Increased excretion of urinary cyclic GMP in primary hepatoma and preneoplastic liver.

Urinary excretion of cyclic GMP (cGMP) and the plasma level of cyclic AMP (cAMP) were determined in patients with liver diseases. The urinary excretion of cGMP, expressed on the basis of creatinine excreted per day, was at significantly higher levels not only in primary hepatoma but also in liver cirrhosis, while the plasma level of cAMP was higher only in liver cirrhosis. Thus, the ratio of urinary cGMP excretion to plasma cAMP level in primary hepatoma was significantly higher than that in liver cirrhosis. In cirrhotic patients studied by catheterization, the level of cGMP in the hepatic vein was significantly lower than that in the superior mesenteric or portal vein, indicating the uptake of cGMP by the liver. Since cGMP excretion correlated with KICG both in liver cirrhosis and primary hepatoma, the increased cGMP excretion appeared to be explained by a reduced uptake of cGMP by the liver.