Atrial natriuretic factor: reduced cardiac content in cirrhotic rats with ascites.

The present study was designed to investigate whether cirrhosis with ascites is associated with altered tissue content of atrial natriuretic factor. Atrial extracts from 14 cirrhotic rats with ascites and increased plasma renin activity (PRA) (14.4 +/- 4.6 ng X ml-1 X h-1) and aldosterone concentration (148.3 +/- 17.3 ng/dl) and from 10 control rats (PRA, 3 +/- 0.5 ng X ml-1 X h-1; aldosterone, 34.7 +/- 3.7 ng/dl) were intravenously injected into anesthetized normovolemic rats. Only one extract was assayed in each bioassay rat. Atrial extracts from control rats increased diuresis and natriuresis 513 +/- 91 and 3,029 +/- 752%, respectively (means +/- SE). In contrast, atrial extracts from cirrhotic rats increased urine volume 199 +/- 49% (P less than 0.001) and sodium excretion 546 +/- 132% (P less than 0.001). These results strongly suggest that atrial content of atrial natriuretic factor is reduced in cirrhotic rats as compared with control animals.