UNIQUE CRYSTALLINE INCLUSIONS IN NEONATAL PIG SMALL-INTESTINAL EPITHELIAL-CELLS

In this study we describe the presence of novel crystalline inclusions in the jejunal and ileal epithelium of newborn pigs. Hampshire/Yorksh ire piglets (0-3 days) were anesthetized with pentobarbital and tissue s were recovered following laparotomy. Sections of jejunum and ileum w ere prepared with a variety of fixatives for paraffin and methacrylate embedment for light and electron microscopy. The characteristics of t hese crystalline structures have been demonstrated by cytochemical sta ining, immunohistochemical staining, and ultrastructural studies. Usin g light microscopy, it was determined that 10.8% of villus epithelial cells in the jejunum contained inclusions, whereas inclusions were pre sent in 26.6% of the villus epithelial cells in the ileum. Inclusions were absent in crypt epithelial cells of both areas of the intestine, and the percentage of cells with inclusions increased towards the vill us tip. Preliminary histochemical analysis has been unrevealing. The i nclusions are periodic acid/Schiff's (PAS) reagent negative, and do no t stain for the presence of concentrated proteins. Using electron micr oscopy, the inclusions are found to be clustered in the supranuclear r egion of the cells and are generally oriented with the long axis of th e cell. The crystals vary in size and have a dense core region surroun ded by a regular less dense periphery.