Eugenol-induced contractions of saponin-skinned fibers are inhibited by heparin or by a ryanodine receptor blocker.
Can J Physiol Pharmacol
; 83(12): 1093-100, 2005 Dec.
Article
em En
| MEDLINE
| ID: mdl-16462908
The effects of eugenol on the sarcoplasmic reticulum (SR) and contractile apparatus of chemically skinned skeletal muscle fibers of the frog Rana catesbeiana were investigated. In saponin-skinned fibers, eugenol (5 mmol/L) induced muscle contractions, probably by releasing Ca(2+) from the SR. The Ca(2+)-induced Ca(2+) release blocker ruthenium red (10 micromol/L) inhibited both caffeine- and eugenol-induced muscle contractions. Ryanodine (200 micromol/L), a specific ryanodine receptor/Ca(2+) release channel blocker, promoted complete inhibition of the contractions induced by caffeine, but only partially blocked the contractions induced by eugenol. Heparin (2.5 mg/mL), an inositol 1,4,5-trisphosphate (InsP3) receptor blocker, strongly inhibited the contractions induced by eugenol but had only a small effect on the caffeine-induced contractions. Eugenol neither altered the Ca(2+) sensitivity nor the maximal force in Triton X-100 skinned muscle fibers. These data suggest that muscle contraction induced by eugenol involves at least 2 mechanisms of Ca(2+) release from the SR: one related to the activation of the ryanodine receptors and another through a heparin-sensitive pathway.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Eugenol
/
Heparina
/
Músculo Esquelético
/
Fibras Musculares Esqueléticas
/
Canal de Liberação de Cálcio do Receptor de Rianodina
Limite:
Animals
Idioma:
En
Revista:
Can J Physiol Pharmacol
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Canadá