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

Rectal biopsy specimens from control subjects and from patients with Crohn's colitis, non-rectal Crohn's disease, and acute ulcerative colitis were homogenized in isotonic sucrose and subjected to analytical subcellular fractionation by sucrose density gradient centrifugation. The gradient fractions and tissue homogenates were assayed for marker enzymes for the principal organelles: 5'nucleotidase (plasma membrane), malate dehydrogenase (mitochondria), catalase (peroxisomes), lactate dehydrogenase (cytosol), N-acetyl-beta-glucosaminidase (lysosomes), and neutral-alpha-glucosidase (endoplasmic reticulum). In normal tissue there was a distinct plasma membrane peak at density 1.12 g/ml. In tissue from patients with Crohn's disease the activity was increased approximately twofold even when the rectum showed no evidence of histological involvement. A second plasma membrane component was noted in Crohn's disease at density 1.19 g/ml. The total activity of the mitochondrial enzyme was similar in the various patient groups, but there was evidence of mitochondrial damage. There were no significant alterations in activity and density gradient distributions of catalase or of neutral alpha-glucosidase in the various patient groups, although less membrane-bound lactate dehydrogenase was noted in the patients with inflammatory bowel disease. There was a reduction of both cytosolic and particulate N-acetyl-beta-glucosaminidase in ulcerative colitis and a selective reduction in particulate activity in non-rectal Crohn's disease, demonstrating lysosomal alterations in these disorders. These results indicate selective and specific alterations in the principal subcellular organelles, especially the plasma membrane, lysosomes, and mitochondria, in the inflammatory bowel disease.
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PMID:Subcellular fractionation of rectal biopsy homogenates from patients with inflammatory bowel disease. 399 79

Analytical subcellular fractionation of tissue whole homogenates and microanalysis of organelle marker enzymes were used to study the activity and subcellular localization of enzymes implicated in HCO3 secretion in rat duodenal and gastric antral mucosae. The following organelles, characterized by their marker enzymes, were located in the density gradients: cytosol (lactate dehydrogenase), plasma membrane (5'-nucleotidase), peroxisomes (catalase), mitochondria (succinate dehydrogenase), endoplasmic reticulum (Tris-resistant alpha-glucosidase), lysosomes (N-beta-acetylglucosaminidase), and brush-border membrane (Zn2+-resistant alpha-glucosidase and alkaline phosphatase). Compared with gastric antrum, rat duodenal mucosa contained over twice the activity of HCO3-ATPase and of Na+-K+-ATPase but less than one-tenth the activity of carbonic anhydrase. Duodenal HCO3-ATPase activity was observed in both mitochondrial and brush-border membrane fractions, whereas antral HCO3-ATPase activity was confined to mitochondria. Na+-K+-ATPase activity was found largely in the basolateral membrane (duodenum) and plasma membrane (antrum). In both tissues carbonic anhydrase activity was localized to the cytosolic fraction. These observations offer further evidence that differing biochemical mechanisms underlie HCO3 secretion by gastric and duodenal epithelia.
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PMID:Activities and subcellular localizations of enzymes implicated in gastroduodenal bicarbonate secretion. 608 73

1. Analytical subcellular fractionation techniques have been applied to endoscopic human rectal biopsies to study the localization of enteroglucagon, somatostatin, vasoactive intestinal peptide and the properties of the principal subcellular organelles. 2. The peptide hormones, detected by radioimmunoassay, showed particulate localizations with single peaks in the density gradients for enteroglucagon (modal density 1.25) and somatostatin (modal density 1.23). Vasoactive intestinal peptide showed a less discrete localization but demonstrated a major peak (modal density, 1.17) with a small subsidiary peak (modal density 1.24). 3. The following organelles, characterized by their marker enzymes, were located in the density gradients; plasma membrane (5'-nucleotidase), mitochondria (malate dehydrogenase), peroxisomes (catalase), lysosomes (beta-N-acetyl-D-glucosaminidase), endoplasmic reticulum (neutral alpha-D-glucosidase) and cytosol (lactate dehydrogenase). 4. This technique can be used to investigate disease of the human rectum at a subcellular level.
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PMID:Subcellular fractionation studies of human rectal mucosa: localization of the mucosal peptide hormones. 610 76

Human lymphocytes were isolated from defibrinated blood by Ficoll-Hypaque centrifugation with erythrocyte hypotonic lysis. Homogenates of mixed lymphocytes were subjected to analytical subcellular fractionation by sucrose gradient centrifugation in a Beaufay automatic zonal rotor. The principal organelles were characterized by their marker enzymes: cytosol (lactate dehydrogenase), plasma membrane (5'-nucleotidase), endoplasmic reticulum (neutral alpha-glucosidase), mitochondria (malate dehydrogenase), lysosomes (N-acetyl-beta-glucosaminidase), peroxisomes (catalase). gamma-Glutamyl transferase was exclusively localized to the plasma membrane. Leucine amino-peptidase, especially when assayed in the presence of Co2+, was also partially localized to the plasma membrane. Experiments with diazotized sulphanilic acid, a non-permeant enzyme inhibitor, showed that these plasma membrane enzymes are present on the cell surface. No detectable alkaline phosphatase was found in the lymphocytes. Acid phosphatase and beta-glucuronidase were localized to lysosomes and there was some evidence for lysosomal heterogeneity. Leucine amino peptidase, optimal at pH 8.0, showed a partial localization to intracellular vesicles, possibly lysosomes, especially when assayed in the presence of EDTA. These studies provide a technique for determining the intracellular distribution of hitherto unassigned lymphocyte constituents and serve as a basis for investigating the cell pathology of lymphocytic disorders.
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PMID:Enzyme analysis and subcellular fractionation of human peripheral blood lymphocytes with special reference to the localization of putative plasma membrane enzymes. 614 55

Circulating non-T lymphocytes had higher activities of 5'nucleotidase (plasma membrane), neutral alpha-glucosidase (endoplasmic reticulum) and basal leucine amino-peptidase than did T lymphocytes. Activities of catalase (peroxisomes), malate dehydrogenase (mitochondria), lactate dehydrogenase (cytosol) and N-acetyl-beta-glucosaminidase, beta-glucuronidase and acid phosphatase (lysosomes), were similar in the lymphocyte subfractions. Lymphocyte 5'nucleotidase (plasma membrane) in patients with common variable hypogammaglobulinaemia is much lower than normal. However, the decrease is less marked in X-linked hypogammaglobulinaemia, chronic lymphatic leukaemia or protein loosing enteropathy or in lymphocytes isolated from cord blood. Cells from patients with nephrotic syndrome had normal levels of 5'nucleotidase. Other plasma membrane marker enzymes (gamma-glutamyl transferase, leucine amino-peptidase) were normal in lymphocytes from patients with common variable hypogammaglobulinaemia. There is a selective reduction of mitochondrial (malate dehydrogenase) and cytosolic (lactate dehydrogenase) enzymes, with normal activities of lysosomal, peroxisomal and endoplasmic reticulum enzymes, in patients with common variable hypogammaglobulinaemia. The lymphocyte subcellular organelles in normal subjects and patients with common variable hypogammaglobulinaemia have similar properties on sucrose density gradient centrifugation. It is suggested that lymphocytes from patients with common variable hypogammaglobulinaemia show a specific enzymopathy and that this is not simply a reflection of cellular immaturity.
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PMID:Lymphocyte enzyme activities in immunodeficiency syndromes with particular reference to common variable hypogammaglobulinaemia. 630 45

Over 24-h culture with hydrocortisone (400 nM), activity of brush-border alkaline phosphatase, alpha-glucosidase, and leucyl-2-naphthylamidase and cytoplasmic-mitochondrial malate dehydrogenase increased (P less than 0.05) by 80-133% compared with controls. Uptake of 3-O-methyl-D-[14C]glucose after 24-h culture was increased (P less than 0.05) by 30% compared with cultures without hydrocortisone. Labeling of protein with L-[14C]tyrosine and glycoprotein with D-[3H]glucosamine increased (P less than 0.05) by 40 and 88%, respectively, with hydrocortisone. The effects of hydrocortisone were dose dependent at normal serum concentrations (100-600 nM) and not further stimulated by larger concentrations. Cytoplasmic lactate dehydrogenase and lysosomal hexosaminidase activity, specific radioactivity of soluble precursor pools for protein and glycoprotein labeling, incorporation of [3H]thymidine into DNA, and morphology were unaffected by hydrocortisone. Inhibitors of glucocorticoid receptor binding (progesterone), mRNA transcription (alpha-amanitin), and protein synthesis (cycloheximide) prevented the effects of hydrocortisone. We suggest that hydrocortisone maintains the digestive, absorptive, and cellular function of cultured human jejunum. These protective effects were associated with increased protein synthesis and glycosylation and dependent on a classical steroid-hormone mechanism.
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PMID:Protection of epithelial function in human jejunum cultured with hydrocortisone. 634 19

Chorionic villi from first trimester and term human placentas have been incubated in vitro and shown to release the lysosomal enzymes, beta-hexosaminidase, alpha-glucosidase and beta-glucuronidase. There was negligible release of the cytoplasmic enzyme, lactate dehydrogenase, under the same conditions. The first trimester villi released proportionally more of their lysosomal enzyme content than did the term villi. Extracellular levels of beta-hexosaminidase were raised and those of alpha-glucosidase and beta-glucuronidase were lowered when tissue was incubated with 1 microM colchicine, suggesting that microtubules are involved in the control of lysosomal enzyme release from placental villi.
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PMID:Secretion of lysosomal enzymes by human placental villi in vitro. 645 98

Rectal biopsy specimens from control subjects, patients with either active or quiescent ulcerative colitis, and patients with Crohn's colitis were examined histologically and assayed for marker enzymes associated with tissue organelles. They were catalase (peroxisome); neutral alpha-glucosidase (endoplasmic reticulum); alkaline phosphatase (plasma membrane); malate dehydrogenase (mitochondria); lactate dehydrogenase (cytosol). There was no significant change in these enzyme activities in patient samples compared with controls. Activities of three acid hydrolases (lysosomal enzymes), beta-glucuronidase, acid phosphatase, and N-acetyl-beta-glucosaminidase, were also assayed in the biopsy samples. Decreased activities of all three enzymes were noted in ulcerative colitis, particularly in active disease. Normal values were obtained in Crohn's colitis. Measurement of lysosomal integrity by assays of latent N-acetyl-beta-glucosaminidase activity revealed similar results in control and colitic subjects. It is suggested that the lysosomal changes reflect a specific tissue release of enzyme and may be implicated in the pathogenesis of the tissue damage.
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PMID:Organelle pathology in ulcerative and Crohn's colitis with special reference to the lysosomal alterations. 671 88

Muscle hypertrophy was induced in the soleus muscle of young rats by tenotomy of the gastrocnemius and plantaris muscles. Three and 7 days afterwards the sciatic nerve was sectioned. The loss of weight of muscles subjected to this combined procedure three days after denervation was 30-40%. Lysosomal enzyme activities (acid phosphatase, alpha-glucosidase, beta-galactosidase and N-acetyl-beta-D-glucosaminidase) and energy enzyme activities (lactate dehydrogenase, LDH, triose-3-phosphate dehydrogenase, TPDH , D-hexokinase, HK and citrate synthase, CS) were determined 3 days after denervation, 3, 7 and 10 days after hypertrophy had been induced and 3 days after denervation of hypertrophying muscles on day 3 and 7. Normal non-operated rats of corresponding body weight served as controls and their enzyme activities were estimated on the same day. In the course of muscle hypertrophy, the 4 lysosomal enzyme activities increased progressively. Although 3 days' denervation of control muscles did not alter lysosomal enzyme activities, denervation of hypertrophying muscles greatly enhanced the activity of these enzymes. Enzymes of energy metabolism were affected to a lesser degree. The results suggest that denervation of hypertrophying muscles causes more extreme changes in muscle weight and lysosomal enzyme activities than denervation alone. The possible implications of this finding are discussed in relation to the rapid atrophy.
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PMID:Lysosomal and energy enzyme activities in hypertrophied rat soleus muscle after denervation. 671 25

The activities of various enzymes involved in detoxication and carbohydrate metabolism in the liver and the gastrointestinal tract of germfree (GF) and conventional (CV) rats, 8 and 40 weeks' old, were measured in relationship to intestinal microflora and aging. In 8-week-old rats, the activities of nitroreductase (NR) and aniline hydroxylase (AH) in the liver, and of alkaline phosphatase (ALP), maltase and lactase in the duodenum were higher in GF than in CV rats, but the activities of arginosuccinate synthetase (ASS) and lactate dehydrogenase (LDH) in the liver were higher in CV than in GF rats. In 40-week-old rats, the activities of NR and glucose-6-phosphatase dehydrogenase (G-6-PDH) of the liver and ALP, maltase and lactase of the duodenum were higher in GF than in CV rats, but those of ASS, UDP-glucuronyl transferase (UDP-GT), AH, beta-glucuronidase, and LDH of the liver were higher in CV than in GF rats. Compared between 8- and 40-week-old rats the activities of NR, beta-glucuronidase, LDH, and acid phosphatase increased with aging in both GF and CV rats. The specific activities of ASS in CV and UDP-GT and AH in GF rats decreased with aging. The total activities of ASS and AH in GF rats also decreased with aging. The activities of ALP, maltase and lactase decreased with aging in both GF and CV rats. Thus, these data suggested that there are influences of indigenous intestinal microflora and aging on the activities of various enzymes in the liver and gastrointestinal tract.
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PMID:Intestinal microflora and aging: age-related change of enzymes in the liver and the small intestine of germ-free and conventional rats. 679 85


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