"The role of L-arginine in the functioning of the antioxidant system of depressed rats"

Author: Temuri Mantashashvili
Keywords: Depression, L-arginine, corticosterone, hippocampus, antioxidant enzymes, NO
Annotation:

Effects of dietary L-arginine on corticosterone-induced depression on some physiological parameters and antioxidant systems of white male laboratory rats were studied. It was shown that the daily intake of L-arginine for 14 days at a dose of 150 mg/kg significantly reduced the signs of depression caused by the administration of corticosterone, in particular, there was an improvement in the cognitive functions caused by depression, and there was also an increase in the amount of serotonin and dopamine that was reduced as a result of depression in the prefrontal cortex and hippocampus of the brain. in cells. Changes are also observed in the case of the forced swimming test, in particular, under the conditions of arginine administration, there is an improvement in the depressive state. In order to elucidate the mechanism of the antidepressant effect of dietary L-arginine in the brain, quantitative changes in nitric oxide (NO) and lipid peroxidation products, namely malondialdehyde, were studied. As a result of depression, the increased amount of these compounds is reliably reduced when taking L-arginine. Along with the reduction of lipid peroxidation products and NO, as a result of L-arginine intake, there is also an increase in enzymes of the antioxidant system, such as mitochondrial superoxide dismutase (SOD) and catalase, whose activity is reduced in the brain cells of depressed individuals. The study of the kinetic parameters (Vmax, Km) of the mentioned enzymes showed that L-arginine increases only the maximum speed in the conditions when their property to the substrate remains unchanged. Based on the above, the activating effect of L-arginine on the activity of enzymes of the antioxidant system in depression caused by corticosterone administration is not caused by their structural changes, but by increasing the intensity of their synthesis.