Levy AnneMarie, Marshall Paul, Zhou Yan, Kreek Mary Jeanne, Kent Katrina, Daniels Stephen, Shore Ari, Downs Tiana, Fernandes Maria Fernanda, Mutch David M, Leri Francesco
Department of Psychology, University of Guelph, Guelph, ON N1G 2W1, Canada.
Laboratory of Addictive Diseases, Rockefeller University, New York, NY 10065, USA.
Nutrients. 2015 May 22;7(5):3869-90. doi: 10.3390/nu7053869.
This study explored whether different ratios of fructose (F) and glucose (G) in sugar can engender significant differences in self-administration and associated neurobiological and physiological responses in male Sprague-Dawley rats. In Experiment 1, animals self-administered pellets containing 55% F + 45% G or 30% F + 70% G, and Fos immunoreactivity was assessed in hypothalamic regions regulating food intake and reward. In Experiment 2, rats self-administered solutions of 55% F + 42% G (high fructose corn syrup (HFCS)), 50% F + 50% G (sucrose) or saccharin, and mRNA of the dopamine 2 (D2R) and mu-opioid (MOR) receptor genes were assessed in striatal regions involved in addictive behaviors. Finally, in Experiment 3, rats self-administered HFCS and sucrose in their home cages, and hepatic fatty acids were quantified. It was found that higher fructose ratios engendered lower self-administration, lower Fos expression in the lateral hypothalamus/arcuate nucleus, reduced D2R and increased MOR mRNA in the dorsal striatum and nucleus accumbens core, respectively, as well as elevated omega-6 polyunsaturated fatty acids in the liver. These data indicate that a higher ratio of fructose may enhance the reinforcing effects of sugar and possibly lead to neurobiological and physiological alterations associated with addictive and metabolic disorders.
本研究探讨了糖中不同比例的果糖（F）和葡萄糖（G）是否会在雄性斯普拉格-道利大鼠的自我给药以及相关的神经生物学和生理反应方面产生显著差异。在实验1中，动物自我给药含有55% F + 45% G或30% F + 70% G的颗粒，并且在下丘脑调节食物摄入和奖赏的区域评估Fos免疫反应性。在实验2中，大鼠自我给药55% F + 42% G（高果糖玉米糖浆（HFCS））、50% F + 50% G（蔗糖）或糖精的溶液，并在参与成瘾行为的纹状体区域评估多巴胺2（D2R）和μ-阿片受体（MOR）基因的mRNA。最后，在实验3中，大鼠在其饲养笼中自我给药HFCS和蔗糖，并对肝脏脂肪酸进行定量。结果发现，较高的果糖比例导致较低的自我给药、下丘脑外侧/弓状核中较低的Fos表达、背侧纹状体和伏隔核核心中D2R减少和MOR mRNA增加，以及肝脏中ω-6多不饱和脂肪酸升高。这些数据表明，较高的果糖比例可能会增强糖的强化作用，并可能导致与成瘾和代谢紊乱相关的神经生物学和生理改变。
