A Modified Procedure for Estimating the Impact of the Uptake on the Overall Biliary Clearance in Sandwich Culture of Rat Hepatocytes

Title:A Modified Procedure for Estimating the Impact of the Uptake on the Overall Biliary Clearance in Sandwich Culture of Rat Hepatocytes

Volume: 9 Issue: 1

Author(s): Katalin Jemnitz, Monika Szabo, Attila Batai-Konczos, Pal Szabo, Balazs Magda and Zsuzsa Veres

Affiliation:

Keywords: Efflux, hepatic clearance, hepatocyte sandwich culture, in vitro, transport proteins, uptake.

Abstract: Sandwich culture of hepatocytes is commonly applied for the prediction of in vivo biliary clearance (CL_bil). In this paper, we present a modified procedure for the determination of in vitro CL_bil in sandwich culture of rat hepatocytes, which allows the estimation of the impact of uptake processes on the overall CL_bil. The main point of this modification is the separation of uptake and efflux processes. Ten drugs from four biopharmaceutics drug disposition classification system classes were chosen in order to demonstrate the advantages of this method: 1) the uptake is performed identically before the canaliculi are opened, thus the efflux starts at the same intracellular concentration of the drugs and the effect of Ca²⁺/Mg²⁺ depletion on the uptake is excluded; 2) exact intracellular concentrations can be measured at the start and at the end of the efflux; 3) the biliary clearance can be determined irrespective of the uptake; 4) the canalicular and the sinusoidal transport can be measured simultaneously; 5) drug-drug interactions concerning uptake and efflux transporters can be estimated independently. Depending on the degree of uptake, CL_bil,app (calculated using the concentration of drugs in the medium) was significantly higher (sulfasalazine, fluvastatin, rosuvastatin, atorvastatin) or lower (pravastatin, procainamide) than CL_bil,int (calculated using the intracellular concentration of drugs). When the uptake had no impact on the CL_bil, the apparent and intrinsic CL_bil did not differ significantly (lovastatin, rifampicin, quetiapine). Our results confirm that transporters may play a significant role in the uptake of drugs both with high and poor permeability and solubility.

Cite this article as:

Jemnitz Katalin, Szabo Monika, Batai-Konczos Attila, Szabo Pal, Magda Balazs and Veres Zsuzsa, A Modified Procedure for Estimating the Impact of the Uptake on the Overall Biliary Clearance in Sandwich Culture of Rat Hepatocytes, Drug Metabolism Letters 2015; 9 (1) . https://dx.doi.org/10.2174/1872312809666150119105646