Montagne L, Toullec R, Lallès J P
Unité Mixte de Recherche sur le Veu et le Porc, Institut National de la Recherche Agronomique, Rennes, France.
J Dairy Sci. 2000 Mar;83(3):507-17. doi: 10.3168/jds.S0022-0302(00)74910-1.
The aim of this study was to develop a specific ELISA for calf intestinal mucin to quantify its contribution to ileal endogenous losses. Mucin was isolated from intestinal scrapings by cesium chloride density gradient ultracentrifugation. The isolated mucin had a high concentration of glutamic and aspartic acids, threonine, and serine (13.2, 11.2, 9.6, and 9.2 mol % of total amino acids assayed, respectively). The carbohydrates present were (mol % of total hexoses): galactose 42.1, N-acetylglucosamine 24.1, N-acetylgalactosamine 23.6, fucose 4.7, mannose 3.1, and sialic acids 2.4. Amino acids and carbohydrates represented 52.6 and 47.4% of the mucin by weight, respectively. A rabbit hyperimmune plasma was raised against purified mucin and used to set up an ELISA. The linear range of this assay was 20 to 640 ng/ml. The plasma cross-reacted with calf abomasal and colonic mucin. It showed no cross-reactivity with nonmucin components and no reactivity with intestinal mucin from other animal species except for the rat. Mucin accounted for approximately 3.5% of the dry matter output at the ileum of calves fed a substitute milk based on skim milk powder. This represented a flow of 3.4 g of mucin/kg of dry matter intake. Mucin flow increased when dietary protein was provided by cow's colostrum. Finally, the developed assay is a suitable tool to investigate the impact of dietary factors on the flow of mucin along the gut of preruminant calves.
本研究的目的是开发一种针对犊牛肠粘蛋白的特异性酶联免疫吸附测定（ELISA），以量化其对回肠内源性损失的贡献。通过氯化铯密度梯度超速离心从肠道刮屑中分离粘蛋白。分离出的粘蛋白含有高浓度的谷氨酸、天冬氨酸、苏氨酸和丝氨酸（分别占测定的总氨基酸的13.2%、11.2%、9.6%和9.2%）。存在的碳水化合物（占总己糖的摩尔百分比）为：半乳糖42.1%、N-乙酰葡糖胺24.1%、N-乙酰半乳糖胺23.6%、岩藻糖4.7%、甘露糖3.1%和唾液酸2.4%。氨基酸和碳水化合物分别占粘蛋白重量的52.6%和47.4%。用纯化的粘蛋白制备兔超免疫血浆并用于建立ELISA。该测定的线性范围为20至640 ng/ml。该血浆与犊牛皱胃和结肠粘蛋白发生交叉反应。它与非粘蛋白成分无交叉反应，除大鼠外与其他动物物种的肠粘蛋白无反应。在饲喂以脱脂奶粉为基础的代乳品的犊牛回肠中，粘蛋白约占干物质输出的3.5%。这相当于每千克干物质摄入量有3.4克粘蛋白的流量。当由牛初乳提供膳食蛋白质时，粘蛋白流量增加。最后，所开发的测定方法是研究膳食因素对反刍前犊牛肠道粘蛋白流量影响的合适工具。
