Phosphodiesterase's (PDE's) are enzymes that catalyze the hydrolysis of cAMP or cGMP to form AMP or GMP. cAMP and cGMP play important roles in a variety of biochemical processes. PDEs are currently classified into 11 different families. Each is classed based on a number of different factors including the distribution within tissue, and substrate specificity. Some hydrolyze cAMP, while others cGMP. A variety can degrade both cAMP and cGMP.
PDEs have excellent promise in a variety of therapeutic areas including heart disease, dementia, infection, depression, and asthma. New inhibitors can provide better therapeutic potential and can limit off-target effects more effectively.
Cyclic nucleotide phosphodiesterases are proven drug targets. Most are a focus of inhibition due to their functional properties. Since PDEs degrade cAMP or cGMP, inhibitors can prolong the effects of the cyclic nucleotide in the signaling cascade within the tissues where the individual enzyme is most likely to reside.