Pharmacological study of the internal and sphincter in patients with chronic anal fissure

Br J Surg. 1993 Jun;80(6):799-801. doi: 10.1002/bjs.1800800650.


A pharmacological study of the internal anal sphincter (IAS) was undertaken in patients with chronic and fissure. The sensitivity of the IAS to the contractile effect of phenylephrine and potassium chloride and to relaxation by isoproterenol was evaluated. Supersensitivity of the IAS to relaxation by isoproterenol was noted. Further research is necessary to determine the pharmacological basis of such a disturbance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anal Canal / drug effects*
  • Anal Canal / physiopathology
  • Chronic Disease
  • Dose-Response Relationship, Drug
  • Fissure in Ano / physiopathology*
  • Humans
  • In Vitro Techniques
  • Isoproterenol / pharmacology*
  • Muscle Contraction / drug effects
  • Phenylephrine / pharmacology*
  • Potassium Chloride / pharmacology*


  • Phenylephrine
  • Potassium Chloride
  • Isoproterenol