Variations in fatty acid synthesis and desaturation in dogs receiving normal and high sugar diets using on‐line gas chromatography/pyrolysis/isotope ratio mass spectrometry

De novo lipogenesis plays a key role in the hypertriglyceridemia associated with type‐2 diabetes. Kinetic approaches are needed to study the effectiveness of potential treatment interventions for this aspect of the disease. Therefore, the objective of this study was to evaluate the effects of dietary sugar on synthesis and desaturation of palmitic, stearic and oleic acids in dogs using stable isotope techniques. Twelve dogs were randomized to a high sugar or low sugar diet and orally administered deuterated water (D 2 O) following consumption of the treatment diet. Blood samples were taken 1 hour before and 1, 2, 4, 6, 8 hours post D 2 O administration. Deuterium incorporation into newly synthesized fatty acids was assessed using GC/TC/IRMS. Plasma concentrations of palmitic, stearic and oleic acids in both groups remained similar over the 8 hours while deuterium enrichment of fatty acids increased linearly. Deuterium enrichment in the high sugar group was 3, 4 and 10‐fold higher for palmitic, stearic and oleic acids, respectively, compared to controls (P < 0.05). The palmitic and stearic acid plasma pools (enrichment/μg) reached plateau enrichment after 6 hours however enrichment of the oleate pool continued in increase at 8 hours. These findings demonstrate the usefulness of this model for the study of both perturbations and therapeutic interventions in de novo synthesis of fatty acids. Sponsored by Merck Frosst &Co, Canada .