Fish oil prevents high-saturated fat diet-induced impairments in adiponectin and insulin response in rodent soleus muscle.
High saturated fatty acid (SFA) diets contribute to the development of insulin resistance, whereas fish oil-derived n-3 polyunsaturated fatty acids (PUFA) increase the secretion of adiponectin (Ad), an adipocyte-derived protein that stimulates fatty acid oxidation (FAO) and improves skeletal muscle insulin response. We sought to determine whether fish oil could prevent and/or restore high SFA diet-induced impairments in Ad and insulin response in soleus muscle. Sprague-Dawley rats were fed 1) a low-fat control diet (CON group), 2) high-SFA diet (SFA group), or 3) high SFA with n-3 PUFA diet (SFA/n-3 PUFA group). At 4 wk, CON and SFA/n-3 PUFA animals were terminated, and SFA animals were either terminated or fed SFA or SFA/n-3 PUFA for an additional 2 or 4 wk. The effect of diet on Ad-stimulated FAO, insulin-stimulated glucose transport, and expression of Ad, insulin and inflammatory signaling proteins was determined in the soleus muscle. Ad stimulated FAO in CON and 4 wk SFA/n-3 PUFA (+36%, +39%, respectively P ≤ 0.05) only. Insulin increased glucose transport in CON, 4 wk SFA/n-3 PUFA, and 4 wk SFA + 4 wk SFA/n-3 PUFA (+82%, +33%, +25%, respectively P ≤ 0.05); this effect was lost in all other groups. TLR4 expression was increased with 4 wk of SFA feeding (+24%, P ≤ 0.05), and this was prevented in 4 wk SFA/n-3 PUFA. Suppressor of cytokine signaling-3 expression was increased in SFA and SFA/n-3 PUFA (+33 and +18%, respectively, P ≤ 0.05). Our results demonstrate that fish oil can prevent high SFA diet-induced impairments in both Ad and insulin response in soleus muscle.
Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada.
Justine M
JM
Tishinsky
Roberto A
RA
Gulli
Kerry L
KL
Mullen
David J
DJ
Dyck
Lindsay E
LE
Robinson
D052242:Adiponectin / Q000378:metabolism*; D000818:Animals; D015992:Body Mass Index; D004041:Dietary Fats / Q000009:adverse effects / Q000494:pharmacology*; D005227:Fatty Acids / Q000009:adverse effects / Q000494:pharmacology*; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D005260:Female; D005395:Fish Oils / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism; D007328:Insulin / Q000378:metabolism*; D023421:Models, Animal; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000378:metabolism
D052242:Adiponectin; D004041:Dietary Fats; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D005395:Fish Oils; D007328:Insulin; C491410:Socs3 protein, rat; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins; C495347:Tlr4 protein, rat; D051197:Toll-Like Receptor 4; D051057:Proto-Oncogene Proteins c-akt; D005947:Glucose