Fig. 2.

The microscopic mechanism of penis erection. GC guanylate cyclase, PKG protein kinase G, MLC myosin light chain, AC adenylate cyclase, PGE1 prostagtandin E1, NANC nonadrenergic noncholinergic, GTP guanosine triphosphate, cGMP cyclic guanosine monophosphate, NO nitric oxide, ATP adenosine triphosphate, AMP adenosine monophosphate, Ach acetylcholine, eNOS endothelial nitric oxide synthase, AKT protein kinase B, PDE5i phosphodiesterase 5 inhibitors, PDE5 phosphodiesterase 5, MLCP myosin light chain phosphatase