title: Age-dependent neuroprotection of retinal ganglion cells by tempol-C8 acyl ester in a rat NMDA toxicity model.
abstract: BACKGROUND
  The efficacy of tempol and its acyl derivative tempol-C8 as retinoprotective agents was compared in a rat model of NMDA-induced retinal ganglion cell (RGC) damage.
  
  
  METHODS
  Tempol or tempol-C8 in different doses was administered intraperitoneally to 6 weeks old (pre-adolescent) and 9-10 weeks old (young adult) rats before and after an intravitreous NMDA injection. Retinal ganglion cell were retrogradely labeled with the fluorescent tracer hydroxystilbamidine and RGC counting was performed on retinal flatmounts.
  
  
  RESULTS
  Intravitreal NMDA reduced RGC counts by about 90%, independently of age < 0.001). In pre-adolescent animals tempol-C8, but not tempol unmodified, showed a significant, dose-dependent RGC rescue effect, with peak activity at 5.8 µmol/kg (p < 0.001). In young adult animals, however, no neuroprotective effect was found for either tempol or tempol-C8.
  
  
  CONCLUSIONS
  In contrast to tempol itself, tempol-C8 acyl ester was neuroprotective in pre-adolescent rats in the NMDA- induced RGC damage model. Therefore, neuroprotection by tempol acyl esters seems to be superior to that of tempol under certain conditions.
authors.affiliation: Dr. Sebastian Thaler, Centre for Ophthalmology, University of Tübingen, Schleichstrasse 12, 72076 Tübingen, Germany, phone: +49 7071 29 83721, fax: +49 7071 29 5018, e-mail: sebastian.thaler@uni-tuebingen.de.
authors.forename: Michal
authors.initials: M
authors.lastname: Fiedorowicz
authors.forename: Robert
authors.initials: R
authors.lastname: Rejdak
authors.forename: Frank
authors.initials: F
authors.lastname: Schuettauf
authors.forename: Michal
authors.initials: M
authors.lastname: Wozniak
authors.forename: Pawel
authors.initials: P
authors.lastname: Grieb
authors.forename: Sebastian
authors.initials: S
authors.lastname: Thaler
mesh_terms: D000375:Aging; D000818:Animals; D003497:Cyclic N-Oxides / Q000494:pharmacology*; D004195:Disease Models, Animal; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity; D016202:N-Methylaspartate / Q000633:toxicity; D018696:Neuroprotective Agents / Q000494:pharmacology*; D051381:Rats; D012165:Retinal Ganglion Cells / Q000187:drug effects* / Q000473:pathology*; D013113:Spin Labels
chemical_list: D003497:Cyclic N-Oxides; D018690:Excitatory Amino Acid Agonists; D018696:Neuroprotective Agents; D013113:Spin Labels; D016202:N-Methylaspartate; C001803:tempol