Suppression of Peripheral Sympathetic Activity Underlies Protease-Activated Receptor 2-Mediated Hypotension
The Korean Journal of Physiology and Pharmacology
;
: 489-495, 2014.
Article
Dans Anglais
| WPRIM
| ID: wpr-727695
ABSTRACT
Protease-activated receptor (PAR)-2 is expressed in endothelial cells and vascular smooth muscle cells. It plays a crucial role in regulating blood pressure via the modulation of peripheral vascular tone. Although some reports have suggested involvement of a neurogenic mechanism in PAR-2-induced hypotension, the accurate mechanism remains to be elucidated. To examine this possibility, we investigated the effect of PAR-2 activation on smooth muscle contraction evoked by electrical field stimulation (EFS) in the superior mesenteric artery. In the present study, PAR-2 agonists suppressed neurogenic contractions evoked by EFS in endothelium-denuded superior mesenteric arterial strips but did not affect contraction elicited by the external application of noradrenaline (NA). However, thrombin, a potent PAR-1 agonist, had no effect on EFS-evoked contraction. Additionally, omega-conotoxin GVIA (CgTx), a selective N-type Ca2+ channel (I(Ca-N)) blocker, significantly inhibited EFS-evoked contraction, and this blockade almost completely occluded the suppression of EFS-evoked contraction by PAR-2 agonists. Finally, PAR-2 agonists suppressed the EFS-evoked overflow of NA in endothelium-denuded rat superior mesenteric arterial strips and this suppression was nearly completely occluded by omega-CgTx. These results suggest that activation of PAR-2 may suppress peripheral sympathetic outflow by modulating activity of I(Ca-N) which are located in peripheral sympathetic nerve terminals, which results in PAR-2-induced hypotension.
Texte intégral:
Disponible
Indice:
WPRIM (Pacifique occidental)
Sujet Principal:
Pression sanguine
/
Thrombine
/
Norépinéphrine
/
Artère mésentérique supérieure
/
Conotoxine-oméga-GVIA
/
Cellules endothéliales
/
Récepteur de type PAR-2
/
Hypotension artérielle
/
Artères mésentériques
/
Muscles lisses
Limites du sujet:
Animaux
langue:
Anglais
Texte intégral:
The Korean Journal of Physiology and Pharmacology
Année:
2014
Type:
Article
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