EFFECTS OF VOLUME LOADING ON THE ATRIAL-N ATRIURETIC-FACTOR AND THE RENIN-ALDOSTERONE SYSTEM IN EXPERIMENTAL LIVER-CIRRHOSIS

Serum concentrations of ANF, Renin and Aldosterone were measured in an imals with experimental cirrhosis and volume overload. We studied 75 W istar rats divided in five groups. Group I: rats with hepatic cirrhosi s induced by CCl4; Group II: Control rats; Group III: rats with hepati c cirrhosis and continuous infusion of saline serum; Group IV: control rats with continuous infusion and Group V: cirrhotic rats and bolus i nfusion of saline. There were no statistical differences in serum conc entrations of ANF (232+/-75 vs 195+/-42 pg/ml) and Renin concentration (182+/-24 vs 171+/-34 ng/ml/hora) between controls and rats with cirr hosis. However, Aldosterone levels were elevated in cirrhotic rats in basal conditions as compared to controls (1197+/-287 vs 475+/-88 pg/ml ; p<0.001). The volume overload caused a paradoxical decrease of ANF i n cirrhotic rats (124+/-15 and 122+/-17; p<0.001). On the other hand, no changes were observed in Renin and Aldosterone after volume expansi on. These results suggest the existence of a hemodynamic response to c ompensate the volume overload. Other studies are necessary to confirm this hypotesis.