Receptor Reserves at α2-adrenergic and Dopaminergic Autoreceptors

  • M. Goldstein
  • E. Meller
  • C. H. Adler
Part of the Wenner-Gren Center International Symposium Series book series (WGCISS)


Repeated observations that the maximal response elicited by an agonist can be obtained when only a fraction of receptors are occupied has led to the concept of “spare receptors” (or “receptor reserve”). A large pool of “spare receptors” has been found in many peripheral tissues and partial agonists with substantial, but submaximal, intrinsic efficacy often produce maximal response (Nickerson 1956; Stephenson 1956; Ariens et al., 1960). The law of mass action relates fractional occupancy to ligand concentration and it follows that a lower agonist concentration will suffice to elicit a particular level of response the greater the excess of functional receptors (larger receptor reserve). In order to delineate the relationship between receptor occupancy and closely coupled physiologic responses at α2-adrenergic and dopaminergic autoreceptors, we have inactivated a portion of these receptors with the recently described irreversible antagonist Nethoxycarbonyl-2-ethoxy-1, 2-dihydroquinoline (EEDQ) (Meller et al., 1985). This compound was found to dose-dependently inactivate central α2-adrenrgic and dopaminergic receptors in vivo.


Dopamine Agonist Maximal Response Receptor Occupancy Receptor Binding Site Dopamine Receptor Agonist 
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© The Wenner-Gren Center 1987

Authors and Affiliations

  • M. Goldstein
  • E. Meller
  • C. H. Adler

There are no affiliations available

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