Comparison of the central and renal dopamine-1 receptor.
The dopamine D-1 receptor from striatal membranes was compared with the dopamine DA-1 receptor from renal proximal tubules. The dopamine-1 receptors were solubilized with 1% sodium cholate and phospholipids after pretreatment with the dopamine-1 agonist, SKF R-38393. The soluble receptors were reconstituted into phospholipid vesicles after removal of sodium cholate. The receptors were studied by radioligand binding using the dopamine-1 antagonist [125I]-SCH 23982. The reconstituted dopamine D-1 and DA-1 receptor densities were similar. However, the affinity of the solubilized D-1 receptor was 17-fold greater than the solubilized DA-1 receptor. The affinity of membrane bound D-1 receptor to the radioligand was also greater than that noted for membrane bound DA-1 receptor. The mechanism for this difference remains to be determined.
Sidhu
A
A
Department of Pediatrics, Georgetown University, Washington, D.C.
Felder
R A
RA
Jose
P A
PA
Fishman
P H
PH
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000378:metabolism; D000345:Affinity Labels; D000818:Animals; D001552:Benzazepines / Q000031:analogs & derivatives* / Q000378:metabolism; D001667:Binding, Competitive; D003342:Corpus Striatum / Q000378:metabolism*; D015259:Dopamine Agents / Q000378:metabolism; D007687:Kidney Tubules, Proximal / Q000378:metabolism*; D051381:Rats; D011954:Receptors, Dopamine / Q000378:metabolism*; D017447:Receptors, Dopamine D1; D012995:Solubility
C049558:8-iodo-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepine-7-ol; D000345:Affinity Labels; D001552:Benzazepines; D015259:Dopamine Agents; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine