Effect of cholecystokinin octapeptide on endogenous amino acid release from the rat ventromedial nucleus of the hypothalamus and striatum.
The sulphated octapeptide of cholecystokinin (CCK-8S) was found to cause a dose-dependent increase in the basal release of aspartate, glycine, and gamma-aminobutyric acid from the striatum and the ventromedial nucleus of the hypothalamus (VMH). No effect on amino acid release was observed after electrical (VMH) or potassium (striatum) stimulation. Experiments performed using the CCKB-selective antagonist L-365,260 and the CCKA-selective antagonist L-364,718 suggested that this action of CCK-8S was mediated via the CCKB receptor. The ability of CCK-8S to evoke amino acid release was not dependent on the presence of extracellular calcium, though the effect was abolished by tetrodotoxin. Inhibition of protein kinase activity by staurosporine prevented the excitatory effects of CCK-8S on amino acid release.
Barnes
S
S
Parke Davis Research Unit, Addenbrookes Hospital Site, Cambridge, England.
Whistler
H L
HL
Hughes
J
J
Woodruff
G N
GN
Hunter
J C
JC
D000470:Alkaloids / Q000494:pharmacology; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002766:Cholecystokinin / Q000037:antagonists & inhibitors; D003342:Corpus Striatum / Q000378:metabolism*; D008297:Male; D010456:Peptides, Cyclic / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D051381:Rats; D011919:Rats, Inbred Strains; D012844:Sincalide / Q000494:pharmacology*; D019311:Staurosporine; D014697:Ventromedial Hypothalamic Nucleus / Q000378:metabolism*; D020960:omega-Conotoxins
D000470:Alkaloids; D000596:Amino Acids; D002121:Calcium Channel Blockers; D010456:Peptides, Cyclic; D020960:omega-Conotoxins; C053423:Conus magus toxin; D002766:Cholecystokinin; D011493:Protein Kinase C; D019311:Staurosporine; D012844:Sincalide; D002118:Calcium