Altered in vitro adrenergic responses of dog detrusor msucle after chronic bladder outlet obstruction.

Muscle strips from the bladder body and dome of normal and control dogs usually demonstrate a relaxing (beta-adrenergic) response to norepinephrine. After bladder outlet obstruction was caused by urethral constriction, all body muscle strips from 7 of 12 dogs (58 per cent) demonstrated contractile (alpha-adrenergic) responses to norepinephrine. Bladder base muscle strips continued to show alpha-adrenergic responses. Desensitization or decreased beta-adrenergic receptor activity may play a part in causing the low compliance and detrusor instability seen in patients with bladder outlet obstruction.