The effects of free fatty acid infusion on glucose metabolism in normal and streptozotocin-treated dogs.

SUMMARY By means of a novel technique for direct intravenous infusion of free fetty acids (FFA) into conscious dogs, it was found that the elevation of FFA levels in normal animals leads to a marked increase in insulin release and to a decrease in plasma glucose concentration. Dogs with streptozotocin-induced diabetes were used for FFA infusion in order to test whether peripheral glucose utili­ sation would be suppressed by FFA in the absence of the usual insulin response. Diabetic dogs receiving a constant infusion of intra­ venous glucose were given infusions of oleic ecid after control periods of 2 - 3 hours. Constant intravenous in­ fusion of U-"C-glucose into the diabetic dogs indicated that FFA infusion caused an average transient drop of 36,8% in glucose flux. After 1% hours of FFA infusion the flux returned to the former rates. Because no change in plasma glucose levels was found during FFA infusion our results can be explained only by a drop in hepatic glucose production concomitant with an equal drop in peripheral glucose utilisation.