短期高脂饮食改变大鼠对蔗糖的喜好和甜味觉的敏感性

Alterations of sucrose preference and sweet taste sensitivity after short-term high-fat diet feeding in rats

目的探讨高脂饮食对大鼠甜味觉敏感性的影响。方法刚断乳雄性SD大鼠,适应1周后,高脂饮食喂养2周,按体质量增加程度将实验动物分为3组,即肥胖易感组(obesity prone,OP)、肥胖抵抗(obesity resistant,OR)组和对照组(control,C)。OP及OR组继续喂养高脂饲料,对照组转由正常饲料喂养(C-C),连续8周。采用条件性厌味(CTA)及双瓶选择实验,检测大鼠对甜味的喜好及其阈值变化,并测定大鼠热量总摄入量和食物转化效率。结果 1高脂喂养的OP大鼠体质量增加明显高于OR及对照组大鼠,而对照组大鼠体质量增加又高于高脂喂养的OR大鼠。2高脂喂养的大鼠(OP与OR)的蔗糖阈值明显低于正常对照组大鼠,但OP与OR大鼠之间的蔗糖阈值无差异。3高脂喂养大鼠(OP与OR)的蔗糖喜好明显高于正常对照组大鼠,而OP与OR大鼠之间的蔗糖喜好无差异。4高脂喂养的OP大鼠总热量摄入明显高于OR大鼠,但高脂饲料喂养与正常饲料喂养的大鼠总热量摄入无差异。5高脂喂养的OP大鼠食物效率明显高于OR大鼠及正常对照大鼠,而高脂喂养的OR大鼠食物效率与正常对照大鼠无差异。结论高脂饮食可通过增高大鼠甜味敏感性,从而影响摄食行为并引起肥胖。

Objective To investigate the effect of high-fat diet on the sweet taste sensitivity in rats. Methods We subjected weaning male SD rats to the new feeding environment for 1 week and then fed them with high-fat diet for 2 weeks. According to the degree of weight gain, the rats were divided into obesity-prone （OP） group, obesity-resistant （OR） group and control （C） group. OP and OR rats continued to intake high-fat diet for 8 weeks, but those in control group were fed with normal diet （C-C） for 8 weeks. By applying the conditioned taste aversion （CTA） and the double-bottle experiment, we detected sucrose detection threshold and sucrose preference, and determined the total energy intake and feed efficiency. Results The weight gain of OP rats fed with high- fat diet was significantly higher than that of both OR rats and control rats, while it was significantly higher in the control rats than in OR rats. The sucrose detection threshold of rats fed with high-fat diet （OP and OR） was significantly lower than that of rats in the control group fed with normal diet, but there was no difference between OP and OR rats. The sucrose preference of high-fat feeding rats （OP and OR） was significantly lower than that of rats in control group fed with normal diet, but there was no difference between OP and OR rats. The total caloric intake of OP rats fed with high-fat diet was significantly higher than that of high-fat feeding OR rats, but there was no difference between the high-fat feeding rats and the normal diet feeding rats. Food efficiency of high-fat feeding OP rats was significantly higher than that of OR rats fed with high-fat diet and control rats fed with normal diet, but there was no difference between high-fat feeding OR rats and normal diet feeding rats. Conclusion High-fat diet influences sweet taste sensitivity, which affects the feeding behavior and then results in obesity.