Inhibitory effect of octopamine on dopamine D-1 receptor in striatal homogenates of the rat.
In the striatal homogenates of rats, octopamine produced a dose-dependent inhibition of dopamine D-1 receptor both in the receptor binding of [3H]Sch-23390 and the formation of cyclic adenosine 3',5'-monophosphate (cyclic AMP) stimulated by dopamine in the presence of sulpiride. Failure of octopamine in the displacement of binding with [3H]N-0437, one of the radioligands for the dopamine D-2 receptor, indicated the specific selectivity of octopamine to dopamine D-1 receptor sites. Lack of effect on forskolin-stimulated formation of cyclic AMP ruled out the possible direct effect of octopamine on adenylate cyclase. These results suggest that octopamine possesses the ability to bind to striatal dopamine D-1 receptors of rats.
Cheng
J T
JT
Department of Pharmacology and Anatomy, College of Medicine, National Cheng Kung University, Tainan City, Republic of China.
Shen
C L
CL
Jou
T C
TC
D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001552:Benzazepines / Q000378:metabolism; D005576:Colforsin / Q000494:pharmacology; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D000242:Cyclic AMP / Q000096:biosynthesis; D004298:Dopamine / Q000494:pharmacology; D018492:Dopamine Antagonists; D005260:Female; D007700:Kinetics; D008297:Male; D009655:Octopamine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013764:Tetrahydronaphthalenes / Q000378:metabolism; D013876:Thiophenes / Q000378:metabolism
D000067956:Adenylyl Cyclase Inhibitors; D001552:Benzazepines; D018492:Dopamine Antagonists; D013764:Tetrahydronaphthalenes; D013876:Thiophenes; D009655:Octopamine; D005576:Colforsin; C047508:rotigotine; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D004298:Dopamine