The binding of [3H]R-PIA to A1 adenosine receptors produces a conversion of the high- to the low-affinity state

FEBS Lett. 1991 Jul 29;286(1-2):221-4. doi: 10.1016/0014-5793(91)80978-c.


Kinetic evidence for negative cooperativity on the binding of [3H]R-PIA to A1 adenosine receptors was obtained from dissociation experiments at different ligand concentrations and from the equilibrium isotherm. The dissociation curves indicate that there is an apparent ligand-induced transformation of high- to low-affinity states of the receptor. At concentrations of 18.2 nM R-PIA or higher there was only found the low-affinity state of the receptor. In view of these results equilibrium binding data were analyzed by the usual two-state model (assuming that there is an interconversion between them) and by the negative cooperativity model employing the Hill equation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Membrane / metabolism
  • In Vitro Techniques
  • Kinetics
  • Phenylisopropyladenosine / metabolism*
  • Receptors, Purinergic / metabolism*
  • Regression Analysis
  • Swine


  • Receptors, Purinergic
  • Phenylisopropyladenosine