腹腔注射L-丝氨酸后大鼠梗死侧脑皮质L-丝氨酸与D-丝氨酸含量的测定

目的:制作大鼠永久性脑梗死模型,腹腔注射L-丝氨酸,测定梗死侧大脑皮质L-丝氨酸与D-丝氨酸含量的变化,为应用L-丝氨酸辅助治疗脑梗死提供方法学上的依据。方法:利用邻苯二甲醛及N-乙酰半胱氨酸柱前衍生,高效液相色谱荧光检测法测定脑组织中L-丝氨酸与D-丝氨酸含量。结果:流动相A为82%0.1 mol·L-1磷酸盐缓冲液,流动相B为18%甲醇条件下,L-丝氨酸与D-丝氨酸得到很好的分离;腹腔注射L-丝氨酸1 h后,梗死侧脑皮质L-丝氨酸含量迅速增加,2 h即达高峰(6.85±0.30)μmol·g-1],为正常脑组织的4倍以上,12 h时仍是正常的2倍以上水平(3.56±0.22)vs(1.52±0.04)μmol·g-1];D-丝氨酸水平升高缓慢,升高幅度低,6 h时达高峰,为正常的2倍多(0.75±0.05)vs(0.32±0.01)μmol·g-1]。结论:腹腔注射L-丝氨酸能快速升高梗死侧大脑皮质L-丝氨酸水平,对D-丝氨酸影响相对较小。

Determination of L-serine and D-serine in the cerebral cortex ipsilateral to the infarcted side of rat after intraperitoneal injection of L-serine

Objective:Permanent middle cerebral artery occlusion(pMCAO) were induced in rats to determine the concentration of L-serine and D-serine in the cerebral cortex ipsilateral to the ischemic side after intraperitoneal injection of L-serine,in order to afford the methodological basis in the therapeutic use of L-serine for cerebral ischemia.Methods:High performance liquid chromatography with UV-fluorescence detection was used to analyze the content of L-serine and D-serine after derivatizating with o-phthaldialdehyde/N-acetyl-L-cysteine.Results:Under the condition of mobile phase A:82% 0.1 mol·L-1 phosphate buffer,and mobile phase B:18% methanol,precise separation of L-serine and D-serine was achieved.The concentration of L-serine in the cerebral cortex ipsilateral to ischemic side of rat brain increased rapidly with L-serine injection 1 h later,reached the peak level at 2 h(6.85±0.30 μmol·g-1),and was more than 2 times over the normal brain tissue at 12 h(3.56±0.22 vs 1.52±0.04 μmol·g-1);but the level of D-serine increased later and slightly with the peak level reaching at 6 h after L-serine injection and being more than 2 times over the normal brain tissue(0.75±0.05 vs 0.32±0.01 μmol·g-1).Conclusions:Intraperitoneal injection of L-serine can quickly increase the level of L-serine in the ischemic cerebral cortex,but has much weak effect on the level of D-serine.