In vivo magnetic resonance spectroscopy of lipid handling in steatotic rat liver

Objective: Examine lipid handling in liver of rats fed with different high-fat diets using 1H-[13C] magnetic resonance spectroscopy (MRS) together with oral administration of 13C labeled lipids. Methods: 6 male Wistar rats (11 weeks old; 348 ± 8g) were divided into three diet groups: low-fat (10% fat, CON), high-fat lard (45% fat, HFL), and high-fat palm oil (45%, HFP). After 10 weeks of diet, MRS experiments were performed at baseline, and 4 and 24 h after oral administration of 1.5 g [U-13C] Algal lipid mixture per kg body weight. Results: At 4 h after administration of the 13C labeled lipids, 13C enrichment of intracellular liver lipids was similarly increased in all three groups compared to baseline (CON: 0.031 ± 0.017 %; HFL: 0.045 ± 0.022 %; HFP: 0.033 ± 0.013 %), demonstrating that lipid uptake was not affected by the diet regimen. At 24 h, on the other hand, 13C enrichment of liver lipids decreased in CON, whereas in both high-fat diet groups the 13C enrichment did not change compared to 4 h, indicating a lower turnover of the stored liver lipids. Conclusion: High-fat diet feeding did not alter liver lipid uptake in rats, but resulted in a decreased turnover of the lipids stored in the liver. This research was funded by the Netherlands Consortium for Systems Biology (NCSB) which is part of the Netherlands Genomics Initiative/Netherlands Organisation for Scientific Research.