Participation of the hypothalamus in regulating the activity of rat liver energy metabolism enzymes

In soluble fraction of rat liver studies have been made on the activity of glycolytic enzymes and dehydrogenases of the pentose phosphate pathway 3 and 20 hours after the electrical stimulation of the medial (HVM) and lateral (AHL) structures of the medial hypothalamus via chronically implanted electrodes. Electrical stimulation of the HVM within 3 hours decreased total hexokinase, glucose-6-phosphate dehydrogenase, and lactate dehydrogenase activities, and to a lower extent -- the activity of glucokinase. This effect was not prevented by the adrenalectomy. During stimulation of the AHL, the decrease of LDH activity was the same, whereas the activity of hexokinase, glucose-6-phosphate dehydrogenase and glucokinase decreased to a lower extent. Electrical stimulation of the medial hypothalamus within 20 hours decreased the response, this effect being presumably associated with the decrease in the content of endogenous noradrenalin in the liver of animals. The role of the hypothalamus and sympathetic nervous system in regulation of the investigated enzymes of energy metabolism in the liver is discussed.