Hepatic handling of an oral glucose load in suckling and weaned rats.

Changes in the net balance of glucose and lactate across the intestine and liver have been studied in 15-day-old suckling and 25-day-old weaned rats over 60 min following an oral glucose load. The intestinal balance of suckling rats showed a net release of glucose that accounted for 80% of the oral load. By contrast, weaned animals showed a nil glucose balance. The hepatic balance of suckling rats switched rapidly from glucose output to glucose uptake following the oral glucose load, and this was associated with a net glycogen deposition. In weaned animals there was a net glucose release by the liver. The liver of 15-day-old suckling rats is able to extract glucose from the blood when circulating levels are raised under physiological circumstances, as well as the ability to synthesize glycogen.