Autocrine inhibition of Na+/K(+)-ATPase by nitric oxide in mouse proximal tubule epithelial cells.

Published

Journal Article

An inducible nitric oxide synthase has recently been described in proximal tubule epithelium. To investigate the effects of proximal tubule NO on Na+/K(+)-ATPase, we induced NO production in mouse proximal tubule epithelial cells by treatment with lipopolysaccharide (LPS) and interferon-gamma (IFN gamma) followed by determinations of ouabain-sensitive ATPase activity. Na+/K(+)-ATPase activity decreased after 4 h of LPS/IFN gamma treatment, reaching maximal inhibition after 24 h (34% reduction in activity). The inhibition of Na+/K(+)-ATPase activity by LPS/IFN gamma was prevented by simultaneous incubation with N omega-nitro L-arginine and markedly blunted by removal of L-arginine from the medium. The NO donors sodium nitroprusside and SIN-1 also inhibited Na+/K(+)-ATPase activity to a similar extent than LPS/IFN gamma. However, treatment with 8-pCPT-cGMP only modestly reduced Na+/K(+)-ATPase activity. Interestingly, superoxide dismutase prevented the inhibitory effects of NO on Na+/K(+)-ATPase activity, suggesting a role for peroxynitrite in this inhibition. We conclude that NO generated by mouse proximal tubule epithelial cell iNOS inhibits Na/K ATPase activity in an autocrine fashion and that this inhibition is accompanied by a reduction in Na-dependent solute transport.

Full Text

Duke Authors

Cited Authors

  • Guzman, NJ; Fang, MZ; Tang, SS; Ingelfinger, JR; Garg, LC

Published Date

  • May 1995

Published In

Volume / Issue

  • 95 / 5

Start / End Page

  • 2083 - 2088

PubMed ID

  • 7537754

Pubmed Central ID

  • 7537754

International Standard Serial Number (ISSN)

  • 0021-9738

Digital Object Identifier (DOI)

  • 10.1172/JCI117895

Language

  • eng

Conference Location

  • United States