X-Ray Microanalysis of the Intestine: Identification of Electrolyte Secreting Cells

Abstract

Frozen dried cryosections of mouse jejunum were investigated. Besides Paneth and Goblet cells, two different types of crypt enterocytes could be distinguished according to clearly different electrolyte concentrations and to the presence (type A) or absence (type B) of small secretion granula in the cytoplasm.Secretion was stimulated by an intraperitoneal injection of either isoproterenol or pilocarpine. In some experiments, isoproterenol stimulation was blocked by alloxan, a potent inhibitor of the adenylate cyclase. Changes of cytoplasmic element concentrations were measured in frozen dried cryosections. In addition, the water content of the cells was measured by fully quantitative bulk specimen x-ray microanalysis.It was expected that actively secreting cells should display a decrease of Cl concentrations. This behaviour was confirmed in crypt A cells exclusively (Fig. 1). Therefore, it was concluded that crypt A cells are the main secretory cells in the intestinal epithelium.The water content of all epithelial cells in the intestine was found to increase under pilocarpine stimulation and to decrease under isoproterenol stimulation (Fig. 2).