Identification of a regulated Na/K/Cl cotransport system in a distal nephron cell line.

Published

Journal Article

Lack of an adequate cell model has limited investigation of Na/K/Cl cotransporter regulation in the kidney. Using A6 cells, an amphibian distal renal cell line, we observed that 63% of rubidium uptake in confluent A6 monolayers was ouabain-insensitive. Ouabain-insensitive rubidium uptake was inhibited in a dose-dependent fashion by furosemide (IC50 6.6 microM) or bumetanide (IC50 1.7 microM). Kinetic studies confirmed that furosemide-sensitive rubidium uptake had features consistent with cotransporter activity in other cell lines. Furthermore, specific binding of [3H]bumetanide occurred with a capacity of 8.6 pmol/mg protein and a Kd of 1.6 microM bumetanide. Finally, furosemide-sensitive rubidium uptake was rapidly regulated by a calcium ionophore, the phorbol ester PDBu, forskolin, and adenosine. These data demonstrate an Na/K/Cl cotransport system in the A6 cell which will serve as a useful model for studying cotransporter regulation by endogenous signaling pathways.

Full Text

Duke Authors

Cited Authors

  • Fan, PY; Haas, M; Middleton, JP

Published Date

  • October 19, 1992

Published In

Volume / Issue

  • 1111 / 1

Start / End Page

  • 75 - 80

PubMed ID

  • 1327143

Pubmed Central ID

  • 1327143

International Standard Serial Number (ISSN)

  • 0006-3002

Digital Object Identifier (DOI)

  • 10.1016/0005-2736(92)90276-r

Language

  • eng

Conference Location

  • Netherlands