[The influence of melatonin and epithalon on blood leukocyte count and leukocyte alkaline phosphatase in rats under different lighting conditions during ontogenesis].

The effect of pineal body hormone melatonin and synthetic tetrapeptide epithalon (Ala-Glu-Asp-Gly) under different light conditions on leucocytes differential count in rats were investigated. It has been established that melatonin and epithalon decrease the level of blood leucocytes and relative content of band neutrophils in 12 months rats which was higher in the constant light more than in other photoperiod. The melatonin prevents age-specific decreasing blood lymphocytes level in standard photoperiod (12 h light/12 h darkness). Contrary to melatonin, epithalon significantly reduces the number of lymphocytes and increases the number of neutrophils in some age period. The leucocytes alkaline phosphatase activity was increased during aging. Constant light in compare with other light conditions promotes early increasing of alkaline phosphatase activity (at 12 months), associated with accelerated development of pathological process in organism. The melatonin and epithalon adjacency effect on increasing of alkaline phosphatase activity under the standard as well as natural light condition demonstrate homeostatic character of geroprotectors action furthermore depend on leucocytes functional status.

[Age related changes in rat blood leucocyte count and morpho-metrical parameters of large granular lymphocytes under different light regimens].

The effect of different light conditions on the age related level of blood leucocytes, leucocytes differential count and the morpho-metrical parameters of large granular lymphocytes in rats was investigated. It has been found that the senescent animals demonstrate disturbance in typical lymphocytes/ neutrophils ratio under condition with light and darkness changes natural and regular illumination. The total leucocytes number, the level of neutrophilic bands, eosynophils and large granular lymphocytes increased under continuous light illumination and natural photoperiod in Karelia. The comparatively lower level of lymphocytes and higher of neutrophils was formed earlier under light conditions without light and dark interchange, i.e. under long time light deprivation (DP) and under constant illumination (LL).