Role of the autonomic nervous system in catheter-induced urethral inflammation.

We have studied role of the autonomic nervous system on experimentally induced urethral inflammation in the rat. Urethral inflammation was produced by inserting latex strips into the urethra. The effects of different experimental procedures were assessed by using a 4-grade inflammation scale based on histological findings. Rats pretreated with the nonspecific catecholamine depletors reserpine or quanethidine had a significantly less severe urethral inflammation than vehicle-treated controls. The severity of urethral inflammation was increased in spontaneous hypertensive rats, which have an increased sympathetic tone as compared to the normotensive rats. Propranolol, a nonselective beta-adrenergic receptor antagonist reduced and butoxamine, a beta 2-antagonist, significantly reduced the urethral inflammation. Neither phenoxybenzamine (nonselective) nor prazosin (alpha 1) or yohimbine (alpha 2), alpha-adrenergic receptor antagonists, affected the degree of urethral inflammation. These data taken together indicate that the autonomic innervation of the urethral mucosa is critically involved in the inflammatory reaction and that the use of beta 2-antagonist may be a treatment alternative in the future for the treatment of catheter-induced inflammation.