Effect of lipid-hydroperoxide-induced oxidative stress on vitamin E, ascorbate and glutathione in the rabbit retina.
BACKGROUND
It is possible that oxidative stress causes several retinal diseases. However, the natural biogenic role of antioxidants in the retina is not clear.


OBJECTIVE
This study investigates the change in concentration of vitamin E (VE), ascorbate and glutathione (GSH) in the retina following vitreous injection of 600 mug 18:2 linoleic acid hydroperoxide (LHP) in male New Zealand rabbits.


METHODS
LHP was injected above the retinal surface. The animals were sacrificed and the eyes enucleated before LHP injection, 1, 3, 6, 12, 24 h and 4 and 7 days after LHP injection. Retinas were removed, VE and ascorbate measured by HPLC, and GSH determined by a fluorometric method.


RESULTS
The concentration of VE in the retina decreased from pretreatment levels of 154.6 +/- 29.7 nmol/g wet weight (n = 7) and was lowest at 6 h (61.1 +/- 18.1 nmol/g wet weight, n = 4, p < 0.05), then increased gradually, returning slowly to pre-LHP levels by 7 days. The concentration of ascorbate in control retinas decreased at 6 h from pretreatment levels of 7.33 +/- 0.93 micromol/g wet weight (n = 7) to 2.74 +/- 0.16 micromol/g wet weight (n = 4, p < 0.05) and returned to pretreatment levels rapidly by 24 h after injection. The concentration of GSH in retinas decreased from baseline levels of 109.53 +/- 8.19 microg/g wet weight (n = 9), was lowest at 12 h (72.40 +/- 11.17 microg/g wet weight, n = 5, p < 0.05) and returned to pretreatment levels by 7 days.


CONCLUSIONS
The results suggest that intravitreous LHP injection is a contributor to oxidative stress in the rabbit retina by causing a reduction in antioxidant capacity.
Kamegawa
Maki
M
Department of Ophthalmology, School of Medicine, Showa University, Tokyo, Japan.
Nakanishi-Ueda
Takako
T
Iwai
Shinichi
S
Ueda
Toshihiko
T
Kosuge
Shotaro
S
Ogura
Hirotsugu
H
Sasuga
Keiko
K
Inagaki
Masahiro
M
Watanabe
Masanobu
M
Oguchi
Katsuji
K
Yasuhara
Hajime
H
Armstrong
Donald
D
Koide
Ryohei
R
D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D005978:Glutathione / Q000378:metabolism*; D007267:Injections; D008041:Linoleic Acids / Q000494:pharmacology*; D008054:Lipid Peroxides / Q000494:pharmacology*; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects*; D011817:Rabbits; D012160:Retina / Q000187:drug effects* / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D014810:Vitamin E / Q000378:metabolism*
D015415:Biomarkers; D008041:Linoleic Acids; D008054:Lipid Peroxides; D014810:Vitamin E; C008285:linoleic acid hydroperoxide; D005978:Glutathione; D001205:Ascorbic Acid