Effect of hypoxia on gluconeogenesis in the albino rat and thirteen-lined ground squirrel (Citellus tridecemlineatus)

Abstract

1.1. The rate of gluconeogenesis from l-lactate, pyruvate, glycerol, α-ketoglutarate, l-glutamate, l-aspartate and oxaloacetate was measured in kidney cortex slices prepared from control and hypxic albino rats and thirteen-lined ground squirrels.2.2. After hypoxic exposure (XpO2 in chamber = 76 mm Hg) for 3 hr, gluconeogenesis in groud squireel renal tissue was increased significantly from all substrates except l-lactate; whereas the gluconeogenic capacity in rat tissue was slightly decreased. In general, the activities of selected hepatic and renal gluconeogenic enzymes were increased in hypoxic ground squirrels but decreased in hypoxic rats.3.3. In both species, significant glycogenolysis occured during hypoxia; however, blood glucose levels remained unchanges. Blood lactate increased significantly in the hypoxic ground squirrel. A possible feedback control of gluconeogenesis is discussed within the context of the above results.4.4. Hypoxic resistance in hibernating mammals may be partially attibuted to an increased capacity for renal and hepatic gluconeogenesis.