Adaptations of Glucose Metabolism During Pregnancy and Lactation
Adaptations of Glucose Metabolism During Pregnancy and Lactation
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DOI：
10.1023/a:1026336505343
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发表时间：
1997-07-01
影响因子：
2.5
通讯作者：
Bauman, Dale E.
中科院分区：
文献类型：
--
作者：
Bell, Alan W.;Bauman, Dale E.
妊娠晚期子宫对葡萄糖的需求增加，对哺乳期乳腺的需求甚至更大，这就需要对母亲肝脏、脂肪组织、骨骼肌和其他组织中葡萄糖的生产和利用进行重大调整。反刍动物的葡萄糖供应一直主要依赖肝脏的糖异生作用，即使在饲料底物供应不足的情况下，妊娠晚期和哺乳期早期的肝脏葡萄糖合成也会增加，以适应子宫或乳腺的需求。与此同时，脂肪组织和肌肉对葡萄糖的利用也减少了。在怀孕的动物中，这些反应因中度营养不良而被夸大，并通过组织对胰岛素的敏感性和反应性降低，与胰岛素反应促进葡萄糖转运体GLUT4的组织表达减少相关。在哺乳早期，外周组织对胰岛素的反应仍然严重减弱，但随着哺乳期中期的进展，胰岛素的反应会恢复。妊娠晚期胰岛素介导的葡萄糖代谢降低的特定顺势效应尚不明确。相比之下，生长激素几乎肯定是哺乳期间主要的顺应性影响因素，因为它的外源性给药会导致各种非乳腺组织的葡萄糖代谢(和许多其他功能)的特定变化，这些组织忠实地模仿正常的早期哺乳适应。
Increased glucose requirements of the gravid uterus during late pregnancy and even greater requirements of the lactating mammary glands necessitate major adjustments in glucose production and utilization in maternal liver, adipose tissue, skeletal muscle, and other tissues. In ruminants, which at all times rely principally on hepatic gluconeogenesis for their glucose supply, hepatic glucose synthesis during late pregnancy and early lactation is increased to accommodate uterine or mammary demands even when the supply of dietary substrate is inadequate. At the same time, glucose utilization by adipose tissue and muscle is reduced. In pregnant animals, these responses are exaggerated by moderate undernutrition and are mediated by reduced tissue sensitivity and responsiveness to insulin, associated with decreased tissue expression of the insulin-responsive facilitative glucose transporter, GLUT4. Peripheral tissue responses to insulin remain severely attenuated during early lactation but recover as the animal progresses through mid lactation. Specific homeorhetic effectors of decreased insulin-mediated glucose metabolism during late pregnancy have yet to be conclusively identified. In contrast, somatotropin is almost certainly a predominant homeorhetic influence during lactation because its exogenous administration causes specific changes in glucose metabolism (and many other functions) of various nonmammary tissues which faithfully mimic normal adaptations to early lactation.