Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The presence and particle association of various hydrolytic enzymes in Naegleria fowleri has been studied in whole cell extracts of trophozoites in an effort to establish authentic markers for surface membrane and lysosomal components. Evidence from the experiments reported here indicates that in N. fowleri a) acid proteinase, N-acetylglucosaminidase, and acid phosphatase are associated with cytoplasmic granules closely resembling lysosomes; b) 5'-nucleotidase is associated with the surface membrane, probably on the external surface; c) aspartate aminotransferase is associated with mitochondria; d) alpha-D-glucosidase and an aminopeptidase have bimodal distributions, activity being associated with both the surface membrane and lysosomal particles.
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PMID:Subcellular distribution of hydrolases in Naegleria fowleri. 299 80

Animal experimentation with total parenteral nutrition (TPN) has revealed the occurrence of atrophy of the intestinal mucosa and decreased enzyme activities of the brush border, notably the disaccharidases. These findings have heretofore not been confirmed in human investigation. We performed endoscopic biopsies in the third part of the duodenum in 7 adults before TPN, after 21 days of TPN, and after a progressive oral refeeding. We noted a clear-cut decrease of major enzyme activities during TPN (sucrase, maltase, lactase, glucoamylase, acid aminopeptidase, dipeptidyl peptidase) without any morphologic modifications as observed with standard histology. Electron microscopy showed a slight but significant decrease in the height of microvilli. The decreased enzyme activities were rapidly restored after oral refeeding. Thus, the functional consequences of the modifications observed during medium-term TPN in adults are probably limited.
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PMID:Decreased brush border hydrolase activities without gross morphologic changes in human intestinal mucosa after prolonged total parenteral nutrition of adults. 307 17

To evaluate the response of the small intestinal mucosa to Saccharomyces boulardii (S.b.), a yeast widely used in some countries as an adjuvant drug with oral antimicrobial therapy, seven healthy adult volunteers were treated with high doses of lyophilized S.b. (250 mg four times per day) for 2 wk. A peroral jejunal suction biopsy was performed on days 0 and 15 of the study. Compared to the initial biopsy, histological examination of the posttrial biopsy revealed no morphological alteration nor change in villus height or crypt depth. After treatment, the specific activity (per U protein) of sucrase, lactase, and maltase was, respectively, increased by 82% (p less than 0.05) 77% (p less than 0.05), and 75% (p less than 0.05) over the basal activity of the enzymes measured on day 0, whereas mucosal protein content remained unchanged. Similar findings were found in the jejunum of adult rats treated for 5 days with either viable or killed S.b. cells. The changes in total enzyme activity (per jejunal segment) paralleled the changes in specific enzyme activity. In vitro assays on freshly prepared suspensions of S.b. (6.0 X 10(8) viable cells/ml) evidenced a high activity for sucrase (mean +/- SE: 8 364 +/- 1280 U X g X protein-1) but no maltase, neutral lactase, acid beta-galactosidase, or aminopeptidase activity. To determine whether treatment with S.b. could influence the incorporation rate of neutral lactase into the brush border membrane, 14-day-old sucklings treated either with saline or with S.b. were given intraperitoneally a dose of 20 microCi D-[1(14)C] glucosamine 3 hours before sacrifice.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Response of human and rat small intestinal mucosa to oral administration of Saccharomyces boulardii. 308 Jul 30

A rapid and improved method to obtain purified lactase from rat intestine is described. The purification procedure involved only two chromatographic steps. The degree of purification was far above (500 fold) the values reached with classical methods. Rabbit antisera raised to the purified lactase were characterized using conventional immunological techniques. The specificity of the lactase antibodies was confirmed by the lack of interference on maltase, aminopeptidase and alkaline phosphatase activities measured after papain extraction of the membrane proteins.
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PMID:Improved purification of rat intestinal lactase. 309 77

Morphologic and functional adaptations of the functioning intestine were evaluated in 41 patients before and after biliopancreatic bypass for morbid obesity. This surgical procedure diverts pancreatobiliary secretions via the duodenum and the jejunum into the colon, the remaining small intestine being anastomosed to the stomach after antrectomy. In the proximal ileum there was an 80% increase of the height of villi; the specific activities of maltase, sucrase, and aminopeptidase in brush border membranes remained unaffected, and that of lactase tended to decrease. In the distal ileum villi heights increased only by 58%, and disaccharidase activities (except for maltase) were slightly enhanced. In the colon the mucosa displayed, in some patients, focal appearance of true villi, and brush border enzyme activities increased concomitantly. We conclude that biliopancreatic bypass induces an adaptation of all intestinal segments of the functioning intestine; this adaptation tends to compensate for the shortening of the gut continuity.
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PMID:Small-intestinal and colonic changes after biliopancreatic bypass for morbid obesity. 310 Nov 67

The influence of insulin on the postnatal development of intestinal functions linked to villus cells (sucrase, lactase, maltase and aminopeptidase) and crypt cells (secretory component of immunoglobulins, SC) has been studied in suckling and weanling rats. At 9 days of age, the animals received a daily injection of insulin 12.5 mU g-1 body weight day-1 for 4 days. Compared with saline-treated controls, insulin had no effect on the development of the intestinal mucosal mass parameters determined in the jejunum, ileum and colon. A premature appearance of sucrase was noted in isolated jejunal villus and crypt cells, the level of activity reached by the enzyme being dependent of the amount of insulin injected. By 6 and 12 h after a single injection of the hormone (12.5 mU g-1 body weight), sucrase activity was detected in all the cell fractions along the villus-crypt axis. In villus cells of insulin-treated rats, maltase, lactase and aminopeptidase activities were significantly (P less than 0.001) increased (+201%, +50%, +207%, respectively, vs. controls), whereas the concentration of SC measured by a sensitive immunoradiometric assay was enhanced over the controls by 75% in villus cells, 83% in crypt cells and 172% in the liver. Weanling rats treated from day 10 to day 20 postpartum with 12.5 mU insulin also exhibited a higher intestinal production of SC (+93%, P less than 0.01) than did saline controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Intestinal development in the suckling rat: effect of insulin on the maturation of villus and crypt cell functions. 313 25

We studied 24 patients with end-stage chronic renal failure not treated with hemodialysis (CRF1) and 16 patients on regular hemodialysis (CRF2), to investigate the digestive, absorptive and morphological aspects of the small intestinal mucosa. Serum d-xylose test and biochemical parameters of absorption (serum calcium and proteins) were determined. Jejunal mucosal biopsies were obtained and tissue homogenates assayed for disaccharidases (sucrase, maltase and lactase) and dipeptidases (glycyl-glycinase, leucyl-glycinase and leucyl-aminopeptidase). Histological changes were classified according to the severity of abnormality and compared with biopsies obtained from control subjects. Serum d-xylose test, calcium and proteins were normal in patients with CRF. Maltase specific activity was higher in CRF1 than in controls (p less than 0.05). Lactase and leucyl-aminopeptidase showed a tendency to decrease in CRF, but this difference did not reach statistical significance. Sucrase, glycyl-glycinase and leucyl-glycinase specific activity in CRF was similar to the control group. Histological changes of the small intestinal mucosa of mild to moderate degree were noted in 68% of patients with CRF vs 36% in control subjects (p less than 0.01). No significant difference was noted in the incidence of absorptive, enzymatic (with the exception of maltase) and histological changes between the two groups of patients with CRF. These changes are not influenced by hemodialysis, a long-term treatment averaging 6 months, they appear to represent primary manifestations of CRF and may be related to the nutritional status of patients with CRF.
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PMID:Small intestinal function and structure in patients with chronic renal failure. 339 24

We studied the activity and kinetic parameters of microvillous enzymes in intestinal villous cells and the concentration of the secretory component (SC) of p-immunoglobulin A in subcellular fractions of crypt cells in 35-day-old rats made iron deficient from birth and in controls. The aim of the study is to investigate the biochemical basis for the decreased activity of brush-border disaccharidases observed in growing animals with chronic iron deficiency. In rats made iron deficient, the specific (per unit protein) and the total (per total intestinal length) activities of sucrase, lactase, maltase, aminopeptidase, and diamine oxidase were decreased from -17 to -66% compared with the activities measured in the controls. The lower activity of sucrase in the brush-border membrane of the iron-deficient rats was associated with much slower enzyme synthesis rate than in control animals. Km of sucrase was identical in both iron-deficient rats and controls, but the maximum velocity of enzyme reaction was reduced proportionally to the enzymatic activity, indicating a lesser amount of enzyme rather than an inactivation. Electron microscopy of epithelial villous cells from iron-deficient rats revealed a marked rarefaction of secretory granules (transport vesicles) without apparent change in the morphology of the brush-border membrane or of cellular organelles. In villus and crypt cells isolated from the jejunum of iron-deficient rats, SC concentration was reduced to a level about half that of the controls. When SC concentration was measured in subcellular fractions of crypt cells, SC content in each fraction was two to three times lower in iron-deprived rats than in controls without evidence of accumulation of the protein at a given subcellular level.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Alteration of intracellular synthesis of surface membrane glycoproteins in small intestine of iron-deficient rats. 378 40

Age-related changes in enzyme activities, protein electrophoretic patterns and lipid composition of kidney-brush-border membranes were studied in 10-20- and 30-month-old male and female Wistar rats. Polyacrylamide gel electrophoresis of membrane proteins revealed very little changes with increasing age, whether males or females were considered. The Km of three hydrolases - maltase, L-aminopeptidase and alkaline phosphatase - were not affected by age while the Vmax of maltase and alkaline phosphatase, but not of L-aminopeptidase, decreased from 10 to 30 months. The phospholipid to protein ratio which remained constant between 10 and 20 months, rose in both sexes from 20 to 30 months. In males, the cholesterol content of the membrane increased faster than that of phospholipid and the cholesterol over phospholipid ratio was then greater at 30 months than at 10 months, while in females this ratio remained unchanged in the course of aging. The fatty acid composition of the brush-border remained more or less constant with age in female rat whereas in the male, a 10% decrease in the proportion of arachidonic acid from 10 to 30 months was responsible for a lower unsaturation index.
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PMID:Age-related changes in enzyme activities, protein content and lipid composition of rat kidney brush-border membrane. 388 47

The uptake of nutrients and activities of membrane enzymes in the kidney were investigated using renal brush border membrane (BBM) vesicles in acute pyelonephritis in rats. A significant decrease (P less than 0.001) in the uptake of D-glucose and L-phenylalanine was observed in both the unobstructed right and obstructed left kidney, while there was a significant increase (P less than 0.001) in the uptake of L-alanine in the left kidney of pyelonephritic rats, demonstrating disturbances in the reabsorption of the glucose and aminoacids in the kidneys. Vmax of alkaline phosphatase, leucine-amino-peptidase and maltase was found to be decreased in the left kidney, suggesting that there was a reduction in the active enzyme molecule number. Km of alkaline phosphatase and leucine-aminopeptidase remained unchanged, while km of maltase decreased in both the right and left kidneys. An increase in the Vmax of alkaline phosphatase and leucine-aminopeptidase and substrate affinity of the maltase in the right kidney demonstrated a compensatory phenomenon for the malfunctioning of the left kidney. This is the first report demonstrating alterations in reabsorption of nutrients and BBM enzymes in experimental pyelonephritis.
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PMID:Pyelonephritis alters the reabsorption of nutrients and brush border membrane enzymes of rat kidney. 390 22


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