Determination of intracellular Ca2+ concentration can be a useful tool to predict neuronal damage and neuroprotective properties of drugs.
The purpose of the present study was to examine the relationship between elevation in intracellular Ca2+ concentration ([Ca2+]i) and development of neuronal damage after cytotoxic hypoxia in vitro. Chick telencephalic neurons were exposed to NaCN 1 mM for up to 2 h. [Ca2+]i was assessed by means of fura-2 based microfluorometry and viability was measured by means of trypan blue exclusion on the same relocated cells for a period 24 h after initiation of hypoxia. Exposure to sodium cyanide resulted in an up to 10 fold increase in [Ca2+]i and led to subsequent neuronal damage. According to [Ca2+]i and viability neurons in four different stages could be revealed. The percentage of neurons showing elevated [Ca2+]i paralleled exactly the percentage of neuronal damage. The elevation in [Ca2+]i clearly preceded neuronal damage suggesting a time window for pharmacological intervention. The NMDA antagonists dizocilpine, memantine and amantadine were capable of reducing the percentage of neurons showing elevated [Ca2+]i and attenuated neuronal damage. Dizocilpine proved to be the most potent and amantadine to be the weakest antagonist whereas the alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionate (AMPA) antagonist 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo-(F)-quinoxaline (NBQX) was ineffective. Under our experimental conditions, measurement of [Ca2+]i was able to predict the extent of neuronal damage as well as the neuroprotective potency of drugs.
Institut für Pharmakologie und Toxikologie, Philipps-Universität, Marburg, Germany.
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D
Ferger
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J
Krieglstein
D000547:Amantadine / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D015415:Biomarkers; D002118:Calcium / Q000032:analysis* / Q000378:metabolism; D015687:Cell Hypoxia; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002645:Chickens; D016291:Dizocilpine Maleate / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D007700:Kinetics; D008559:Memantine / Q000494:pharmacology; D016202:N-Methylaspartate / Q000037:antagonists & inhibitors; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000473:pathology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D011810:Quinoxalines / Q000494:pharmacology; D012966:Sodium Cyanide / Q000633:toxicity*; D013687:Telencephalon / Q000166:cytology*; D013997:Time Factors
D015415:Biomarkers; D018691:Excitatory Amino Acid Antagonists; D018696:Neuroprotective Agents; D011810:Quinoxalines; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D016202:N-Methylaspartate; D016291:Dizocilpine Maleate; D000547:Amantadine; D012966:Sodium Cyanide; D002118:Calcium; D008559:Memantine