Dependence of ventricular wallstress-induced refractoriness changes on pacing cycle lengths and its mechanism / 生理学报
Acta Physiologica Sinica
; (6): 336-338, 2003.
Article
de Zh
| WPRIM
| ID: wpr-290963
Bibliothèque responsable:
WPRO
ABSTRACT
The aim of this article was to investigate the dependence of ventricular wallstress-induced refractoriness changes on pacing cycle lengths and its mechanism in anaesthetized rabbits. The rabbit heart preparation was used. The left ventricular afterload was increased by partially clipping the root of the ascending aorta. The changes in effective refractory periods (ERP) induced by the left ventricular afterload rising were examined at different pacing cycle lengths (1000, 500, 300 and 200 ms). In addition, the effect of streptomycin on these changes was also observed. The results are as follows: (1) The rising of left ventricular afterload led to marked changes in ERP at rapidly pacing cycle lengths (300 ms, 21+/-5 ms, 17.0%; 200 ms, 19+/-3 ms, 18.8%. P<0.01) than at slow ones (1000 ms, 3+/-2 ms, 1.5%; 500 ms, 7+/-3 ms, 4.0%. P>0.05); (2) Streptomycin inhibited the changes caused by the left ventricular afterload rising at pacing cycle lengths 300 ms and 200 ms (P>0.05). It is suggested that ventricular wallstress-induced refractoriness changes are pacing cycle length-dependent, and the effect of streptomycin appears to be consistent with the inhibition of stretch-activated ion channels.
Texte intégral:
1
Indice:
WPRIM
Sujet Principal:
Aorte
/
Pharmacologie
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Physiologie
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Période réfractaire en électrophysiologie
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Streptomycine
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Entraînement électrosystolique
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Fonction ventriculaire
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Constriction
/
Mécanorécepteurs
Limites du sujet:
Animals
langue:
Zh
Texte intégral:
Acta Physiologica Sinica
Année:
2003
Type:
Article