Effect of diabetes upon penile sympathetic nerves in impotent patients.

Samples of erectile tissue taken from the corpora cavernosa of 16 male diabetic patients suffering from impotence were studied. The content of norepinephrine, which reflects sympathetic nerve activity of that tissue, was significantly lower in insulin-dependent patients 104.2 +/- 24.8 (SE) pg/mg wet weight (P less than .001) and diet-controlled patients 483.7 +/- 103.7 (P less than .01) than the normal men (881.7 +/- 62.0). Myelinated and unmyelinated nerve fibers were observed intact and unaltered in each group of patients. The results indicated that normally a dense adrenergic innervation of human erectile tissue is present, but that a reduction occurs in norepinephrine content in diabetic patients with impotence. It appears, however, that the anatomic integrity of the sympathetic nerves is intact. The presence of intact nerve fibers along with a diminished content of neurotransmitter suggests the possibility of pharmacologic treatment of impotence.