RESUMO
The present study aimed to assess relationships between plasma levels of atrial natriuretic peptide (ANP) and plasma volume, systemic vascular resistances, cardiac output and plasma renin activity in patients with cirrhosis. Thirty patients were included: eight with no history of liver disease were used as controls; 22 patients had biopsy-proven alcoholic cirrhosis without ascites (n = 11) and with ascites (n = 11). Mean ANP plasma level was significantly higher in both groups of cirrhotic patients than in controls (P less than 0.05). In the control group, ANP and plasma renin activity were inversely correlated (P less than 0.05) but no correlation was found in cirrhotic patients. In the group of patients with ascites, ANP plasma levels were inversely correlated to plasma volume (P less than 0.05) and to cardiac output (P less than 0.01) and directly correlated to systemic vascular resistances (P less than 0.01). Using multiple regression analysis, ANP remained correlated only with systemic vascular resistances (P less than 0.05). These results suggest that cirrhotic patients have high plasma levels of ANP whether or not they have ascites. In the light of current knowledge of ANP actions, the relationships between ANP plasma levels and plasma volume, cardiac output, and systemic vascular resistances are paradoxical in cirrhotic patients with ascites. ANP does not seem to play a critical role in the pathogenesis of sodium and water retention observed in these patients.
