Strategies for neuroprotection against L-trans-2,4-pyrrolidine dicarboxylate-induced neuronal damage during energy impairment in vitro.
Increased levels of extracellular excitatory amino acids and failure of energy metabolism are two conditions associated with brain ischemia. In the present study we have combined the simultaneous inhibition of glutamate uptake and mitochondrial electron transport chain to simulate neuronal damage associated with brain ischemia. Results show that cerebellar granule neurons are not vulnerable to transient glutamate uptake inhibition by L-trans-pyrrolidine-2,4-dicarboxylate (PDC) despite the increase in the extracellular concentration of glutamate, unless they are simultaneously exposed to the mitochondrial toxins 3-nitropropionic acid (3-NP) or sodium azide. Cell damage was assessed by light microscopy observation, by reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and by the fluorescent markers for live and dead cells, calcein and ethidium homodimer, respectively. The protective effect of alternative energy substrates, such as pyruvate, acetoacetate, and beta-hydroxybutyrate against PDC-induced neuronal death during 3-NP exposure was studied and compared to the effects of the antioxidant vitamin E, the spin trapper alpha-phenyl-N-tert-butylnitrone (PBN), voltage-dependent calcium channel antagonists, and glutamate receptor antagonists. Results show that neuronal damage can be efficiently prevented in the presence of pyruvate and the N-methyl-D-aspartate (NMDA) receptor antagonist MK-801, whereas the non-NMDA receptor antagonist NBQX, acetoacetate, vitamin E, and PBN showed partial protection. In contrast, beta-hydroxybutyrate and voltage-dependent calcium channels blockers did not show any protective effect at the concentrations tested.
García
O
O
Departamento de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., México.
Massieu
L
L
D000818:Animals; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002531:Cerebellum / Q000187:drug effects / Q000378:metabolism; D004396:Coloring Agents / Q000378:metabolism; D003292:Convulsants / Q000494:pharmacology; D003497:Cyclic N-Oxides; D003998:Dicarboxylic Acids / Q000494:pharmacology*; D004734:Energy Metabolism / Q000187:drug effects* / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018698:Glutamic Acid / Q000187:drug effects* / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology*; D014179:Neurotransmitter Uptake Inhibitors / Q000494:pharmacology*; D009574:Nitro Compounds; D009589:Nitrogen Oxides / Q000494:pharmacology; D011422:Propionates / Q000494:pharmacology; D011759:Pyrrolidines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D019810:Sodium Azide / Q000494:pharmacology; D013778:Tetrazolium Salts / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism; D014810:Vitamin E / Q000494:pharmacology
D004396:Coloring Agents; D003292:Convulsants; D003497:Cyclic N-Oxides; D003998:Dicarboxylic Acids; D004791:Enzyme Inhibitors; D018696:Neuroprotective Agents; D014179:Neurotransmitter Uptake Inhibitors; D009574:Nitro Compounds; D009589:Nitrogen Oxides; D011422:Propionates; D011759:Pyrrolidines; D013778:Tetrazolium Salts; D013844:Thiazoles; D014810:Vitamin E; C029217:phenyl-N-tert-butylnitrone; D018698:Glutamic Acid; D019810:Sodium Azide; C083486:pyrrolidine-2,4-dicarboxylic acid; C022616:thiazolyl blue; C015392:3-nitropropionic acid