흰쥐 해마박편에서 veratrine과 고농도 포타슘자극시 칼슘이온이 gamma-aminobutyric acid 유리에 미치는 영향에 관한 연구 : A role of calcium = Veratrine and potassium-induced release of gamma-aminobutyric acid from rat hippocampal slice

다국어 초록 (Multilingual Abstract)

Present study was performed to clarify the effect of calcium on the release of gamma-aminobutyric acid (GABA) employing hippocampal slices.
Hippocampal slices(300-400㎛ thick) were prepared by the method of Kim et al(1988) and pre-equilibrated in Krebs-bicarbonate medium(KBM, pH 7.4) for 1hr at 37℃. In case of veratrine-induced GABA release, pre-equilibrated slices were incubated in fresh KBM and then veratrine (25μM)-containing KBM for 10min period in the presence or absence of 2.5mM Ca^2+. In case of potassium-induced GABA relaese, pre-equilibrated slices were incubated in fresh KBM and then potassium(50mM)-containing KBM for 5min period in the presence or absence of 2.5mM Ca^2+. Basal and veratrine and potassium-induced release of GABA was determined from recovered medium by HPLC.
The observed results were as follows:
1. The release of GABA induced by the 10min-exposure of 25μM veratrine and 5min-exposure of 50mM potassium in the presence of 2.5mM Ca^2+ was 228.9±11.2 nmol and 100.1±8.9nmol, respectively. When compared with released amounts of GABA during the corresponding spontaneous periods, these were 6.8 and 4.6-fold increase respectively.
2. The release of GABA induced by the 10min-exposure of 25μM veratrine and 5min-exposure of 50mM potassium in the absence of Ca^2+ was 381.4±30.2 nmol and 55.1±4.1 nmol, respectively. When compared with released amounts of GABA during the corresponding spontaneous periods, these were 11.3 and 2.4-fold increase respectively.