Details

Autor(en) / Beteiligte

• Gassanov, Natig
• Brandt, Mathias C.
• Michels, Guido
• Lindner, Michael
• Er, Fikret
• Hoppe, Uta C.

Titel

Angiotensin II-induced changes of calcium sparks and ionic currents in human atrial myocytes: Potential role for early remodeling in atrial fibrillation

Ist Teil von

• Cell calcium (Edinburgh), 2006-02, Vol.39 (2), p.175-186

Ort / Verlag

Netherlands: Elsevier India Pvt Ltd

Erscheinungsjahr

2006

Quelle

MEDLINE

Beschreibungen/Notizen

• Atrial angiotensin II (ANG II) levels have been shown to be increased in atrial fibrillation (AF). The purpose of the study was to evaluate a potential role of ANG II in the early remodeling and susceptibility to chronicization of AF. Isolated human atrial myocytes were incubated in ANG II and/or angiotensin type 1 receptor blocker candesartan. ANG II markedly increased the frequency of spontaneous Ca 2+ sparks, spark full duration, time to peak Ca 2+ fluorescence and decay time measured by confocal imaging. Sarcoplasmic reticulum calcium content estimated by caffeine-evoked calcium release did not differ between ANG II-treated cells and controls. Patch-clamp recordings revealed that ANG II significantly decreased I to and increased I Ca,L current densities. Candesartan blocked these ANG II-mediated alterations. ANG II exhibited no effect on I K1, I Kur and I f current size. Expression of connexin 40 and connexin 43 was not significantly changed by ANG II as assessed by immunohistochemistry and Western blot analysis. ANG II-induced alterations of calcium handling and electrophysiological changes in human atrial cells similar to those previously observed in the onset of AF. Prevention of these alterations by candesartan might constitute a useful pharmacological strategy for the treatment of AF.