Interrelationship between atrial natriuretic peptide and plasma renin, aldosterone and catecholamines in hepatic cirrhosis: the effect of passive leg rising.

To assess the role of atrial natriuretic peptide (ANP) in relation to the sympathoadrenal and renin-angiotensin-aldosterone system, and sodium excretion, 88 cirrhotic patients (mean age 52 years; 28 compensated, 28 decompensated with ascites, and 32 decompensated and treated with diuretics) and 26 control subjects were investigated. Basal ANP levels were not different between any group of cirrhotics and controls. Circulating ANP was not related to elevated plasma noradrenaline and adrenaline, and enhanced plasma renin/aldosterone levels in ascitic patients. Furthermore, ANP was not related to urinary sodium excretion, blood pressure, and heart rate. In 30 cirrhotic patients (12 compensated, 18 decompensated with ascites including eight on diuretic therapy) and nine controls, a passive leg rising procedure for 1 h was performed in order to augment central blood volume and atrial pressure physiologically. Ascitic patients (with and without diuretic treatment) experienced a slight but significant increase in plasma ANP indicating preserved responsiveness of ANP release in cirrhosis. Plasma aldosterone was markedly depressed. The data support the underfilling concept of ascitic formation in advanced stages of cirrhosis. The failure of enhanced ANP release under basal conditions may be due to the diminished effective blood volume, resulting in insufficient atrial stretching.