Gene expression of adrenomedullin in failing myocardium: comparison to atrial natriuretic peptide

1 Klinik III für Innere Medizin and 4 Klinik II für Innere Medizin, Universität zu Köln, 50924 Köln; 2 Medizinische Klinik und Poliklinik, Innere Medizin III, Universitätskliniken des Saarlandes, 66421 Homburg/Saar; and 3 Cardiovascular Research, Aventis Pharma Deutschland GmbH, 65926 Frankfurt, Germany The expression of adrenomedullin (AM) and atrial natriuretic factor (ANF) were investigated in the myocardium of a rat model of chronic ischemic heart failure (CHF) compared with sham-operated controls. In addition, human myocardium of patients with end-stage heart failure due to idiopathic dilated cardiomyopathy compared with myocardium of normal subjects (NF) was studied. In CHF, similar AM levels but increased ANF expression were observed in left ventricular myocardium, as assessed by semiquantitative PCR. Functional experiments with freshly excised papillary muscles showed no influence of AM on myocardial contractility. In NF human myocardium, the expression of AM mRNA was threefold higher in atrial compared with ventricular tissue. In analogy, ANF mRNA was increased by ~15-fold in atrial tissue. In dilated cardiomyopathy, the expression of AM was significantly increased in right and left ventricles compared with NF. In parallel, ventricular ANF expression was enhanced. heart failure; adrenomedullin; myocardial inotropy; atrial natriuretic factor; gene expression