General Physiology and Biophysics Vol.33, No.3, p.357–364, 2014
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Title: Heart ventricles specific stress-induced changes in β-adrenoceptors and muscarinic receptors |
Author: Andrej Tillinger, Martina Novakova, Olga Krizanova, Richard Kvetnansky, Jaromir Myslivecek |
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Abstract: The left and right ventricles fulfill different role in heart function. Here we compare chamber specific changes in local catecholamine concentrations; gene expression and the receptor protein amount of all three β-adrenoceptors (β-AR) in rat right heart ventricles exposed to acute (1 session) and repeated (7 sessions) immobilization stress (IMMO) vs. previously observed changes in left ventricles. Density of muscarinic receptors as main cardio-inhibitive receptors was also measured. In the right ventricles, noradrenaline and adrenaline were increased. No β1-AR changes were observed, in spite of the increased sympathetic activity. On the other hand, we have found a decrease of β2-AR gene expression (reduction to 30%) after 7 IMMO and protein (to 59%) after 1 IMMO. β3-AR gene expression was increased after 7 IMMO. Muscarinic receptor density was not changed. When comparing correlation in left and right ventricles, there was strong correlation between adrenaline and β2-AR gene expression, protein and β3-AR gene expression in the left ventricles while only correlation between adrenaline and β2-AR mRNA and protein in the right ventricles was found. Our results show that maintenance of cardiac homeostasis under stress conditions are to a great extent achieved by a balance between different receptors and also by a balanced receptor changes in left vs. right ventricles. Taken together, decrease of cardio-stimulating β2-AR represents a new important mechanism by which β2-AR contributes to the heart physiology.
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Keywords: Beta-adrenergic receptors — Binding sites — Catecholamines — Gene expression — Heart — Stress |
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Published online: 12-Jun-2014
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Year: 2014, Volume: 33, Issue: 3 |
Page From: 357, Page To: 364 |
doi:10.4149/gpb_2014002
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