Is sympathetic control of the urethra mediated through vasomotor action?

The suggestion that the sympathetic nervous influence on urethral smooth muscle activity is mediated through vasomotor control was tested directly by using an arterial long circuit in pentobarbital‐anesthetized cats. Hypogastric nerve stimulation produced a frequency‐dependent contraction of the bladder and constriction of the urethra but had no influence on the resistance of the isolated vascular circuit. Altering the speed of the pump that controlled circuit flow to either increase or decrease vascular circuit pressure had no influence on urethral perfusion pressure. It was concluded that the hypogastric nerve induces urethral constriction directly and not by vasomotor action. Furthermore, short‐term alterations in vascular status are not reflected in changes in urethral tension.