Effect of insulin on fatty acid transport and regional metabolism

Abstract

The effects of insulin on organ or regional free fatty acid (FFA) movements were measured in the unanesthetized dog. Using chronic indwelling catheters in the portal vein, hepatic vein, and splenic artery together with hepatic blood flow measurement by a modified Bromsulphalein method, the net rate of hepatic FFA uptake or output was calculated. Similarly, the rate of FFA metabolism by the nonhepatic splanchnic area was approximated. There was a marked increase in the rate of FFA uptake by the liver after insulin and a lesser uptake by the nonhepatic splanchnic area. The rate of omental FFA output or uptake was obtained by collecting the omental efflux with a system of catheters and snares into graduate cylinders over time periods. The omental FFA output was calculated as the product of the omental venous-arterial concentration difference and the omental blood flow. The omentum took up FFA in the period immediately after insulin but later on released them. The hindquarters also showed a decreased FFA output after insulin administration.