The adenosine receptors present on the plasma membrane of chromaffin cells are of the A2b subtype

J Neurochem. 1992 Aug;59(2):425-31. doi: 10.1111/j.1471-4159.1992.tb09388.x.


The adenosine receptors in the plasma membrane of chromaffin cells from bovine adrenal medulla were characterized. The presence of A1 receptors was discounted owing to the absence of R-[3H]phenylisopropyladenosine (R-PIA) and [3H]8-cyclopentyl-1,3-dipropylxanthine ([3H]-DPCPX) binding. The binding of the specific A2a ligand CGS-21680 was low. In contrast, the binding of 5'-(N-[3H]-ethylcarboxamidoadenosine ([3H]NECA) was relatively high (1.7 pmol/mg of protein at a ligand concentration up to 90 nM). This binding did not correspond to non-adenosine receptor NECA binding sites because the specific [3H]-NECA binding was similar when unlabeled adenosine, NECA, or R-PIA was used to measure the nonspecific binding. The rank order of potency of different ligands for the displacement of specific [3H]NECA binding was DPCPX greater than NECA greater than chloroadenosine greater than R-PIA greater than theophylline = CGS-21680. These results indicate that the receptors present on the plasma membrane of chromaffin cells are exclusively of the A2b subtype.

MeSH terms

  • 2-Chloroadenosine / metabolism
  • Adenosine / analogs & derivatives
  • Adenosine / metabolism
  • Adenosine-5'-(N-ethylcarboxamide)
  • Animals
  • Cattle
  • Cell Fractionation
  • Cell Membrane / chemistry
  • Cell Membrane / metabolism
  • Cell Membrane / ultrastructure
  • Chromaffin System / chemistry
  • Chromaffin System / cytology*
  • Chromaffin System / ultrastructure
  • Phenylisopropyladenosine / metabolism
  • Radioligand Assay
  • Receptors, Purinergic / analysis*
  • Receptors, Purinergic / chemistry
  • Receptors, Purinergic / metabolism
  • Tritium
  • Vasodilator Agents / metabolism
  • Xanthines / metabolism


  • Receptors, Purinergic
  • Vasodilator Agents
  • Xanthines
  • Tritium
  • 2-Chloroadenosine
  • Phenylisopropyladenosine
  • Adenosine-5'-(N-ethylcarboxamide)
  • 1,3-dipropyl-8-cyclopentylxanthine
  • Adenosine