[Dynamics of changes in hexokinase activity in subcellular tissue fractions of hypoxic newborn rats].

The activity of hexokinase (HK) in the total homogenate, cytoplasmic and mitochondrial fractions of the brain, heart and liver of the newborn rats was studied in relation to the severity of the hypoxic action. A mild from of hypoxic hypoxia caused in the tissue of the brain and liver an increase in the activity of mitochondrial-bound form of the enzyme with a simultaneous fall in the activity of the cytoplasmic HK; this was accompanied by a marked acceleration of glucose phosphorylation in the brain. Severe hypoxia led to the reduction of the HK activity in the total homogenate and both intracellular fractions in all the tissues under study. The data obtained pointed to disturbance of some adaptive mechanisms in severe hypoxia in the tissues of the newborn rats.