Influence of lactate infusion on glucose and FFA metabolism in man.

Sodium L(+)-lactate was infused at rates of 5 to 12 mmol/min intravenously for 30 min in health volunteers, and the exchange of lactate, glucose, and free fatty acids (FFA) was measured in the leg, the forearm muscle, and the splanchnic region. Arterial lactate levels were 3 to 5 mmol/l during the infusion. Leg blood flow increased about 2.5-fold and leg oxygen uptake rose by 35%. Blood flow, oxygen uptake, and glucose production in the splanchnic area remained unaltered. The fractional uptake of lactate by the leg, the splanchnic region, and the forearm decreased during the course of the infusion.