Cyclic guanosine monophosphate (cGMP)

Cyclic guanosine monophosphate (cGMP) is a cyclic nucleotide derived from guanosine triphosphate. It acts as an essential intracellular second messenger in many physiological processes. Synthesized primarily by the action of soluble or particulate guanylyl cyclases—activated respectively by nitric oxide and natriuretic peptides—cGMP mediates cellular responses such as smooth muscle relaxation, regulation of ion channels, modulation of protein kinases like PKG, and control over gene expression. Its signaling is terminated through hydrolysis by specific phosphodiesterases. While drugs such as PDE inhibitors and GC stimulators modulate the pathway involving cGMP for therapeutic benefit in cardiovascular diseases and erectile dysfunction among others, cGMP itself is not considered a direct therapeutic target like receptors or enzymes, but rather an intracellular mediator whose concentration is pharmacologically manipulated.

Other names

cGMPCyclic GMPGuanosine 3',5'-cyclic monophosphateGuanosine cyclic monophosphate

Drugs do not directly bind to cGMP but modulate its levels by affecting enzymes involved in its synthesis or degradation. For example, phosphodiesterase inhibitors prevent the breakdown of cGMP; guanylate cyclase stimulators enhance its production.