[Changes in myocardial beta adrenergic receptors in left ventricular hypertrophy caused by barometric and volumetric overloads].
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.
Galinier
M
M
Laboratoire de pharmacologie médicale et clinique, INSERM U317, Faculté de médecine, Toulouse.
Senard
J M
JM
Srour
A
A
Ligou
V
V
Valet
P
P
Glock
Y
Y
Massabuau
P
P
Roux
D
D
Montastruc
J L
JL
Bounhoure
J P
JP
D002395:Catecholamines / Q000097:blood; D015536:Down-Regulation; D005260:Female; D006349:Heart Valve Diseases / Q000150:complications; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000737:chemistry*; D011943:Receptors, Adrenergic, beta / Q000032:analysis* / Q000502:physiology
D002395:Catecholamines; D011943:Receptors, Adrenergic, beta
Modifications des récepteurs bêta-adrénergiques myocardiques au cours de l'hypertrophie ventriculaire gauche des surcharges barométriques et volumétriques.