压力对体外培养大鼠视网膜Müller细胞的影响

目的　探讨压力作用下体外培养的大鼠Müller细胞形态、活性和谷氨酸代谢功能是否有改变,以明确Müller细胞在青光眼损伤过程中的作用。方法　将体外培养的大鼠Müller细胞随机分为对照组和加压处理组,加压组在50mmHg(1mmHg=0. 133kPa)压力下处理1h,然后两组细胞继续培养3d后,使用倒置显微镜和电镜观察细胞的形态,MTT比色法测定两组细胞的活性,RT PCR法检测两组细胞内谷氨酰胺合成酶mRNA表达,并用图像分析系统测定吸光度值。结果　体外培养的Müller细胞经压力处理后与对照组相比倒置显微镜下改变不明显,电镜下可见细胞内空泡增多,线粒体肿胀;MTT比色法显示细胞活性降低,差异有统计学意义(P<0 05); RT PCR法示细胞内谷氨酰胺合成酶mRNA表达减少,差异有统计学意义(P<0 .05)。结论　经压力处理后体外培养的Müller细胞有损伤的改变,细胞由于谷氨酸谷氨酰胺循环中的关键酶谷氨酰胺合成酶mRNA表达减少而代谢谷氨酸的能力下降,这可能是青光眼玻璃体中谷氨酸浓度升高的原因之一。

The experimental study of effect of pressure on rat retinal Muller cell in vitro

Objective To observe the changes of morphology, activity and ability of metabolizing glutamate in Muller cell and investigate the role of Muller cell in the damage induced by glaucoma. Method Cultured Muller cells were divided into two groups at random, one was control group without any treatment, in the experimental group the cells were cultured under pressure of 50 mm Hg(1 mm Hg=0.133 kPa) for 1 hour, after 3 days additional incubation, the morphology of the cells in two groups was observed by inverse phase microscope and electron microscope, the cells survival were evaluated by MTT colorimetry assay and the expression of mRNA of glutamine synthetase was semi-quantified by RT-PCR. Result No obvious morphology changes were found by inverse phase microscope in the two groups, swelling mitochondrion and Vacuoles in cytoplasm were found in pressured group by electron microscope; the numbers of MTT reading and the mRNA expression in the cells under pressure were decreased, the differences was statistic significance compared with control( P <0.05). Conclusion Morphology changes were found in the cells under pressure, and the ability of metabolizing glutamate was decreased, which may be one of the reasons of the elevated level of glutamate in the vitreous of glaucoma patients.