Wang Zhihui, Al-Regaiey Khalid A, Masternak Michal M, Bartke Andrzej
Geriatrics Research, Department of Physiology and Internal Medicine, School of Medicine, Southern Illinois University, 801 N. Rutledge, Springfield, IL 62794-9628, USA.
J Gerontol A Biol Sci Med Sci. 2006 Apr;61(4):323-31. doi: 10.1093/gerona/61.4.323.
Ames dwarf mice are long-lived and insulin sensitive, and have a normal or reduced percentage of body fat. Calorie restriction (CR) is known to improve insulin sensitivity and reduce body fat. The purpose of this study was to evaluate the mechanism of improved insulin sensitivity in the Ames dwarfs and the effects of CR on adipose signaling and metabolism in normal and dwarf mice. Enhanced insulin sensitivity in dwarf mice may be partly due to increased release of adiponectin and the reduced release of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6). Altered levels of adipocytokines might be consequent to the decreased lipid synthesis, plasma triglycerides, and free fatty acid levels. In normal mice, CR improves insulin sensitivity by affecting the release of adipocytokines, and decreasing circulating fatty acid and triglycerides concentrations as well as liver triglyceride accumulation. However, CR may reduce rather than enhance some of the insulin effects in the highly insulin-sensitive dwarf mice.
艾姆斯侏儒小鼠寿命长且对胰岛素敏感，体脂百分比正常或降低。已知热量限制（CR）可改善胰岛素敏感性并减少体脂。本研究的目的是评估艾姆斯侏儒小鼠胰岛素敏感性改善的机制以及CR对正常和侏儒小鼠脂肪信号传导和代谢的影响。侏儒小鼠胰岛素敏感性增强可能部分归因于脂联素释放增加以及肿瘤坏死因子-α（TNF-α）和白细胞介素-6（IL-6）释放减少。脂肪细胞因子水平的改变可能是脂质合成、血浆甘油三酯和游离脂肪酸水平降低的结果。在正常小鼠中，CR通过影响脂肪细胞因子的释放、降低循环脂肪酸和甘油三酯浓度以及肝脏甘油三酯积累来改善胰岛素敏感性。然而，CR可能会降低而非增强高度胰岛素敏感的侏儒小鼠的某些胰岛素作用。
