title: NMDA and AMPA receptors mediate intracellular calcium increase in rat cortical astrocytes.
abstract: OBJECTIVE
  To study the effect of glutamate on the intracellular calcium signal of pure cultured rat astrocytes and the role of N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors in the procedure.
  
  
  METHODS
  The fluorescence of calcium was measured by Fura-2/AM (F(345)/F(380)).
  
  
  RESULTS
  L-Glutamate induced [Ca(2+)](i) increase in most of the cells in concentration- and time-dependent manner. NMDA 50 mmol/L induced the fluorescence increase by almost three to four times, while the effect of AMPA 50 mmol/L was just half of that of D-(-)-2-amino-5-phosphonopentanoic acid (D-AP-5; a selective antagonist of the NMDA receptor). 6-Cyano-7-nitroquinoxaline-2,3-dione (CNQX, a selective antagonist of the AMPA receptor) abolished the effects of NMDA and AMPA, respectively. D-AP-5 and CNQX simultaneously or respectively attenuated the effect of L-glutamate at different degrees, but could not abolish it entirely.
  
  
  CONCLUSIONS
  Glutamate modulated intracellular Ca(2+) of pure cultured rat astrocytes through different pathways. The activation of NMDA and AMPA receptors took part in the complex mechanisms.
authors.affiliation: Neurology Department, Union Hospital, Tongji College, Huazhong University of Science and Technology, Wuhan 430022, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Hu
authors.forename: Sheng-Gang
authors.initials: SG
authors.lastname: Sun
authors.forename: E-Tang
authors.initials: ET
authors.lastname: Tong
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000166:cytology / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000378:metabolism; D018698:Glutamic Acid / Q000494:pharmacology*; D016202:N-Methylaspartate / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
chemical_list: D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D018698:Glutamic Acid; D016202:N-Methylaspartate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D015763:2-Amino-5-phosphonovalerate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D002118:Calcium