Peculiarities of adaptational changes in leukocytes and platelets of yakutian ground squirrels during the pre-hibernation period in autumn

Abstract

Earlier, it was shown that a series of physiological and biochemical changes in Yakutian long-tailed ground squirrels start to happen during autumn (the pre-hibernation period): in the brain, heart, skeletal muscles, etc. This study was conducted to analyze the composition of peripheral blood cells obtained from Yakutian ground squirrels in autumn, and for the first time an increase in the total number of leukocytes, particularly granulocytes, and a decrease in the number of lymphocytes were observed when compared with those obtained in summer; a shift of the leukogram from the lymphocytic fraction to the granulocytic fraction was revealed. Significant increase in a platelet count and thrombocrit with preservation of the percentage ratio of mature and young cell fractions was shown. Still, information on the cellular components of blood during the autumn season when hibernators prepare for winter months of hibernation remains scarce. Nonetheless, the results of our study indicate that there are very significant adaptive changes that occur in leukocytes and platelets of ground squirrels in this period. Possible causes of these changes are discussed.