Cookies help us deliver our services. By using our services, you agree to our use of cookies. More information

Stephenson 2012 Am J Physiol Endocrinol Metab

From Bioblast
Revision as of 15:11, 13 November 2017 by Kandolf Georg (talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Publications in the MiPMap
Stephenson EJ, Camera DM, Jenkins TA, Lee JS, Kosari S, Hawley JA, Stepto NK (2012) Skeletal muscle respiratory capacity is enhanced in rats consuming an obesogenic Western diet. Am J Physiol Endocrinol Metab 302:E1541-49.

» PMID: 22496344

Stephenson EJ, Camera DM, Jenkins TA, Lee JS, Kosari S, Hawley JA, Stepto NK (2012) Am J Physiol Endocrinol Metab

Abstract: Obesity-induced lipid oversupply promotes skeletal muscle mitochondrial biogenesis. Previous investigations have utilized extreme high-fat diets (HFD) to induce such mitochondrial perturbations despite their disparity from human obesogenic diets. Here, we evaluate the effects of Western diet (WD)-induced obesity on skeletal muscle mitochondrial function. Long-Evans rats were given ad libitum access to either a WD (40% energy (E) from fat, 17% protein and 43% carbohydrate (30% sucrose), n=12) or a control diet (CON, 16% of E from fat, 21% protein and 63% carbohydrate, n=12) for 12 wk. Rats fed the WD consumed 23% more E than CON (P=0.0001), which was associated with greater increases in body mass (23%, P=0.0002) and adiposity (17%, P=0.03). There were no differences in fasting blood glucose concentration or glucose tolerance between diets, although fasting insulin was increased by 40% (P=0.007). Fasting serum triglycerides were also elevated in WD (86%, P=0.001). The maximal capacity of the Electron transfer-pathway was greater following WD (37%; P=0.02), as were the maximal activities of several mitochondrial enzymes (citrate synthase, β-hydroxyacyl-CoA dehydrogenase, carnitine palmitoyl-transferase). Protein expression of citrate synthase, UCP3 and individual respiratory complexes were greater after WD (P<0.05) despite no differences in the expression of peroxisome proliferator-activated receptors (PPAR)α, PPAR-δ, or PPAR-γ coactivator (PGC)-1 mRNA or protein abundance. We conclude that the respiratory capacity of skeletal muscle is enhanced in response to the excess energy supplied by a WD. This is likely due to an increase in mitochondrial density, which at least in the short term, and in the absence of increased energy demand, may protect the tissue from lipid-induced impairments in glycemic control. Keywords: Western diet (WD)-induced obesity, PGC-1alpha, skeletal muscle mitochondria, mitochondrial biogenesis, peroxisome proliferator-activated receptor-δ

O2k-Network Lab: AU Melbourne Stepto NK

Labels: MiParea: Respiration, mt-Biogenesis;mt-density, Exercise physiology;nutrition;life style, mt-Medicine  Pathology: Obesity 

Organism: Rat  Tissue;cell: Skeletal muscle 

Coupling state: LEAK, OXPHOS, ET  Pathway: N, S, NS  HRR: Oxygraph-2k