ABSTRACT
Distribution and morphology of argyrophil and argentaffin cells in small intestine of 11 rats were studied by means of Huang's method of argyrophil reaction and Singh's method of argentaffin reaction on paraffin sections of intestine rolls. The results are as follows:1. The density of argyrophil and argentaffin cells in rat small intestine is the highest in the duodenum and progressively decreases from jejunum to ileum.2. The staining intensity of argyrophil and argentaffin cells is lowest in the basal portion of crypts and progressively increases from crypts to villus. Intensely stained argyrophil and argentaffin cells in the villus tip were observed. The basal portion of the argyrophil cells has cytoplasmic processes extending to connective tissue of the lamina propria and the argyrophil granules are released to lamina propria along these processes. Argyrophil granules can usually be found to extend to the luminal surface of these cells; occasionally they were observed extracellularly in the gland cavity, suggesting that argyrophil and argentaffin cells may have both endocrine and exocrine functions.3. Some argyrophil cells can be found in connective tissue of the lamina propria. The cells are irregular in shape and possesses processes. There are argyrophil granules in perikaryon and the processes and occasionally outside the cells. The argyrophil cells in the lamina propria are the same as those among epithelial cells in shape, argyrophil property and density of the granules. It is possible that these cells belong to endocrine cells.