The role of Kir3.1 and Kir3.4 subunits in the regulation of cardiac GIRK channels in atrial myocytes
Die Rolle von Kir3.1- und Kir3.4- Untereinheiten in der Regulation kardialer GIRK-Kanäle in Vorhofmyozyten
- Cardiac GIRK channels are composed of Kir3.1 and Kir3.4 subunits and contribute to vagally induced bradycardia. Here, the effects of altered subunit expression ratios on cardiac GIRK currents were studied using adenovirally induced overexpression and RNA interference in primary cultured atrial myocytes of adult rats. We show that \(Na^{+}\)-dependent activation of GIRK channels is restricted to Kir3.4 homomers. Adenovirus-driven RNA interference specifically targeting Kir3.1 and Kir3.4 resulted in both cases in parallel reduction of Kir3.1 and Kir3.4 mRNA, suggesting a co-regulation of transcription. To study the role of GIRK channel regulation in chronic atrial fibrillation (cAF), \(Na^{+}\)-sensitivity of GIRK currents in atrial myocytes of cAF patients were compared to normal sinus rhythm (SR). The receptor dependent GIRK current in SR-myocytes increased with \([Na^{+}]_{i}\). This \(Na^{+}\)-sensitivity was impaired in cAF, suggesting decreased Kir3.4 expression due to cAF induced remodeling processes.
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| Author: | Elisa Mintert-JanckeGND |
|---|---|
| URN: | urn:nbn:de:hbz:294-31442 |
| Referee: | Lutz PottORCiDGND, Christian H.R. WetzelORCiDGND |
| Document Type: | Doctoral Thesis |
| Language: | English |
| Date of Publication (online): | 2011/09/12 |
| Date of first Publication: | 2011/09/12 |
| Publishing Institution: | Ruhr-Universität Bochum, Universitätsbibliothek |
| Granting Institution: | Ruhr-Universität Bochum, Fakultät für Biologie und Biotechnologie |
| Date of final exam: | 2011/01/18 |
| Creating Corporation: | Fakultät für Biologie und Biotechnologie |
| GND-Keyword: | Kaliumkanal; Herzmuskelzelle; RNS-Interferenz; Adenoviren; Vorhofflimmern |
| Institutes/Facilities: | Institut für Physiologie, Abteilung für Zelluläre Physiologie |
| Dewey Decimal Classification: | Naturwissenschaften und Mathematik / Biowissenschaften, Biologie, Biochemie |
| faculties: | Fakultät für Biologie und Biotechnologie |
| Licence (German): |  Keine Creative Commons Lizenz - es gelten der Veröffentlichungsvertrag und das deutsche Urheberrecht |
