黑皮质素4型受体在大鼠脊髓星形胶质细胞释放兴奋性氨基酸中的作用

Role of melanocortin receptor 4 in excitatory amino acid release from rat astrocytes in spinal cord

目的 探讨黑皮质素4型受体（MC4R）在大鼠脊髓星形胶质细胞释放兴奋性氨基酸中的作用.方法 原代培养大鼠脊髓星形胶质细胞,随机分为3组,每组6孔：正常白对照组（C组）、T组和TH组.C组未作任何处理,T组加入终浓度为10μg/L的TNF-α;TH组同时加入终浓度为10μg/L的TNF-α和终浓度为1 μmol/L的MC4R特异性阻断剂HS014.各组孵育3 h后采用高效液相-串联四级杆质谱法检测上清液谷氨酸（Glu）和天门冬氨酸（Asp）的浓度.结果 与C组比较,T组Glu和Asp浓度升高（P＜0.01）,TH组Glu和Asp浓度差异无统计学意义（P＞0.05）;与T组比较,TH组Glu和Asp浓度降低（P＜0.01）.结论 MC4R介导了大鼠脊髓星形胶质细胞释放兴奋性氨基酸的作用.

Objective Role of melanocortin receptor 4 （MCAR） in excitatory amino acid release from rat astrocytes in spinal cord. Methods Astrocytes were isolated from the spinal cord of newborn pathogen-free Wistar rats （ 1-3 days after birth） and cultured in serum-free Neurobasal/B27 liquid culture medium. After 4 passages the primary cultured astrocytes were randomly divided into 3 groups （6 wells each）： group Ⅰ control （group C）; group Ⅱ the astrocytes were exposed to TNF-α 10 μg/L （group T） and group Ⅲ the astrocytes were exposed to TNF-α 10 μg/L and HS014 （selective MC4R antagonist） 1 μmol/L （group TH）. The astrocytes were incubated at 37 ℃ for 3 h. The supernatant was collected for determination of glutamic acid （Glu） and aspartic acid （Asp）concentrations by HPLC-MS/MS. Results TNF-α significantly increased Glu and Asp release from astrocytes in group T as compared with group C. The Glu and Asp concentrations were significantly lower in group TH than in group T. Conclusion MG4R is involved in the excitatory amino acid release from astrocytes in the spinal cord.