Effect of free fatty acids on metabolism of pyruvic and lactic acids

¹ Nutrition Laboratory, Mount Sinai Hospital, and Department of Pharmacology, New York University School of Medicine, New York City

The influence of infused free fatty acid (FFA) and of FFA-mobilizing hormones: growth hormone, epinephrine, and norepinephrine, on blood concentrations of glucose, pyruvate, and lactate subsequent to intravenous glucose loads were determined in normal dogs. Infusion of glucose (500 mg/kg in 30 min) to dogs injected with bovine growth hormone for 4 days (1 mg/kg per day) resulted in higher levels of pyruvate, but not lactate, than in control experiments. Intravenous infusion of palmitate alone had no discernible effect on blood pyruvate and lactate; however, administration of glucose immediately following palmitate infusion resulted in higher concentrations of blood pyruvate and lactate than in animals given glucose alone. Infusion of norepinephrine alone elevated only plasma FFA but not glucose; nevertheless a superimposed glucose load resulted in higher values for blood pyruvate and lactate than in control animals given glucose alone. These studies suggest that increased utilization of FFA influences the metabolic fate of glucose, resulting in higher concentrations of tissue and subsequently blood pyruvate and lactate.

Key Words: growth hormone on blood pyruvate and lactate • epinephrine and norepinephrine on blood pyruvate and lactate • palmitate on blood pyruvate and lactate

Submitted on April 23, 1964