[Pro- and antioxidant effect of electromagnetic fields of extremely high frequency (460 MHz) on brain tissues in experiment].

The article concerns biological effects of non-ionized electromagnetic irradiation which is considered in modern world as a serious ecological factor. Influence of decimetric microwave irradiation (460 MHz) on free radical processes in the rat brain tissues--visual cortex and hypothalamus--were investigated. Oxidative effects of both lipid peroxidation and specific activity of glutathione reductase were determined.

[The role of melanin in regulating free radical processes in the epithelial eye pigment in acute hypoxia].

Retinal response to the acute hypoxia and reoxygenation were shown to be independent of melanin presence in the eye pigmental epithelium (PE), i.e. in the retinas of both pigmented animals and albinos hypoxia survived an increase in the content of hydroperoxidases and malonyl dialdehyde; subsequent reoxygenation resulted in a more considerable accumulation of lipid peroxidation (LPO) products in both retinal types.

[Effect of melanin on the free-radical states of gamma-irradiated proteins and lipids].

It was shown that the concentration of paramagnetic centres of dihydroxyphenylalanine-melanin increased after gamma-irradiation (60Co) both at room temperature (an irreversible increase) and at 77 K (a reversible increase). The accumulation of paramagnetic centres in gamma-irradiated albumin at room temperature was found to slow down appreciably in the presence of melanin. This effect is thought to be associated with the antiradical activity of the pigment.

[Glutathione peroxidase activity of frog eye pigment epithelium].

A highly active glutathione peroxidase (80% of which is localized in the water-soluble fraction) was detected in frog eye pigment epithelium tissue. It was shown that more than 75% of the glutathione peroxidase activity of the pigment epithelium tissue is bound to the Se-dependent enzyme. The Km values for glutathione and tret-butyl hydroperoxide were determined.