Possible adrenergic effects on heart protein metabolism.

It is known that the heart will adapt to actual demand by increasing or decreasing its size through different mechanisms. In this presentation, the possible role of catecholamines in regulating heart protein synthesis and developing cardiac hypertrophy and cardiomyopathy is discussed. Injecting animals with catecholamines has been found to induce cardiac hypertrophy. In vitro perfusion of rat heart in the presence of catecholamines has been found to induce a time-dependent and dose-dependent stimulation of amino acid transport and incorporation into proteins. Acute haemodynamic effects of catecholamines increase cardiac performance while long-term treatment seems to cause depression of cardiac function, especially during ischaemic conditions. Chronic beta-blockade in patients with primary congestive cardiomyopathy improved both cardiac function and clinical condition in more than half the patients. Furthermore, a beneficial effect on survival was also found, when compared with a matched control group. It is hypothesised that catecholamines may play a role in developing cardiac hypertrophy as well as congestive cardiomyopathy.