Quantitative autoradiographic analysis of dopamine receptors, and DAT and DTBZ densities in the substantia nigra.

<p>Autoradiograms show total binding of 1.44 nM [<sup>3</sup>H]SCH23390, 2.50 nM[<sup>3</sup>H]raclopride, 3.54 nM [<sup>3</sup>H]<b>WC-10</b>, 2.19 nM [<sup>3</sup>H]WIN35428, 4.53 nM [<sup>3</sup>H]DTBZ (A), and nonspecific binding in presence of 1 uM (+) butaclamol (for [<sup>3</sup>H]SCH23390), 1 µM <i>S</i>(-)-eticlopride (for [<sup>3</sup>H]raclopride and [<sup>3</sup>H]<b>WC-10</b>), 1 µM nomifensine (for WIN35428) and 1 µM <i>S</i>(-)-tetrabenazine (for DTBZ) (B) in the substantia nigra (SN) of aged human brain sections. [<sup>3</sup>H]Microscale standards (ranging from 0 to 36.3 nCi/mg) were also counted (C). Quantitative analysis of dopamine D<sub>1</sub>, D<sub>2</sub> and D<sub>3</sub> receptors, and DAT and DTBZ densities (fmol/mg) and the dopamine D<sub>2</sub> ∶ D<sub>3</sub> receptor density ratio in human SN and red nucleus are shown in D and E respectively. The numbers 1 through 3 designate the following CNS anatomical regions: 1: Substantia nigra (SN); 2: Red nucleus (RN); 3: Thalamus.</p>