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Differences in Gastrocnemius mRNA Expression in Sedentary and Chronically Resistance Trained Rats Fed a Standard Chow Diet, or a Low‐Carbohydrate Diet, or a Western Diet
Author(s) -
Hyatt Hayden W,
Mobley C. Brooks,
Kephart Wesley C,
Holland A. Maleah,
Mumford Petey,
Lowery Ryan P,
Roberts Michael D,
Wilson Jacob M,
Kavazis Andreas N
Publication year - 2016
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.30.1_supplement.1287.1
Subject(s) - endocrinology , medicine , pdk4 , sed , gastrocnemius muscle , carnitine , skeletal muscle , insulin resistance , carbohydrate , biology , chemistry , gene expression , insulin , biochemistry , gene
Low‐carbohydrate diets (LCD) can facilitate weight loss, but their effects on skeletal muscle remain equivocal. In this experiment we investigated the effects of three diets on skeletal muscle gene expression in sedentary and resistance exercised rats. Male Sprague‐Dawley rats (9–10 weeks of age, 300–325 g) were divided into three groups: fed a standard chow diet (SCD) (30 g/day, 3.1 kcal/g, 58.0% CHO, 18.0%, fat 24.0% protein); fed a LCD (17 g/day, 5.2 kcal/g, 20.2% protein, 10.3% CHO, 69.5% fat); or fed a Western diet (WD) (20 g/day, 4.5 kcal/g, 15.2% protein, 42.7% CHO, 42.0% fat), for 6 weeks. During these six weeks animals were either sedentary (SED) or voluntarily exercised using resistance‐loaded running wheels (EXE). At the end of the experimental protocol, the gastrocnemius muscle was harvested and used to compare the gene expression of key metabolic targets in the gastrocnemius. There was a significant interaction (p = 0.04) in carnitine palmitoyltransferase 1B (CPT1B) mRNA levels in the gastrocnemius. Specifically, SCD‐EXE showed a decline compared to SCD‐SED, whereas LCD‐EXE and WD‐EXE showed an increase compared to LCD‐SED and WD‐SED, respectively. Also, there was a trend (p = 0.05) for an interaction effect in peroxisome proliferator‐activated receptor gamma, coactivator 1‐alpha (PGC‐1α) mRNA and there was a trend (p = 0.08) for an activity effect in pyruvate dehydrogenase kinase, isozyme 4 (PDK4) mRNA in the gastrocnemius. There were no significant (p > 0.05) differences for phosphofructokinase (PFK), phosphoenolpyruvate carboxykinase (PEPCK), or glucose transporter type 4 (GLUT4) mRNA levels in the gastrocnemius. Our data indicate that the three diets tested affect the mRNA expression of metabolic genes in the gastrocnemius of sedentary and chronic resistance exercise rats. Future experiments should investigate if these changes translate to protein and/or activity level differences. Support or Funding Information Funding for this project was provided by JMW.