In vivo 13C NMR analysis of acyl chain composition and organization of perirenal triacylglycerides in rats fed vegetable and fish oils

• Published in: Journal of lipid research Vol. 35; no. 4; pp. 678 - 689
• Main Authors: Fan, T.W.M, Clifford, A.J, Higashi, R.M
• Format: Journal Article
• Language: English
• Published: United States Elsevier 01-04-1994
• Subjects: ACEITE DE CARTAMO; ACEITE DE OLIVA; ACEITES DE PESCADO; ACIDE GRAS; ACIDOS GRASOS; Adipose Tissue - chemistry; Animals; Chromatography, Gas; CORPS GRAS; DIETA; Dietary Fats - metabolism; ESPECTROMETRIA; Fatty Acids - analysis; Fish Oils - metabolism; GRASAS; HUILE D'OLIVE; HUILE DE CARTHAME; HUILE DE POISSON; Kidney; Magnetic Resonance Spectroscopy; Male; MENHADEN; Plant Oils - metabolism; Rats; Rats, Sprague-Dawley; REGIME ALIMENTAIRE; REIN; RINONES; SPECTROMETRIE; TEJIDO ADIPOSO; TISSU ADIPEUX; TRIGLICERIDOS; TRIGLYCERIDE; Triglycerides - analysis; Triglycerides - chemistry
• ISSN: 0022-2275; 1539-7262
• DOI: 10.1016/s0022-2275(20)41182-4

Lipid composition of body fat can be a key indicator of nutritional status and a number of human disorders. In vivo 13C NMR provides for repeated, noninvasive analysis of fatty acyl chain composition on individuals, which circumvents classical problems of individual variation and repetitive invasive sampling. It also offers a unique opportunity to examine acyl chain organization in situ. This approach was used to examine the fatty acyl chain composition in the perirenal fat pads of rats fed olive, safflower, and menhaden oil-containing diets. These changes were then monitored during a diet switch between olive and menhaden oil-fed rats. The fatty acid composition of perirenal fat pads and livers was also analyzed using gas chromatography for comparison with the in vivo NMR analysis. Both tissues assumed the general characteristics of diet fatty acyl chain and fatty acid composition and the diet switch induced a switch-over of the perirenal composition in 30-45 days. These results indicate that a large portion of the diet fatty acyl chains were incorporated directly into adipose and liver tissues although some were also metabolized, particularly in menhaden oil-fed rats. Furthermore, changes in the in vivo spin-lattice relaxation times (T1) of fatty acyl carbons in the perirenal fat pads and their lipid extracts were followed and effective correlation times (tau(eff)) were calculated from the T1 data. The result indicated that the in vivo segmental mobility of acyl carbons was sensitive to changes in diet-derived fatty acyl chain composition and that the central region of the acyl chain was more sensitive to these changes. There was a qualitative similarity but quantitative differences in the tau(eff) of acyl carbons acquired in vivo and from extracts. These results suggest that adipose triacylglycerides experience an overall liquid-like microenvironment in vivo but with more restriction in their mobility