Renal function derangements induced by portacaval anastomosis in normal rats

The purpose of this study was to determine the renal function derangements that portacaval shunting caused in previously normal rats. Eight rats suffered a surgical portacaval shunt (PCS) and another 8 a sham operation (SHAM). Renal function was investigated by determining urinary volume, sodium, potassium, creatinine and aldosterone excretion, in basal conditions and after sodium overload. Plasma renin concentration and urinary excretion of PGE2, 6-keto-PGF1 alpha and TXB2 were also determined in basal conditions. PCS rats showed increased urinary volume, creatinine excretion and endogenous creatinine clearance, either in basal conditions or after sodium load. After the latter, PCS animals also showed sodium retention and hyperaldosteronuria. PCS caused in basal conditions a striking diminution in urinary excretion of all prostaglandins and no changes in plasma renin. In conclusion, PCS in the normal rat caused a renal dysfunction consisting of polyuria, possibly related to ADH disfunction and an inability to manage a sodium load.