Protein kinase A signalling is involved in the relaxant responses to the selective β-oestrogen receptor agonist diarylpropionitrile in rat aortic smooth muscle in vitro

Objectives  The oestrogen receptor β (ERβ) selective agonist diarylpropionitrile (DPN) relaxes endothelium‐denuded rat aorta, but the signalling mechanism is unknown. The aim of this study was to assess whether protein kinase A (PKA) signalling is involved in DPN action. Methods  cAMP was measured b...

Full description

Saved in:
Bibliographic Details
Published in:Journal of pharmacy and pharmacology 2011-02, Vol.63 (2), p.222-229
Main Authors: Valero, Marta S., Pereboom, Desiree, Barcelo-Batllory, Silvia, Brines, Laia, Garay, Ricardo P., Alda, José O.
Format: Article
Language:English
Subjects:
Adenylyl Cyclase Inhibitors
Adenylyl Cyclases - metabolism
Animals
Aorta - drug effects
Aorta - metabolism
Cyclic AMP - metabolism
Cyclic AMP-Dependent Protein Kinases - antagonists & inhibitors
Cyclic AMP-Dependent Protein Kinases - metabolism
diarylpropionitrile
Endothelium, Vascular - drug effects
Endothelium, Vascular - metabolism
Estrogen Receptor beta - agonists
Estrogen Receptor beta - metabolism
HSP20 Heat-Shock Proteins - metabolism
Ion Channels - metabolism
Male
Membrane Potentials - drug effects
Muscle Proteins - metabolism
Muscle, Smooth, Vascular - drug effects
Muscle, Smooth, Vascular - enzymology
Muscle, Smooth, Vascular - metabolism
Nitriles - pharmacology
oestrogen receptors
Phosphorylation - drug effects
Propionates - pharmacology
protein kinase A
Protein Kinase Inhibitors - pharmacology
rat aorta
Rats
Rats, Wistar
Signal Transduction - drug effects
smooth muscle
Vasodilation - drug effects
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Objectives  The oestrogen receptor β (ERβ) selective agonist diarylpropionitrile (DPN) relaxes endothelium‐denuded rat aorta, but the signalling mechanism is unknown. The aim of this study was to assess whether protein kinase A (PKA) signalling is involved in DPN action. Methods  cAMP was measured by radioimmunoassay, HSP20 phosphorylation by 2D gel electrophoresis with immunoblotting, and membrane potential and free cytosolic calcium by flow cytometry. Key findings  DPN increased cAMP content and hyperpolarised cell membranes over the same range of concentrations as it relaxed phenylephrine‐precontracted aortic rings (10–300 µM). DPN‐induced vasorelaxation was largely reduced by the PKA inhibitors Rp‐8‐Br‐cAMPS (8‐bromoadenosine‐3′, 5′‐cyclic monophosphorothioate, Rp‐isomer) and H‐89 (N‐(2‐bromocynnamyl(amino)ethyl)‐5‐isoquinoline sulfonamide HCl) (−73%) and by the adenylate cyclase inhibitor MDL12330A (cis‐N‐(2‐phenylcyclopentyl)‐azacyclotridec‐1‐en‐2‐amine)) (−65.5%). Conversely, the PKG inhibitor Rp‐8‐Br‐cGMP was inactive against DPN vasorelaxation. In aortic smooth muscle segments, DPN increased PKA‐dependent HSP20 phosphorylation, an effect reversed by H‐89. Relaxant responses to DPN were modestly antagonised (−23 to −48% reduction; n = 12 per compound) by the potassium channel inhibitors iberiotoxin, PNU‐37883A, 4‐aminopyridine, or BaCl2. All four potassium channel inhibitors together reduced DPN relaxation by 86 ± 9% (n = 12) and fully blocked DPN hyperpolarisation. Conclusions  ERβ‐dependent relaxation of rat aortic smooth muscle evokes an adenylate cyclase/cAMP/PKA signalling pathway, likely activating the cystic fibrosis transmembrane conductance regulator chloride channel and at least four potassium channels.
ISSN:0022-3573
2042-7158
DOI:10.1111/j.2042-7158.2010.01203.x