D2 dopamine receptor-mediated inhibition of forskolin-stimulated adenylate cyclase activity in rat striatum.
Forskolin markedly stimulates striatal adenylate cyclase activity in a concentration-dependent manner, and at 10(-4) M produces an approximate 40-fold increase in enzyme activity above basal levels. Dopamine (in the presence of 100 nM SCH 23390), bromocryptine and quinpirole (LY 171555) significantly inhibit both basal and forskolin-stimulated adenylate cyclase activity. There is a significant increase in the absolute but not in the percent inhibition of enzyme activity by dopaminergic agonists as a function of forskolin concentration. This inhibition is agonist-concentration dependent and antagonized by the D2 antagonist, spiperone. These results suggest that forskolin may be used as a tool for amplifying the abolute D2-receptor-mediated inhibition of adenylate cyclase in rat striatal homogenates.
Battaglia
G
G
Norman
A B
AB
Hess
E J
EJ
Creese
I
I
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D001971:Bromocriptine / Q000494:pharmacology; D002090:Butyrophenones / Q000494:pharmacology*; D005576:Colforsin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D003342:Corpus Striatum / Q000201:enzymology*; D004873:Ergolines / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D019257:Quinpirole; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects*; D017448:Receptors, Dopamine D2; D013134:Spiperone / Q000494:pharmacology*
D001552:Benzazepines; D002090:Butyrophenones; D004873:Ergolines; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D005576:Colforsin; D019257:Quinpirole; D001971:Bromocriptine; D013134:Spiperone; D000262:Adenylyl Cyclases