丙泊酚对大鼠海马突触体释放谷氨酸和γ-氨基丁酸的影响

目的观察丙泊酚对大鼠海马突触体谷氨酸和γ氨基丁酸(GABA)Ca2+依赖性释放和非Ca2+依赖性释放的影响。方法制备突触体后用人工脑脊液(aCSF)孵育,分为7组,应用丙泊酚(propofol)的浓度分别为3(Pro3组)、10(Pro10组)、30(Pro30组)、100(Pro100组)和300μmol·L-1(Pro300组),脂肪乳剂对照组加入脂肪乳(Intralipid组),空白对照组(Control组)不加入任何药物。在观察Ca2+依赖性释放时,加入二氢海人藻酸和哌啶酸;在观察非Ca2+依赖性释放的时候,去除aCSF中的Ca2+。在37℃的条件下,应用20μmol·L-1藜芦定或30mmol·L-1KCl诱发递质释放。应用反相高效液相色谱法测定aCSF中谷氨酸和GABA的浓度。结果①Ca2+依赖性递质释放:应用藜芦定时,Pro30、Pro100和Pro300组的谷氨酸和GABA释放量低于Intralipid组(P<0.01或P<0.05);应用KCl时,各组的谷氨酸和GABA释放量无差异(P>0.05)。②非Ca2+依赖性释放:各组应用藜芦定和KCl诱发的谷氨酸和GABA释放量无差异(P>0.05)。结论丙泊酚可以抑制Ca2+依赖性谷氨酸和GABA的释放,而对非Ca2+依赖性谷氨酸和GABA释放无影响。

Effect of propofol on glutamate and γ-aminobutyric acid release from rat hippocampal synaptosomes

AimTo investigate the effect of propofol on the release of glutamate and γ-aminobutyric acid (GABA) from rat hippocampal synaptosomes. Methods Synaptosomes were made from hippocampus and incubated with artificial cerebrospinal fluid (aCSF). When Ca2+-dependent release of glutamate and GABA were observed, dihydrokainic acid (DHK) and nipectic acid were added into aCSF. When Ca2+-independent release of glutamate and GABA were observed, Ca2+ was omitted from aCSF. The release of glutamate andGABA were measured using high-performance liquid chromatograph (HPLC). Results ①30,100 and 300 μmol·L-1 propofol significantly inhibited veratridine-evoked Ca2+-dependent release of glutamate and GABA (P<0.01 or P<0.05). However, propofol has no effect on elevated KCl-evoked Ca2+-dependent release of glutamate and GABA (P>0.05). ②Veratridine- or elevated KCl-evoked Ca2+-independent release of glutamate and GABA was not affected significantly by propofol (P>0.05). Conclusion Propofol could inhibit Ca2+-dependent release of glutamate and GABA. However, it has no effect on the Ca2+-independent release of glutamate and GABA.