ABSTRACT
Objective:Obesity results when energy intake is greater than energyexpenditure. Skeletal muscles [SK.M] UCP3 and central NPY play an im-portant role in energy balance. The aim is to study the changes of [SK.M]UCP3 expression, and hypothalamic NPYmRNA expression after pro-longed feeding with high-fat diet [HFD]
Design:Obese-prone Sprague Dawley rats were fed beef tallow[46%] of energy as fat "HFD" and control group fed libitum diets contain-ing 4.5% of energy as fat [control], for 16 weeks. Body weight and foodintake were measured every 3 days throughout the experimental period.After the feeding period is completed, hindlimb skeletal muscle was iso-lated for subsequent determinations of triglyceride. Skeletal UCP3 mRNAand hypothalamic NPY mRNA were assessed by [RT-PCR] respectively
Results:Plasma glucose, triglyceride, insulin, leptin and free fatty ac-ids levels were higher in rats fed the HFD compared to control group. HFDresulted in significant increase in [SK.M] triglyceride, and mRNA levels of[SK.M] UCP3 by [3.84 folds], but without significant change in hypotha-lamic NPY mRNA expression compared to control group
Conclusion:high fat diet induces obesity with marked induction ofUCP3. The dissociation between the UCP3 mRNA levels and NPY mRNAexpression could point that obesity may be caused by mechanisms inde-pendent of thermogensis