EFFECTS OF ACEPROMAZINE MALEATE AND PHENOXYBENZAMINE ON URETHRAL PRESSURE PROFILES OF ANESTHETIZED, HEALTHY, SEXUALLY INTACT MALE CATS

Objectives-To evaluate the effects of 2 compounds with alpha-adrenergi c antagonist properties on the urethral pressures of anesthetized, hea lthy, sexually intact male cats, and to evaluate one of the compounds for effect on striated muscle. Animals-20 healthy, sexually intact mal e cats. Procedure-Cats were anesthetized with halothane, and urethral pressure profilometry was performed before and after treatment. I-125- labeled alpha-bungarotoxin bound to nicotinic receptors of murine skel etal muscle was used in a competitive binding study with acepromazine maleate. Results-Acepromazine maleate significantly decreased intraure thral pressures in the preprostatic (19%) and prostatic (21%) regions of the urethra. There was no effect on the postprostatic/penile segmen t. Acepromazine did not inhibit I-125-labeled alpha-bungarotoxin bindi ng to nicotinic receptors in murine skeletal muscle. Phenoxybenzamine significantly decreased intraurethral pressures (14%) in the preprosta tic region of the urethra only. Conclusions-Acepromazine maleate and p henoxybenzamine have effects on the smooth muscle of the urethra of he althy, male cats. Acepromazine has no effect on striated muscle. Clini cal Relevance-alpha-Adrenergic compounds may be used in the pharmacolo gic management of feline urinary tract disease.