Characterization with 3H-haloperidol of the dopamine receptor in the rat kidney particulate preparation

The dopamine receptor of rat kidney particulate preparation was identified and characterized by the use of 3H-haloperidol binding. Binding of 3H-haloperidol to the kidney particulate preparation was slow and saturable. The dissociation constants (KD) were 0.41 nM and 5.88 nM, respectively, according to the model of two classes of independent binding sites. Maximal binding of high affinity site was obtained with 166 fmol/mg protein which was about 40% of the total receptor density. A wide variety of neuroleptics at specifically low concentrations in nanomolar range inhibited the 3H-haloperidol binding. There was an excellent correlation between the affinity of numerous neuroleptics for the kidney particulate preparation and that for the brain striatum.