Adaptive adjustments of energy intake and body fat play an important role in allowing animals' to meet the energy demands of thermoregulation during cold conditions and reproduction. Body fat is usually metabolized during lactation, which is one of the most energetically demanding activities of female mammals, however the effect of this on the energy budget and body fat regulation after lactation remains unclear. We compared the energy intake and body fat of female striped hamsters (Cricetulus barabensis) fed either a high-fat or low-fat diet for 21 days after the end of lactation (post-lactation, PL) to those of virgin controls. Serum leptin levels and the expression of hypothalamic orexigenic and anorexigenic neuropeptide genes were also measured and compared. Although lactating females consumed significantly more food, they had significantly lower body fat than virgin controls. The energy intake and body fat levels of the PL females were, however, significantly higher than those of virgin females. This was particularly true for the PL females that were fed high-fat diet. These females had significantly higher serum leptin concentrations, but lower hypothalamic leptin receptor gene expression, than virgin females. Neither orexigenic nor anorexigenic neuropeptide levels in the hypothalamus differed significantly between the PL and virgin females. This suggests that a negative energy balance during lactation drives fat accumulation after lactation. Furthermore, leptin resistance may occur after the end of lactation, causing females to consume more food, and accumulate more fat, than virgin females.

能量摄入和体内脂肪的适应性调节在使动物满足寒冷条件下和繁殖过程中体温调节的能量需求方面发挥着重要作用。体脂通常在哺乳期被代谢，这是雌性哺乳动物最需要能量的活动之一，然而，这种物质对哺乳后能量预算和体脂调节的影响尚不清楚。我们比较了雌性条纹仓鼠（Cricetulus barabensis）的能量摄入和体脂）在哺乳结束后（泌乳后，PL）与原始对照组相比，饲喂高脂或低脂饮食21天。还测量并比较了血清瘦素水平以及下丘脑的食源性和厌食性神经肽基因的表达。尽管哺乳期女性消耗的食物明显更多，但与原始对照组相比，她们的体内脂肪明显降低。但是，PL雌性动物的能量摄入和体脂水平显着高于处女雌性。对于接受高脂饮食的PL雌性来说尤其如此。这些女性的血清瘦素浓度显着高于处女女性，但下丘脑瘦素受体基因表达较低。PL和处女之间下丘脑的食源性或厌食性神经肽水平均无显着差异。这表明哺乳期能量平衡失调会导致哺乳后脂肪堆积。此外，泌乳结束后可能会产生瘦素抵抗性，这导致女性比原始女性食用更多的食物，并积累更多的脂肪。