SYSTEMIC AND TOPICAL DRUG ADMINISTRATION IN THE PIG URETER: EFFECT OF PHOSPHODIESTERASE INHIBITORS α1, β AND β2-ADRENERGIC RECEPTOR AGONISTS AND ANTAGONISTS ON THE FREQUENCY AND AMPLITUDE OF URETERAL CONTRACTIONS

Abstract

Intravenous phenylephrine increases, and isoproterenol and fenoterol decrease the frequency and amplitude of ureteral contractions in the pig. The same effects are observed with the topical administration of phenylephrine, which causes a significant local but not systemic side effect. Topical administration of isoproterenol and fenoterol produced local as well as systemic effects, suggesting absorption by the urothelium. However, to our knowledge a drug that relaxes ureteral peristalsis in pigs without causing systemic side effects has not yet been identified.