Subtype selectivity of a new alpha 1-adrenoceptor antagonist, JTH-601: comparison with prazosin

Eur J Pharmacol. 1996 Apr 4;300(1-2):155-7. doi: 10.1016/0014-2999(96)00043-x.


The existence of alpha 1-adrenoceptors with low affinity for prazosin (alpha 1L group: alpha 1L and alpha 1N subtypes) has been proposed in addition to alpha 1-adrenoceptor subtypes with high affinity for prazosin (alpha 1H group: alpha 1A, alpha 1B and alpha 1D subtypes). A newly synthesized alpha 1-adrenoceptor antagonist, JTH-601 (N-(3-hydroxy-6-methoxy-2,4,5-trimethylbenzyl)-N-methyl-2-(4-hydro xy-2-isopropyl-5-methyl-phenoxy) ethylamine hemifumarate) showed approximately a 10 times higher affinity for the alpha 1L group, a similar affinity for the alpha 1A subtype, but a more than 10 times lower affinity for the alpha 1B and alpha 1D subtypes when compared with prazosin. These results provide a further pharmacological evidence that alpha 1-adrenoceptors with low affinity for prazosin exist in addition to those with high affinity for prazosin, suggesting that JTH-601 may be useful for characterising the alpha 1-adrenoceptor subtypes.

Publication types

  • Comparative Study

MeSH terms

  • Adrenergic alpha-Antagonists / metabolism*
  • Animals
  • Cattle
  • Cells, Cultured
  • Cresols / metabolism*
  • Cricetinae
  • Dogs
  • Male
  • Muscle, Smooth, Vascular / drug effects
  • Prazosin / metabolism*
  • Rabbits
  • Rats
  • Receptors, Adrenergic, alpha / classification
  • Receptors, Adrenergic, alpha / metabolism*
  • Species Specificity


  • Adrenergic alpha-Antagonists
  • Cresols
  • Receptors, Adrenergic, alpha
  • JTH 601
  • Prazosin