Kelly J M, Summers M, Park H S, Milligan L P, McBride B W
Department of Animal and Poultry Science, University of Guelph, ON, Canada.
J Dairy Sci. 1991 Feb;74(2):678-94. doi: 10.3168/jds.S0022-0302(91)78215-5.
Consistent with the increased demand for nutrients imposed by lactation and growth, those tissues directly involved in the digestion, absorption, and processing of the required additional nutrients show response to these states. During lactation, the rumen, upper intestine, and liver increase in size, and more energy is spent on Na+,K+ transport and on protein turnover. The massive endocrine influences during lactation suggest that the metabolism of other tissues besides these and mammary tissue would be influenced, but evidence is rather sparse. Ion transport and protein metabolism in some muscles may indeed be increased. Although substrate cycles characteristically account for a substantially smaller portion of the energy expenditure in the intact animal than do ion transport and protein turnover, stage of lactation influences some of these cycles, particularly the triacylglycerol fatty acid cycle. The needs for additional quantitative in vivo measurements of metabolic conversions and for mechanistic model description of metabolic events in nonmammary tissues are discussed.
与泌乳和生长对营养物质需求的增加相一致，那些直接参与所需额外营养物质消化、吸收和加工的组织会对这些状态产生反应。在泌乳期间，瘤胃、上段肠道和肝脏体积增大，并且更多能量用于钠钾转运和蛋白质周转。泌乳期间大量的内分泌影响表明，除了这些组织和乳腺组织外，其他组织的代谢也会受到影响，但相关证据相当稀少。某些肌肉中的离子转运和蛋白质代谢可能确实会增加。尽管在完整动物中，底物循环在能量消耗中所占的比例通常比离子转运和蛋白质周转小得多，但泌乳阶段会影响其中一些循环，尤其是三酰甘油脂肪酸循环。本文讨论了对非乳腺组织中代谢转化进行额外定量体内测量以及对代谢事件进行机制模型描述的需求。
