title: Heart ventricles specific stress-induced changes in β-adrenoceptors and muscarinic receptors.
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.
authors: Institute of Experimental Endocrinology, Centre of Excellence CENDO, Slovak Academy of Sciences, Vlarska 3, 833 06 Bratislava, Slovak Republic.
authors: Andrej
authors: A
authors: Tillinger
authors: Martina
authors: M
authors: Novakova
authors: Olga
authors: O
authors: Krizanova
authors: Richard
authors: R
authors: Kvetnansky
authors: Jaromir
authors: J
authors: Myslivecek
mesh_terms: D000818:Animals; D001665:Binding Sites; D002395:Catecholamines / Q000096:biosynthesis; D004837:Epinephrine / Q000096:biosynthesis; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006352:Heart Ventricles / Q000378:metabolism* / Q000503:physiopathology*; D008297:Male; D009638:Norepinephrine / Q000096:biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D011976:Receptors, Muscarinic / Q000378:metabolism*; D012149:Restraint, Physical; D013312:Stress, Physiological
chemical_list: D002395:Catecholamines; D012333:RNA, Messenger; D011943:Receptors, Adrenergic, beta; D011976:Receptors, Muscarinic; D009638:Norepinephrine; D004837:Epinephrine