Carbohydrate-responsive gene expression in the adipose tissue of rats.
Although obesity is often associated with high-fat diets, it can develop from a variety of meal patterns. Excessive intake of simple carbohydrates is one consistent eating behavior leading to obesity. However, the impact of overconsumption of diets with high carbohydrate to fat ratios (C/F) on body composition and global adipose tissue gene expression remains unclear. We used total enteral nutrition to evaluate the effects of caloric intake and C/F on body weight gain and development of obesity. Female Sprague Dawley rats were fed diets with either low C/F or high C/F (HC) (reflecting a 19.5-fold increase in C/F) at two levels of caloric intake: 187 or 220 kcal/kg(3/4) x d (15% excess) for 4 wk. At the end of the study period, rats fed HC diets had about 20% higher body weight at either caloric intake compared with rats fed low C/F diets (P < 0.05). Body composition (assessed by nuclear magnetic resonance, computerized tomography, and adipose tissue weights) revealed higher percent fat mass (P < 0.05) in HC rats. Obesity was associated with increased serum resistin, leptin, fasting hyperinsulinemia, and insulin resistance after an oral glucose challenge (P < 0.05). Microarray analyses of adipose tissues revealed HC diets led to changes in 270 and 464 transcripts at 187 and 220 kcal/kg(3/4) x d intakes. Genes regulating glucose transport, glycolysis, fatty acid and triglyceride biosynthesis, desaturation and elongation, adipogenesis, and adipokines were affected by HC diets. These results suggest that C/F and interactions with excessive caloric intake per se may regulate body composition and play important roles in the development of obesity and metabolic syndrome.
Shankar
Kartik
K
U.S. Department of Agriculture-Arkansas Children's Nutrition Center, 15 Children's Way, Slot 512-20B, Little Rock, Arkansas 72202, USA. shankarkartik@uams.edu
Harrell
Amanda
A
Kang
Ping
P
Singhal
Rohit
R
Ronis
Martin J J
MJ
Badger
Thomas M
TM
D000273:Adipose Tissue / Q000033:anatomy & histology / Q000187:drug effects* / Q000378:metabolism*; D050154:Adiposity / Q000187:drug effects / Q000235:genetics; D000818:Animals; D001823:Body Composition / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D001835:Body Weight / Q000187:drug effects; D050260:Carbohydrate Metabolism / Q000235:genetics; D050528:Diet, Carbohydrate-Restricted; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004703:Endocrine System / Q000187:drug effects; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D053263:Gene Regulatory Networks / Q000187:drug effects / Q000502:physiology; D007333:Insulin Resistance / Q000235:genetics; D050356:Lipid Metabolism / Q000187:drug effects / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D051381:Rats; D017207:Rats, Sprague-Dawley
D004040:Dietary Carbohydrates