Changes in the D1 receptor-adenylate cyclase complex after priming.
The D1 agonist, SKF 38393, failed to induce contralateral turning in drug-naive rats lesioned unilaterally with 6-hydroxydopamine from 17 days. Priming with a dopamine agonist, such as the D2 agonist, LY 171555, three days before, made SKF 38393 fully effective in inducing contralateral turning. Analysis of D1 receptor binding in striata of drug-naive and primed rats showed no change in the Bmax and Kd. In contrast, dopamine-stimulated adenylate cyclase showed a decrease in its Km for dopamine in the lesioned side of primed rats as compared with drug-naive rats. Thus, priming appears to elicit changes at the level of the transduction mechanism of D1 receptors rather than in the D1 recognition site itself.
Morelli
M
M
Institute of Experimental Pharmacology and Toxicology, University of Cagliari, Italy.
De Montis
G
G
Di Chiara
G
G
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology*; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D001345:Autoradiography; D003342:Corpus Striatum / Q000187:drug effects / Q000201:enzymology; D006892:Hydroxydopamines / Q000494:pharmacology; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D016627:Oxidopamine; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000378:metabolism*; D013563:Sympathectomy, Chemical
D006892:Hydroxydopamines; D011954:Receptors, Dopamine; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D016627:Oxidopamine; D000262:Adenylyl Cyclases