Bernard J. Haverback

Trypsin, trypsinogen and trypsin inhibitor in human pancreatic juice.

Abstract 1.1. Benzoylarginine-paranitroanilide was employed as substrate in a method which permits simple, sensitive and rapid assay of trypsin. 2.2. Human pancreatic juice obtained by catheter drainage of the duct of Wirsung exhibited no spontaneous tryptic activity. It does, however, contain substantial amounts of spontaneous trypsin inhibitor. Human pancreatic juice inhibitor, which is soluble in trichloracetic acid, is not digested by trypsin. 3.3. Trypsinogen in human juice is not activated by incubation with bile, streptokinase-streptodornase, calcium ion, magnesium ion, barium ion, ammonium ion, or acidification of juice to a pH of 4.5. Bovine or human trypsin does not activate or only slightly activates trypsinogen in human pancreatic juice. However, the addition of small amounts of calcium markedly enhances the conversion of trypsinogen to trypsin by trypsin. Slight tryptic activity was noted in human juice, which had been frozen for several months, when incubated in calcium ion. 4.4. Trypsinogen in juice undergoes autodegradation even though no measurable trypsin is present. Calcium ion retards this reaction. In many instances addition of trypsin to pancreatic juice enhanced degradation of trypsinogen. 5.5. Enterokinase actively converts trypsinogen in juice to trypsin. The time of maximal conversion is inversely proportional to the amount of enterokinase. 6.6. Calcium ion enhances conversion of trypsinogen to trypsin in pancreatic juice in many ways. These may explain the association of pancreatitis with hyperparathyroidism.

Protein binding of pancreatic proteolytic enzymes.

In human serum there are two protein fractions that are potent inhibitors to trypsin. These inhibitors travel with the a1-globulin and a2-globu-lin fractions when serum proteins are separated by electrophoresis (1-3). One ml of normal serum has sufficient amounts of trypsin inhibitor to neutralize the proteolytic effect of 1.15 (± 0.10) mg of crystalline trypsin. Approximately 90 per cent of the trypsin inhibitory proteins in serum migrate in the electrophoretic cell with the a1-globulin fraction, and the remainder with the a_2-globulin fraction (3). It is known that in many diseases of unrelated etiology the level of total serum trypsin inhibitor may be increased. This increase, therefore, is not specific for any disease, including acute pancreati-tis. Also, it is likely that an increase in the a1-globulin trypsin inhibitor is no more specific in the various diseases than is a sedimentation rate. However, the results of a previous study indicate that in acute pancreatitis the a2-globulin inhibitor decreases, and in severe pancreatitis it frequently disappears. The divergent changes of the two serum globulin trypsin inhibitors in acute pancre-atitis result in a marked increase in the ratio of the a,-to a2-globulin trypsin inhibitors. The decrease in the a2-globulin trypsin inhibitor in acute pancreatitis has been helpful in our laboratory in the diagnosis of acute pancreatitis (3). The determination of the serum a1,-and a2-glob-ulin trypsin inhibitors involves the lengthy procedure of serum protein separation by electrophore-sis, elution of protein fractions which involves many hours, and then the determination of the trypsin-inhibiting capacity of the protein fractions. The present complexities of this procedure make the determination difficult for the routine hospital laboratory. Because of these factors we sought methods that would permit an easier assay of the a2-globulin trypsin inhibitor. Many studies were made which included the determination of the inhibiting activities of the a,-and a2-globulin fractions to chymotrypsin, elastase, thrombin, plasmin, and collagenase. Although interesting data were obtained, these studies did not permit the differential assay of the serum a1-and a2-globu-lin trypsin inhibitors unless electrophoresis was done. Continuing along this line of investigation, we determined that when trypsin was added to serum and the mixture subjected to electrophoresis, a substance with trypsin-like activity was detected, migrating with the a2-globulin fraction. This was an unexpected finding, since the serum to which trypsin was added contained sufficient trypsin in-hibitor to completely neutralize many times the amount of trypsin added. Also, other known in-hibitors of trypsin and …

Carcinoembryonic antigen in patients with gynecologic malignancies

The determination of carcinoembryonic antigen (CEA) in plasma has been of much interest currently concomitant with the search for an immunologic diagnosis test. Recent reports have shed some doubt on the specificity of carcinoembryonic antigens for gastrointestinal tract malignancies. This report details the plasma CEA values in 341 patients with varying gynecologic malignancies. These studies have demonstrated that plasma CEA is elevated in close to 50 per cent of patients with invasive gynecologic cancer. The incidence of positive values is appreciably higher in the advanced stages of disease. Of particular interest was that 84 per cent (21 of 25) of the patients with recurrent squamous-cell carcinoma of the cervix had a positive CEA value. Similar results were found in patients with cancer of the vulva, ovary, and endometrium.

Indole Metabolism in the Malabsorption Syndrome

PREVIOUS studies have demonstrated that the excretion of the serotonin metabolite, 5-hydroxyindoleacetic acid, is elevated in patients with nontropical sprue.1 , 2 Other studies have shown that whe...

Free and bound carcinoembryonic antigen in neoplasms and in normal adult and fetal tissue

Abstract Using a radioimmunoassay, CEA or an immunologically indistinguishable substance is found in normal adult as well as fetal tissue. The highest level in normal adult tissue was found in the lung (average 300 ng/g) and in fetal tissue, the colon (average 1000 ng/g). Of many carcinomas, the highest levels were found in primary and metastatic carcinomas of the colon (range 850–92,800 ng/g). Blood levels of CEA may reflect the concentration of CEA in the cancer as well as the volume of the cancer. Purification of CEA through polyacrylamide gel electrophoresis and isoeletric focusing indicated the presence of at least six antigens which differ in isoeletric points or mol. wt. A perchloric acid extract of one gastric hepatic metastatic adenocarcinoma contained no demonstrable CEA using double immunodiffusion techniques. Following exposure of this perchloric acid precipitate to 15% NaCl, CEA could be demonstrated by double immunodiffusion and the radioimmunoassay showed an increase from 53 to 5750 ng/g. This phenomenon existed in a number of carcinomas to a varying extent as well as in normal adult tissue. Thus it may be importance to include dissociation techniques when studying the level of CEA in blood or tissue.

The Gastrointestinal Tract and Naturally Occurring Pharmacologically Active Amines

Publisher Summary This chapter discusses the gastrointestinal tract and naturally occurring pharmacologically active amines. Naturally occurring pharmacologically active amines are of interest to the chemist, physiologist, pharmacologist, and clinician. Not only has a vast amount of research been concerned with the physiologic and pathologic roles of these amines, but inquiry into the routes of their formation and degradation has been of equal interest. Much of the literature relative to amines has been concerned with serotonin and histamine. The large concentration and wide distribution of serotonin in the gastrointestinal tract has suggested a relationship between motility and this amine. The gastric secretion produced by histamine injection is high in acid content, but low in pepsin content. Histamine evokes its gastric secretory action after the section and subsequent denervation of the vagus nerves. Both serotonin and histamine are potent stimulants to smooth muscle in the gastrointestinal tract, bronchi, and blood vessels. The administration of either of these agents will produce flushing, hyperperistalsis, and bronchial constriction in humans. However, marked differences exist between some of the actions of these two amines. Histamine causes marked gastric acid stimulation, while the administration of serotonin or 5-hydroxytryptophan causes the inhibition of gastric acid secretion and stimulation of mucus secretion from the stomach.

Elevated serum trypsin binding activity in patients with hereditary pancreatitis.

SummaryA new kindred with a high incidence of hereditary pancreatitis has been described. Five members (3 males and 2 females) are definitely affected and 2 others are suspected of having the disease. The laboratory finding of interest is a twofold increase in the serum trypsin binding activity in 2 of 3 affected members—despite the fact that their serum α2-macroglobulin levels were within the normal range. The biological significance of this finding is not yet known. Recurrent attacks of abdominal pain began in early childhood in all affected members. Pancreatic calcifications are present in 3 members and diabetes mellitus and steatorrhea in 2 persons. Aminoaciduria was sought for in 2 members but was not found. None of the affected members had evidence of hyperlipemia or cholclithiasis or hyperparathyroidism, nor is any of them either a sporadic or a chronic alcoholic. Although the disease is reported to be transmitted as an autosomal dominant trait, incomplete penetrance or recessiveness are very likely mechanisms.