Malfunction of Intestinal Mucus and Mucus Production

Abstract

The mucus layer is a complex, frustrating, sheet of proteins, glycoproteins, cells, bacteria, ions and water which covers and presumably protects, underlying epithelial cells, while remaining sufficiently porous to permit the passage of vital nutrients and secretions. The possibilities for malfunction are real and varied. It seems evident that thinning of the layer may predispose the intestine to ulceration and inflammation, while thickening may lead to obstruction of bronchi and small ductules as in cystic fibrosis. Porosity may be affected by cross-linking agents such as drugs (Kellaway and Marriot, 1975; Braybrooks, et al., 1975) and in unknown ways a change in porosity may affect the passage of spermatozoa causing infertility fDavajan, et al., 1971)- The mechanisms underlying these disorders are not well understood partially because of the nature of mucus itself. It is too heterogeneous and varied for simple characterization, and without an adequate description of each batch, reproducibility of experimental results beyond the most superficial level of enquiry is almost impossible. Fortunately the major glycoprotein or mucin components can be isolated, purified and manipulated in a reproducible manner and examination of these molecules can tell us much about the behaviour of the mucus.