Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Biochem J. 1995 Dec 1;312 ( Pt 2):333-9.

Oxidative release of nitric oxide accounts for guanylyl cyclase stimulating, vasodilator and anti-platelet activity of Piloty's acid: a comparison with Angeli's salt.

Author information

  • 1Department of Nitric Oxide Research, Schwarz Pharma AG, Monheim, Federal Republic of Germany.

Abstract

The decomposition of benzenesulphohydroxamic acid (Piloty's acid; PA) and some of its derivatives has been reported to yield nitroxyl ions (NO-), a species with potent vasodilator properties. In a previous study we demonstrated that the oxidative breakdown of PA results in the formation of nitric oxide (NO) and suggested that NO rather than NO- may account for its vasorelaxant properties. Using isolated aortic rings in organ baths, we now show that high concentrations of cysteine potentiate the vasorelaxant response to PA, whereas responses to Angeli's salt (AS), a known generator of NO-, were almost completely inhibited. These different behaviours of PA and AS are mirrored by their distinct chemistries. By using HPLC it was shown that, at physiological pH and in the absence of oxidizing conditions, PA is a relatively stable compound. Direct chemical determination of NO, stimulation of soluble guanylyl cyclase, and measurement of platelet aggregation under various experimental conditions confirmed the requirement for oxidation to release NO from PA, and quite weak oxidants were found to be sufficient to promote this reaction. In contrast, at pH 7.4 AS decomposed rapidly to yield nitrite (NO2-) and NO-, bu did not produce NO on reaction with dioxygen (O2) or hydrogen peroxide (H2O2). Thus sulphohydroxamic acids are a new class of thiol-independent NO-donors that generate NO rather than NO- under physiological conditions.

PMID:
8526840
[PubMed - indexed for MEDLINE]
PMCID:
PMC1136268
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for Portland Press Icon for PubMed Central
    Loading ...
    Write to the Help Desk