A decreased metabolic clearance of glucose is involved in the hyperglycemic effect of a serum temperature induced factor (TIF)

We have studied the effects of a hyperglycemic temperature induced factor (TIF) on glucose metabolism, in 3 groups of Wistar rats: 10 rats injected with non-heated serum, 10 rats injected with heated serum and 10 rats injected with semi-purified TIF. Seric levels of insulin and glucagon were not modified in rats injected with heated serum. The injection of heated serum induced hyperglycemia (p< 0.0001), a decrease of lactate (p< 0.001 ) and pyruvate (p< 0.05) levels, and an increase of acetoacetate level (p< 0.001). The levels of β hydroxybutyrate and aminoacids (alanine and glutamine) were not changed. Glucose turn over rate (12.3 ± 1.3 g/min/kg) and metabolic clearance of glucose (10.0± 0.8 ml/min/kg) were significantly lower in rats treated with heated serum and purified TIF than in controls (respectively, p< 0.05 and p< 0.001). These data suggested that the hyperglycemic effect of heated serum and isolated TIF could correspond to an impaired metabolic clearance of glucose and to an increased gluconeogenesis