Objective: To explore the relation among myocardial AT(1)-/AT(2)- receptor expression, myocardial remodeling and cardiac function in patients with congestive heart failure.
Methods: Pathologic and morphologic studies on myocardial tissue of 31 patients with CHF due to valvular heart disease and 5 control subjects were carried out with optical and electronic microscopy. Message RNA expression of and AT(1)-/AT(2)-receptors in myocardial tissue were analyzed using the reverse transcriptase-polymerase chain reaction.
Results: Pathological changes of myocardial tissue in CHF due to valvular heart disease showed typical myocardial remodeling. AT(1)-receptor mRNA expression was slightly increased in the patients with mild CHF than in the control subjects, but decreased in the moderate and severe CHF patients. No difference was observed in AT(2)-receptor mRNA expression among all the groups.
Conclusions: The expression of AT(1)-receptor was up-regulated in mild CHF. Cardiomyocyte hypertrophy may be mediated by AT(1)-receptor. The expression of AT(1)-receptor was down-regulated in moderate and severe CHF. The do minant receptor subtype was transformed to AT(2). The significance of these alterations may be a local protective mechanism of myocardium. Cardiomyocyte apoptosis may be induced via AT(2)-receptor, leading to deterioration of cardiac function.