SLC23A3 is a renal hypoxanthine transporter
Makoto Hosoyamada1, Naoko H Tomioka1, Tamaki Watanabe2
1Laboratory of Human Physiology and Pathology, Faculty of Pharma-Science, Teikyo University, Tokyo, Japan.
Abstract:
LLC-PK1 renal cells show Na+-dependent and Na+-independent hypoxanthine uptake. While the latter is inhibited by adenine, neither are inhibited by xanthine. In rats, intestinal Na+-dependent hypoxanthine transporter Slc23a4 is not expressed in the kidney, and its action is inhibited by xanthine. This study aimed to clone Slc23a4-paralog SLC23A3 from the human kidney and investigate its hypoxanthine transport activity. We observed Na+-dependent 10 nM [3H]-hypoxanthine uptake in SLC23A3 RNA-injected Xenopus oocytes. Moreover, 100 μM xanthine did not inhibit Na+-independent 300 nM [3H]-hypoxanthine uptake, whereas 100 μM adenine did. These results confirm that SLC23A3 is a hypoxanthine transporter in the human kidney.
Related Concept Videos
Renal Drug Excretion: Tubular Reabsorption
Renal Drug Excretion: Tubular Secretion
Drug Elimination by Renal Route: Tubular Secretion
Renal Corpuscle
Glomerulus: Structure and Function
The glomerulus is a tiny, intricate network of capillaries located at the beginning of the nephron. It's enveloped by the Bowman's capsule and receives its blood supply from an afferent arteriole, which divides into numerous...
Renal Drug Excretion: Overview
A nephron consists of two primary structures: the renal corpuscle and the renal tubule. The renal corpuscle contains the glomerulus, a network of capillaries where the first step of renal excretion, glomerular filtration, occurs. Blood pressure forces water, ions, and small molecules...
Renal Tubule and Collecting Duct
Proximal Convoluted Tubule (PCT):
The PCT is the initial segment of the renal tubule, extending from the Bowman's capsule that encloses the glomerulus. Its convoluted structure and microvilli-lined cells increase the surface area for reabsorption. The PCT reabsorbs glucose, amino acids, sodium, and water from the filtrate, ensuring essential...


