Vasorelaxation to the Nitroxyl Donor Isopropylamine NONOate in Resistance Arteries Does Not Require Perivascular Calcitonin Gene-Related Peptide.

Autor: Pinkney AMH; From the Department of Pharmacology, University of Oxford, United Kingdom., Lemmey HAL; From the Department of Pharmacology, University of Oxford, United Kingdom., Dora KA; From the Department of Pharmacology, University of Oxford, United Kingdom., Garland CJ; From the Department of Pharmacology, University of Oxford, United Kingdom. christopher.garland@pharm.ox.ac.uk.
Jazyk: angličtina
Zdroj: Hypertension (Dallas, Tex. : 1979) [Hypertension] 2017 Jul 31. Date of Electronic Publication: 2017 Jul 31.
DOI: 10.1161/HYPERTENSIONAHA.117.09737
Abstrakt: Nitroxyl (HNO) donors offer considerable therapeutic potential for the treatment of hypertension-related cardiovascular disorders, particularly heart failure, as they combine an inotropic action with peripheral vasodilation. Angeli's salt is the only HNO donor whose mechanism has been studied in depth, and recently, Angeli's salt vasodilation was suggested to be indirect and caused by calcitonin gene-related peptide (CGRP) released from perivascular nerves after HNO activates TRPA1 (transient receptor potential cation channel subfamily A member 1) channels. We investigated resistance artery vasorelaxation to the HNO donor, isopropylamine NONOate (IPA/NO), one of the structures providing a template for therapeutic development. Wire myography in combination with measurements of smooth muscle membrane potential was used to characterize the effect of IPA/NO in mesenteric resistance arteries. Immunohistochemistry was assessed in pressurized arteries. IPA/NO concentration dependently hyperpolarized and relaxed arteries precontracted with the α 1 -adrenoreceptor agonist, phenylephrine. These effects were blocked by the soluble guanylyl cyclase inhibitor, ODQ (1 H -[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one) but not by the K ATP channel inhibitor, glibenclamide. Vasorelaxation persisted in the presence of raised [K + ] o , used to block hyperpolarization, capsaicin to deplete perivascular CGRP, or HC030031 (2-(1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydro-7 H -purin-7-yl)- N -(4 isopropylphenyl) acetamide) to block TRPA1 receptors. Without preconstriction, hyperpolarization to IPA/NO was suppressed by glibenclamide, capsaicin, or HC030031. Hyperpolarization but not vasorelaxation to exogenous CGRP was inhibited with glibenclamide. Thus, vascular hyperpolarization is not necessary for vasorelaxation to the HNO donor IPA/NO, even though both effects are cGMP dependent. The reduced hyperpolarization after depletion of perivascular CGRP or block of TRPA1 receptors indicates some release of CGRP, but this does not contribute to HNO vasorelaxation. Therefore, HNO-TRPA1-CGRP signaling does not seem important for vasodilation to IPA/NO in resistance arteries.
(© 2017 American Heart Association, Inc.)
Databáze: MEDLINE
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