Academic Journal
Both beta(2)- and beta(1)-adrenergic receptors mediate hastened relaxation and phosphorylation of phospholamban and troponin I in ventricular myocardium of fallot infants, consistent with selective coupling of beta(2)-adrenergic receptors to G(s)-protein
| العنوان: | Both beta(2)- and beta(1)-adrenergic receptors mediate hastened relaxation and phosphorylation of phospholamban and troponin I in ventricular myocardium of fallot infants, consistent with selective coupling of beta(2)-adrenergic receptors to G(s)-protein |
|---|---|
| المؤلفون: | Molenaar, P., Bartel, S., Cochrane, A., Vetter, D., Jalali, H., Pohlner, P., Burrell, K., Karczewski, P, Krause, E., Kaumann, A. J. |
| المساهمون: | Willerson, J. T. |
| بيانات النشر: | Lippincott Williams & Wilkins |
| سنة النشر: | 2000 |
| المجموعة: | The University of Queensland: UQ eSpace |
| مصطلحات موضوعية: | Cardiac & Cardiovascular Systems, Hematology, Peripheral Vascular Disease, Tetralogy Of Fallot, Catecholamines, Myocardial Contraction, Receptors, Adrenergic, Beta, Adenylate-cyclase Stimulation, Heart-failure, Beta-2-adrenergic Receptors, G-protein, Tetralogy, Beta-2-adrenoceptors, Beta-1-adrenoceptor, Sensitivity, Adrenaline, Increase, 320502 Basic Pharmacology, C1, 730106 Cardiovascular system and diseases |
| الوصف: | Background-In adult human heart, both beta(1)- and beta(2)-adrenergic receptors mediate hastening of relaxation; however, it is unknown whether this also occurs in infant heart. We compared the effects of stimulation of beta(1)- and beta(2)-adrenergic receptors on relaxation and phosphorylation of phospholamban and troponin I in ventricle obtained from infants with tetralogy of Fallot. Methods and Results-Myocardium dissected from the right ventricular outflow tract of 27 infants (age range 2-1/2 to 35 months) with tetralogy of Fallot was set up to contract 60 times per minute. Selective stimulation of beta(1)-adrenergic receptors with (-)-norepinephrine (NE) and beta(2)-adrenergic receptors with (-)-epinephrine (EPI) evoked phosphorylation of phospholamban (at serine-16 and threonine-17) and troponin I and caused concentration-dependent increases in contractile force (-log EC50 [mol/L] NE 5.5+/-0.1, n=12; -EPI 5.6+/-0.1, n=13 patients), hastening of the time to reach peak force (-log EC50 [mol/L] NE 5.8+/--0.2; EPI 5.8+/-0.2) and 50% relaxation (-log EC50 [mol/L] NE 5.7+/-0.2: EPI 5.8+/-0.1), Ventricular membranes from Fallot infants, labeled with (-)-[I-125]-cyanopindolol, revealed a greater percentage of beta(1)- (71%) than beta(2)-adrenergic receptors (29%). Binding of (-)-epinephrine to beta(2)-receptors underwent greater GTP shifts than binding of (-)-norepinephrine to beta(1)-receptors. Conclusions-Despite their low density, beta(2)-adrenergic receptors are nearly as effective as beta(1)-adrenergic receptors of infant Fallot ventricle in enhancing contraction, relaxation, and phosphorylation of phospholamban and troponin I, consistent with selective coupling to G(s)-protein. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| تدمد: | 0009-7322 1524-4539 |
| الاتاحة: | https://espace.library.uq.edu.au/view/UQ:36787 |
| رقم الانضمام: | edsbas.28E0E97 |
| قاعدة البيانات: | BASE |
Full Text Finder | تدمد: | 00097322 15244539 |
|---|