Nitric oxide modulates excitation-contraction coupling in the diaphragm.

Journal Article (Journal Article)

We investigated the enzymatic source, cellular production, and functional importance of nitric oxide (NO) in rat diaphragm. Neuronal and endothelial isoforms of constituitive nitric oxide synthase (nc-NOS, ec-NOS) were identified by immunostaining. NOS activity measured in diaphragm homogenates averaged 5.1 pmol/min/mg. Passive diaphragm fiber bundles produced NO derivatives (NOx) at the rate of 0.9 pmol/min/mg as measured by the cytochrome c reduction assay; NO production was confirmed by photolysis/ chemiluminescence measurements. Endogenous NO depressed diaphragm contractile function. The force of submaximal contraction was increased by NOS inhibitors, an effect that was stable for up to 60 min and was reversed by NO donors. We conclude that diaphragm muscle fibers express nc-NOS, ec-NOS, or both; passive myocytes produce NOx; and NO or NO-derivatives inhibit force production by modulating excitation-contraction coupling.

Full Text

Duke Authors

Cited Authors

  • Reid, MB; Kobzik, L; Bredt, DS; Stamler, JS

Published Date

  • January 1998

Published In

Volume / Issue

  • 119 / 1

Start / End Page

  • 211 - 218

PubMed ID

  • 11253787

Pubmed Central ID

  • 11253787

International Standard Serial Number (ISSN)

  • 1095-6433

Digital Object Identifier (DOI)

  • 10.1016/s1095-6433(97)00417-0


  • eng

Conference Location

  • United States