Objective    To investigate the effect of reduced glutathione (rGSH) on the retina and optic nerve in rats with experimental optic neuritis

and the underlying mechanism.     Methods    Animal model of experimental allergic encephalomyelitis (EAE)

which was as used for acute demyelinating optic neuritis were established in 48 female SD rats

and then the rats were randomly divided into EAE group (n=18) and GSH group  (n=30). Another 6 female SD rats served as normal control. Rats of GSH group received an intraperitoneal injection of

100 mg·kg

-1

·d

-1

GSH for 14 d from the beginning of immunization

while the rats of EAE group were given saline alternatively. To observe pathological changes in the optic nerve

retinal ganglion cells (RGCs) apoptosis

and measure malondialdehyde (MDA)

glutathione peroxidase (GSH-PX)

nitric oxide (NO) levels in the retina were observed and measured in the early period

peak period and recovery period (12 to 14 d

16 to 18 d

or 26 to 28 d after the immunization) of the neuritis.     Results    There were 18 rats (60%) from GSH group having the disease with a symptom score of 1 to 3. Compared with those of EAE group

their optic nerve fibers were in a comparatively good order

and more glial cells and not obvious demyelination were observed in morphology; Significant lesser apoptotic RGCs were observed in GSH group than in EAE group at the early and peak period (P0.01); The retinal contents of MDA and NO were decreased and the activity of GSH-PX was increased

in comparison with EAE group (P0.05).     Conclusion    GSH reduces the incidence of EAE and symptoms score

inhibits apoptosis of RGCs

reduces the retinal contents of MDA and NO

and enhances the vitality of GSH-PX in the retina. GSH exerts protective effect on the retina and optic nerve in experimental optic neuritis.