Nadph Diaphorase Histochemical Presence in some Mammal's Penis

Intrabdominal and extrabdominal portion of penis (rat, guinea pig, hamster and rabbit) have been used for histochemical activity Nadph-diaphorase. Pharmacological and electrophysiological studies, both in vivo and in vitro, make us to belive that, in man, dog, rabbit and rat, the relaxation of vascular smooth muscle of the cavernous body of penis, that is responsible for erection, is produced by the activation of a Non-Adrenergic, Non-Cholinergic (NANC) nervous pathway whose mediator is a new neurotrasmitter: Nitric Oxide (NO). Our observations provide the morphohistochemical base for the localization of NADPH-diaphorase in the different constitutive structures of the penis in some mammalian species. NADPH-diaphorase is a histoenzymatic revealing method that has been used to identify the structural components responsible for NO synthesis.