Cyclic nucleotide phosphodiesterase activity in muscle of patients with carcinoma.

Cyclic nucleotide phosphodiesterase activity has been measured in muscle biopsies taken from healthy controls and from cancer patients. In both groups the muscles were clinically and morphologically normal. The phosphodiesterase activity was significantly increased in muscles from cancer patients using both cyclic AMP and cyclic GMP as substrate. These findings are in line with previous reports indicating that malignancy may interfere with metabolism of the host muscular tissues, and suggest the possibility that the observed biochemical changes might be an aspect of an early muscle neurogenic involvement.