Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the present experiments, selective quenching by trinitrophenyl groups as well as steady-state fluorescence polarization and differential polarized phase fluorescence techniques, using three different lipid soluble fluorophores, were used to directly examine the fluidity of the exofacial and cytofacial leaflets of rat small intestinal brush-border membranes. These studies revealed that the fluidity of the exofacial hemileaflet was greater than the cytofacial hemileaflet. Differences in the distribution of phosphatidylcholine and phosphatidylethanolamine, as assessed by phospholipase A2 treatment and trinitrophenylation of aminophospholipids, were, at least partially, responsible for the asymmetrical fluidity of the hemileaflets. Moreover, in vitro addition of benzyl alcohol (final concn 25 mM) preferentially fluidized the exofacial leaflet and concomitantly decreased leucine aminopeptidase activity but did not affect the activities of maltase, sucrase, alkaline phosphatase, or gamma-glutamyltranspeptidase. In vivo addition of the membrane-mobility agent 2-(2-methoxyethoxy)ethyl 8-(cis-2-n-octylcyclopropyl)octanate] (A2C) (final concn 7.5 microM) preferentially fluidized the cytofacial leaflet and increased Na(+)-gradient-dependent D-glucose transport but not Na(+)-gradient-dependent L-leucine transport.
 ...
PMID:Characterization and modulation of rat small intestinal brush-border membrane transbilayer fluidity. 201 33

Transport of nutrients and kinetic parameters (Vmax and Km) of brush border membrane (BBM) enzymes were studied in duodenum, jejunum, and ileum from atherogenic diet-fed monkeys. The Km remained unaltered while feeding of atherogenic diet resulted in higher Vmax of sucrase, maltase, and alkaline phosphatase and lower Vmax of gamma-glutamyltranspeptidase and leucine-aminopeptidase compared to controls. Na+-dependent D-glucose transport was higher in duodenum and jejunum and unaltered in ileum. In contrast to D-glucose transport, the transport of amino acids was decreased in all three intestinal segments from atherogenic diet-fed monkeys.
 ...
PMID:Effects on intestinal nutrient uptake and brush border membrane enzymes in response to atherogenic diet in rhesus monkeys. 257 71

The digestive (hydrolytic enzymes) and absorptive (sugar and amino acid transport) functions of dog small intestine have been evaluated in different segments and analysed in relation to morphometric and biochemical parameters. The dog small intestine is a cylinder of decreasing diameter in which the underlying mucosa thins down from duodenum to ileum, though maintaining its cellular homogeneity as revealed by measuring the mucosal weight, the total DNA and protein content and the protein content of the brush border membrane. Sucrase, gamma-glutamyltranspeptidase, leucylnaphthylamidase and alkaline phosphatase specific activities, measured both in homogenates of the mucosa and purified brush border membrane fractions, were found distributed along proximo-distal gradients of activity. However, different patterns were obtained which are specific for the enzyme considered. Kinetic parameters, Vmax and Km, were estimated for sucrase and alkaline phosphatase in purified brush border membrane fractions. It appeared that Vmax correlated well with the observed distribution of catalytic sites along the small intestine. Sugar (glucose) and amino acid (alanine and leucine) transport capacities were also distributed according to specific proximo-distal gradients but passive and facilitated diffusions were not affected. Only the active, Na+ -dependent component of transport was sensitive to position along the small intestine and we postulated that this adaptation should involve variations in carrier densities. It is therefore concluded that absorbo-digestive functions are intrinsic characteristics of the brush border membrane which are regulated according to the position along the small intestine.
 ...
PMID:Digestive and absorptive functions along dog small intestine: comparative distributions in relation to biochemical and morphological parameters. 614 47

The effect of feeding ethanol daily for 40 days was studied on various brush border enzymes in rat intestine. Brush border alkaline phosphatase (AP), lactase, gamma-glutamyltranspeptidase (gamma-GTP), p-nitrophenyl (PNP)-beta-D-galactosidase (P < 0.01) and sucrase (P < 0.001) were significantly enhanced while leucine aminopeptidase and PNP-beta-D-glucosidase activities were unaltered in ethanol fed rats compared to the controls. Kinetic studies revealed that an increase in Vmax together with a decrease in affinity in case of gamma-GTP and an increase in Vmax for AP and sucrase were responsible for the observed stimulation of enzyme activities in ethanol administered rats. Significant changes in enzyme activities were observed in different populations of enterocytes along the crypt-villus unit in the ethanol fed animals. These observations suggest that ethanol feeding modifies the brush border enzymes in rat intestine but the underlying mechanisms seem to be distinct in differentiating enterocytes.
 ...
PMID:Expression of brush border enzymes in ethanol fed rat intestine. 782 69

The effect of dietary fat content on brush border enzymes has been studied in mice intestine. The results obtained from 26 per cent fat (high fat; HF)-fed mice were compared with those fed 10 per cent fat (pair-fed; PF and ad libitum-fed). Brush border alkaline phosphatase (AP), leucineaminopeptidase (LAP) and gamma-glutamyltranspeptidase (gamma-GTP) activities were significantly enhanced while sucrase activity was reduced (P < 0.001) in HF group compared to the controls. Activities of lactase, p-nitrophenyl (PNP)-beta-D-glucosidase and PNP-beta-D-galactosidase were unaltered under these conditions. Kinetic studies with AP, sucrase and LAP revealed that changes in enzyme levels in response to HF diet were due to change in Vmax. Significant changes in enzyme activities as a consequence of HF intake were observed in enterocytes all along the crypt-villus unit as compared to the control group. These results indicated that feeding a fat-rich diet produced selective changes in brush border enzyme activities in mice intestine.
 ...
PMID:Effect of feeding high fat, high fiber diet on brush border enzymes in mice intestine. 822 50

To understand how blood glucose level is lowered by oral administration of vinegar, we examined effects of acetic acid on glucose transport and disaccharidase activity in Caco-2 cells. Cells were cultured for 15 d in a medium containing 5 mmol/L of acetic acid. This chronic treatment did not affect cell growth or viability, and furthermore, apoptotic cell death was not observed. Glucose transport, evaluated with a nonmetabolizable substrate, 3-O-methyl glucose, also was not affected. However, the increase of sucrase activity observed in control cells (no acetic acid) was significantly suppressed by acetic acid (P < 0.01). Acetic acid suppressed sucrase activity in concentration- and time-dependent manners. Similar treatments (5 mmol/L and 15 d) with other organic acids such as citric, succinic, L-maric, L-lactic, L-tartaric and itaconic acids, did not suppress the increase in sucrase activity. Acetic acid treatment (5 mmol/L and 15 d) significantly decreased the activities of disaccharidases (sucrase, maltase, trehalase and lactase) and angiotensin-I-converting enzyme, whereas the activities of other hydrolases (alkaline phosphatase, aminopeptidase-N, dipeptidylpeptidase-IV and gamma-glutamyltranspeptidase) were not affected. To understand mechanisms underlying the suppression of disaccharidase activity by acetic acid, Northern and Western analyses of the sucrase-isomaltase complex were performed. Acetic acid did not affect the de novo synthesis of this complex at either the transcriptional or translational levels. The antihyperglycemic effect of acetic acid may be partially due to the suppression of disaccharidase activity. This suppression seems to occur during the post-translational processing.
 ...
PMID:Acetic acid suppresses the increase in disaccharidase activity that occurs during culture of caco-2 cells. 1070 77

The effect of intestinal colonization with Bifidobacterium bifidum (Gram-positive anaerobic bacterium colonizing the intestine of healthy new-born mammals, exhibiting a probiotic effect, protecting the intestinal mucosa against colonization by pathogenic microflora) on enterocyte brush-border enzymes was examined in weaned 23-d- and in 2-month-old gnotobiotic inbred mice and compared with that in corresponding germ-free (GF) and conventional (CV) controls. The two groups of GF mice were associated with human B. bifidum 11 d before the end of the experiment. Specific activity of enterocyte brush-border enzymes--lactase, alkaline phosphatase and gamma-glutamyltranspeptidase was significantly higher in both age groups of GF mice in comparison with CV ones; on the other hand, sucrase and glucoamylase activities were higher in CV mice. Monoassociation with B. bifidum accelerates biochemical maturation of enterocytes resulting in a shift of specific activities of brush-border enzymes between the values found for GF and CV mice. This effect of B. bifidum supplementation was less pronounced for alkaline phosphatase, sucrase, glucoamylase and dipeptidyl peptidase i.v. in immature gut of weaned mice than of 2-month-old ones.
 ...
PMID:Bifidobacterium bifidum monoassociation of gnotobiotic mice: effect on enterocyte brush-border enzymes. 1189 51

A disturbance of the integrity of the intestinal epithelium with an increased risk for bacterial translocation is one of the suggested factors underlying the increased incidence of infections and septicaemia during vitamin A deficiency. In the present study the effects of vitamin A deficiency on the enzymic activity of enterocytes in response to bacterial colonization with a non-pathogenic Escherichia coli strain were studied in monocolonized and conventional Wistar rats. The monocolonized, but not the conventional, vitamin A-deficient rats had markedly reduced weight compared to their pair-fed controls and presented neurological symptoms, such as hind leg weakness, tremor and slow gait. Moreover, only in the monocolonized vitamin A-deficient rats were severe diarrhoea and bacterial translocation to extraintestinal sites-mainly kidneys-detected. Measurements of enterocyte brush-border enzyme activities revealed that lactase, sucrase, gamma-glutamyltranspeptidase (GGT) and dipeptidyl peptidase IV (DPP IV) were significantly reduced in the monocolonized vitamin A-deficient rats compared to the pair-fed controls, indicating a severe functional disturbance of the enterocytes. In conventional vitamin A-deficient rats only sucrase activity was markedly lower than in the respective controls. Our observation, that the deficient vitamin A status led to a strong reduction of enterocyte enzymic activities, associated with diarrhoea and increased bacterial translocation, mainly in the gnotobiotic rats, suggests that the composition of the bacterial flora, i.e. the colonization state, has a strong influence on triggering the severity of the functional disturbances of the intestinal epithelium, and adds to the clinical manifestations of vitamin A deficiency.
 ...
PMID:Vitamin A deficiency leads to severe functional disturbance of the intestinal epithelium enzymes associated with diarrhoea and increased bacterial translocation in gnotobiotic rats. 1273 96

This study was designed to investigate the effect of monoassociation of germ-free piglets with Escherichia coli strains on the development of intestinal brush-border enzyme activities. Piglets were delivered by hysterectomy, reared for seven days under germ-free conditions and fed milk formula diet. One group was maintained germ-free, the other four groups were monoassociated on day eight with one of four E. coli strains: non-pathogenic O86 or O83 and G58-1, or pathogenic 933D. The development of brush-border digestive enzyme functions in the small intestine was evaluated after 15 days. Germ-free controls exhibited slower developmental declines of lactase, gamma-glutamyltranspeptidase and alkaline phosphatase, and delayed increases of sucrase and glucoamylase compared to conventionally grown animals. Association of germ-free piglets with the non-pathogenic E. coli strains O86 and O83 resulted in increased enterocyte differentiation along the length of the small intestine, accompanied by declining activities of lactase, gamma-glutamyltranspeptidase and alkaline phosphatase, and elevated activities of maturational markers such as sucrase and glucoamylase. Maturational changes also occurred along the villus-crypt axis, as revealed by histochemical localization of aminopeptidase N on the villi tips in piglets colonized with E. coli O83. Interestingly, colonization with the pathogenic E. coli strain 933D stimulated changes in the main differentiation enzyme markers lactase, sucrase and glucoamylase to an extent comparable with those produced by the non-pathogenic and probiotic E. coli strains. In conclusion, germ-free piglets represent a valuable tool to study the consequences of colonization of the immature sterile gut with defined strains of bacteria.
 ...
PMID:Effect of bacterial monoassociation on brush-border enzyme activities in ex-germ-free piglets: comparison of commensal and pathogenic Escherichia coli strains. 1694 22