[Intensity of gluconeogenesis in liver tissue of rats of various age groups]

Intensity of glucose synthesis from different substrates in the liver slices was investigated in 1-, 13-15-, 30-day old and adult (3-6 month old) rats. Maximal gluconeogenesis activity was observed in the liver tissue of 13-15 day old rats. There was a change in the substrate specificity of gluconeogenesis during ontogenesis. Under cold stress and low body temperature (30 degrees C) a rate of gluconeogenesis from some substrates in young rats increased, while in adults-decreased. The activation of gluconeogenesis in adult rats occurred only at prolonged hypothermia to 3 h and almost complete exhaustion of glycogen reserves in the liver.