Improved n-3 fatty acid status does not modulate insulin resistance in fa/fa Zucker rats.
The objective was to examine the effect of polyunsaturated fatty acid type (plant vs fish oil-derived n-3, compared to n-6 fatty acids in the presence of constant proportions of saturated, monounsaturated and polyunsaturated fatty acids) on obesity, insulin resistance and tissue fatty acid composition in genetically obese rats. Six-week-old fa/fa and lean Zucker rats were fed with a 10% (w/w) mixed fat diet containing predominantly flax-seed, menhaden or safflower oils for 9 weeks. There was no effect of dietary lipid on obesity, oral glucose tolerance (except t=60min insulin), pancreatic function or molecular markers related to insulin, glucose and lipid metabolism, despite increased n-3 fatty acids in muscle and adipose tissue. The menhaden oil diet reduced fasting serum free fatty acids in both fa/fa and lean rats. These data suggest that n-3 composition does not alter obesity and insulin resistance in the fa/fa Zucker rat model when dietary lipid classes are balanced.
Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, MB, Canada R2H 2A6.
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M
Gillam
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Noto
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P
Zahradka
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CG
Taylor
D052436:Adipose Tissue, White / Q000187:drug effects / Q000473:pathology; D000821:Animal Feed / Q000032:analysis; D000818:Animals; D050218:Body Fat Distribution; D001835:Body Weight / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D004041:Dietary Fats / Q000032:analysis / Q000494:pharmacology; D015525:Fatty Acids, Omega-3 / Q000097:blood*; D020869:Gene Expression Profiling; D005951:Glucose Tolerance Test; D006304:Health Status; D007333:Insulin Resistance / Q000502:physiology*; D007515:Islets of Langerhans / Q000187:drug effects / Q000473:pathology; D050356:Lipid Metabolism / Q000187:drug effects / Q000235:genetics; D009765:Obesity / Q000097:blood* / Q000378:metabolism / Q000473:pathology; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011924:Rats, Zucker
D004041:Dietary Fats; D015525:Fatty Acids, Omega-3