Abstract
Endogenous peroxidases were histochemically demonstrated in epithelial cells over Peyer's patches in the jejunum of the rats. By one week after birth, the peroxidase-positive cells were found in the epithelial cells over the lymphoid aggregate in the jejunum. Those peroxidase-containing epithelial cells increased in number thereafter, while the peroxidase in those in the ileum remained negative. Electron microscopically the peroxidase was localized in the perinuclear spaces, cisternae of the endoplasmic reticulum and apically located cytoplasmic vesicles of the cell. The number of the peroxidase-positive cells in adult germ-free rats was much fewer than that in the conventional, although the distribution patterns of the peroxidase activity in the intestine were similar to each other. In point of the histochemical properties of the enzyme, this epithelial peroxidase appears to be analogous to the peroxidases of some other epithelial cells such as large intestine, salivary and lacrimal glands, and to differ from the myelo-peroxidase in the myeloid-derived cells.
