高脂饮食联合光照周期改变对不同性别小鼠体重的影响

摘要 目的：随着夜间光照与肥胖现象日趋普遍化，机体内的昼夜节律与生理代谢均受到不同程度的影响，其中不同性别间的差异有待进一步研究。本文旨在通过比较高脂饲料喂养，以及改变光照周期从而对不同性别小鼠体重产生的影响来模拟高脂肪饮食时人类受到夜间光照的性别差异。方法：随机选取C57BL/6小鼠雌鼠、雄鼠各12只，分别按照性别、喂养饲料随机均分成4组，其中随机选取一组雌鼠和一组雄鼠喂养60%高脂饲料作为实验组，另外的一组雌鼠和一组雄鼠喂养普通饲料作为对照组，连续喂养8周，观察并记录各组小鼠体重变化；第1~6周将实验小鼠置于24h/0h光照周期下生活，第6~8周实验小鼠生活的光照周期改为12h/12h。结果：在高脂饲料喂养以及光照周期失调（24h/0h）的条件下，雌、雄鼠体重均有增长（P<0.05），但雄鼠体重增加量是雌鼠的三倍。当光照周期恢复正常（12h/12h）后，雌、雄小鼠体重增长量均下降。不同性别的小鼠食用高脂饲料以及生物节律被打乱时体重均增加，但雄鼠体重增加量明显大于雌鼠，提示同在高脂饲料饮食的条件下，雌鼠受生物节律影响比雄鼠更大。结论：高脂饮食实验小鼠模型中雌鼠受生物节律的影响比雄鼠更大。

Effects of Eigh Fat Diet Combined with Light Cycle Change on Body Weight of Mice with Different Sex

ABSTRACT Objective: With the increasing prevalence of night light and obesity, circadian rhythm and physiological metabolism in the body are affected to varying degrees, and the differences between different genders need to be further studied. The aim of this study was to simulate the sex differences in human exposure to nocturnal light on a high-fat diet by comparing the effects of high-fat diet and photoperiod change on body weight in mice of different genders. Methods: Twelve female and male C57BL/6 mice were randomly divided into 4 groups according to sex and feeding diet. One group of female mice and one group of male mice were randomly fed with 60% high-fat diet as the experimental group, and the other group of female mice and one group of male mice were fed with ordinary diet as the control group. The body weight of each group was observed and recorded for 8 weeks. The mice were exposed to 24h/0h light cycle during the 1st to 6th weeks, and the light cycle was changed to 12h/12h during the 6th to 8th weeks. Results: The body weight of both male and female rats increased under the condition of high fat diet and irregular light cycle (24h/0h) (P<0.05), but the body weight of male rats increased three times as much as that of female rats. After light cycle returning to normal (12h/12h), the amount of mouse body weight increment reduced. Mice of different genders gained weight when they were fed high-fat diet and their biological rhythms were disrupted, but the weight gain of male mice was significantly greater than that of female mice under the condition of high fat diet. Conclusion: Female mice were more affected by biorhythm than male mice in the high-fat diet mouse model.