Facilitation of GABA release by cholecystokinin and caerulein in rat cerebral cortex.
Cholecystokinin octapeptide and its analogue, caerulein, facilitated the K+-evoked release of 14C-GABA from tissue slices of rat parietal cortex. The effect of caerulein was maximal at 1 nM where an enhancement of 36% was produced. Cholecystokinin octapeptide gave rise to a similar maximal enhancement (29%), but was two orders of magnitude less potent. The enhancement of 14C-GABA release by caerulein was reversed by proglumide, a putative competitive antagonist at the cholecystokinin receptor. The possibility that the cholecystokinin-induced facilitation of GABA release in the cortex is involved in the anticonvulsant properties of cholecystokinin-like peptides is discussed.
D000818:Animals; D002250:Carbon Radioisotopes; D002108:Ceruletide / Q000494:pharmacology*; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D010296:Parietal Lobe / Q000187:drug effects / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012844:Sincalide / Q000494:pharmacology*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D002250:Carbon Radioisotopes; D005680:gamma-Aminobutyric Acid; D002108:Ceruletide; D012844:Sincalide; D011188:Potassium