흰쥐 해마절편에서 포도당/산소 고갈에 의한 5-hydroxytryptamine 유리변동에 미치는 Adenosine의 영향

Effect of Adenosine on the Release of [3H]-5-hydroxytryptamine during Glucose/Oxygen Deprivation from Rat Hippocampal Slices

<P> The effects of adenosine, adenosine A<SUB>1</SUB> receptor antagonist (DPCPX), or NMDA receptor antagonist (APV) on the spontaneous release of [<SUP>3</SUP>H]-5-hydroxytryptamine ([<SUP>3</SUP>H]-5-HT) during normoxic/normoglycemic or hypoxic/hypoglycemic period were studied in the rat hippocampal slices. The hippocampus was obtained from the rat brain and sliced 400 &#1356;m thickness with the tissue slicer. After 30 min s preincubation in the normal buffer, the slices were incubated for 30 min in a buffer containing [<SUP>3</SUP>H]-5-HT (0.1 &#12557;M, 74 &#12557;Ci/8 ml) for uptake, and washed. To measure the release of [<SUP>3</SUP>H]-5-HT into the buffer, the incubation medium was drained off and refilled every ten minutes through sequence of 14 tubes. Induction of glucose/oxygen deprivation (GOD; medium depleting glucose and gassed with 95% N<SUB>2</SUB>/5% CO<SUB>2</SUB>) was done in 6th and 7th tube. The radioactivities in each buffer and the tissue were counted using liquid scintillation counter and the results were expressed as a percentage of the total radioactivities. <P> When slices were exposed to GOD for 20 mins, the spontaneous release of [<SUP>3</SUP>H]-5-HT was markedly increased and this increase of [<SUP>3</SUP>H]-5-HT release was blocked by adenosine (10 &#12557;M) or DL-2-amino-5-phosphonovaleric acid (APV; 30 &#12557;M). Adenosine A<SUB>1</SUB> receptor specific antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) exacerbate GOD-induced increase of spontaneous release of [<SUP>3</SUP>H]-5-HT. <P> These results suggest that Adenosine may play a role in the GOD-induced spontaneous release of [<SUP>3</SUP>H]-5-HT through adenosine A<SUB>1</SUB> receptor activity.