Russell J C, Proctor S D
Metabolic and Cardiovascular Diseases Laboratory, Alberta Institute for Human Nutrition, University of Alberta, Edmonton, Alberta, Canada.
Br J Pharmacol. 2007 May;151(2):216-25. doi: 10.1038/sj.bjp.0707226. Epub 2007 Mar 20.
The metabolic syndrome, characterized by obesity, insulin resistance and dyslipidemia, is a major cause of cardiovascular disease. The origins of the syndrome have been hypothesized to lie in continuous availability of energy dense foods in modern societies. In contrast, human physiology has evolved in an environment of sporadic food supply and frequent food deprivation. Intermittent food restriction in rats has previously been shown to lead to reduction of cardiovascular risk and a greater life span. The non-metabolizable glucose analogue, 2-deoxy-D-glucose (2-DG) is taken up by cells and induces pharmacological inhibition of metabolism of glucose. We hypothesized that intermittent inhibition of glucose metabolism, a metabolic deprivation, may mimic intermittent food deprivation and ameliorate metabolic and pathophysiological aspects of the metabolic syndrome.
Insulin resistant, atherosclerosis-prone JCR:LA-cp rats were treated with 2-DG (0.3% w/w in chow) on an intermittent schedule (2 days treated, one day non-treated, two days treated and two days non-treated) or continuously at a dose to give an equivalent averaged intake.
Intermittent 2-DG-treatment improved insulin sensitivity, which correlated with increased adiponectin concentrations. Further, intermittent treatment (but not continuous treatment) reduced plasma levels of leptin and the inflammatory cytokine IL-1 beta. Both 2-DG treatments reduced micro-vascular glomerular sclerosis, but only the intermittent schedule improved macro-vascular dysfunction.
Our findings are consistent with reduction in severity of the metabolic syndrome and protection against end stage micro- and macro-vascular disease through intermittent metabolic deprivation at a cellular level by inhibition of glucose oxidation with 2-DG.
代谢综合征以肥胖、胰岛素抵抗和血脂异常为特征,是心血管疾病的主要病因。该综合征的起源被认为与现代社会中能量密集型食物的持续供应有关。相比之下,人类生理机能是在食物供应不连续且经常挨饿的环境中进化而来的。此前研究表明,大鼠间歇性禁食可降低心血管疾病风险并延长寿命。不可代谢的葡萄糖类似物2-脱氧-D-葡萄糖(2-DG)可被细胞摄取并诱导对葡萄糖代谢的药理学抑制。我们推测,间歇性抑制葡萄糖代谢(一种代谢剥夺)可能模拟间歇性禁食,并改善代谢综合征的代谢和病理生理方面。
对胰岛素抵抗、易患动脉粥样硬化的JCR:LA-cp大鼠,采用间歇性方案(给药2天,停药1天,再给药2天,停药2天)或持续给予2-DG(饲料中含0.3% w/w),剂量要使平均摄入量相当。
间歇性2-DG治疗可改善胰岛素敏感性,这与脂联素浓度升高相关。此外,间歇性治疗(而非持续治疗)可降低血浆瘦素和炎性细胞因子IL-1β水平。两种2-DG治疗均能减轻微血管肾小球硬化,但只有间歇性方案能改善大血管功能障碍。
我们的研究结果表明,通过用2-DG抑制葡萄糖氧化在细胞水平进行间歇性代谢剥夺,可减轻代谢综合征的严重程度,并预防终末期微血管和大血管疾病。