Quantitative measurement of lactose absorption.
Quantitative measurement of lactose absorption.
复制标题
乳糖吸收的定量测量。
DOI：
10.1016/s0016-5085(76)80311-3
复制
发表时间：
1976
期刊：
影响因子：
29.4
通讯作者：
Michael Levitt
中科院分区：
文献类型：
--
作者：
John H. Bond;Michael Levitt
用三种间接方法测定了4名正常人和6名乳糖酶缺乏者摄入12.5g 1- 14 O-乳糖和4g聚乙二醇后的未吸收乳糖量：（1）测定肺氢（H_2）排泄量，（2）测定肺~（14）CO_2排泄量，（3）测定粪便~（14）C排泄量。将结果与直接根据多个末端回肠抽吸物的14 C：PEG比率确定的吸收进行比较。，通过回肠抽吸确定的乳糖未吸收分数在正常人中为0 - 8%，在牛奶不耐受受试者中为42 - 75%。而所有三种间接方法是有用的，在定性分离正常的缺陷的科目，乳糖吸收的量测定的H2排泄相关最密切的回肠测量（r= 0.94）。摄入14 C-乳糖后24小时的肺14 CO2排泄量不能区分正常（每24小时摄入14 C的17 ± 4%（SEM））和乳糖酶缺乏受试者（21.1 ± 3%）。同样，粪便14 C：PEG比率严重低估了吸收不良，粪便中出现的非吸收床14 C不到四分之一。这项研究表明，乳糖酶缺乏的受试者摄入牛奶后腹泻的易感性的个体差异可能是由于乳糖未吸收的量的差异和/或乳糖在结肠中的细菌代谢率的差异。在乳糖餐通过期间收集的回肠液的分析表明，进入结肠的渗透负荷的约三分之二由内源性电解质组成。因此，输送到结肠的水负荷是计算的由未吸收的糖维持的水负荷的约3倍。
The quantity of lactose not absorbed by 4 normal and 6 lactase-deficient subjects was determined by three indirect methods which involved: (1) measurement of pulmonary hydrogen (H2) excretion, (2) pulmonary14CO2excretion, and (3) stool14C excretion, after ingestion of 12.5 g of 1-14O-lactose and 4 g of polyethylene glycol (PEG). Results were compared with absorption determined directly from the14C:PEG ratio of multiple terminal ileal aspirates., The fraction of lactose not absorbed determined by ileal aspiration ranged from 0 to 8% in normals and 42 to 75% in milk-intolerant subjects. Whereas all three indirect methods were useful in qualitatively separating normal from deficient subjects, the quantity of lactose absorbed as determined by H2excretion correlated most closely with ileal measurements (r= 0.94). Pulmonary14CO2excretion for 24 hr after14C-lactose ingestion did not distinguish normal (17 ± 4% (SEM) of ingested14C per 24 hr) from lactase-deficient subjects (21.1 ± 3%). Likewise, stool14C:PEG ratios grossly underestimated malabsorption with less than one-quarter of the nonabsorbed14C appearing in the stool. This study suggests that individual differences in susceptibility to diarrhea after milk ingestion by lactase-deficient subjects may be due to differences in the quantity of lactose not absorbed and/or differences in the rate of bacterial metabolism of lactose in the colon. Analysis of ileal fluid collected during passage of the lactose meal indicated that about two-thirds of the osmotic load entering the colon consists of endogenous electrolytes. Thus the water load delivered to the colon is about 3 times that calculated to be osmotically held by the nonabsorbed sugar.