Oxidative stress and antioxidant activity in orbital fibroadipose tissue in Graves' ophthalmopathy.
OBJECTIVE
To investigate the oxidative stress and antioxidant activity in the orbit in Graves' ophthalmopathy (GO).


METHODS
Orbital fibroadipose tissue samples were obtained from 13 cases during orbital fat decompression surgery. All cases demonstrated features of moderate or severe GO according to the European Group on Graves' Orbitopathy classification. The disease activity was evaluated with the Clinical Activity Score, and the clinical features of GO were evaluated with the Ophthalmopathy Index. Orbital fibroadipose tissue samples of 8 patients without any thyroid or autoimmune disease were studied as controls. In the tissue samples, lipid hydroperoxide level was examined to determine the level of oxidative stress; glutathione level to determine antioxidant level; superoxide dismutase, glutathione reductase, and glutathione peroxidase activities to determine antioxidant activity.


RESULTS
Lipid hydroperoxide level and all three antioxidant enzyme activities were found to be significantly elevated, while glutathione level significantly diminished in tissue samples from GO cases compared to controls (p < 0.05). Glutathione levels in tissue samples of GO cases showed negative correlation with Ophthalmopathy Index (r = -0.59, p < 0.05).


CONCLUSIONS
The antioxidant activity in the orbit is enhanced in GO. However, the oxidative stress appears to be severe enough to deplete the tissue antioxidants and leads to oxidative tissue damage. This study may support the possible value of antioxidant treatment in GO.
Gazi University Medical School, Department of Ophthalmology, Ankara, Turkey. ahondur@yahoo.com
Ahmet
A
Hondur
Onur
O
Konuk
Aylin Sepici
AS
Dincel
Ayse
A
Bilgihan
Mehmet
M
Unal
Berati
B
Hasanreisoglu
D000273:Adipose Tissue / Q000378:metabolism*; D000975:Antioxidants / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D019299:Decompression, Surgical; D005260:Female; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D049970:Graves Ophthalmopathy / Q000145:classification / Q000378:metabolism* / Q000601:surgery; D006801:Humans; D008054:Lipid Peroxides / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009915:Orbit / Q000378:metabolism*; D018384:Oxidative Stress; D013482:Superoxide Dismutase / Q000378:metabolism
D000975:Antioxidants; D008054:Lipid Peroxides; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005978:Glutathione