Molecular Biology, Nutrition and Biotechnology (Nutrigenomics), University of the Balearic Islands (UIB) and CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Palma de Mallorca, Spain.
Peptides. 2010 Jul;31(7):1361-7. doi: 10.1016/j.peptides.2010.03.028. Epub 2010 Mar 27.
The aim of this study was to assess the effects of dietary leucine supplementation in lactating dams, particularly on energy homeostasis through signaling mechanisms in the central nervous system. Dams were fed ad libitum with standard diet during pregnancy (control dams) or supplemented with 2% leucine (leucine-supplemented dams) from delivery onwards. Food intake, body weight and composition were periodically recorded. Hypothalamus was collected at the end of lactation, and the expression of neuropeptide Y (NPY), agouti-related protein (AgRP) pro-opiomelanocortin (POMC), cocaine and amphetamine regulated transcript (CART), insulin receptor (InsR), ghrelin receptor (GSHR), melanocortin receptor (MCR4), leptin receptor (Ob-Rb) and suppressor of cytokine signaling 3 (SOCS3) were analyzed. Dietary leucine supplementation to lactating rats increased plasma leucine by 56%, modulated body composition and contributed to a tendency of higher ratio of lean/fat mass content of dams during lactation, without affecting food intake, thermogenesis capacity or body or tissue/organs weights. No differences in body weight of offspring from control and leucine-supplemented dams were found. The expression of orexigenic peptides (NPY and AgRP) decreased in leucine-dams, whereas the expression of anorexigenic peptides (POMC and CART), the hypothalamic receptors of insulin, ghrelin, melanocortin and leptin and SOCS3 did not change by leucine supplementation. In conclusion, increased leucine intake during lactation may contribute to a healthier profile of body composition in dams, without compromising the growth and development of the progeny by a mechanism associated with lower expression of orexigenic neuropeptides in hypothalamus.
本研究旨在评估哺乳期母鼠膳食亮氨酸补充的效果，尤其是通过中枢神经系统信号通路对能量平衡的影响。母鼠在妊娠期间自由进食标准饮食（对照组母鼠）或从分娩开始补充 2%亮氨酸（亮氨酸补充组母鼠）。定期记录食物摄入量、体重和体成分。哺乳期结束时采集下丘脑，分析神经肽 Y（NPY）、刺鼠相关蛋白（AgRP）、前阿黑皮素原（POMC）、可卡因和安非他命调节转录物（CART）、胰岛素受体（InsR）、胃饥饿素受体（GSHR）、黑素皮质素受体（MCR4）、瘦素受体（Ob-Rb）和细胞因子信号转导抑制因子 3（SOCS3）的表达。亮氨酸补充到哺乳期大鼠的饮食中可使血浆亮氨酸增加 56%，调节体成分，并有助于哺乳期母鼠瘦/脂肪质量比的增加趋势，而不影响食物摄入、产热能力或体重或组织/器官重量。对照组和亮氨酸补充组母鼠的后代体重无差异。亮氨酸组的食欲肽（NPY 和 AgRP）表达减少，而食欲肽（POMC 和 CART）、胰岛素、胃饥饿素、黑素皮质素和瘦素的下丘脑受体以及 SOCS3 的表达不受亮氨酸补充的影响。结论：哺乳期亮氨酸摄入增加可能有助于母鼠体成分更健康，而不会通过降低下丘脑食欲肽表达的机制影响后代的生长发育。
