Ultrastructure of human penile erectile tissue in patients with abnormal norepinephrine content.

Past studies of the alteration of nerve morphology of penile erectile tissue in men with impotence using light and histofluorescent techniques have been inconclusive. We evaluated the ultrastructure of erectile tissue of five men; the content of the neurotransmitter norepinephrine in this tissue was also known. Our results show that in nerve fibers of men whose penile tissue samples displayed very low norepinephrine content, nerve fibers were extremely sparse. In two men with insulin dependent diabetes, alteration of the intracellular caveolae, glycogen, and microfilaments of smooth muscles were found. In addition, in these patients, there was an increased amount of cell surface coat material. In diabetic patients, these changes may translate into biomechanical alterations of the smooth muscle function within the erectile tissue.