INVESTIGADORES
DORFMAN Damian
congresos y reuniones científicas
Título:
Early Distal Axonopathy of the Visual Pathway in Experimental Diabetes
Autor/es:
ROSENSTEIN RE; PASQUINI LA; DORFMAN D; ALDANA MARCOS HJ; FERNANDEZ DC
Lugar:
Fort Lauderdale
Reunión:
Congreso; Association for Research in Vision and Ophthalmology; 2012
Institución organizadora:
Association for Research in Vision and Ophthalmology
Resumen:
Purpose
Diabetic
retinopathy is a leading cause of acquired blindness. Visual function disorders
have been observed in diabetic patients with very early retinopathy or even
before the onset of retinopathy. The aim of the present work was to analyze the
visual pathway in an early stage of experimental diabetes.
Methods
Diabetes was
induced in Wistar rats by an i.p. injection of streptozotocin.
Anterograde transport was examined after an intravitreal injection of cholera
toxin β-subunit. Apoptosis of ganglion cells was examined by TUNEL analysis,
and the optic nerve levels of glial fibrillary acidic protein, platelet-derived
growth factor receptor-α, and myelin basic protein were analyzed by
immunohistochemistry. The optic nerve structure was examined by electron
microscopy.
Results
A deficit in
anterograde transport from the retina to the superior colliculus was observed 6
weeks after streptozotocin injection. At this time point, morphologic studies
did not reveal retinal ganglion cell loss or substantial alterations in the
superior colliculus. The optic nerve was morphometrically evaluated at
intraorbital (unmyelinated and myelinated) and intracranial sections. In
animals that had been diabetic for 6 weeks, a large increase in astrocyte
reactivity occurred in the distal (but not the intraorbital) portion, which
coincided with significant axon loss. Moreover, profound myelin alterations and
altered morphologic features of oligodendrocyte lineage were observed at the
distal (but not the proximal) optic nerve portion.
Conclusions
The present results suggest that axoglial alterations at the distal portion
of the optic nerve could be the first structural change in the diabetic visual
pathway.