The dopamine/neuroleptic receptor.

The neuroleptic/dopamine receptor, with its picomolar affinity for potent neuroleptics, is the functional dopamine receptor of the brain. This receptor has been termed the D2 dopamine receptor, and it inhibits or interferes with dopamine-stimulated adenylate cyclase. This D2 receptor has two states, each having different affinity for dopamine. The high-affinity state, termed D2 high, has a 10 nM affinity for dopamine and is the functional correlate for dopamine autoreceptors and for the dopamine receptor in the pituitary gland. The low-affinity state, termed D2 low, has a 2000 nM affinity for dopamine, and may possibly represent the desensitized state of the dopamine receptor or the functional post-synaptic receptor.