Analysis of alpha1-adrenoceptors in rabbit lower urinary tract and mesenteric artery

Eur J Pharmacol. 1997 May 26;327(1):25-32. doi: 10.1016/s0014-2999(97)89674-4.


In this study, we have investigated the effects of a series of alpha1-adrenoceptor antagonists on the phenylephrine-mediated contractions of rabbit isolated prostate, urethra, trigone and mesenteric artery. With the exception of RS-17053 (N-[2-(2-cyclopropylmethoxyphenoxy)ethyl]-5-chloro-alpha,alpha-dim ethyl-1 H-indole-3-ethanamine hydrochloride), the antagonists displayed the lowest potency in the urethra. Catecholamine uptake1 and uptake2 appeared not to be the cause for the low pK(B)/pA2 values obtained in the urethra because cocaine and corticosterone had no effect on the potency of phenylephrine in this tissue. The low potencies displayed by prazosin. RS-17053 and HV723 (alpha-ethyl-3,4,5-trimethoxy-alpha-(3-((2-(2-methoxyphenoxy)ethyl)amino )propyl)benzene-acetonitrile fumarate) suggest that the functional receptors in all four tissues belong to the alpha(1L)-adrenoceptor class. Whether or not the significant between-tissue differences in antagonist potencies are due to heterogeneity of this receptor class remains to be elucidated.

MeSH terms

  • Adrenergic alpha-Antagonists / pharmacology
  • Animals
  • In Vitro Techniques
  • Male
  • Mesenteric Arteries / drug effects*
  • Mesenteric Arteries / physiology
  • Phenylephrine / pharmacology
  • Piperazines / pharmacology
  • Prostate / drug effects
  • Prostate / physiology
  • Rabbits
  • Receptors, Adrenergic, alpha-1 / classification
  • Receptors, Adrenergic, alpha-1 / physiology*
  • Urethra / drug effects
  • Urethra / physiology
  • Urinary Tract / drug effects*
  • Urinary Tract Physiological Phenomena


  • Adrenergic alpha-Antagonists
  • Piperazines
  • Receptors, Adrenergic, alpha-1
  • Phenylephrine
  • BMY 7378