EFFECT OF EXERCISE ON PLASMA ADRENOMEDULLIN AND NATRIURETIC PEPTIDE LEVELS IN MYOCARDIAL-INFARCTION

1. We investigated the effect of exercise on plasma adrenomedullin, at rial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) con centrations and studied the relationship between these peptides and ha emodynamic parameters in nine patients with old myocardial infarction (MI) and in eight normal subjects. 2. The exercise protocol consisted of two fixed work loads (40 and 80 W) for 4 min each and venous blood samples were taken at rest, during each exercise stage and after exerc ise while monitoring the mean arterial pressure (MAP) and heart rate ( HR), In MI, pulmonary arterial pressure (PAP), pulmonary capillary wed ge pressure (PCWP), left ventricular end-diastolic pressure (LVEDP) an d cardiac output (CO) were measured throughout exercise. 3. Adrenomedu llin levels did not significantly increase with exercise. Adrenomedull in levels correlated with PAP and PCWP at rest (P < 0.05). Atrial natr iuretic peptide levels correlated with PAP, PCWP and LVEDP throughout exercise (P < 0.05) but, on multiple regression analysis, PCWP correla ted only with ANP (P < 0.01). Brain natriuretic peptide levels correla ted with LVEDP throughout exercise (P < 0.01) and its increment correl ated closely with basal BNP levels at rest (P < 0.01). 4. These result s suggest that adrenomedullin does not respond to the acute haemodynam ic changes of exercise, whereas ANP responds to it and PCWP is the maj or stimulus factor. Brain natriuretic peptide responds to exercise in proportion to the basal synthesis of BNP in patients with left ventric ular dysfunction and LVEDP may play a role in increasing BNP during ex ercise.