Abstract
The levels of catecholamines in penile blood during a papaverine test were measured to investigate whether the secretion of endogenous catecholamines is involved in response to intracorporeal papaverine injection. The level of norepinephrine was higher in patients with psychogenic impotence than in the normal controls and patients with vasculogenic impotence (p less than 0.01), and it was significantly higher in negative responders than in positive responders in the psychogenic impotence group (p less than 0.001). There was no significant difference in the level of epinephrine among the groups. The false negative response to the papaverine test in psychogenically impotent men is believed to be derived from secretion of cavernous norepinephrine, which overwhelms the action of cavernous smooth muscle relaxation by papaverine.