Biochemical Physiological Actions
: An important second messenger, cGMP is a major intracellular mediator of extracellular signals such as nitric oxide and natriuretic peptides. Cyclic GMP interacts with three types of intracellular receptor proteins: cGMP-dependent protein kinases, cGMP-regulated channels, and cGMP-regulated cyclic nucleotide phosphodiesterases. A primary action of elevated cGMP levels in vivo is the stimulation of cGMP-dependent protein kinase (PKG).