM) 200 200 64 64 Cout,75min (μM) 185 ± 3 196 ± 2 1.06 5 ± 2 31 ± 4 6.2 CHC,75min (μM) 566 ± 99 23 ± 19 0.04 2611 ± 498 5044 ± 693 1.93 Cbile,75min (μM) 16,791 ± 2085 92 ± 44 0.0005 97,017 ± 11,289 13,258 ± 8363 0.14 Cbile,75min/CHC,75min 30.6 ± 7.5 3.5 ± 2.9 0.11 38.4 ± 8.8 2.6 ± 1.6 0.07 v75min (nmol/min)a 464 ± 80 111 ± 47 0.24 1797 ± 61 1022 ± 113 0.57 CL (ml/min)b 2.32 ± 0.40 0.56 ± 0.24 0.24 28.12 ± 0.22 15.64 ± 1.77 0.56 Ec 0.08 ± 0.01 0.02 ± 0.01 0.25 0.93 ± 0.03 0.53 ± 0.06 0.57 vbile,75min (nmol/min)d 390 ± 84 1 ± 1 0.003 990 ± 166 105 ± 65 0.11 fL CLint,bile (ml/min)e 0.72 ± 0.23 0.04 ± 0.03 0.06 0.39 ± 0.11 0.02 ± 0.01 0.05 fL CLef (ml/min)f 0.13–0.07g 0.41–0.00g 0.01 ± 0.01 0.01 ± 0.01 fB CLin (ml/min) 2.69 ± 0.37 0.60 ± 0.20 0.22 28.54 ± 0.27 15.64 ± 1.77 0.55 ↵a Drug removal rate from sinusoids (v) = QH ⋅ (Cin − Cout).
↵b Hepatic CL: QH ⋅ (Cin − Cout)/Cin.
↵c Extraction ratio (E) = Cin − Cout/Cin.
↵d vbile = Qbile ⋅ Cbile.
↵e CLint,bile (fL ⋅ CLint,bile) = vbile/CHC.
↵f CLef back to sinusoids (fL ⋅ CLef) = vef/CHC, with vef = QH ⋅ Cout.
↵g Mean ranges over time.
