1c:I[419806,["/_next/static/chunks/bb923814e1f4d2e9.js","/_next/static/chunks/dd3ee9f5b7716ca6.js","/_next/static/chunks/4204a0ae82542ca8.js","/_next/static/chunks/30036bedc5269936.js","/_next/static/chunks/6e1aa89a642f40be.js","/_next/static/chunks/cd5e572bc3e4eb92.js","/_next/static/chunks/8ffd0b71567920d8.js","/_next/static/chunks/67ea6dfd21f16c5f.js","/_next/static/chunks/24eb4379f68013fd.js","/_next/static/chunks/b8cd775ffdf935bd.js","/_next/static/chunks/983103cd9eb7b428.js","/_next/static/chunks/d4ac9dcf27f6ff52.js","/_next/static/chunks/294b9525248c8e5f.js"],"default"] 1d:T4fd,Abstract A method of purification of a vitamin D-dependent calcium-binding protein from chick intestinal mucosa is described. The purification procedure involved the use of ammonium sulfate precipitation, gel filtration on Sephadex G-100, and preparative disc electrophoresis. The assay system for calcium-binding protein is based upon the competition between calcium-binding protein and an ion exchange resin for added 45Ca. An equation linearly relating binding protein concentration to binding activity is given. Sedimentation velocity and gel filtration behavior indicated that the product was homogeneous with respect to size. Two acrylamide gel systems gave single bands, whereas a third showed the presence of a possible degradation product in addition to calcium-binding protein. The molecular weight of calcium-binding protein was found to be about 2.8 x 104 by calibrated gel filtration and about 2.5 x 104 by equilibrium sedimentation (assumed partial specific volume = 0.72). The formation constants between calcium-binding protein and calcium, strontium, and barium were 2.6 x 105 m-1, 3.9 x 104 m-1, and 5.8 x 103 m-1, respectively, and it appears that 1 mole of protein binds 1 atom of calcium. Preliminary analysis of the composition of the protein is reported.1e:T407,In the "short bowel" syndrome, the segment of small intestine which remains may compensate functionally for the portion which has been lost.^1,2The initial period of diarrhea and steatorrhea which ordinarily follows massive small bowel resection gradually improves.³Epithelial cell hyperplasia of the villi⁴and increased absorption of nutrients have been described in the remaining segments of gut after massive bowel resections.^2-5 This study extends the observations of functional adaptation by demonstrating in four patients with massive small bowel resection an increased absorption of water and sodium per unit length of intestine by the remaining bowel.

Materials and Methods

The intestinal absorption of water and sodium were studied in four patients with massive small bowel resections (Table) and in six control subjects with intact bowel. Informed consent was obtained from all patients. The subjects fasted overnight for 12 hours and then a triple lumen polyvinyl tube1f:T538,A calcium binding protein has been demonstrated in human duodenal mucosa which we believe to be human vitamin D dependent CaBP. Sephadex gel filtration demonstrated that the duodenal mucosa of both the human and pig contained a calcium binding protein with a similar molecular weight to the reported vitamin D dependent rat CaBP (M.W. 12 000–13 000) but dissimilar to chick CaBP (M.W. 24 000–28 000). In addition the rat, pig, and human mucosa contained a high molecular weight calcium binding protein which is probably not vitamin D dependent.A relatively simple procedure, utilizing the tagging of CaBP by 47 Ca, has been developed to partially purify normal pig CaBP by Sephadex gel filtration. Further fractionation of the 12 000–13 000 M.W. area, using disc electrophoretic procedures, separated two calcium binding proteins which had similar electrophoretic mobilities and calcium binding formation constants (3.5 and 5.5 × 10 6 , respectively), indicating that both are forms of CaBP but that either one or both have been altered during the procedures. The electrophoretic mobilities of both of these proteins are relatively low in the presence of calcium ions but m

	Year	Citations

References