Regulation of myocardium β-adrenoceptors pathway in ventricular remodeling of heart failure patients

Abstract

To study the role of myocardium β-adrenoceptors pathway in ventricular remodeling of heart failure patients, β-adrenegic receptor density (B_max) and the content of cAMP were measured in the papillae of left ventricle and blood lymphocyte of 20 patients suffered from heart failure (CHF) (NYHZ classification II to III) B_max were investigated using³H-dihydroalpheolol as ligand. cAMP were assessed by competitive immunoassay. Left ventricle mass index (LVMI) were measured using echocardiogram. The results showed that the B_max and cAMP in failing myocardium significantly negatively correlated with LVMI (r=−0. 77,P < 0.01 andr=−0.46P < 0.05 respectively); the B_max of myocardium and blood lymphocyte in CHF patients with NYHA I (63 ± 12 fmol/mgpro and 514±115 fmol/10⁷ cell) significantly lowered than that of NYHA I. patients (94±20 fmol/mgpro and 702 ±138 fmol/10⁷ cell); and the B_max of myocardium and blood lymphocyte in patients with abnormal LVMI (62±12 fmol/mgpro and 516±122 fmol/10⁷ cell) decreased more significantly than that with normal LVMI patients; even in nromal LVMI patients (92±21 fmol/mgpro and 682±146 fmol/10⁷ cell), the B_max of blood lymphocyte was already decreased (P < 0.01), when comparing with controls. The intralymphocyte cAMP content sygnificantly decreased than that of controls (P < 0.05). These results indicated that B_max could reflect the severity of ventricle remodeling and the impairment of myocardium. The regulation of myocardium intracellular messenger transduction was earlier than the pathologic structural change of LV remodeling.