Nature of [3H]rilmenidine binding to membranes of rat cerebral cortex

Am J Hypertens. 1992 Apr;5(4 Pt 2):64S-68S. doi: 10.1093/ajh/5.4.64s.


The binding of [3H]rilmenidine to membranes of rat cerebral cortex was studied in order to ascertain which receptor populations this novel antihypertensive interacts with in the cortex. A catecholamine-sensitive, alpha 2-adrenoceptor binding site was identified which represented up to 50% of specific, 2 nmol/L [3H]rilmenidine binding and was displaceable by the catecholamines in the rank order epinephrine----norepinephrine----dopamine----isoproterenol. Some imidazolines such as clonidine, naphazoline, and idazoxan and the guanidino compound guanabenz completely and potently inhibited [3H]rilmenidine binding from both catecholamine-sensitive and -insensitive sites. The substituted imidazole and guanidine, cimetidine, and amiloride, respectively, showed no affinity for [3H]rilmenidine binding. The pharmacologic profile of the catecholamine-insensitive [3H]rilmenidine site in rat cerebral cortex suggests it may be novel, as it has the features of an imidazoline-guanidino-oxazoline binding site. However, its identity requires further characterization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic alpha-Agonists / metabolism*
  • Amiloride / pharmacology
  • Animals
  • Binding Sites
  • Catecholamines / pharmacology
  • Cell Membrane / metabolism
  • Cell Membrane / ultrastructure
  • Cerebral Cortex / metabolism*
  • Cerebral Cortex / ultrastructure
  • Guanidine
  • Guanidines / pharmacology
  • Imidazoles / pharmacology
  • Oxazoles / metabolism*
  • Oxazoles / pharmacology
  • Prazosin / pharmacology
  • Rats
  • Receptors, Adrenergic / drug effects
  • Rilmenidine
  • Tritium
  • Yohimbine / pharmacology


  • Adrenergic alpha-Agonists
  • Catecholamines
  • Guanidines
  • Imidazoles
  • Oxazoles
  • Receptors, Adrenergic
  • Tritium
  • Yohimbine
  • Amiloride
  • Guanidine
  • Rilmenidine
  • Prazosin