Biological properties of griseolic acid, a cyclic AMP phosphodiesterase inhibitor with an adenine group

Griseolic acid inhibited cAMP phosphodiesterase (PDE) at low concentrations, the I50 being of the order of 0.01–0.1 μM. Administration of griseolic acid to rats increased the cAMP level in liver and plasma several-fold. It increased glycogen degradation in mouse liver and stimulated lipolysis in isolated rat fat cells. Griseolic acid did not block the adenosine-elicited accumulation of cAMP in guinea pig brain slices. It had no effect on cAMP-dependent protein kinase from rat liver nor on the adenyl cyclase from rat brain.