Caki-1 cells as a model system for the interaction of renally secreted drugs with OCT3.

<i>Background/Aims:</i> Organic cation transporters (OCT) in the proximal tubules (PTs) participate in the renal secretion of several therapeutic agents. The exact role of OCT3 in renal secretion remains undetermined, partially due to the lack of an appropriate in vitro model system. The current work introduces the PT representative cell line, Caki-1, as a model system for studying the involvement of OCT3 in renal secretion. <i>Methods:</i> Caki-1 cells were characterized for OCT3 expression via real-time RT-PCR and immunocytochemical staining techniques. Uptake kinetics of OCT3 in Caki-1 cells was determined using prototypical substrates and inhibitors. Inhibition o…

OCTN2-Mediated Carnitine Uptake in a Newly Discovered Human Proximal Tubule Cell Line (Caki-1)

The proximal tubular reabsorption of carnitine in the human kidney is significant because more than 95% of the carnitine filtered in the kidney is reabsorbed by the proximal tubules therefore maintaining the homeostatic balance of carnitine in the body. Objectives of this study include the characterization of OCTN2 function in the Caki-1 cell line and the potential interactions of carnitine uptake with renally secreted drugs, including drugs of quaternary ammonium structure. Caki-1 cells were additionally characterized to be of proximal tubule nature, and an apical membrane expression pattern of OCTN2 in Caki-1 cells was discovered. Uptake studies with radiolabeled L-carnitine in Caki-1 cel…

dsRNA-functionalized multifunctional gamma-Fe2O3 nanocrystals: a tool for targeting cell surface receptors.

Caki-1 Cells Represent an in vitro Model System for Studying the Human Proximal Tubule Epithelium

<i>Background/Aims:</i> The human proximal tubule (PT) epithelium is distinguished from other nephron segments via several unique characteristics. Studies assessing PT epithelium increasingly employ cell lines, bypassing the complexity of primary cell cultures. However, few human model systems exist for studying PT cells in vitro. The current work involves an intensive characterization of Caki-1 cells, a commercially available human renal cell line. <i>Methods:</i> Caki-1 cells were validated as a representative model system for PT cell research via morphological, physiological and biochemical investigations including light and transmission electron microscopy, trans…

dsRNA-funktionalisierte γ-Fe2O3-Nanokristalle: ein Instrument zur gezielten Adressierung von Rezeptoren an der Zelloberfläche

Different Dissolution Media Lead to Different Crystal Structures of Talinolol with Impact on Its Dissolution and Solubility

During the performance of dissolution tests with immediate and controlled-release talinolol tablets it was detected that the type of the buffer used as dissolution medium had a strong influence on the solubility and the dissolution behavior of the drug. It was proven that talinolol appeared in different crystal structures with strongly differing solubilities when pure water, acetate, or phosphate buffers were employed as dissolution media. The resulting crystal structures were characterized by means of light microscopy, differential scanning calorimetry, and X-ray powder diffraction. All methods were adjuvant to detect changes in talinolol crystal structures. The different solubility and di…