INVESTIGADORES
DORFMAN Damian
congresos y reuniones científicas
Título:
Retinal neuroprotection against ischemia/reperfusion damage induced by global and local hypothermia
Autor/es:
SALIDO EM; DORFMAN D; CHIANELLI MS; ROSENSTEIN RE
Reunión:
Congreso; Society for Neuroscience Annual Meeting 2013; 2013
Resumen:
Purpose: Retinal
ischemia could provoke blindness. There is no effective treatment against
retinal ischemic damage. We investigated whether a brief global or local
hypothermia could induce ischemic tolerance in the rat retina.
Methods: Ischemia was induced in male Wistar rats by increasing
intraocular pressure to 140 mm Hg for 50 minutes. One day before ischemia,
animals underwent a 20-minute period of hypothermia by lowering the whole body
temperature to 32ºC or by cooling only one eye to 25ºC for 30 min. Two weeks
after ischemia, animals were subjected to electroretinography (ERG) and
histological analysis. Moreover, glutamate uptake was assessed using 3H-glutamate,
and glutamine synthetase activity was assessed by a spectrophotometric assay.
Results: Retinal ischemia induced a significant decrease in oscillatory
potentials, and scotopic ERG a- and b-wave amplitude, which was significantly
prevented by global or monocular hypothermia. Retinal ischemia induced a
significant decrease in glutamate uptake and glutamine synthetase activity,
whereas monocular hypothermia prevented the effect of ischemia on glutamate
recycling. The intravitreal injection of supraphysiological concentrations of
glutamate mimicked electroretinographic and histological alterations provoked
by ischemia, which were significantly abrogated by hypothermic preconditioning.
Conclusions: These results indicate that hypothermia significantly protected
retinal function and histology against ischemia/reperfusion injury. Hypothermic
preconditioning could provide a relatively low-risk approach for treating
retinal ischemic pathologies.