Characterization, solubilization, and separation of two distinct dopamine receptors in canine caudate nucleus.

Two types of [3H]dopamine binding were found in the synaptic membrane fractions of canine caudate nucleus and referred to as Dl (associated with adenylate cyclase) and Dz (independent of adenylate cyclase) dopamine receptors.Both receptors were present primarily in the membrane fractions and showed a similar subcellular distribution except for the microsomal fractions.Binding of [3H]dopamine to the Dl and Dz receptors was rapid, reversible, saturable, temperature-dependent, and of high affinity with the equilibrium dis-' The abbreviation used is: EGTA, ethylene glycol bis(8-aminoethyl ether)N,N,N,N-tetraacetic acid.10909