Change in Viscosity of Mucin with pH

Abstract

For many years physiologists have known that mucin plays a lubricating, protective, and soothing role in gastro-intestinal function. It is synthesized in the mucous cells and is the characteristic constituent of mucus. The slimy, viscid mucus spreads over the surface of the mucosa and facilitates the passage of food particles over the mucosa with minimum of injury.

Fogelson 1 and Atkinson 2 have shown that when patients with peptic ulcer are given mucin, there is prompt relief of the subjective symptoms without recurrence in most patients for as long as one year.

Since mucin is a physiological secretory product of the gastrointestinal tract and since mucin administered orally to ulcer patients gives every indication of healing, it suggests that the metabolic difficulty leading to ulcer formation may be a disturbance of mucin metabolism.

This is the first of a series of papers on the study of mucin metabolism, its importance in the functioning of mucous membrane, and its probable bearing upon ulcer formation.

Fogelson 1 and Atkinson 2 have pointed out that mucin has a high acid combining power and thus helps to control gastric acidity. Jones and Ivy 3 have shown that the buffer action of mucin is less than the buffer action of peptones. Since peptones are not peculiarly beneficial in ulcer therapy, they conclude that control of gastric acidity is not the important beneficial factor in mucin therapy.

It is obvious that the more viscous and tenacious the mucin is, the more effective it will be in protecting the mucosa. We have studied the change in viscosity of mucin with pH at the temperatures 25° and 37°C.