Localization of organic cation transporters OCT1 and OCT2 in rat kidney

Citation
U. Karbach et al., Localization of organic cation transporters OCT1 and OCT2 in rat kidney, AM J P-REN, 279(4), 2000, pp. F679-F687
Citations number
32
Language
INGLESE
art.tipo
Article
Categorie Soggetti
da verificare
Journal title
AMERICAN JOURNAL OF PHYSIOLOGY-RENAL PHYSIOLOGY
ISSN journal
0363-6127 → ACNP
Volume
279
Issue
4
Year of publication
2000
Pages
F679 - F687
Database
ISI
SICI code
0363-6127(200010)279:4<F679:LOOCTO>2.0.ZU;2-M
Abstract
Renal excretion and reabsorption of organic cations are mediated by electro genic and electroneutral organic cation transporters, which belong to a rec ently discovered family of polyspecific transporters. These transporters ar e electrogenic and exhibit differences in substrate specificity. In rat, th e renal expression of the polyspecific cation transporters rOCT1 and rOCT2 was investigated. By in situ hybridization, significant amounts of both rOC T1 and rOCT2 mRNA were detected in S1, S2, and S3 segments of proximal tubu les. By immunohistochemistry, expression of the rOCT1 protein was mainly ob served in S1 and S2 segments of proximal tubules, with lower expression lev els in the S3 segments. At variance, rOCT2 protein was mainly expressed in the S2 and S3 segments. Both transporters were localized to the basolateral cell membrane. Neither rOCT1 nor rOCT2 was detected in the vasculature, th e glomeruli, and nephron segments other than proximal tubules. The data sug gest that rOCT1 and rOCT2 are responsible for basolateral cation uptake in the proximal tubule, which represents the first step in cation secretion.