Cyclic GMP sodium (cGMP) is an important regulator of short-term changes in smooth muscle tone and longer-term responses to chronic drug research or proliferative signals, it is in response to atrial natriuretic peptide (ANP) or nitric oxide (NO). Cyclic GMP sodium interacts with cation channels to regulate ion transport or activate the cyclic GMP-dependent protein kinase to result in protein phosphorylation.