谷氨酸对视网膜内层神经细胞影响的研究

目的探讨谷氨酸对视网膜内层神经细胞(inner stratum retinal neurons, ISRN)的影响及其毒性作用的量效关系。方法将30只新生小鼠神经层视网膜组织块均匀接种于2块24孔培养板(48孔)，将其 分成正常对照组、谷氨酸作用24 h组和正常培养18 h后，谷氨酸继续作用6 h组。培养24 h 后， 将视网膜组织块常规进行切片，HE染色，油镜下观察视网膜神经节细胞层(retinal ganglion cells, RGCs)和内核层(inner nuclear layer, INL)的细胞形态，并分别计算细胞形态正常的RGCs数和INL细胞数 。结果视网膜组织正常培养24 h后，ISRN(RGCs和INL细胞)中可见少数细胞胞核固缩和坏死。谷氨酸作用24 h组：当谷氨酸浓度为2、4 mmol时，ISRN的细胞形态与对照组之间差异无显著性意义(P>0.05)；谷氨酸浓度≥6 mmol，视网膜内层形态正常的神经细胞数量明显较对照组减少(P<0.05)，且随着谷氨酸浓度的增加，其数量逐渐减少。谷氨酸后6 h作用组：谷氨酸浓度为6 mmol时，INL中形态正常的细胞数量明显较对照组减少(P <0.05)，而RGCs层中形态正常的细胞数量与对照组之间差异无显著性的意义(P>0.0 5)； 谷氨酸浓度≥8 mmol时，RGCs层和INL中形态正常的细胞数量均较对照组明显减少(P<0. 05)。 结论谷氨酸对离体视网膜内层神经细胞具有毒性作用,其毒性作用呈剂量依赖性。(中华眼底病杂志,2001,17:311-314)

The experimental study of glutamate neurotoxicity on inner stratum retinal neurons

ObjectiveTo investigate the glutamate toxicity on inner stratum retinal neurons(ISRN) and the neurotoxicity quantity-efficacy relation.MethodRetinal explants obtained from 30 neonatal mices were implanted into two pieces of 24-well culture plates (48 wells). The 48 wells were divided into three groups: control group, glutamate exposure 24 h group, and glutamate exposure with further lasting 6 h group. The retinal explants were sectioned, and then stained with HE after 24 h in vitro. The cells in retinal ganglion cells (RGCs) layer and inner nuclear layer (INL) were analyzed by light microscope at 1 000× magnification , and the number of normal morphological cells was counted under three 1 000× magnificat ion fields.ResultsSome cells in ISRN (include RGCs and INL c ells) showed pykno tic nuclei and necrosis after 24 h in control culture. Glutamate exposure 24 h group:at the 2 mmol and 4 mmol concentrations of glutamate, the situation of the normal morphological cells in ISRN had no difference from that of the control group (P>0.05). At the concentration of glutamate more than or equal to 6 mmol, the number of normal morphological cells in ISRN was significantly less than that of the control group (P<0.05), and with the increase of glutamate concentration, the number of normal morphological cells was reduced. Glutamate exposure with fur ther lasting 6 h group: at the concentration of glutamate equal to 6 mmol, the n umber of normal morphological cells in INL was significantly less than that of the control group (P<0.05), while the number of normal morphological cells in RGCs layer had no difference between two groups (P>0.05). At the concentration of glutamate more than or equal to 8 mmol, the number of normal morphological cels in RGC s layer and INL was significantly less than that of the control group (P<0.05 ).ConclusionGlutamate has the neurotoxicity for ISRN in vitro, and the effect is dose-dependant.(Chin J Ocul Fundus Dis, 2001,17:311-314)