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SHORT TERM HIGH FAT FEEDING ALTERS EXPRESSION OF GLUCOREGULATORY PROTEINS IN SKELETAL MUSCLE OF MALE ADOLESCENT RATS
Author(s) -
Crawford Melisa Shaunte,
Liss Tyler,
Sweazea Karen
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.710.8
Subject(s) - endocrinology , medicine , skeletal muscle , obesity , overweight , triglyceride , insulin , oxidative stress , dyslipidemia , type 2 diabetes , diabetes mellitus , cholesterol
Childhood obesity affects approximately 17% of children and adolescents in the United States. Prolonged consumption of energy‐dense foods, in addition to a sedentary lifestyle, continue to increase the prevalence of overweight and obese adolescents. Unfortunately, this trend is accompanied by serious metabolic conditions including, type II diabetes, cardiovascular disease, and skeletal muscle atrophy. Skeletal muscle, the most abundant tissue in the human body, is responsible for insulin‐mediated glucose uptake and many of the metabolic abnormalities associated with obesity. While it is known that a high‐fat diet (HFD) can impair insulin signaling, endothelium‐dependent vasodilation and increase the risk of oxidative stress, less is known about the effects of a short‐term HFD on skeletal muscle of adolescents. We hypothesized that short‐term high fat intake by adolescent rats would promote similar pathologies observed with chronic poor nutrition in adults. To examine this, six‐week‐old male Sprague Dawley rats were fed either a standard rodent chow diet (18.9% protein, 57.33% carbohydrates) or a HFD (20% protein, 20% carbohydrates [6.8% sucrose], 60% fat) for 6 weeks. Blood samples were collected then animals were euthanized (sodium pentobarbital; 200 mg/kg, i.p.) and pectoralis major muscles were extracted for analyses. Consistent with the development of obesity and type II diabetes, HFD rats had significantly lower plasma α‐amylase (24.7% decrease; p=0.007 ). However, Oil Red‐O and triglyceride assays showed no significant increase in muscle lipids ( p>0.05 ). Data also suggests no significant increase in expression of proteins associated with insulin signaling (p‐PI3K; p=0.462) and inflammation (iNOS; p=0.406 ). In contrast, there was a tendency towards increased expression of the alpha subunit of the insulin receptor (180.9%, p=0.076 ) as well as the insulin‐responsive (GLUT‐4; 83.9%, p=0.093 ) and insulin‐independent (GLUT‐1; 89.9%, p=0.103 ) glucose transporters. The increased expression of these latter proteins likely reflect early compensation for the HFD. Further studies will confirm these findings and examine the effects of a short‐term HFD on the progression of inflammation, macrophage invasion and the impairment of insulin signaling intermediates in skeletal muscle of adolescent rats. Support or Funding Information This project was partially funded by the Barrett Honors College, Arizona State University