[Circadian rhythms in connective tissue]

A study of circadian rhythms in the connective tissue showed cell elements (particularly histiocytes) to be characterized by circadian rhythms of the metabolic processes. This is expressed in a distinct diurnal activity of the succinic dehydrogenase (SDH) and lactic dehydrogenase (LDH). In the processes of adaptation to the high altitude hypoxia the activity of SDH and LDH was higher than in control, but dynamics of the changes of their activity repeated the changes in control group. It is concluded that circadian rhythms of the metabolic processes in the connective tissue were sufficiently stable: no visible changes were observed during adaptation to high altitudes.