Gluconeogenesis from glycerol by ketotic sheep pregnant with twins.

The concentrations of glycerol and glucose in plasma, the entry rates of glycerol and glucose into the plasma pool and the production of glucose from glycerol were measured in four normal sheep pregnant with twins and in the same sheep after the induction of ketosis and after the oral administration of 3 ml/kg body-weight of glycerol in two doses six hours apart. After starvation there was a significant fall in the concentration of glucose and a rise in that of ketone bodies in the plasma. The rise in the concentration of glycerol was not significant. The divided oral dose of glycerol was followed by significant increases in the concentrations of glycerol and glucose and a significant fall in that of ketone bodies in plasma. After starvation, glucose and glycerol entry rates fell significantly from 42.0 +/- 3.5 to 18.1 +/- 1.4 mmol per hour and from 28.1 +/- 4.6 to 13.5 +/- 2.9 mmol per hour respectively. The amount of glucose formed from glycerol decreased from 5.4 +/- 1.2 to 3.0 +/- 0.5 mmol per hour. After a divided oral dose of glycerol, glycerol entry in the ketotic sheep rose significantly from 13.5 +/- 2.9 to 320 +/- 24.1 mmol per hour and glucose entry rate rose significantly from 18.1 +/- 1.4 to 71.5 +/- 10.1 mmol per hour. The amount of glucose produced from glycerol increased from 3.0 +/- 0.5 to 62.1 +/- 9.2 mmol per hour after the administration of glycerol. The oral dose of glycerol had no obvious effect on the clinical signs of induced ketosis.