Lipid metabolism and resistin gene expression in insulin-resistant Fischer 344 rats

• Published in: American journal of physiology: endocrinology and metabolism 2002-03, Vol.282 (3), p.E626-E633
• Main Authors: Levy, James R, Davenport, Byrd, Clore, John N, Stevens, Wayne
• Format: Article
• Language: English
• Subjects: Acyl-CoA Oxidase; Animals; Blood Glucose - analysis; Body Composition; Body Weight; Carnitine O-Palmitoyltransferase - genetics; Drug Resistance; Gene Expression; Glucose Tolerance Test; Hormones, Ectopic - genetics; Insulin - analysis; Insulin - blood; Insulin Resistance - genetics; Kinetics; Leptin - blood; Leptin - pharmacology; Lipid Metabolism; Lipids - blood; Liver - chemistry; Muscle, Skeletal - chemistry; Nerve Growth Factor; Oxidoreductases - genetics; Proteins; Rats; Rats, Inbred F344; Rats, Sprague-Dawley; Receptors, Cytoplasmic and Nuclear - genetics; Resistin; Transcription Factors - genetics; Triglycerides - analysis
• ISSN: 0193-1849; 1522-1555
• DOI: 10.1152/ajpendo.00346.2001

1  Section of Endocrinology and Metabolism, McGuire Veterans Administration Medical Center and 2  Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia 23249 The interrelationship between insulin and leptin resistance in young Fischer 344 (F344) rats was studied. Young F344 and Sprague-Dawley (SD) rats were fed regular chow. F344 animals had two- to threefold higher insulin and triglyceride concentrations and increased stores of triglycerides within liver and muscle. F344 animals gained more body fat. Both acyl-CoA oxidase (ACO) and carnitine palmitoyltransferase I gene expression were 20-50% less in F344 animals than in age-matched SD animals. Peroxisome proliferator-activated receptor- gene expression was reduced in 70-day-old F344 animals. Finally, resistin gene expression was similar in 70-day-old SD and F344 animals. Resistin gene expression increased fivefold in F344 animals and twofold in SD animals from 70 to 130 days, without a change in insulin sensitivity. We conclude that young F344 animals have both insulin and leptin resistance, which may lead to diminished fatty oxidation and accumulation of triglycerides in insulin-sensitive target tissues. We did not detect a role for resistin in the etiology of insulin resistance in F344 animals. Fischer 344 rats; acyl-coenzyme A oxidase; carnitine palmitoyltransferase I; peroxisome proliferator-activated receptor-