Denervation supersensitivity of the urethra to alpha-adrenergics in the chronic neurogenic bladder.

The response of the urethral pressure profile to the administration of various autonomic drugs was compared between a group of eight patients with chronic neurogenic bladder as evidenced by denervation supersensitivity to besacholineR and a group of 10 control subjects. A supersensitive response to the administration of an alpha-stimulant with a rise of maximum urethral pressure of 10 mmHg or more above the control urethral pressure was uniformly observed in the urethra of patients with chronically denervated bladders. Mechanisms of supersensitivity are postulated and the significance of alpha-adrenergic innervation of the urethra are stressed. These results appear to add pharmacological evidence of alpha-adrenergic predominance in the urethra which is now believed to be dually innervated.