EndothelinA (ETA) and ETB receptor-mediated regulation of nitric oxide synthase 1 (NOS1) and NOS3 isoforms in the renal inner medulla

J. C. Sullivan, T. T. Goodchild, Z. Cai, D. M. Pollock, J. S. Pollock

Research output: Contribution to journalArticle

21 Scopus citations

Abstract

Aim: Our laboratory and others have shown that endothelin (ET)-1 directly stimulates nitric oxide (NO) production in inner medullary collecting duct (IMCD) cells. The goal of this study was to determine which NO synthase (NOS) isoforms in IMCD are sensitive to ET-1, and the role of ETA and ETB receptor activation in vivo and in vitro. Methods: NOS enzymatic activity and NOS isoform protein expression were examined in cultured IMCD-3 cells and isolated renal inner medulla. ETB receptor-deficient homozygous rats (sl/sl) have elevated levels of circulating ET-1 and lack a functional ETB signalling pathway in kidneys, and furthermore provides a unique model to study ETA receptor signalling in the renal inner medulla in vivo. Results: Incubation of IMCD-3 cells with exogenous ET-1 (50 nm) resulted in ETA-dependent increased NOS1 protein expression in IMCD-3 cells with no effect on NOS2 or NOS3 expression. ETB receptor antagonism has no effect on NOS expression in IMCD-3 cells. Consistent with in vitro results, cytosolic NOS1 protein expression was significantly greater in the renal inner medulla of sl/sl rats compared with heterozygous (sl/+) controls, with no alteration in NOS3 expression. In contrast to protein expression data, NOS1- and NOS3-specific enzymatic activities decreased in the cytosolic fraction from the renal inner medulla of sl/sl compared with sl/+. Conclusion: These results provide evidence that both ETA and ET B receptors regulate NOS isoform activity in the renal inner medulla and specifically support the hypothesis that ETA receptor activation increases NOS1 expression.

Original languageEnglish (US)
Pages (from-to)329-336
Number of pages8
JournalActa Physiologica
Volume191
Issue number4
DOIs
StatePublished - Dec 2007

Keywords

  • Endothelin
  • Inner medulla
  • Kidney
  • Nitric oxide
  • Nitric oxide synthase

ASJC Scopus subject areas

  • Physiology

Fingerprint Dive into the research topics of 'Endothelin<sub>A</sub> (ET<sub>A</sub>) and ET<sub>B</sub> receptor-mediated regulation of nitric oxide synthase 1 (NOS1) and NOS3 isoforms in the renal inner medulla'. Together they form a unique fingerprint.

  • Cite this