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PubMed1975

Intestinal disaccharidases in Greenland Eskimos.

Jejunal biopsies from 19 adult Greenland Eskimos were studied regarding disaccharidases, two intracellular beta-galactosidases, and morphological appearance. Fifteen of the patients (79%) had low lactase activity, and 3 of these (16%) had sucrase-isomaltase deficiency as well. Two patients had low trehalase activity. Microscopical appearance was essentially normal in all the biopsies, except for a certain stromal plasma cell infiltration. All the patients with low lactase activity had a measurable residual activity of brush border lactase, which was localized in the middle and apical parts of villi, as normally seen for digestive enzymes. Lysosomal acid beta-galactosidase and cytosol hetero beta-galactosidase were not altered. In the patients with sucrase-isomaltase deficiency there was a complete absence of active sucrase-isomaltase complex. The residual maltase, as well as the very weak residual isomaltase, was exerted exclusively by the heat stable maltases (maltase II and III). The material is the first one in which multiple, but not generalized disaccharidase deficiencies are demonstrated.

Adolescent↗
PubMed1975

[Disaccharidases of the small intestine mucosa in infants and children. "Normal values", log normal distribution and age dependence].

In 63 infants and children with a histological normal mucosa of the duodenum, without an isolated defect of enzyme and with a normal increase of xylose and glucose in serum after a combined xylose-lactose loading test the activities of disaccharidases were log normal distributed. The asymmetric distributions were transformed into symmetric ones and the geometric mean (x) as well as the range (+/- 2 s) of maltase, saccharase, isomaltase, lactase and trehalase were calculated. Only the activity of lactase shows a significant dependency on age. In the first year of age the lower limit (x -- 2 s) of this enzyme is much higher than later.

Age Factors↗
PubMed2001

Protection against rotavirus diarrhoea in mice by trypsin inhibitor.

To investigate the role of soyabean trypsin inhibitor (TI) during rotavirus (RV) diarrhoea, changes in enzyme activities of six relevant mucosal enzymes (lactase, sucrase, maltase, trehalase, glucoamylase and alkaline phosphatase) were assayed following inoculation of suckling mice with EB rotavirus (serotype 3) along with the TI and compared with the age-matched healthy control mice. The animals were divided into three groups i.e. group 1 (controls), group 2 (RV inoculated) and group 3 (RV + TI inoculated and sacrificed under light anaesthesia on 0, 1, 3, 5, 7 and 10 day post inoculation (dpi). Then intestines were excised and divided into two parts (jejunum and ileum). They were separately homogenized in 0.9% cold normal saline and activities of mucosal enzyme were measured. Alkaline phosphatase and disaccharidases were found to be decreased significantly in RV inoculated animals in both the anatomical portions of small intestine of mice. These enzyme levels were restored with the administration of TI i.e. in group 3 and became comparable to the controls in both intestinal portions. These studies suggest that activity of intestinal enzymes which are important in digestive absorptive functions of small intestine were restored with the addition of TI whengiven to infant mice showing its protective efficacy during rotavirus infection.

Animals↗
PubMed1975

[Electrofocusing of hydrolases in rat brush border enterocytes].

Different hydrolases (cellobiase, enterokinase, lactase, leucine aminopeptidase, alcaline phosphatase and trehalase) of the brush border's enterocytes of the rat have been studied by electrofocusing. Every hydrolase is focused in a single peak, the pI of which is given.

Animals↗
PubMedDate not supplied

Effect of malnutrition on the digestive enzymes of the upper gastrointestinal tract of young rhesus monkeys.

The present study was planned to observe the effect of protein-energy malnutrition on the gastric and duodenal mucosa. The activities of digestive enzymes (i.e. lactase, sucrase, maltase, trehalase, glucoamylase, leucine aminopeptidase, alkaline phosphatase and gamma-glutamyl transpeptidase) from the gastric (fundus, body and antrum) and duodenal mucosa [i.e. first (D1) and second (D2) part of the duodenum] were determined in 6 control, 6 protein-energy malnourished (PEM) and 6 rehabilitated young rhesus monkeys. There was a significant increase in the activity of the lactase enzyme in the antrum, and D1 and D2 portions of the duodenum of PEM monkeys, while the activity of all other enzymes was significantly increased in the D1 and D2 portions only. The increase in the activity of the above-mentioned enzymes became normal upon rehabilitation. There was no change in the enzyme activities of the gastric mucosa in mild-to-moderate PEM states. This study demonstrates that even mild-to-moderate malnutrition states affect the activity of enzymes in the gastric and duodenal mucosa. Enzyme activity recovers on rehabilitation.

Animals↗
PubMed1992

Early prenatal development of the brush border enzymes in the embryonal intestine.

Standard methods were used for the study of the activity of brush border enzymes in the epithelium of the intestine of 45 human embryos aged from 4 to 22 weeks of the intrauterine life. Enzymes of the peptidase group (DPP IV, APM, APA, GGT, BBEP), of the phosphatase group (ALP, ACP, AMP, ATP), and of the disaccharidase group (saccharose, lactase, trehalase) were studied. In the embryonal developmental period (to week 8), the activity of proteases was mainly detected on the luminal surface of the primitive pseudostratified columnar epithelium of the intestine anlage. The highest activity was displayed by DPP IV. In the period from the 8th week, villi are formed from the duodenum up to the ileum. After week 9, differentiation of Lieberkühn crypts was observed. The activity of proteases was very high (DPP IV especially) in the differentiating microvillous zone of primitive enterocytes. Gradient of apex-base activity of the villus was maximal on the apex of villi. After week 12 of the intrauterine life, the activity of disaccharidases ALP and AMP occurs in the differentiating brush border, and a low activity of BBEP of the protease group is present.

Disaccharidases↗
PubMed2004

Content of saccharides and activity of alpha-glycosidases in Galleria mellonella larvae infected with entomopathogenic nematodes Heterorhabditis zealandica.

Concentration of glycogen, maltose, and trehalose as well as the activity of hydrolases catabolising them: alpha-amylases, glucoamylase, maltase, and trehalase were studied during a 48 h infection of Galleria mellonella (Lepidoptera) instar larvae infected with infective Heterorhabditis zealandica (20 nematodes/insect). The content of trehalose in the infected insects during the first day of infection was higher (p < 0.05) than in the controls. The concentration of maltose and glycogen were similar in both groups despite the fact that the activity of all examined alpha-glycosidases was generally much higher in the infected insects than in the controls.

Animals↗
PubMed2006

Purification and characterization of trehalose-6-phosphate synthase from Saccharomycopsis fibuligera A11.

Mutant A11, a mutant of Saccharomycopsis fibuligera Sdu with low acid and neutral trehalase was found to accumulate over 18% (w/w) trehalose from starch in its cells. In this study, trehalose-6-phosphate synthase (Tps1) was purified to homogeneity from this mutant, with a 30-fold increase in the specific enzyme activity, as compared to the concentrated cell-free extract, from initial cells. The molecular mass of the purified enzyme as determined by SDS-PAGE was 66 kDa. The optimum pH and temperature of the purified enzyme were 6.6 and 37 degrees C, respectively. The enzyme was activated by Ca2+, K+ and Mg2+, with K+ showing the highest activation at 35 mM. On the other hand, Mn2+, Cu2+, Fe3+, Hg2+ and Co2+ inhibited the enzyme. The enzyme was also strongly inhibited by protease inhibitors such as iodoacetic acid, EDTA and PMSF.

Cell-Free System↗
PubMed1991

Prenatal diagnosis of cystic fibrosis by microvillar membrane enzyme analysis in amniotic fluid.

Prenatal diagnosis was performed in 92 pregnancies high-risk for cystic fibrosis during six years. Amniotic fluid samples obtained by amniocentesis were examined with regard to their microvillar membrane enzyme activity. Though trehalase, alkaline phosphatase isoenzymes and L-gamma-glutamyltransferase in the amniotic fluid are not specific markers of cystic fibrosis, their activity is significantly lower than in normal pregnancies. By measuring the three enzymes simultaneously, sensitivity, specificity and reliability of the method were found to be over 92%. It is concluded that mid-trimester amniotic fluid diagnosis is indispensable for some heterozygotic couples for cystic fibrosis even in the possession of DNA (desoxyrobonucleic acid) methods.

Amniotic Fluid↗
PubMed1978

Effect of exchange exocrine pancreatic insufficiency on small intestine in the mouse.

A genetically conditioned mouse model of exocrine pancreatic insufficiency (epi) has been used to study the effect of the absence of lumenal proteases on small intestinal mucosal proteins. The small bowel was divided into eight equal segments. Enzyme activity was increased only in the first three segments in the case of maltase, sucrase, and lactase (all mol wt above 200,000). Alkaline phosphatase (mol wt 145,000), trehalase (mol wt 95,000), and peptidase (mol wt 175,000) activities were unaffected in proximal segments from epi mice. Proximal brush border proteins were identified and measured quantitatively by sodium dodecyl sulfate acrylamide gel electrophoresis. Those enzymes with increased activity were associated with increased amounts of protein in epi mice. Double labeled studies of protein turnover revealed a longer half-life for large brush border proteins (mol wt above 175,000) in epi mice than in normal mice. Enterokinase activity (a marker for duodenal mucosa) was nearly absent from the duodenum of epi mice. Receptors for the intrinsic factor-vitamin B12 complex (markers for ileal mucosal) were present in the ileum equally in normal and in epi mice. Enterokinase activity can be induced in epi mice by feeding its substrate trypsinogen, but not by trypsin or chymotrypsinogen. Epi mice thus retain the ability to synthesize enterokinase. Pancreatic proteases play an important role in the turnover of certain large mucosal proteins and in the induction of enterokinase.

Animals↗
PubMed1990

Genetic counselling and prenatal diagnosis of cystic fibrosis in Debrecen (Hungary)--prenatal diagnosis by microvillar enzyme assay from amniotic fluid.

Amniotic fluid intestinal alkaline phosphatase, gammaglutamyltransferase and trehalase activity were quantitated to assess their reliability for the prenatal diagnosis of cystic fibrosis. To obtain optimal diagnostic discrimination, the three enzyme values obtained for each sample were combined into a single linear discriminant function that proved to be a more accurate indicator of the outcome of the pregnancy. From the cases studied here, it appears that this method can be expected to give a correct prediction in 92.0% of all high risk pregnancies.

Amniotic Fluid↗
PubMed1990

On the determination of trehalose-6-phosphate synthase in Saccharomyces.

Trehalose-6-phosphate synthase activity was determined by colorimetric, spectrophotometric and trehalose specific assays. All methods gave comparable results thus confirming our previous findings (1) and those reported by Elander (2). Different strains and mutants of Saccharomyces were carefully re-investigated in relation with the recent claim made by Vandercammen et al. (3) that our spectrophotometric assay over-estimated the enzyme activity and that no differences exist between wild type and mutant strains. In this paper we also confirm the de-activation of the trehalose synthase complex in response to a "glucose signal", and present trehalose-6-phosphate synthase and trehalase activities in different strains measured during all phases of growth on glucose.

Colorimetry↗
PubMed1990

[Prenatal diagnosis of cystic fibrosis by analysis of microvillar enzymes of the amniotic fluid].

Prenatal diagnosis was performed in 92 pregnancies high-risk for cystic fibrosis during six years. Amniotic fluid samples obtained by amniocentesis were examined with regard to their microvillar membrane enzyme activity. However, trehalase, alkaline phosphatase isoenzymes and L-gamma-glutamyl-transferase in the amniotic fluid are not specific markers of the cystic fibrosis, their activity is significantly lower than in normal pregnancies. By measuring the three enzymes simultaneously, sensitivity, specificity and reliability of the method were found to be over 92%. It is concluded that the mid-trimester amniotic fluid diagnosis is useful for some heterozygotic couples for cystic fibrosis even in the possession of the DNA methods.

Amniocentesis↗
PubMedDate not supplied

[Malabsorption of carbohydrates in children (author's transl)].

Physiological bases of digestion and absorption of carbohydrates are reviewed, as a preliminary step, in order to draw a general scheme of its patholophysiology. Clasification of different types of carbohydrate malabsorption is presented. Various exploration methods are discussed in terms of autors' own experiences. Relationship between a sugar screening test, faecal lactic acid contents and a simplified lactose tolerance test, is described in detail. Systematic diagnoses of these diseases are established. Different clinical pictures are reviewed. It is not yet well defined if a starch malabsorption can be caused by either a primary or secondary duodenal amylase deficiency. The clinical forms of congenital sucrose-isomaltose intolerance may be more attenuated than its classical form; incertain cases, secondary sucrose intolerance may also be present due to mucosa anatomic lesions. Maltose malabsorption has no clinical implications. As compared to other alpha-glycosidades, the trehalase activity has been not more affected by not using trehalose in feeding. Primary congenital lactase deficiency is not frequent, whereas secondary forms as much more usual and appear, in primary malabsorption syndromes and in the coeliac disease, very often along with clinical tolerance to lactose. In Spain, lactose nonabsorbers in 16.5% for adults 11.2% for adolescents and 18.3% for children, meaning, that it is being favored by environmental factors in the latter. The unspecified sugar malabsorption during the child's first year is still the most frequent cause of carbohydrate intolerance in children and, although certain progress has been achieved in its diagnosis and therapy, its pathogenic mechanism is not satisfactorily known yet.

Adolescent↗
PubMed1989

The formamidine amitraz as a hyperglycemic alpha-agonist in worker honeybees (Apis mellifera mellifera L.) in vivo.

Intra-abdominal injection of amitraz (0.25 nmol per honeybee, i.e., approx 2.3 nmol/g) to emerging worker bees, in vivo, led to a significant hypertrehalosemia (300-400%) followed by a hyperglucosemia (approximately equal to 600%). Maxima were reached at 0.5 and 2 h, respectively. A strong negative correlation between glucosemia and trehalosemia appeared after injection of pure phentolamine (1 nmol per bee), suggesting stimulation of trehalase activities. Simultaneous administration of the alpha-blocker at greater than or equal to 0.25 nmol per individual suppressed the hyperglycemic response of amitraz. The formamidine pesticide thus likely acts on the honeybee alpha-aminergic system.

Adrenergic alpha-Agonists↗
PubMed1989

Comparisons of maltase activities in kidney brush border membranes from normal, diabetic, glucose-infused and maltose-infused rabbits.

The specific activities of membrane-bound maltase (alpha-D-glucoside glucohydrolase, EC 3.2.1.20) in isolated brush border membranes (BBMs) of alloxan-induced diabetic, glucose-infused and maltose-infused rabbits were 30%, 140% and 160%, respectively, of those of control rabbits. Differences in the relative activities of trehalase (EC 3.2.1.28), another disaccharidase, in these groups were similar but less marked. However, the activities of two other marker enzymes of the brush border, alkaline-phosphatase and gamma-glutamyl transpeptidase, were similar in the 4 groups of rabbits. The decreases in the activities of the two disaccharidases were due to changes in the Vmax values of the enzymes without change in their Km values for maltose and trehalose. The maltase activities in the 4 groups showed similar dependences on Tris-HCl, KCl and NaCl. The electrophoretic profiles of the BBMs of the 4 groups on SDS-polyacrylamide gel showed slight differences. From these results, we conclude that diabetes, glucose infusion and maltose infusion probably change the concentrations of active enzymes in the BBM of the kidney in rabbits.

Alloxan↗
PubMed1989

Purification of a new, calcium-independent, high molecular weight phospholipase A2/lysophospholipase (phospholipase B) from guinea pig intestinal brush-border membrane.

A phospholipase A2 activity directed against phosphatidylcholine was previously described in brush-border membrane from guinea pig intestine (Diagne, A., Mitjavila, S., Fauvel, J., Chap, H., and Douste-Blazy, L. (1987) Lipids 22, 33-40). In the present study, this enzyme was solubilized either with Triton X-100 or upon papain treatment, suggesting a structural similarity with other intestinal hydrolases such as leucine aminopeptidase, sucrase, or trehalase. The papain-solubilized form, which is thought to lack the short hydrophobic tail responsible for membrane anchoring, was purified 1800-fold to about 90% purity by ion exchange chromatography on DEAE-Sephacel, gel filtration on Ultrogel AcA44, and hydrophobic chromatography on phenyl-Sepharose. Upon polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, a main band with an apparent molecular mass of 97 kDa was detected under reducing and nonreducing conditions. In the latter case, phospholipase A2 activity could be recovered from the gel and was shown to coincide with the 97-kDa protein detected by silver staining. The enzyme activity was unaffected by EGTA and slightly inhibited by CaCl2. The purified enzyme displayed a similar activity against phosphatidylcholine and phosphatidylethanolamine, whereas 1-O-alkyl-2-acyl-sn-glycero-3-phosphocholine hydrolysis was reduced by 50% compared to diacylglycerophospholipids. Using phosphatidylcholine labeled with either [3H]palmitic acid or [14C]linoleic acid in the 1- or 2-positions, respectively, the purified enzyme catalyzed the removal of [3H]palmitic acid, although at a lower rate compared to [14C]linoleic acid. This resulted in the formation of sn-glycero-3-phosphocholine, but only 1-[3H]palmitoyl-sn-glycero-3-phosphocholine was detected as an intermediary product. In agreement with this, 1-acyl-2-lyso-sn-[14C]glycero-3-phosphocholine was deacylated at almost the same rate as the sn-2-position of phosphatidylcholine. Since upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the two hydrolytic activities were detected at the same position as 97-kDa protein, the enzyme is thus considered as a phospholipase A2 with lysophospholipase activity (phospholipase B), which might be involved in phospholipid digestion.

Animals↗
PubMed1987

Mechanism of stimulation of endogenous fermentation in yeast by carbonyl cyanide m-chlorophenylhydrazone.

Addition of the uncoupler and protonophore carbonyl cyanide m-chlorophenylhydrazone (CCCP) to starved yeast cells starts endogenous alcoholic fermentation lasting about 20 min. Hexose 6-phosphates, fructose 2,6-bisphosphate, and pyruvate accumulate in less than 2 min after addition of CCCP from almost zero concentration to concentrations which correspond to 1/5-1/10 of the steady-state concentrations during fermentation of glucose. CCCP immediately causes a decrease of the intracellular cytosolic pH from 6.9 to 6.4. This change activates adenylate cyclase (Purwin, C., Nicolay, K., Scheffers, W.A., and Holzer, H. (1986) J. Biol. Chem. 261, 8744-8749) and leads to the previously observed transient increase of cyclic AMP. It is shown here that the following enzymes known from in vitro experiments to be activated by cyclic AMP-dependent phosphorylation are activated in the CCCP-treated starved yeast cells in vivo: glycogen phosphorylase, trehalase (pH 7), 6-phosphofructo-2-kinase. The activation of 6-phosphofructo-2-kinase leads to an accumulation of fructose 2,6-bisphosphate, which is known from in vitro experiments to activate 6-phosphofructo-1-kinase and to inhibit fructose-1,6-bisphosphatase. All effects observed in the intact yeast cells fit with the idea that the CCCP-initiated activation of adenylate cyclase leads to a sequence of events which by protein phosphorylation and allosteric effects initiates endogenous alcoholic fermentation.

Carbonyl Cyanide m-Chlorophenyl Hydrazone↗