泌乳大鼠的膳食蛋白质、采食量与身体及组织组成变化之间的关系。

Relationships among dietary protein, feed intake and changes in body and tissue composition of lactating rats.

作者信息

Sainz R D, Calvert C C, Baldwin R L

出版信息

J Nutr. 1986 Aug;116(8):1529-39. doi: 10.1093/jn/116.8.1529.

DOI:10.1093/jn/116.8.1529

Abstract

To quantify effects of protein and energy intake on changes in tissue composition in lactating rats, 36 rats were fed three diets (L, M and H, containing 12,24, and 36% protein, respectively) at four levels of intake (100, 70, 50 and 30% of ad libitum) from d 7 to 14 of lactation. Three rats per treatment were killed on d 14; carcass, viscera, liver and mammary glands were dissected and analyzed for water, fat, protein and ash. Twelve rats killed on d 7 provided initial composition estimates. All rats lost weight loss was affected slightly by diet but drastically by intake, ranging from 22.4 g in ad libitum-fed rats to 79.9 g in the 30% group. Fat losses, mostly from carcass, were insensitive to diet but were increased to maximum at the 70% intake level, and further restriction did not result in significantly greater fat losses. Protein losses in all tissues increased with degree of feed restriction. Protein losses in viscera, liver and mammary decreased with higher dietary protein. Possible homeorrhetic adaptations responsible for these patterns of nutrient partition are discussed in terms of changes in rates of fat and protein turnover and hormonal effects upon these rates.

摘要

为了量化蛋白质和能量摄入对泌乳大鼠组织组成变化的影响，在泌乳第7至14天，给36只大鼠喂食三种日粮（L、M和H，分别含12%、24%和36%的蛋白质），摄入量为四个水平（自由采食的100%、70%、50%和30%）。每种处理在第14天处死3只大鼠；解剖并分析胴体、内脏、肝脏和乳腺的水分、脂肪、蛋白质和灰分。在第7天处死的12只大鼠提供初始组成估计值。所有大鼠均体重减轻，体重减轻受日粮影响较小，但受摄入量影响极大，自由采食组大鼠体重减轻22.4克，30%摄入量组大鼠体重减轻79.9克。脂肪损失主要来自胴体，对日粮不敏感，但在70%摄入量水平时增至最大，进一步限制并未导致脂肪损失显著增加。所有组织中的蛋白质损失均随饲料限制程度增加。内脏、肝脏和乳腺中的蛋白质损失随日粮蛋白质含量升高而减少。根据脂肪和蛋白质周转率的变化以及激素对这些周转率的影响，讨论了造成这些营养分配模式的可能的顺势适应情况。