Localisation of the adenosine uptake site in the human brain: a comparison with the distribution of adenosine A1 receptors.

Using quantitative receptor autoradiography we investigated the distribution of the adenosine uptake site labelled with [3H]NBTI in post-mortem human brain and compared its distribution with that of the A1 adenosine receptor labelled with [3H]CHA. The highest levels of [3H]NBTI binding were found in the cortex and striatum, with moderate levels in the hippocampus, globus pallidus, cerebellum and some midbrain and spinal cord nuclei. The distribution of A1 receptors and this adenosine uptake site differed in the hippocampus where A1 receptors were highest in CA1 but the uptake site was low in CA1 and higher in the molecular layer of the dentate gyrus. These results define the anatomical distribution of the high affinity NBTI sensitive adenosine uptake site in the normal human brain.