5-Methyl-urapidil discriminates between subtypes of the alpha 1-adrenoceptor

Eur J Pharmacol. 1988 Jul 7;151(2):333-5. doi: 10.1016/0014-2999(88)90819-9.

Abstract

The affinity of 5-methyl-urapidil for alpha 1-adrenoceptors was determined from the inhibition of [3H]prazosin binding on membrane of different rat tissues. In hippocampus, vas deferens and heart 5-methyl-urapidil displaced [3H]prazosin in a biphasic manner with mean pKI values between 9.1 and 9.4 for the high-affinity site and 7.2 to 7.8 for the low-affinity site. Only the low affinity site was found in spleen and liver. At present, 5-methyl-urapidil is the antagonist which most clearly discriminates between alpha 1-adrenoceptor subtypes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic alpha-Antagonists / metabolism
  • Adrenergic alpha-Antagonists / pharmacokinetics
  • Animals
  • Binding Sites
  • Binding, Competitive
  • In Vitro Techniques
  • Male
  • Piperazines / metabolism*
  • Piperazines / pharmacokinetics
  • Prazosin / metabolism
  • Rats
  • Rats, Inbred Strains
  • Receptors, Adrenergic, alpha / metabolism*
  • Tissue Distribution

Substances

  • Adrenergic alpha-Antagonists
  • Piperazines
  • Receptors, Adrenergic, alpha
  • 5-methylurapidil
  • Prazosin