谷氨酸影响星形胶质细胞表达神经生长因子的实验研究

EFFECT OF GLUTAMATE ON PRODUCTION OF NERVE GROWTH FACTOR IN ASTROCYTES

本文利用双向ＥＬＩＳＡ 法定量检测体外培养乳鼠大脑皮质星形胶质细胞在不同浓度的谷氨酸条件培养基中ＮＧＦ的表达分泌量，观察谷氨酸的调节作用，并利用氯胺酮或ＥＧＴＡ 限制谷氨酸ＮＭ ＤＡ 型受体介导的钙离子内流，观察谷氨酸调节作用的改变。结果表明：体外培养的星状胶质细胞２４ ｈ 能表达分泌ＮＧＦ ３．１２３ ｐｇ／１０５ 细胞；１０ μｍ ｏｌ／Ｌ～１ ｍ ｍ ｏｌ／Ｌ的谷氨酸能显著促进ＮＧＦ表达，其中以１００ μｍ ｏｌ／Ｌ的谷氨酸作用为最强，而１０ ｍ ｍ ｏｌ／Ｌ 的谷氨酸反而起抑制作用；限制谷氨酸ＮＭＤＡ 型受体介导的钙离子内流，能消除谷氨酸的这种调节作用。结果提示：谷氨酸可因其浓度不同促进或抑制星形胶质细胞表达ＮＧＦ，这种调节作用可能通过其ＮＭ ＤＡ 受体介导的钙离子内流来实现。

To study the influence of glutamate on nerve growth factor(NGF)production in cultured newborn rat astrocytes. Various concentrations of glutamate conditioned media were applied on purified cultured astrocytes for 24 hours, NGF levels in cultured suspension media were measured by a sensitive two site enzyme linked immunosorbent assay. Astrocytes produced NGF 3.123 pg/10 5 cells/24 hours in vitro, glutamate regulated NGF production in different ways, 10 μmol/L～1 mmol/L glutamate enhanced NGF synthesis dramatically, but 10 mmol/L glutamate decreased NGF level significantly. These effects were diminished by blocked glutamate NMDA receptors or eliminating influx of extracellular Ca 2+ . These results suggest that glutamate, acting via its NMDA receptors, does regulate NGF production in astrocytes in different ways.