Introduction. Diabetic retinopathy pathogenesis includes mechanisms of free radical generation and intensification of lipid peroxidation. It was shown that stimulation of cerbellar structures is able both to alleviate intensified lipid peroxidation and cause neuroprotective action in neuronal tissue.
The aim was to investigate the total level of nitrites and nitrates as well as the level of malone dialdehyde in retina of rats with modeled streptozotocin — induced diabetes and to determine their peculiarities under conditions of paleocerebellar cortex electrical stimulations.
Methods of investigations. In Wistar rats diabetes have been modeled via i. p. streptozotocin administration (50.0 mg/kg, i. p.). Electrical stimulations (100 Hz, 0.25 ms, 50–100 mcA, 2.5 s) of paleocerebellar cortex (V–VII lobules), which have been delivered during one month daily starting 15 days from the moment of streptozotocin administration. In 1.5 months from the moment of streptozotocin injection in the retina homogenate total nitrate and nitrite levels were measured using the Griess reaction method with spectrophotometry at 540 nm. Malondialdehide was determined using thiobarbituric acid, and spectrophotometrical measurements at 532 nm.
Results of investigations. The content of nitrate/nitrites in the retina of false-operated control group of rats was (17.5±0.12) mcMol/mg of protein, malondialdehide — (2.01±0.30) nMol/mg of protein. In rats suffered from diabetes mentioned indices have increased by 2.14 and 3.1 times correspondently, when compared with control ones (p<0.05). Three times per day cerebellar stimulations caused the decreasing of the nitrite level in retina by 43.1% and malondialdehide two-times when compared with not-treated diabetic rats (p<0.05).
Conclusions. Streptozotocin-induced diabet is followed by oxidative stress in retina, which is manifested in elevated level of nitrate/nitrites along with elevation of malondialdehide. Electrical stimulation of paleocerebellum prevented increasing of the indices of oxidative stress in diabetic rats, and this effect is more pronounced in case of ES delivered three times daily.