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

Insectivorous/frugivorous passerine species studied so far lack the ability to modulate intestinal maltase activity, in contrast to galliformes. We tested for dietary modulation of small intestine (SI) enzymes including maltase in house sparrows to understand whether the difference between the galliformes on the one hand, and the passerines on the other, reflects a phylogenetic pattern (maltase modulated in galliformes but not passerines), a dietary pattern (maltase modulated in granivores but not insectivore/frugivores), some other pattern, or chance. We also tested the prediction that intestinal peptidase activity would be increased on a high protein (HP) diet. Birds were fed three diets high in starch, protein, or lipid for 10 days. For birds on the HP diet (60.3% protein) we observed the predicted upward modulation of aminopeptidase-N activity, as compared with the lower-protein, high starch (HS) (12.8% protein) diet. In contrast, birds eating the HS diet had similar maltase and sucrase activities, and only slightly higher isomaltase activity, compared with birds eating the high protein (HP), starch-free diet. Birds eating high lipid (HL) diet had low activities of both carbohydrases and peptidase. Considering that the statistical power of our tests was adequate, we conclude that house sparrows show little or no increase in carbohydrases in response to elevated dietary carbohydrate. We cannot reject the hypothesis that maltase lability among avian species has a phylogenetic component, or that high dietary fat has a depressing effect on both carbohydrase and peptidase activities.
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PMID:Dietary modulation of intestinal enzymes of the house sparrow (Passer domesticus): testing an adaptive hypothesis. 1077 27

Spermine is a constituent of all vertebrate cells. Nevertheless, it exerts toxic effects if it accumulates in cells. Spermine is a natural substrate of the FAD-dependent polyamine oxidase, a constitutive enzyme of many cell types. It has been reported that the toxicity of spermine was enhanced if polyamine oxidase was inhibited. We were interested to examine spermine toxicity to human colon carcinoma-derived CaCo-2 cells because, in contrast to most tumor cell lines, CaCo-2 cells undergo differentiation, which is paralleled by changes in polyamine metabolism. CaCo-2 cells were remarkably resistant to spermine accumulation, presumably because spermine is degraded by polyamine oxidase at a rate sufficient to provide spermidine for the maintenance of growth. Inactivation of polyamine oxidase increased the sensitivity to spermine. A major reason for the enhanced spermine cytotoxicity at low polyamine oxidase activity is presumably the profound depletion of spermidine, and the consequent occupation of spermidine binding sites by spermine. Hydrogen peroxide and the aldehydes 3-aminopropanal and 3-acetamidopropanal, the products of polyamine oxidase-catalyzed splitting of spermine and N1-acetylspermine, contribute little to spermine cytotoxicity. Activation of caspase by spermine was insignificant, and the formation of DNA ladders, another indicator of apoptotic cell death, could not be observed. Thus it appears that cell death due to excessive accumulation of spermine in CaCo-2 cells was mainly nonapoptotic. The content of brush border membranes did not change between days 6 and 8 after seeding, and it was not affected by exposure of the cells to spermine. However, the activities of alkaline phosphatase, sucrase, and aminopeptidase in nontreated cells were considerably enhanced during this period, but remained low if cells were exposed to spermine. These changes appear to indicate that differentiation is prevented by intoxication with spermine, although other explanations cannot be excluded.
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PMID:Spermine cytotoxicity to human colon carcinoma-derived cells (CaCo-2). 1091 67

The efficacy of ornithine alpha-ketoglutarate (OKG) in preventing bacterial translocation and dissemination, metabolic disorders and changes in mucosal enzyme activities was assessed in a model of bacterial translocation in rats. Antibiotic decontamination was performed 4 d before intragastric inoculation with an Escherichia coli strain (10(10) bacteria/kg body). Two days later, the rats were given either a lipopolysaccharide (LPS) 0127:B8 or a saline injection and were deprived of food for 24 h. Enteral nutrition, [Osmolite, 880 kJ/(kg. d)] supplemented with either OKG (LPS + OKG) or glycine (Saline + Gly or LPS + Gly), was then given for 2 d. Urinary total nitrogen losses and 3-methylhistidine excretion were determined daily. On killing at d 3, bacterial translocation to the mesenteric lymph nodes (MLN) and dissemination to the spleen and liver were evaluated, jejunal mucosa enzyme activities were assayed and tissue free amino acids in muscles were measured. Endotoxin induced translocation from the gut lumen to the MLN in all groups, whereas dissemination occurred only in LPS-treated rats. OKG significantly reduced dissemination of the bacteria in the spleen. 3-Methylhistidine excretion was greater in the LPS + Gly group (+25%, P: < 0.05) than in either the LPS + OKG or Saline + Gly group. The group fed the OKG-enriched diet had higher muscular glutamine, ornithine and arginine concentrations than did the Gly-supplemented groups (P: < 0.05). Intestinal sucrase and aminopeptidase activities were higher in the LPS + OKG group than in the LPS + Gly group (-30%, P: < 0.05). OKG supplementation limits bacterial dissemination and metabolic changes after injury in rats and thus may be useful in the prevention of gut-derived sepsis in critically ill patients.
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PMID:Bacterial dissemination and metabolic changes in rats induced by endotoxemia following intestinal E. coli overgrowth are reduced by ornithine alpha-ketoglutarate administration. 1111 Aug 43

Cedar waxwings (Bombycilla cedrorum) feed predominantly on fruits that are rich in simple sugars and low in nitrogen, supplementing this diet with arthropod prey during the summer months as well as flowers and tree sap in springtime. In contrast, thrushes feed extensively on fatty, protein-rich invertebrate prey, supplemented with sugary and lipid-rich fruits. Simple sugars and fats are digested and/or absorbed by distinctly different physiological mechanisms, which suggests the possibility of contrasting digestive strategies in animals specialized to diets containing one of these two energy sources. In this study, we quantified enzymatic activity of three membrane-bound intestinal enzymes of cedar waxwings and five species of thrushes to explore this aspect of their digestive physiology. These enzymes catalyze the final steps in the digestion of carbohydrates (sucrase-isomaltase and maltase-glucoamylase) and protein (aminopeptidase-N). The two carbohydrases are homologous enzymes with overlapping functions; both enzymes catalyze the hydrolysis of maltase and isomaltase. The membrane-bound digestive enzyme systems that we described for cedar waxwings and thrushes can be explained by the particular nutrients contained within their respective natural diets. Consistent with previous work, cedar waxwings displayed intestinal sucrase activity, whereas thrushes did not. Correspondingly, cedar waxwings eat some foods containing sucrose, whereas thrushes do not. Sucrase-isomaltase conferred all maltase and isomaltase activity in cedar waxwings. In contrast, all maltase and isomaltase activity in thrushes was necessarily sucrase independent, which indicated the presence of maltase-glucoamylase. The absence of sucrase-independent maltase activity in cedar waxwings suggests that sucrase-isomaltase obviates the need for maltase-glucoamylase. Indeed, total maltase and isomaltase activities were much higher in cedar waxwings than in thrushes. Neither waxwings nor thrushes eat starchy foods; sucrase-isomaltase in waxwings and maltaseglucoamylase in thrushes probably function in digesting glycogen in animal foods. We suggest that digestive traits associated with specialization to monosaccharide-rich fruits (lack of a grinding gizzard) by frugivorous waxwings and thrushes may prevent utilization of starchy seeds. Total aminopeptidase-N activity in cedar waxwings was indistinguishable from the allometric pattern among thrush species, but the distribution of this enzyme along the intestines of waxwings and thrushes was distinctly different, which demonstrates that total enzyme activity can be insufficient as a descriptor of the functional activity of brush border enzymes. Aminopeptidase-N activity peaked in the anterior part of the intestines of thrushes and in the terminal portion of the intestines of waxwings, which suggests contrasting strategies for protein digestion from fatty versus sugary diets, respectively.
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PMID:The membrane-bound intestinal enzymes of waxwings and thrushes: adaptive and functional implications of patterns of enzyme activity. 1143 43

Six decades of studies have speculated that digestive capacity might limit avian growth rate or that developmental changes in the gut might determine developmental changes in digestive efficiency. However, there are no studies on digestive enzymes during avian development, except for studies on mainly domestic birds that exhibit the precocial mode of development. We studied alimentary organ masses, intestinal enzyme activities (sucrase, maltase, isomaltase, aminopeptidase-N), and pancreatic enzyme activities (amylase, trypsin, chymotrypsin) during development of a wild passerine bird exhibiting the altricial mode of development. Wild nestling house sparrows were studied immediately after removal from the nest (days 0, 3, 6 of age; day 0=hatch), whereas captives were raised in the laboratory beginning day 3 on a formulated casein/starch-based diet until fledging age (after day 12). Digestive biochemistry was dynamic. Tissue-specific activities of some digestive enzymes continued to increase through fledging, by >10 times in some cases (e.g., sucrase and maltase in midintestine). Total pancreatic amylase activity increased 100 times between hatch and day 12 through a combination of increases in tissue-specific activity and pancreas mass. House sparrows differ from poultry, in whom after about 2 wk of age the specific activity of intestinal and pancreatic digestive enzymes is generally constant or declines during development. The data on intestinal and pancreatic enzymes help explain why digestive efficiency of nestling house sparrows improves with age, and the data seem consistent with the idea that digestive capacity might limit feeding rate and hence growth rate.
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PMID:Developmental changes in digestive physiology of nestling house sparrows, Passer domesticus. 1151 62

Smaller guts and slow initial mass gains at stopover sites have led to the idea that digestive physiology limits refueling rates in migrating birds. We tested the digestive-limitation hypothesis in yellow-rumped warblers using food restriction to simulate infrequent feeding during migration, which may cause a reduction in alimentary tract mass. Restricted birds had small intestine, pancreas, and liver masses 18%-22% lower than ad lib.-fed controls. Total activities of sucrase, maltase, aminopeptidase, and amylase were significantly lower in restricted birds, while those of trypsin and chymotrypsin were not. Only aminopeptidase mass-specific activity was significantly lower in restricted birds. Previously restricted birds were able to feed and digest at a high rate immediately following return to ad lib. feeding. Digestive efficiency did not differ between groups. These results suggest that before migration yellow-rumped warblers have some spare digestive capacity to compensate for declines in their digestive organ masses during migration.
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PMID:Digestive response to restricted feeding in migratory yellow-rumped warblers. 1217 34

Flowerpiercers are the most specialized nectar-feeding passerines in the Neotropics. They are nectar robbers that feed on the sucrose-rich diet of hummingbirds. To test the hypothesis that flowerpiercers have converged with hummingbirds in digestive traits, we compared the activity of intestinal enzymes and the gut nominal area of cinnamon-bellied flowerpiercers (Diglossa baritula) with those of eleven hummingbird species. We measured sucrase, maltase, and aminopeptidase-N activities. To provide a comparative context, we also compared flowerpiercers and hummingbirds with 29 species of passerines. We analyzed enzyme activity using both standard allometric analyses and phylogenetically independent contrasts. Both approaches revealed the same patterns. With the exception of sucrase activity, hummingbirds' digestive traits were indistinguishable from those of passerines. Sucrase activity was ten times higher in hummingbirds than in passerines. Hummingbirds and passerines also differed in the relationship between intestinal maltase and sucrase activities. Maltase activity was two times higher per unit of sucrase activity in passerines than in hummingbirds. The sucrase activity of D. baritula was much lower than that of hummingbirds, and not unlike that expected for a passerine of its body mass. With the exception of aminopeptidase-N activity, the digestive traits of D. baritula were not different from those of other passerines.
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PMID:Sugar and protein digestion in flowerpiercers and hummingbirds: a comparative test of adaptive convergence. 1475 1

A 303-bp cDNA of intestinal zinc exporter (ZnT1) was isolated from chicken jejunum by reverse transcriptase-polymerase chain reaction and sequenced, and showed 42% homology to Homo sapiens and Rattus novergicus intestinal ZnT1 genes. This specific probe was used to examine the effect of zinc-methionine (ZnMet) administration on the mRNA expression of ZnT1 and on small intestinal development and functionality. In this study, ZnMet was injected into the naturally consumed amniotic fluid of 17-day-old chicken embryos. The ZnT1 gene showed an approximately 200% increase in its mRNA levels from 48 h post-ZnMet injection, as compared to the control. An analysis of the gene expression of the brush-border enzymes and transporters showed increased mRNA expression of sucrase isomaltase, leucine-aminopeptidase, sodium-glucose cotransporter and Na+K+ATPase transporter (Na+K+ATPase) from 48 h post-ZnMet injection, in comparison to controls. Significant increases (P<.05) in the biochemical activity of the brush-border enzymes and transporters, and in jejunal villus surface area were detected from day of hatch (96 h post-ZnMet injection) as compared to controls. These results suggest that ZnMet administration into prenatal intestine via injection into the amniotic fluid enhances intestinal development and improves its functionality.
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PMID:Changes in chicken intestinal zinc exporter mRNA expression and small intestinal functionality following intra-amniotic zinc-methionine administration. 1593 45

Many studies dealing with trinitrobenzene sulfonic acid (TNBS) colitis in rats have been carried out referring only to the colon. In humans, ulcerative colitis (UC) can extend a variable distance into the terminal ileum in a phenomenon known as backwash ileitis (BWI). The aim of this study was therefore to examine the effect of TNBS-induced colitis on different aspects of the rat ileum and jejunum. We hypothesized that TNBS administration would lead to a systemic influence on the small intestine. Rats were induced colitis by administration of 0.25 ml of 2,4,6-trinitrobenzene sulfonic acid and 72 h after colitis induction animals were sacrificed. Segments were taken of the colon, ileum and jejunum. In addition to mucin mRNA expression, morphological changes were observed in the jejunum and ileum. We examined the mRNA expression and biochemical activity of brush border enzyme, sucrase iso-maltase and aminopeptidase, in all three segments. The villous surface area of colitis-induced rats was smaller in jejunum and ileum compared to control. In the jejunum of TNBS-induced rats, goblet-cell volume increased and their density decreased. The relative amount of MUC2 mRNA decreased in the jejunum, ileum and colon of colitis rat. However, MUC3 mRNA expression increased in the ileum and colon of these rats. Sucrase isomaltase expression and activity decreased in the ileum of TNBS-induced rats, while aminopeptidase activity was lower in the jejunum. These observations suggest that intrarectal administration of TNBS to rats influences not only their colon and terminal ileum, but also the proximal ileum and jejunum. Involvement of the ileum and jejunum in TNBS-induced colitis may be related to the systemic reaction of the immune system and mucosa to colitis.
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PMID:Mucosal function in rat jejunum and ileum is altered by induction of colitis. 1696 28

This study aims to describe the morphological alterations in the small and large intestines as well as the expression of some enterocyte enzymes and carriers in a rat model of iodoacetamide-induced colitis. Biopsies from the large and small intestines were taken at 1, 2, 4, 8, and 16 days postinduction and studied by light microscopy. The expressions of lactase, sucrase, aminopeptidase, and Glut-5 in the jejunum were studied by immunohistochemistry. Gene expressions of enterocyte lactase and sucrase were determined by RT-PCR using specific oligonucleotides. Microscopic examination of the large intestines revealed manifestations concordant with inflammation. Such alterations peaked at 2 days, were maintained to a lesser extent for 4 days, regressed by 8 days, and healed by 16 days. In the jejunum, the expression of lactase, sucrase, and aminopeptidase decreased 2 days after colitis induction, and recovered 2 days later. Similarly, Glut-5 expression decreased transiently with partial recovery by day 8. Compared with sham, gene expression of jejunal brush border enzymes sucrase and lactase showed a 4-fold increase in lactase and a 9-fold increase in sucrase after 4 days. We conclude that colitis can induce significant functional abnormalities in distant noninflamed small bowel regions.
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PMID:Morphological and biochemical alterations in the jejunum following iodoacetamide-induced colitis in rats. 1721 84


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