Department of Psychological Sciences, Purdue University, West Lafayette, IN 47907, USA.
Behav Brain Res. 2012 Jul 15;233(1):1-14. doi: 10.1016/j.bbr.2012.04.024. Epub 2012 Apr 26.
Previous work from our lab has demonstrated that experience with high-intensity sweeteners in rats leads to increased food intake, body weight gain and adiposity, along with diminished caloric compensation and decreased thermic effect of food. These changes may occur as a result of interfering with learned relations between the sweet taste of food and the caloric or nutritive consequences of consuming those foods. The present experiments determined whether experience with the high-intensity sweetener saccharin versus the caloric sweetener glucose affected blood glucose homeostasis. The results demonstrated that during oral glucose tolerance tests, blood glucose levels were more elevated in animals that had previously consumed the saccharin-sweetened supplements. In contrast, during glucose tolerance tests when a glucose solution was delivered directly into the stomach, no differences in blood glucose levels between the groups were observed. Differences in oral glucose tolerance responses were not accompanied by differences in insulin release; insulin release was similar in animals previously exposed to saccharin and those previously exposed to glucose. However, release of GLP-1 in response to an oral glucose tolerance test, but not to glucose tolerance tests delivered by gavage, was significantly lower in saccharin-exposed animals compared to glucose-exposed animals. Differences in both blood glucose and GLP-1 release in saccharin animals were rapid and transient, and suggest that one mechanism by which exposure to high-intensity sweeteners that interfere with a predictive relation between sweet tastes and calories may impair energy balance is by suppressing GLP-1 release, which could alter glucose homeostasis and reduce satiety.
先前我们实验室的工作表明，大鼠接触高强度甜味剂会导致食物摄入量增加、体重增加和肥胖，同时减少热量补偿和食物的热效应。这些变化可能是由于干扰了食物的甜味与摄入这些食物的热量或营养后果之间的习得关系。本实验旨在确定高强度甜味剂糖精与热量甜味剂葡萄糖的接触经验是否会影响血糖稳态。结果表明，在口服葡萄糖耐量试验中，先前摄入过糖精甜味补充剂的动物血糖水平升高更为明显。相比之下，当直接将葡萄糖溶液注入胃中进行葡萄糖耐量试验时，两组间的血糖水平没有差异。口服葡萄糖耐量反应的差异并不伴有胰岛素释放的差异；先前暴露于糖精和先前暴露于葡萄糖的动物的胰岛素释放相似。然而，与葡萄糖暴露动物相比，口服葡萄糖耐量试验时 GLP-1 的释放明显降低，但在管饲葡萄糖耐量试验时则没有降低。与糖精接触的动物的血糖和 GLP-1 释放差异是快速和短暂的，这表明高强度甜味剂干扰甜味与卡路里之间的预测关系可能会破坏能量平衡的一种机制是通过抑制 GLP-1 的释放，这可能会改变葡萄糖稳态并减少饱腹感。
