A non-invasive method to determine postprandial fatty acid tissue partition may elucidate the link between excess dietary fat and type 2 diabetes. We hypothesized that the positron-emitting fatty acid analog 14(R,S)-[18F]-fluoro-6-thia-heptadecanoic acid (18FTHA) administered orally during a meal would be incorporated into chylomicron-triglycerides, allowing determination of inter-organ dietary fatty acid uptake. We administered 18FTHA orally at the beginning of a standard liquid meal ingested in nine healthy men. There was no significant 18FTHA uptake in the portal vein and the liver in the first hour. Whole body PET/CT acquisition revealed early appearance of 18FTHA in the distal thoracic duct, reaching a peak at time 240 min. 18FTHA mean standard uptake value (SUV) increased progressively in the liver, heart, quadriceps, subcutaneous and visceral adipose tissues between time 60 and 240 min. Most circulating 18F activity between time 0 and 360 min was recovered into chylomicron-triglycerides. Using Triton WR-1339 treatment in rats that received 18FTHA by gavage, we confirmed that over 90% of this tracer reached the circulation as triglycerides. This novel non-invasive method to determine tissue dietary fatty acid distribution in humans should prove useful in the study of the mechanisms leading to lipotoxicity.
- Postprandial lipid metabolism
- dietary fatty acids
- positron emission tomography
- organ fatty acid uptake
- Copyright © 2010, American Journal of Physiology - Endocrinology and Metabolism