MATERNAL GUT/MAMMARY GLAND INTERFACE IN LACTATION

长期目标是了解哺乳期母亲的肠道如何满足 母亲对营养物质的需求增加， 牛奶 驱动动机是生理和临床 哺乳的意义，以及肠道/乳腺的优势 接口作为解决广泛的定量问题的模型 身体内的整合。 具体目标是，利用小鼠模型， 包括以下内容：1.确定膳食营养素的上限值， 哺乳期的营养素摄入：是否仅限于热量当量 是基础代谢率的七倍 2.识别 限制哺乳期营养输出的近因。 候选 因素包括某些营养素的饮食供应，母乳， 生产能力，肠道消化能力，或后两者 因素相互匹配。 3.为了测试生理能力 在哺乳期是相互匹配的。 能力可能 会对性能造成瓶颈，或者可能超出需求一些储备 容量，而串联容量可能不匹配。 的 研究设计包括实验性地推动能源负担， 通过扩大产仔数，延长哺乳期， 哺乳期的持续时间，或将哺乳期的负担与 由于环境温度较低，产热增加的负担;变化 肠消化能力手术，通过部分切除的 小肠;和不同的乳腺分泌能力手术， 选择性消融。 肠刷的活动和能力- 边缘和基底外侧营养转运蛋白和刷状缘水解酶 将被测量以与其底物的膳食摄入量进行比较。

The long-term goal is to understand how a lactating mother's gut meets the mother's increased requirement for nutrients to be exported into milk. The driving motivations are the physiological and clinical significance of lactation, and the advantages of the gut/mammary gland interface as a model for attacking broad questions of quantitative integration within the body. The specific aims, utilizing mouse models, include the following: 1. To identify the ceiling value of dietary nutrient intake during lactation: is it limited to the caloric equivalent of about seven times the basal metabolic rate? 2. To identify the proximate factors limiting lactational nutrient output. Candidate factors include the dietary supply of certain nutrients, mammary milk- producing capacity, intestinal digestive capacity, or the latter two factors matched to each other. 3. To test how physiological capacities are matched to each other and to demand during lactation. Capacities may impose bottlenecks on performance or may exceed demand by some reserve capacity, while series capacities may not to matched to each other. The research design includes experimentally pushing the energy burden of lactation towards a limit by expanding litter size, extending the duration of lactation, or combining the burden of lactation with the burden of increased heat production as low ambient temperatures; varying intestinal digestive capacity surgically, by partial resection of the small intestine; and varying mammary gland secretory capacity surgically, by selective ablation. Activities and capacities of intestinal brush- border and basolateral nutrient transporters and brush-border hydrolases will be measured for comparison with dietary intakes of their substrates.