Displacement of [3H]7-OH-DPA from dopamine D3 receptor in Sprague-Dawley rat olfactory tubercle homogenate after 60 mins by liquid scintillation counting
Receptor Binding Assay: (1) The prepared membrane was first applied with appropriate amount of homogenized liquid, and homogenizer was used for evenly dispersing. 15 tubes were mixed into a 100 ml container, and appropriate amount of homogenized liquid was added to give 50 ml of membrane suspension, which was reserved for future use.(2) 100 uL of membrane preparation and 100 uL of buffer were added into each reaction tube.(3) 100 uL of homogenized liquid was added into the total binding tube (TB), 100 uL of mianserin (final concentration 10-5 M) was added into the non-specific binding tube (NB), and 100 uL of the test compound (final concentration 10-5 M) was added into the specific binding tube (SB) for each compound.(4) 10 uL of radioactive ligand [3H]-mesulergine was respectively added into each reaction tube (2 parallel tubes were used for each reaction tube, and each of them was placed on ice when adding sample).(5) Each of the reaction tubes was incubated at 37 degree.
Receptor Assay: Competitive binding test for receptors: 20 μl of each of the test compounds and 20 μl of the radioactive ligand together with 160 μl of the receptor proteins were added into the reaction tubes, and the final concentrations of the test compound and the positive drug were all 10 μmol/L. After 50 min of incubation in 30° C. water bath, the tubes were immediately moved to ice bath to terminate the reactions. GF/C glass fiber filter papers were used for rapid sucking filtration on a Millipore cell sample collector, elution buffer (50 mM Tris-HCl, PH 7.4) was applied for 3 ml×3 times, and microwave was applied for 4-5 min for drying. The filter papers were moved into 0.5 ml centrifuge tubes, and 500 μl of lipid-soluble scintillation solution was added. The tubes were allowed to stand still for over 30 min in dark, and the intensities of radioactivity were measured by a counter.