Abstract
This study investigated the influence of chronic beta(3)-adrenoceptor deficiency on myocardial function. Therefore, we investigated Ca(2+)-regulatory proteins, SERCA 2a activity, and myofibrillar and mitochondrial function in hearts of wild-type (WT, n=7) and beta(3)-adrenoceptor knockout mice (beta(3)-KNO, n=7). Morphometric heart analysis showed no difference between WT and beta(3)-KNO. No alterations were observed for the protein expression of the ryanodine receptor or phospholamban. However, in beta(3)-KNO mice, protein expression of SERCA 2a and phospholamban phosphorylation were significantly increased. These changes were accompanied by an increased SERCA 2a activity in beta(3)-KNO. Alterations in phospholamban phosphorylation were independent of alterations in beta(1)/beta(2)-adrenoceptor distribution and protein expression of G proteins in beta(3)-KNO. Measurement of myofibrillar Ca(2+) sensitivity showed no difference in the Ca(2+)/force relation for WT and beta(3)-KNO. The same seems to hold true for mitochondrial function since the protein expressions of cytochrome c, uncoupling protein 3 and cytochrome c oxidase subunit IV were similar in WT and beta(3)-KNO. The conclusion is that depression of beta(3)-adrenergic stimulation may modulate the protein expression of SERCA 2a and phospholamban phosphorylation, thereby improving sarcoplasmic reticulum Ca(2+) uptake. Thus, beta(3)-adrenergic depression may be a therapeutic aim in situations of impaired SERCA 2a activity, e.g. for the treatment of heart failure.
Original language | English |
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Journal | Pflügers Archiv : European journal of physiology |
Volume | 453 |
Issue number | 4 |
Pages (from-to) | 443-53 |
Number of pages | 11 |
ISSN | 0031-6768 |
DOIs | |
Publication status | Published - 01.01.2007 |
Research areas and keywords
- Animals
- Calcium
- Calcium-Binding Proteins
- Echocardiography
- GTP-Binding Proteins
- Gene Expression
- Heart Failure
- Immunoblotting
- Male
- Mice
- Mice, Knockout
- Mitochondrial Proteins
- Myofibrils
- Phosphorylation
- Receptors, Adrenergic, beta-3
- Ryanodine Receptor Calcium Release Channel
- Sarcoplasmic Reticulum
- Sarcoplasmic Reticulum Calcium-Transporting ATPases
- Signal Transduction