ВПЛИВ СВІТЛОВОГО РЕЖИМУ НА ЕСТРАЛЬНИЙ ЦИКЛ САМИЦЬ ЩУРІВ

We studied the reproductive function of female rats at different modes of artificial lighting cytological picture of the estrous cycle. In the conducted research,  showed that artificially increasing the duration and constant performance lighting as biogenic external environmental factors, leading to changes in the design of the estrous cycle mature female rats. The animals, which were under constant artificial light (in the group) and under 12-hour lighting (12/12-group) observed a statistically significant prolongation of the estrous cycle due to the growth stage of estrus, including estrus, proestrus and also between estrus phase of the cycle compared to the original data. In the control group of animals that were kept under natural light, during an experimental period and phase structure of the estrous cycle has not changed. It is likely that the artificial extension  of coverage for a few hours and constant lighting leads to hormonal imbalance, a key mechanism here is the change in threshold sensitivity to inhibition of the hypothalamic estrogen. This cyclical production of gonadotropins, prolactin, estrogen and progesterone, which characterizes the normal reproductive period of life, reconstructed on acyclic mechanism. Key words:  lightening. estralcycle, estrus,diestrus.