There is a pH-dependent effect on organic anion transporting polypeptide 3A1 (OATP3A1) uptake, with more efficient simvastatin acid uptake at pH5.5 in HEK293 cells transfected with the OATP3A1 gene. The Michaelis-Menten constant (Km) for simvastatin acid uptake by OATP3A1 was 0.017 μM and the Vmax was 0.995 fmol/min/105 cells.
1. [IF=1.902] Yu Zhang et al."A Validated LC-MS/MS Method for Simultaneous Quantification of Simvastatin and Simvastatin Acid in Beagle Plasma: Application to an Absolute Bioavailability Study."Biomedical Chromatography. 2021 Dec 01