Increase of L-type Ca2+ current by protease-activated receptor 2 activation contributes to augmentation of spontaneous uterine contractility in pregnant rats.
Biochem Biophys Res Commun
; 418(1): 167-72, 2012 Feb 03.
Article
en En
| MEDLINE
| ID: mdl-22244874
We evaluated the effects of protease-activated receptor (PAR)-2 on spontaneous myometrial contraction (SMC) in isolated term pregnant myometrial strips of rat, and elucidated the cellular mechanisms of this effect using a conventional voltage-clamp method. In isometric tension measurements, trypsin and SL-NH(2), PAR-2 agonists, significantly augmented SMC in frequency and amplitude; however, boiled trypsin (BT) and LR-NH(2) had no effect on SMC. These stimulatory effects of PAR-2 agonists on SMC were nearly completely occluded by pre-application of Bay K 8644, an L-type voltage-gated Ca(2+) channel activator, thus showing the involvement of L-type voltage-gated Ca(2+) channels in PAR-2-induced augmentation of SMC. In addition, PAR-2 agonists significantly enhanced L-type voltage-gated Ca(2+) currents (I(Ca-L)), as measured by a conventional voltage-clamp method, and this increase was primarily mediated by activation of phospholipase C (PLC) and protein kinase C (PKC) via G-protein activation. Taken together, we have demonstrated that PAR-2 may actively regulate SMC during pregnancy by modulating Ca(2+) influx through L-type voltage-gated Ca(2+) channels, and that this increase of I(Ca-L) may be primarily mediated by PLC and PKC activation. These results suggest a cellular mechanism for the pathophysiological effects of PAR-2 activation on myometrial contractility during pregnancy and provide basic and theoretical information about developing new agents for the treatment of premature labor and other obstetric complications.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Contracción Uterina
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Útero
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Canales de Calcio Tipo L
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Receptor PAR-2
Límite:
Animals
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Pregnancy
Idioma:
En
Revista:
Biochem Biophys Res Commun
Año:
2012
Tipo del documento:
Article
Pais de publicación:
Estados Unidos