Serum pepsinogen

Tani, S., A. Ishikawa, H. Yamazaki, and Y. Kudo. 1987. Serum pepsinogen levels in normal and experimental peptic ulcer rats measured by radioimmunoassay. Chemical and Pharmaceutical Bulletin (Tokyo) 35 1515-1522. 

Results Showing Relationship Between Serum Pepsinogen Index and Gastric Acidity"... 

Gastric juice Number of cases Serum pepsinogen Pepsin activity in 100 ml of gastric juice, equivalent to mg of DIFCO pepsin 1 10,000... 

The survey reveals that a decrease in the serum pepsinogen index below 0.65 is always accompanied by histamine-resistant achlorhydria. For this reason in 36 patients with pernicious anemia the serum pepsinogen always lay below 0.65, and in 97 patients with other diseases it lay in all cases above 0.65, with the exception of one patient, when it lay exactly at the border value. Further investigation of 300 patients with pernicious anemia found values always below 0.65. This does not mean, naturally, that the serum pepsinogen level is a specific indicator of pernicious anemia, and no difference was found in the extent of the decrease between pernicious anemia and other forms of histamine-resistant achlorhydria or achylia. It is, nevertheless, a valuable diagnostic aid, because... 

Clinical Studies of Serum Pepsinogen and Uropepsin, 92 Uropepsin and Stress, 92... 

In the diet, vitamin B12 is bound to proteins. Although some release of protein-bound vitamin B12 begins in the mouth, most of the release occurs in the stomach on exposure of food to gastric acid (HC1) and the proteolytic enzyme pepsin. For this reason, either hypo-chlorhydria (abnormally low concentration of HC1 in gastric fluid) or achlorhydria (the absence of HC1 in gastric fluid) may decrease the availability of dietary vitamin B12 for absorption by preventing the activation of pepsinogen to pepsin, the principal enzyme responsible for proteolysis in the stomach. Achlorhydric patients with adequate production of IF may have low normal or subnormal serum B12 concentrations because of failure to liberate B12 bound to food. 

Ichinose, M., Miki, K., Furihata, C., Kageyama, T., Hayashi, R., Niwa, H., Oka, H., Matsushima, T., and Takahoshi, K., Radioimmunoassay of serum Group I and Group II pepsinogens in normal controls and patients with various disorders. Clin. Chim. Acta 126, 183-191 (1982). 

Other proteins similarly studied are bovine serum albumin 5, 6, 36, 65, 67) and ovalbumin 65) actin 61) fumarase 43) a-chymotrypsin 44) lysozyme 59, 64) arachin 5) 0-lactoglobulin and /c-casein 45) 7-globulin 56) ribonuclease 24, 35, 68) glutamic dehydrogenase (7) soybean trypsin inhibitor 15, 57) and pepsinogen 14, 21, 58). 

Lynch, K. M., D. Sellers, D. Ennulat, and L. Schwartz. 2004. Evaluation and use of a human ELISA method for measuring pepsinogen I in monkey serum. Clinical Chemistry 50 (SuppL) A36. 

Pilotto A, Franceschi M, Lagni M) Fabrello R, Fortunate A, Meggiato T, Soffiati G, Oliani G, Di Mario F. The effect of omeprazole on serum concentrations of theophylline, pepsinogens A and C, and gastrin in elderly duodenal ulcer patients. Am J Ther (1995) 2, 43-6. 

Clinically important above all are examinations in patients with altered gastric secretion. A fair correlation is found between the content of pepsinogen in the gastric juice and in the serum. This is easily comprehensible as an expression of the bipolar (exo- and endocrine) function of the pepsin cells of the gastric mucosa. There exists, however, a clinically useful relationship between pepsinogen and gastric acidity, illustrated by the survey in Table X. 

Our investigations were aimed at improving the polarographic checking of autoproteolytic estimation of pepsinogen in the serum in order to make it applicable to clinical practice. 

Enzymological application of polarography was tried in the cerebrospinal fluid, the proteolytic activity being investigated after addition of inactivated serum as substrate (198). A comparison with the serum revealed the presence, in healthy subjects, of the cathepsin system in the cerebrospinal fluid, whereas in the serum two systems are found, viz., those of pepsinogen and cathepsin. The cathepsin activity in the cerebrospinal fluid is about half as high as that in the serum. In the cerebrospinal fluid of newborn infants lower values are found than in that of older children and adults. In 74 examinations no relationship with the diagnosis could be established, so that further study is necessary in this direction. 

In sperm, proteolytic activity at acidic reaction can also be proved (236). It is, of course, well known that sperm contains pepsinogen. Inactivated serum serving as substrate was added to sperm, and at pH 1.6 individually variable proteolytic activity was recorded. This proteolytic activity is nearly constant within the pH range 1.6-4.5, and it falls abruptly at pH 4.8. The activity can be destroyed by heating to 56 C for 30 min. Any quantitative evaluation of proteolytic activity would have to be individual, and would be feasible with utmost difficulty only. 

In order to make possible an expression of pepsinogen activity in tissues by comparable values, a basic unit was chosen, represented by the proteolysis of 0.4 ml of serum that was subjected to the same procedure as 0.5 ml of an extract from 0.1 g of tissue (wet weight). In both cases inactivated human serum was added as substrate. The average content of dry matter is 25% in tissues and 6% in serum, so that in both cases the... 

For analysis of pepsinogen and pepsin, inactivated serum is needed as a supplementary substrate. It is prepared by pooling remainders of sera of healthy subjects, or at least of subjects in whose electrophoretic pic-... 

Figure 36. Example of pepsinogen examination in serum. Very low (first from left) and very high (third from l t) activities.

For analysis of cathepsin, inactivated serum is needed as a supplementary substrate, as for the preceding determination of pepsinogen. Mix 6.5 ml of the buffer solution (reagent (xi), p. 531) for cathepsin activity determination with 0.2 ml of the analyzed serum and 0.4 ml of inactivated serum, stir, and pipette two 2-ml portions into separate test tubes. Put the first test tube—the proper test— into a thermostat at 37 C for 24 hours. Into the second tube—the control—add immediately 2 ml of 20% sulfosalicylic acid solution, drop by drop, shaking vigorously. Allow to stand for 10 min, and then filter in the way described before (p. 539, Brdi5ka filtrate reaction). The filtrate, which must be clear, may be stored at 4°C during the incubation of the proper test. After a 24-hr incubation, treat the test like the control (deproteinize by sulfosalicylic acid and filter, as described). 

Source Adapted from Samloff IM, Secrist DM, Passaro E Jr. A study of the relationship between serum Group I pepsinogen levels and gastric acid secretion. Gastroenterology 69 1196-1200, 1975. 

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