[Mechanism of the slow inotropic response of the mouse atrium mediated by the beta2-adrenoreceptor]
In: Rossiiskii fiziologicheskii zhurnal imeni I.M. Sechenova, Jg. 97 (2012-03-07), Heft 11
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Zugriff:
The abundant beta2-adrenoceptors (AR) expression was revealed in the mouse atrial cardiomyocytes, albeit its function is poorly understood. Recently we revealed the slow developing (for 20-40 min) positive inotropic effect in the mouse atrium which was induced by the specific agonist of the beta2-adrenoceptors (5 mkM fenoterol) and the task of this study involved investigation of the found effect. It was shown that stimulation of beta2-AR is enough for rapid triggering of up-regulation of two signalling pathways that have the opposite influence on the contraction force. On one hand, activation of the adenylate cyclase--protein kinase A cascade occurs leading to increasing of intracellular Ca2+ concentration and amplitude of contraction; on the other hand, activation of the NO-synthase and enhance of NO production occurs which prevents the potentiating of the contraction force. During the first 15-20 minutes, superposition of these activation effects was revealed, which prevented the contraction strength increasing. Then the positive inotropic effects occurred due to the decreasing of NO production. It was shown that L-type Ca-channels and ryanodine receptors were the key targets incorporated in the beta2 adrenoreceptors signalling puzzle.
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[Mechanism of the slow inotropic response of the mouse atrium mediated by the beta2-adrenoreceptor]
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Autor/in / Beteiligte Person: | Iu G, Odnoshivkina ; A M, Petrov ; A L, Zefirov |
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Zeitschrift: | Rossiiskii fiziologicheskii zhurnal imeni I.M. Sechenova, Jg. 97 (2012-03-07), Heft 11 |
Veröffentlichung: | 2012 |
Medientyp: | unknown |
ISSN: | 0869-8139 (print) |
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