[GLUCOSE CONTENT FLUCTUATION IN BLOOD OF NEWBORN RATS DEPENDING ON SEASON AND PATTERN OF SPONTANEOUS MOTOR ACTIVITY]

Earlier we have shown that in newborn rats the glucose level in blood serum changes depending on the pattern of spontaneous periodic motor activity (SPMA). During rest periods, both under dominant decasecond rhythm and under dominant minute rhythm, the glucose level in blood serum is higher than during activity periods. We have also shown that the glucose level in the blood serum rises with age reaching the level of adult animals by day 10. In the present study carried out on 3-10-day-old rats under conditions of free behavior the blood glucose content was investigated in different periods of <> cycle during different seasons. It is found that in newborn rats of all ages studied (3-, 5-, 7-, and 10-day-old ones) the lowest glucose concentration in the blood is observed in the winter period. In spring its level increases and in summer reaches the maximum different significantly from the winter and spring levels in all age groups except day 5. In autumn the glucose level decreases and approaches the spring values but it is still different from the winter indices. In 5-day-old rats statistically significant differences of glucose levels in different seasons were not observed. The data obtained provide evidence of seasonal fluctuations of the glucose level in blood serum of newborn rats. At the same time during all seasons except spring the dependence of glucose level on the pattern of motor activity persists. In spring these differences are smoothed. Key words: ontogenesis, motor activity, metabolic factors, glucose, seasonal variations.