Rapid Method To Determine Intracellular Drug Concentrations in Cellular Uptake Assays: Application to Metformin in Organic Cation Transporter 1–Transfected Human Embryonic Kidney 293 Cells

• DOI: 10.1124/dmd.115.066647
• Publication Date: 2015-12-24T04:05:33Z
• Authors: Huan-Chieh Chien; Arik A Zur; Tristan S Maurer; Sook Wah Yee; John Tolsma; Paul Jasper; Dennis O Scott; Kathleen M Giacomini
• Keywords: HEK 293 cells

Because of the importance intracellular unbound drug concentrations in prediction vivo that are determinants efficacy and toxicity, a number assays have been developed to assess vitro drugs. Here we present rapid method determine cultured cells, apply along with mechanistic model predict metformin subcellular compartments stably transfected human embryonic kidney 293 (HEK293) cells. Intracellular space (ICS) was calculated by subtracting [³H]-inulin distribution volume (extracellular space, ECS) from [¹⁴C]-urea (total water TWS). Values obtained for (mean ± S.E.M.; <i>μ</i>l/10⁶ cells) monolayers HEK cells (HEK-empty vector [EV]) overexpressing organic cation transporter 1 (HEK-OCT1), 1.21± 0.07 1.25±0.06, respectively, were used concentrations. After incubation 5 <i>µ</i>M metformin, 26.4 7.8 <i>μ</i>M 268 11.0 <i>μ</i>M, HEK-EV HEK-OCT1. In addition, lower high K⁺ buffer (140 mM KCl) compared normal (5.4 HEK-OCT1 (54.8 3.8 198.1 11.2 respectively; <i>P</i> &lt; 0.05). Our suggests that, depending on credible range assumed physiologic values, positively charged accumulates particularly levels endoplasmic reticulum and/or mitochondria. This together computational can be accumulation drugs other complex systems such as primary