ABSTRACT
This chapter deals with two groups of immunochemically and biochemically distinct aspartic proteinases. The first is a group of pepsin A which consists of 5 isozymes and the second is a group of gastricsin consisting of two isozymes. The fundamental physiological function of pepsin A and gastricsin is the digestion of food in stomach. In addition to these physiological processes, both enzymes were thought to play a role in some patho-physiological states, such as cancer or ulcer disease. The investigation of anodal mobility in family studies of urinary pepsinogen phenotypes proved that there exists a genetic polymorphism of pepsinogen A. The polymorphism detected with the pepsinogen A and progastricsin and their distributions in patients have often been connected with different pathological states. The patho-physiological conditions which are often cited in context with pepsin A and gastricsin and especially with serum levels of their zymogens are, gastric ulcer, gastritis and intestinal metaplasia, and gastric cancer.
