NOS1 and diabetes mellitus: In an interesting study on diabetes mellitus-induced ED rats, the ESWT with modified Ojayeonjonghwan (Korean herbal formula, KH-204) synergistically improved erectile function through enhancing intracavernosal pressure (ICP) and restoring smooth muscle contents and other potency-associated parameters such as vascular endothelial growth factor, neuronal nitric oxide synthase (NOS), endothelial NOS, and platelet endothelial cell adhesion molecule-1 [29].