Van Deest B W, Fordtran J S, Morawski S G, Wilson J D
J Clin Invest. 1968 Jun;47(6):1314-24. doi: 10.1172/JCI105823.
Studies were carried out to test the hypothesis that abnormal bile salt metabolism (interruption of the enterohepatic circulation) is responsible for steatorrhea in patients with ileal disease and (or) ileectomy.Duodenal bile salt concentration after a single, standard meal eaten at 8 a.m. was measured in 8 patients with ileectomy steatorrhea and compared with 11 normal control subjects and 7 hospitalized patients without gastrointestinal disease. Mean bile salt concentration was approximately half normal in the ileectomy group, but some of the patients fell well within the normal range, even on repeat studies. However, it was shown that the second and third meals eaten during a single day were associated with a marked depression of duodenal bile salt concentration in ileectomy patients, which suggested that the first meals in these patients flush out a large fraction of the bile salt pool. Simultaneously measured turnover studies with taurocholate-(14)C showed at t((1/2)) of 3.1 hr in these patients compared with 29.5 and 32 hr in two control subjects, proving that the enterohepatic circulation had indeed been interrupted by ileectomy. Hepatic synthesis can apparently partially reconstitute the bile salt pool during the overnight period. Additional studies were carried out to determine the relation between bile salt and micellar fat concentration in proximal small bowel contents after ingestion of the same standard meal. Below a bile salt concentration of 1.7 mg/ml, less than 0.8 mg/ml of lipid existed in the micellar phase of intestinal contents, whereas when bile salt concentration exceeded this level the amount of fat in the micellar phase rose progressively. Only 1 of 11 samples from three ileectomy patients had a micellar fat concentration > 0.8 mg/ml, whereas 33 of 42 samples from control subjects had micellar fat concentration > 0.8 mg/ml.Thus, abnormally low duodenal bile salt concentration during at least a portion of the day, with the associated depression of micellar fat, appears to be a major cause of decreased fat absorption in patients with ileectomy steatorrhea.
开展了多项研究，以验证以下假说：胆汁盐代谢异常（肠肝循环中断）是导致回肠疾病患者和（或）接受回肠切除术患者脂肪泻的原因。对8例回肠切除术后脂肪泻患者在上午8点进食一顿标准餐后的十二指肠胆汁盐浓度进行了测量，并与11名正常对照者和7例无胃肠道疾病的住院患者进行比较。回肠切除组的平均胆汁盐浓度约为正常水平的一半，但部分患者即使在重复检测时也处于正常范围内。然而，研究表明，回肠切除患者在一天内进食的第二餐和第三餐会导致十二指肠胆汁盐浓度显著降低，这表明这些患者的第一餐排出了大部分胆汁盐池。同时进行的牛磺胆酸盐-（14）C周转研究显示，这些患者的t（1/2）为3.1小时，而两名对照者的t（1/2）分别为29.5小时和32小时，证明回肠切除术确实中断了肠肝循环。肝合成显然可以在夜间部分重建胆汁盐池。还开展了其他研究，以确定摄入相同标准餐后近端小肠内容物中胆汁盐与微胶粒脂肪浓度之间的关系。当胆汁盐浓度低于1.7mg/ml时，肠内容物微胶粒相中脂质含量低于0.8mg/ml，而当胆汁盐浓度超过该水平时，微胶粒相中的脂肪量逐渐增加。来自3例回肠切除患者的11个样本中只有1个微胶粒脂肪浓度>0.8mg/ml，而来自对照者的42个样本中有33个微胶粒脂肪浓度>0.8mg/ml。因此，至少在一天中的部分时间里十二指肠胆汁盐浓度异常低，并伴有微胶粒脂肪减少，似乎是回肠切除术后脂肪泻患者脂肪吸收减少的主要原因。
