Changes in myocardial beta adrenergic receptors in left ventricular hypertrophy caused by barometric and volumetric overloads
Galinier, M.; Senard, J.M.; Srour, A.; Ligou, V.; Valet, P.; Glock, Y.; Massabuau, P.; Roux, D.; Montastruc, J.L.; Bounhoure, J.P.
Archives des Maladies du Coeur et des Vaisseaux 87(8): 1015-1018
1994
ISSN/ISBN: 0003-9683 PMID: 7755450 Document Number: 422877
While most prior studies examined late stages of heart failure, we determined initial changes of beta-adrenergic receptors (beta-AR) during left ventricular chronic volume and pressure overload. We investigated right auricular (RA) and left ventricular (LV) beta-AR density (Bmax, fmoles/mg protein) and beta 1-AR percentage in two groups of patients undergoing valve replacement without LV systolic dysfunction (LV ejection fraction > or = 60%), with normal plasma catecholamine levels and echocardiography LV hypertrophy. These results were compared with the values of a control group, composed by 8 patients with mitral stenosis and 5 cardiac transplant donors, and the values of 5 patients undergoing heart transplantation because of end-stage idiopathic dilated cardiomyopathy. These results show that, before alteration of LV systolic function occurs, left ventricular chronic overload induces a selective down-regulation of LV beta 1-AR compensated by an increase in beta 2-AR. These variations may be due to LV hypertrophy induced by volume or pressure overload.