Aging causes changes in body composition and energy balance. Estrogen plays an important role in body's metabolism. The aim of this study was to determine whether estrogen has beneficial effects on leptin responsiveness in aged mice. Young 4 months and aged 19-21 female mice fed High Fat Diet (HFD) or Standard Diet (SD) for 12 weeks and following received estrogen for 4 weeks. Responsiveness to leptin was compared by measuring energy balance parameters. Results showed that HFD caused weight gain compared to SD in young, but had no effect on aged animals. Estrogen reduced body weight, energy intake and visceral fat in young, while none of these parameters was affected in aged animals. Although there was leptin sensitivity in aged compared to ovariectomized animals, estrogen only improved the sensitivity of young to leptin. Estrogen prevented increase in TNF-α and a decrease in IL-10 in HFD young and aged animals. Response to estrogen depended on age, and estrogen increased leptin sensitivity only in young animals. Determining the exact mechanism of this action is suggested in future studies.

中文翻译：

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衰老与高脂饮食喂养的小鼠中雌激素对瘦素反应性的有益作用的丧失有关：雌激素受体α和细胞因子的作用。

衰老会导致身体成分和能量平衡发生变化。雌激素在人体的新陈代谢中起着重要作用。这项研究的目的是确定雌激素是否对衰老小鼠的瘦素反应性具有有益作用。4月龄的幼小和19-21岁的雌性小鼠喂食高脂饮食（HFD）或标准饮食（SD）持续12周，之后接受雌激素持续4周。通过测量能量平衡参数比较了对瘦素的反应能力。结果表明，与SD相比，HFD引起体重增加，但对成年动物没有影响。雌激素降低了年轻人的体重，能量摄入和内脏脂肪，而这些参数在老年动物中均未受到影响。尽管与切除卵巢的动物相比，老年人对瘦素的敏感性更高，但雌激素仅能提高年轻人对瘦素的敏感性。雌激素可防止HFD幼龄和成年动物的TNF-α升高和IL-10降低。对雌激素的反应取决于年龄，雌激素仅在幼小动物中增加瘦素敏感性。在未来的研究中建议确定这种作用的确切机制。