Subcellular fractionation of human intestinal mucosa by large-scale zonal centrifugation. I. Characterization of subcellular organelles in the distal part of the ileum.

The subcellular organelles in human ileal mucosa have been characterized by large-scale rate zonal and isopycnic density-gradient centrifugation. Mucosal scrapings were obtained from surgical specimens and the cells disrupted by extrusion under controlled pressure. The homogenized cells were then centrifuged to prepare a cell extract and the extract fractionated in a single-step procedure by zonal centrifugation on a continuous sucrose gradient. The subcellular organelles (brush borders, basal-lateral membranes, lysosomes, mitochondria, and endoplasmic reticulum) were located in the density gradient by assay of marker enzymes. Since a large number of analyses can be done on each fraction of interest, this fractionation technique may be used to study a variety of compounds and concepts involved in the subcellular physiology and pathology of human ileal mucosa.