Guanosine 3', 5'-cyclic monophosphate level in plasma of patients with cancer and various diseases.

Guanosine 3'5'-cyclic monophosphate (cGMP) in the plasma of normal persons and patients with lung or breast cancer and other kinds of neoplasma or other diseases was determined using radioimmunoassay. In comparison with normal persons, significant elevation occurred in the cGMP in the plasma of patients with various kinds of cancer or renal insufficiency. The average cGMP values in the plasma of eight normal persons, 16 patients with lung cancer, 16 patients with breast cancer, five patients with oesophagus cancer, three patients with liver cancer, three patients with stomach cancer, ten patients with renal insufficiency and two patients with myocardial infarction, were respectively 3.46, 9.05, 5.39, 5.42, 7.33, 11.66, 19.55, and 8.0 pmol per ml of plasma. There was no elevation in the cGMP in the plasma of the patients with other diseases studied.