All are true about nitric oxide, EXCEPT:
Regulates vasomotor tone
Acts via cAMP
Present in cigarette smoke
It is important in penile erection
Nitric oxide is a potent vasodilator and serves to regulate vascular tone. Produced in the endothelium it freely diffuses to the nearby smooth muscle cell and activates a soluble guanylyl cyclase (sGC) raising cytosolic cGMP concentration. This in turn activates a cGMP-dependent protein kinase (PKG).