Glucose regulation by isolated near term fetal monkey liver

Near term fetal monkey livers were perfused with a closed recirculating system and a defined perfusion medium. Livers from normal fetal animals were able to release glucose rapidly into the perfusate when they were exposed to glucagon, cyclic AMP, or an aglycemic perfusate, but they did not remove glucose rapidly from the perfusate, synthesize glycogen, or activate liver glycogen synthetase in response to hyperglycemia (Figs. 1,2, and 3; Table 1). Insulin decreased glucose mobilization in response to aglycemia, but did not stimulate glucose uptake during hyperglycemia; insulin activated glycogen synthetase (Table 1; Figs. 1 and 3). Livers from fetuses of streptozotocin-treated mothers and livers from 2-week-old neonates released more glucose into the perfusate in response to aglycemia then did livers from normal fetal monkeys (Fig. 4). These observations support the possibility that neonatal monkey liver is capable of rapidly mobilizing glucose during periods of hypoglycemia but is unable to take up glucose and store glycogen rapidly during periods of hyperglycemia.