Lipid peroxidation in rabbit and rat visual system structures

: In our work, the lipid peroxidation (LPO) in the retina, optic chiasma, and visual cortex of rat and rabbit brain was investigated. The contents of the LPO products (diene conjugates, triene conjugates, TBA-reactive products, Schiff bases) and oxidation index (calculated as 232/2 15) were similar in the retina and visual brain cortex of rats. In vivo, lipid oxidation in the optic chiasma was higher as compared with two other parts of visual tract. The similar data were obtained in our experiments with rabbit's visual tract. The sensitivity of tissues to peroxidation in vitro was studied in homogenates incubated with 0.2 mM ascorbate and 10 mkM FeSO4 for 20 min at 37 degrees C. The results of these experiments deviated from the data obtained in vivo, namely: the LPO in optic chiasma was lower than in the retina and the brain cortex. This data are in compliance with lipid composition of investigated parts of the visual tract of both animals. In our opinion, the high level of LPO in optic chiasma demonstrated in vivo is due to low antioxidants level in this part of the visual tract. Our findings also indicate that LPO in retina both in vivo and in vitro experiments are similar to those in the brain cortex and may be attributed to similar lipid composition and activity of antioxidant enzymes (such as superoxiddismutasa and glutathionereductase).