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Incubation Time Influences Organic Anion Transporter 1 Kinetics In Vitro and Renal Clearance Predictions for Para-Aminohippurate

Aaron, Buaben and Pelis, Ryan (2023) Incubation Time Influences Organic Anion Transporter 1 Kinetics In Vitro and Renal Clearance Predictions for Para-Aminohippurate. Journal of xenobiotics., 13. pp. 205-217. ISSN 2039-4713


Examined was the effect of in vitro incubation time on ligand interactions with organic anion transporter 1 (OAT1), and how the time chosen influences renal clearance (CLR) predictions for para-aminohippurate (PAH). Transport studies were performed with Chinese hamster ovary cells expressing OAT1 (CHO-OAT1). The Mechanistic Kidney model (MechKiM) within the Simcyp Simulator (v15, Certera, Inc) was used for pharmacokinetic predictions. Increasing in vitro incubation time led to a decrease in the maximal transport rate and intrinsic uptake clearance (CLint) for PAH, with CLint values ranging 11-fold when using incubation times ranging from 15 sec (CLint,15s) to 45 min (CLint,45min). There was also a significant effect of time on the Michaelis constant. Inhibition potency of five drugs against PAH transport was tested using incubation times of either 15 sec or 10 min. There was no effect of time on inhibition potency for omeprazole or furosemide. Indomethacin was less potent at 10 min, whereas probenecid (~2-fold) and telmisartan (~7-fold) were more potent when using the longer incubation. Pre-treatment of CHO-OAT1 cells with telmisartan for increasing periods of time (30 sec – 30 min) using multiple concentrations (10 nM – 200 nM) showed that its inhibitory effect is time-sensitive. A MechKiM model was developed for PAH using the PAH CLint obtained at 15 sec, in vitro-in vivo extrapolation, and parameter estimation of the OAT1 relative activity factor. Using these parameters, the simulated plasma concentration-time profile, CLR and cumulative urinary excretion-time profile of PAH agreed reasonably well with reported data. Next we used the CLint values obtained from studies using incubation times greater than 15 sec (up to 45 min). The simulated CLR of PAH was sensitive to the time-associated CLint value used, with CLR values 2.7-fold higher when using CLint,15s vs. CLint,45min. The simulated percentages of the PAH dose excreted in the urine after 2 h were 100% (CLint,15sec) vs. 81% (CLint,45min). Simulations predicted a maximum intracellular PAH concentration in tubule cells that was 3.4-fold higher when using CLint,15s vs. CLint,45min. These data show that in vitro incubation time influences transport kinetics and predictions of the involvement of drug transport in pharmacokinetics.

Item Type: Article
Date Deposited: 20 Jun 2023 00:45
Last Modified: 20 Jun 2023 00:45


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