STUDIES OF GASTRIC PEPSIN. I. METHODS OF MEASUREMENT AND FACTORS WHICH INFLUENCE IT

Abstract

I. It has been found that the Gates method as modified by Gilman and Cow-gill gives accurate and reproducible values fbr the proteolytic activity of a specimen of gastric contents. The variability in readings obtained when successive specimens of fasting residuum from the same subject were used was so great as to destroy their clinical value. More consistent results were obtained with juice obtained after an Ewald type of meal. Standards of normal for pepsin after this type of test meal are published in this paper. Bile, mucin, blood proteins, albumin, peptones, and alkalies markedly reduced peptic activity. The fact that these substances may modify peptic activity must be kept in mind in making a clinical study of gastric pepsin. [long dash]II. Values for pepsin are usually increased in the presence of peptic ulcer, and there is a high degree of correlation between the amount of the ferment and the severity and intractability of the symptoms. Unfortunately the determination cannot be used to prove the presence of ulcer because very high values for pepsin are commonly found in cases in which patients are tense and nervous, and present a syndrome resembling that of ulcer. Its main value, therefore, seems to be in estimating the prognosis in cases of known ulcer.