Dietary deficiency of vitamin E aggravates retinal ganglion cell death in experimental glaucoma of rats.
OBJECTIVE
Investigate the effect of dietary vitamin E (Vit E) on the retinas of a rat model of induced glaucoma, in which surgically induced elevation of intraocular pressure (IOP) is associated with an increase in reactive oxygen species.


METHODS
Rats were fed a standard chow, Vit E-supplemented diet, or Vit E-deficient diet and subjected to surgically induced IOP elevation (or sham surgery) for five weeks. The retinal ganglion cells (RGCs) were subjected to retrograde fluorescent tracer labeling.


RESULTS
The mean number of RGCs of rats on the standard chow, Vit E-supplemented diet, and Vit E-deficient diet were 79.6%, 78.6%, and 71.3% of controls, respectively. Lipid peroxidation of the retinas of rats given a Vit E-deficient diet were significantly higher after IOP elevation for three days (14.42 +/- 0.25 microM, P = 0.016) and five weeks (10.46 +/- 0.11 microM, p = 0.042), compared to rats given standard chow (11.37 +/- 0.31 microM; 8.95 +/- 0.16 microM). Compared with rats given standard chow, rats given a Vit E-deficient diet had significantly elevated concentrations of glutathione (p = 0.032), but no significant differences in the levels of total superoxide dismutase (SOD), Cu/Zn SOD, or catalase activities three days after IOP elevation.


CONCLUSIONS
Rats fed a Vit E-deficient diet with surgically induced IOP elevation experience significantly more RGC death than rats fed a normal diet. This phenomenon may be related to the increased level of lipid peroxidation in Vit E-deficient rats.
Ko
Mei-Lan
ML
Department of Ophthalmology, General Hsin-Chu Hospital, Hsinchu, Taiwan.
Peng
Pai-Huei
PH
Hsu
Shens-Yao
SY
Chen
Chau-Fong
CF
D000818:Animals; D017209:Apoptosis; D002374:Catalase / Q000378:metabolism; D002452:Cell Count; D004032:Diet; D004195:Disease Models, Animal; D005260:Female; D005901:Glaucoma / Q000150:complications* / Q000175:diagnosis / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D007429:Intraocular Pressure; D015227:Lipid Peroxidation; D008054:Lipid Peroxides / Q000378:metabolism; D018384:Oxidative Stress; D051381:Rats; D017208:Rats, Wistar; D012162:Retinal Degeneration / Q000175:diagnosis / Q000209:etiology* / Q000378:metabolism; D012165:Retinal Ganglion Cells / Q000473:pathology*; D013482:Superoxide Dismutase / Q000378:metabolism; D014810:Vitamin E / Q000097:blood; D014811:Vitamin E Deficiency / Q000150:complications*
D008054:Lipid Peroxides; D014810:Vitamin E; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione