Direct coupling of a G-protein to dihydropyridine binding sites.
Electrophysiological data support the existence of GTP-binding proteins interacting with voltage dependent calcium channels. Along this line the present study investigates the effect of GMP-PNP, a stable GTP analogue, on the displacement of [3H]-PN 200-110 binding by agonist and antagonist dihydropyridines in synaptic membranes prepared from rat cortex. The results show that GMP-PNP increases the ability of the agonist dihydropyridine BAY K 8644 to displace [3H]-PN 200-110 binding. The in vivo treatment with Pertussis Toxin abolishes the effect produced by the non-hydrolysable GTP analogue.
Bergamaschi
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Institute of Pharmacological Sciences, University of Milan, Italy.
Govoni
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D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000818:Animals; D001665:Binding Sites; D015220:Calcium Channels / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D004095:Dihydropyridines / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives; D008297:Male; D037342:Pertussis Toxin; D011485:Protein Binding; D051381:Rats; D011919:Rats, Inbred Strains; D013570:Synaptic Membranes / Q000187:drug effects / Q000378:metabolism; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D015220:Calcium Channels; D004095:Dihydropyridines; D010566:Virulence Factors, Bordetella; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; C038806:1,4-dihydropyridine; D006160:Guanosine Triphosphate; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins