The application of a new synthetic substrate to the determination of enteropeptidase in rat small intestine and human intestinal biopsies.

The application of a new synthetic substrate to the direct determination of enteropeptidase is described. The substrate Gly-(L-Asp)4-L-Lys-2-naphthylamide contains the amino acid sequence of the activation peptides of trypsinogen linked via an amide bond to the fluorophore 2-naphthylamine. The sequence of amino acids is responsible for the specificity and substrate recognition of the enteropeptidase-catalyzed activation of trypsinogen.

The role of enteropeptidase in the digestion of protein and its development in human fetal small intestine.

Enteropeptidase converts trypsinogen into active trypsin, which not only hydrolyses some peptide bonds of food proteins but also activates a number of pancreatic zymogens. For this reason enteropeptidase is a key enzyme in the digestion of dietary proteins and its absence may result in gross protein malabsorption.

Studies in meconium. An approach to screening tests to detect cystic fibrosis.

Screening for cystic fibrosis (CF) in newborns is desirable, and efforts should continue in establishing a system of easily available, reliable, simple, and inexpensive tests. In addition to the Boehringer-Mannheim (BM) test for the detection of albumin, we propose the assay for lactase and beta-D-fucosidase in meconium. These latter two enzymes are present in the meconium of babies with CF and absent in meconium of most healthy babies.

Disaccharidase activities in small intestinal mucosa in patients with cystic fibrosis.

The disaccharidase activities in small intestinal biopsies were related to the morphology of the mucosa and the ages of 63 patients with cystic fibrosis and 177 healthy control subjects of Caucasian origin. In patients with CF and in the healthy control subjects under 5 years of age with normal intestinal mucosa, no low lactase activity was found. In those patients with CF who were over 5 years of age, one group had high and one group had low lactase activity, as occurs in healthy Caucasian control subjects of the same age.

Studies in meconium in cystic fibrosis: the activities of alpha-D-mannosidase, beta-glucuronidase, beta-D-fucosidase, acid and alkaline phosphatase.

The specific activities of alpha-D-mannosidase, beta-glucuronidase, beta-D-fucosidase, acid and alkaline phosphatase were studied in meconium from infants with cystic fibrosis (CF) and control subjects. The study revealed significant variations in the specific activity of the enzymes except for acid phosphatase. The variations were not uniform.

Developmental pattern of small intestinal enterokinase and disaccharidase activities in the human fetus.

The concomitant appearance of enterokinase (EK) and trypsin activities in the human intestinal mucosa is indicative of the importance of EK as an activator of trypsinogen and therefore as the key enzyme in protein digestion. Enterokinase can be detected in fetal mucosa from the 26th week of gestation on, paralleling appearance of tryptic activity in meconium. The developmental pattern of EK activity increases with age.

Disaccharidase and lysosomal enzyme activities in amniotic fluid, intestinal mucosa and meconium. Correlation between morphology and disaccharidase activities in human fetal small intestine.

Brush border membrane bound disaccharidases (sucrase and maltase) and lysosomal enzyme (alpha-glucosidase, beta-D-fucosidase and N-acetyl-beta-glucosaminidase) activities awere studied in amniotic fluid (AF). The above enzymes except N-acetyl-beta-glucosaminidase showed a decrease in activity with gestational age beginning at about the 19th week. The activities of sucrase and maltase correlate with the morphological maturation of fetal intestinal mucosa.

Enterokinase and trypsin activities in pancreatic insufficiency and diseases of the small intestine.

The interrelationship of enterokinase and trypsin activities were investigated in 133 infants and children with a variety of gastrointestinal and pancreatic disorders. Fourteen patients with diarrhea and grade II mucosal injury revealed a significant (P less than 0.01) reduction of enterokinase, trypsin, and disaccharidase activites as compared to 59 children with normal mucosa.

Studies in meconium: disaccharidase activities in meconium from cystic fibrosis patients and controls.

Meconium ileus represents the earliest clinical manifestation of cystic fibrosis. The differences found in the composition and amount of protein, mucoprotein, mucopolysaccharides, and reducing sugars in meconium from newborns with cystic fibrosis might be of significance relative to the pathogenesis and early diagnosis of this disease. We studied the enzymatic activity of disaccharidases (lactase, sucrase, maltase, and palatinase) in meconium of infants with cystic fibrosis and controls.

The interrelationship of enterokinase and trypsin activities in intractable diarrhea of infancy, celiac disease, and intravenous alimentation.

Enterokinase initiates digestion of protein by conversion of trypsinogen into trypsin. The interactions between enterokinase and trysin were investigated in 6 patients with intractable diarrhea of infancy and 34 children with celiac disease. The six infants between 2 and 3 months with intractable diarrhea of infancy had reduced mucosal enterokinase activity (9.

Correlation of lactase activity, lactose tolerance and milk consumption in different age groups.

Small intestinal lactase activity in the health adult is either the same as in early infancy or may drop to very low levels. The behavior of the enzymatic state varies with the ethnic group studied. In those adults with low lactase activity little information is availalbe as to the age at which the lactase decreases.

The effect of scurvy on glycosaminoglycans of granulation tissue and costal cartilage.

1. The effect of ascorbic acid deficiency on glycosaminoglycans of granulation tissue and cartilage of guinea pigs was investigated by determination of the changes in the glucosamine and galactosamine contents 12 days after tendonectomy. 2.