Departments of Medicine and Physiology, Division of Endocrinology and Metabolism, University of Toronto, Toronto, ON, Canada.
Arterioscler Thromb Vasc Biol. 2012 Jun;32(6):1513-9. doi: 10.1161/ATVBAHA.112.246207. Epub 2012 Apr 5.
Incretin-based therapies for the treatment of type 2 diabetes mellitus improve plasma lipid profiles and postprandial lipemia, but their exact mechanism of action remains unclear. Here, we examined the acute effect of the glucagon-like peptide-1 receptor agonist, exenatide, on intestinal and hepatic triglyceride-rich lipoprotein production and clearance in healthy humans.
Fifteen normolipidemic, normoglycemic men underwent 2 studies each (SC 10 μg exenatide versus placebo), 4 to 6 weeks apart, in random order, in which triglyceride-rich lipoprotein particle kinetics were examined with a primed, constant infusion of deuterated leucine and analyzed by multicompartmental modeling under pancreatic clamp conditions. A fed state was maintained during each study by infusing a high-fat, mixed macronutrient, liquid formula at a constant rate directly into the duodenum via a nasoduodenal tube. Exenatide significantly suppressed the plasma concentration and production rate of triglyceride-rich lipoprotein-apolipoprotein B-48, but not of triglyceride-rich lipoprotein-apolipoprotein B-100.
These results suggest a possible direct effect of exenatide on intestinal lipoprotein particle production, independent of changes in weight gain and satiety as seen in long-term studies and independent of changes in gastric emptying. This finding expands our understanding of the effects of exenatide in metabolic regulation beyond its primary therapeutic role in regulation of glucose homeostasis. Clinical Trial Registration- URL: http://www.clinicaltrials.gov, NCT01056549.
用于治疗 2 型糖尿病的肠促胰岛素类药物可改善血浆脂质谱和餐后脂血症,但它们的确切作用机制仍不清楚。在这里,我们研究了胰高血糖素样肽-1 受体激动剂艾塞那肽对健康人肠道和肝脏富含甘油三酯的脂蛋白生成和清除的急性影响。
15 名血脂正常、血糖正常的男性,在 4 至 6 周的间隔内,以随机顺序,分别进行了 2 项研究(SC 10μg艾塞那肽与安慰剂),在胰腺钳夹条件下,通过用氘标记亮氨酸的脉冲持续输注,并用多室模型分析,研究富含甘油三酯的脂蛋白颗粒动力学。在每项研究中,通过通过鼻十二指肠管以恒定速度向十二指肠内输注高脂肪、混合宏量营养素的液体配方,使进食状态得以维持。艾塞那肽显著抑制富含甘油三酯的脂蛋白-载脂蛋白 B-48 的血浆浓度和生成率,但不抑制富含甘油三酯的脂蛋白-载脂蛋白 B-100。
这些结果表明,艾塞那肽可能对肠道脂蛋白颗粒生成有直接作用,而与长期研究中所见的体重增加和饱腹感变化无关,也与胃排空变化无关。这一发现扩展了我们对艾塞那肽在代谢调节中的作用的理解,超出了其在血糖稳态调节中的主要治疗作用。