Beta-adrenergic receptors and catecholamines in acute myocardial infarction

Lymphocyte beta-adrenergic receptor density and plasma catecholamine concentrations were determined in 28 patients with acute myocardial infarction and compared with those in patients with angina pectoris and healthy persons. In patients with acute myocardial infarction beta-adrenergic receptor density was significantly lower (p less than 0.001) and plasma catecholamine levels significantly higher (p less than 0.001) as compared with corresponding values in patients with angina pectoris or healthy persons. beta-adrenergic receptor density in patients with angina pectoris were not significantly different from those in controls. A significant negative correlation between beta-adrenergic receptor density and plasma norepinephrine levels was observed in patients with acute myocardial infarction (r = -0.593; p less than 0.001; r = -0.615; p less than 0.001 respectively). It is suggested that decreased beta-adrenergic receptor density is a consequence of elevated plasma catecholamine levels in patients with acute myocardial infarction. It has been well documented that acute myocardial infarction is associated with enhanced activity of the sympathetic nervous system. Several studies have already been done showing that urinary excretion of catecholamines and plasma catecholamine concentrations are raised in the acute phase of myocardial infarction. Particularly high levels of plasma catecholamines appeared to be related to the severity of clinical course of myocardial infarction and were found in patients with cardiogenic shock, heart failure and arrhythmias. It is of interest that the peak elevation of plasma catecholamines correlated with the extent of myocardial damage as reflected by peak plasma CK activity and also correlated with acute and long-term mortality.(ABSTRACT TRUNCATED AT 250 WORDS)