Imipramine hydrochloride: pharmacodynamic effects on lower urinary tract of female dogs.

Our study of the pharmacodynamics of imipramine hydrochloride of the female canine lower urinary tract indicates the primary mode of action to be the stimulation of alpha adrenergic neuroreceptors in the bladder neck and urethra. This stimulation results in increased resting urethral pressure, adequate sphincter closure, possibly an increase in the bladder capacity and efficient urinary control. Imipramine had no anticholinergic effect on the bladder and the urethra. It also appears unlikely that in enuretic patients imipramine acts by central augmentation of the adrenergic system. No change was noticed in the intravesical or arterial pressures.