Laboratory assessment of terazosin and alpha-1 blockade in prostatic hyperplasia

Urology. 1988 Dec;32(6 Suppl):21-6.


The alpha-1 adrenergic innervation of the human prostate has been studied using radioligand receptor binding methods and in vitro contractile experiments. The density of alpha-1 adrenergic binding sites is of the same order of magnitude as alpha-2 adrenergic and muscarinic-cholinergic (MCh) receptors in the human prostate adenoma. The contractile response of human prostate adenomas to selective alpha-1, alpha-2, and MCh agonists indicated that smooth muscle contraction of the human prostate is mediated by alpha-1 adrenoceptors. The selective affinities of terazosin for alpha-1 and alpha-2 binding sites were determined using competitive displacement assays. Terazosin was shown to have a four hundred-fold greater affinity for alpha-1 binding sites. The concentration of terazosin-inhibiting phenylephrine-induced contractions suggested that terazosin inhibits prostate smooth muscle contraction via alpha-1 adrenoceptors.

Publication types

  • Clinical Trial
  • Multicenter Study

MeSH terms

  • Adrenergic alpha-Antagonists / pharmacology*
  • Double-Blind Method
  • Humans
  • Male
  • Multicenter Studies as Topic
  • Muscle Contraction / drug effects
  • Muscle, Smooth / drug effects
  • Prazosin / analogs & derivatives*
  • Prazosin / pharmacology
  • Prostate / innervation*
  • Prostatic Hyperplasia / drug therapy*
  • Prostatic Hyperplasia / physiopathology
  • Radioligand Assay
  • Random Allocation
  • Receptors, Adrenergic, alpha / drug effects
  • Receptors, Adrenergic, alpha / physiology*


  • Adrenergic alpha-Antagonists
  • Receptors, Adrenergic, alpha
  • Terazosin
  • Prazosin