Anti-excitotoxic activity of trimetazidine in the retina.
The purpose of this study was to investigate the mechanism of the neuroprotective activity of trimetazidine in animal retina stressed by ischemia or kainate. Flash electroretinograms were recorded in guinea pigs after ischemia, induced by an acute increase in the intraocular pressure (IOP), or after an intravitreal injection of kainate. Treatment with trimetazidine per os afforded a significant protection of the electroretinogram against the ischemic as well as the excitotoxic insult as an antioxidant (dimethylthiourea) and a nitric oxide synthase inhibitor (nitroarginine) did. The effect of the drug on the extracellular accumulation of glutamate induced by chemical ischemia was studied by incubating rat retina in vitro. Trimetazidine was able to inhibit the extracellular glutamate accumulation, which represents the first step of the excitotoxic phenomenon. Then the compound activity on the glial uptake of glutamate was studied in a rat Müller cell line (rMC-1) in culture. Chemical ischemia inhibited the active 3H-glutamate transport, an effect that was reversed by trimetazidine, at micromolar concentrations. These results demonstrate that trimetazidine which is recognized as an efficient drug against ischemic injuries, is also capable of protecting the retina against excitotoxicity by reducing ischemia-induced accumulation of glutamate due in particular to glial transporter inhibition.
Laboratoire de Physiologie Cellulaire, UMR CNRS 5074, Faculté de Pharmacie, Université Montpellier 1, Montpellier, France.
Olivier
O
Payet
Christine
C
D'Aldin
Laurence
L
Maurin
Claude
C
Bonne
Agnès
A
Muller
D000284:Administration, Oral; D000818:Animals; D002460:Cell Line; D004195:Disease Models, Animal; D004596:Electroretinography; D018691:Excitatory Amino Acid Antagonists / Q000627:therapeutic use*; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D006168:Guinea Pigs; D007511:Ischemia / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D007608:Kainic Acid / Q000633:toxicity; D051381:Rats; D017208:Rats, Wistar; D012160:Retina / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D012164:Retinal Diseases / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D014292:Trimetazidine / Q000627:therapeutic use*
D018691:Excitatory Amino Acid Antagonists; D018698:Glutamic Acid; D014292:Trimetazidine; D007608:Kainic Acid