[Secretion as a way to form enterocyte homeostasis]

The contents of K, Cl and Na in the mucus containing compartments of rat small intestine epithelium were examined with X-ray microanalysis. Measurements of concentration were made on sections prepared according to techniques based on cryofixation of soft biological tissues. The concentration of potassium and chlorine within the brush border region and in the secretion product of goblet cells is 200 mM and 90 mM, respectively, while sodium concentration was lower than the detection limit of 20 mM of the method used.