Cholecystokinin releases [3H]GABA from the perfused subarachnoid space of the anaesthetized rat spinal cord.
The neuropeptide cholecystokinin(26-33) (CCK) is widely distributed in the mammalian central nervous system, including the spinal cord. We have studied the possible interaction of CCK with GABA release mechanisms. Low doses of CCK-8 (1 nM) have been found to evoke calcium-dependent [3H]GABA release from an in vivo perfused spinal cord preparation in the anaesthetized rat. Tachyphylaxis was seen to the [3H]GABA releasing action of CCK-8. The injection of proglumide (150 mg/kg i.p.) totally blocked the [3H]GABA release produced by CCK-8 or by a medium containing 50 mM potassium. Substance P (10 microM) did not produce release of [3H]GABA, although in the same animals 50 mM potassium containing solutions could be shown to evoke release of [3H]GABA.
D000768:Anesthesia, General; D000818:Animals; D002766:Cholecystokinin / Q000494:pharmacology*; D008297:Male; D009994:Osmolar Concentration; D010477:Perfusion; D011188:Potassium / Q000494:pharmacology; D011377:Proglumide / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012844:Sincalide / Q000037:antagonists & inhibitors / Q000494:pharmacology; D013116:Spinal Cord / Q000378:metabolism*; D013346:Subarachnoid Space; D013373:Substance P / Q000494:pharmacology; D014316:Tritium; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D014316:Tritium; D013373:Substance P; D005680:gamma-Aminobutyric Acid; D002766:Cholecystokinin; D011377:Proglumide; D012844:Sincalide; D011188:Potassium