Effects of acepromazine maleate and phenoxybenzamine on urethral pressure profiles of anesthetized, healthy, sexually intact male cats

Am J Vet Res. 1996 Oct;57(10):1497-500.


Objectives: To evaluate the effects of 2 compounds with alpha adrenergic antagonist properties on the urethral pressures of anesthetized, healthy, sexually intact male cats, and to evaluate one of the compounds for effect on striated muscle.

Animals: 20 healthy, sexually intact male cats.

Procedure: Cats were anesthetized with halothane, and urethral pressure profilometry was performed before and after treatment. 125I-labeled alpha-bungarotoxin bound to nicotinic receptors of murine skeletal muscle was used in a competitive binding study with acepromazine maleate.

Results: Acepromazine maleate significantly decreased intraurethral pressures in the preprostatic (19%) and prostatic (21%) regions of the urethra. There was no effect on the postprostatic/penile segment. Acepromazine did not inhibit 125I-labeled alpha-bungarotoxin binding to nicotinic receptors in murine skeletal muscle. Phenoxybenzamine significantly decreased intraurethral pressures (14%) in the preprostatic region of the urethra only.

Conclusions: Acepromazine maleate and phenoxybenzamine have effects on the smooth muscle of the urethra of healthy, male cats. Acepromazine has no effect on striated muscle.

Clinical relevance: alpha-Adrenergic compounds may be used in the pharmacologic management of feline urinary tract disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acepromazine / pharmacology*
  • Anesthesia, General
  • Animals
  • Binding, Competitive
  • Bungarotoxins / metabolism
  • Cats
  • Halothane
  • Iodine Radioisotopes
  • Male
  • Mice
  • Muscle, Skeletal / physiology
  • Muscle, Smooth / drug effects
  • Muscle, Smooth / physiology
  • Phenoxybenzamine / pharmacology*
  • Pressure
  • Radioligand Assay
  • Receptors, Nicotinic / metabolism
  • Urethra / drug effects
  • Urethra / physiology*


  • Bungarotoxins
  • Iodine Radioisotopes
  • Receptors, Nicotinic
  • Phenoxybenzamine
  • Acepromazine
  • Halothane