Somatostatin acts through G-proteins on dopaminergic adenylate cyclase in the caudate-putamen of the rat.
Somatostatin was incubated in an adenylate cyclase assay of a particulate fraction of caudate-putamen tissue of the rat in order to examine the effect of the peptide on D-1 receptor coupled adenylate cyclase in vitro. Somatostatin was able to enhance cyclic AMP formation in the presence of guanylylimidodiphosphate and guanosine-triphosphate. In contrast to this, somatostatin inhibited both dopamine and forskolin-stimulated cyclic AMP accumulation. Pertussis toxin and cholera toxin also depressed forskolin-induced stimulation. Somatostatin was found to antagonize these inhibitory effects of pertussis toxin and cholera toxin. The results suggest that somatostatin acts through a stimulatory as well as an inhibitory guanine nucleotide regulatory protein subtype to affect dopaminergic adenylate cyclase activity.
Moser
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A
Dept. of Neurology, Med. University of Lübeck, F.R.G.
Cramer
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H
D037361:Adenylate Cyclase Toxin; D000262:Adenylyl Cyclases / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D002421:Caudate Nucleus / Q000201:enzymology*; D002772:Cholera Toxin / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D004298:Dopamine / Q000502:physiology*; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D019204:GTP-Binding Proteins / Q000502:physiology*; D037342:Pertussis Toxin; D011699:Putamen / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D013004:Somatostatin / Q000502:physiology*; D010566:Virulence Factors, Bordetella / Q000037:antagonists & inhibitors / Q000494:pharmacology
D037361:Adenylate Cyclase Toxin; D010566:Virulence Factors, Bordetella; D005576:Colforsin; D013004:Somatostatin; D002772:Cholera Toxin; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases; D004298:Dopamine