Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Oral administration of cimetidine, an antiulcerogenic drug, at a dose of 100 mg per kg body weight in mice, caused significant inhibition of glucose and amino acid uptake in small intestinal segments either after 2 and 24 h (single treatment) or 15 days (daily). Cimetidine also caused a significant decrease in intestinal brush border membrane associated enzymes, sucrase, lactase, maltase and alkaline phosphatase, but increases the activity of leucine aminopeptidase. Kinetic analysis indicated that cimetidine decreased the maximum of apparent initial enzyme velocity (Vmax) of disaccharidases, while substrate affinity constant (Km) was not altered, indicating the noncompetitive nature of inhibition. However, the inhibition of alkaline phosphatase was found to be of mixed type as both Km and Vmax were altered. In vitro addition of cimetidine also produced significant inhibition of enzymes, the inhibition constant (Ki) for sucrase, lactase, maltase and alkaline phosphatase being 22.8, 4.5, 11.5 and 4.8 mM, respectively. It was further observed that in vitro addition of cimetidine also decreased Vmax in case of maltase, sucrase and lactase, Km was unchanged, whereas in case of alkaline phosphatase there was a decrease in Vmax and increase in Km, as compared to the controls.
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PMID:Effect of cimetidine on intestinal absorption & digestive functions in mice. 237 90

1. Intestinal structure, lactase (beta-galactosidase; EC 3.2.1.23) activity and alkaline phosphatase activity have been determined in mouse jejunal and ileal tissues before and during infection with the intestinal parasite Nematospiroides dubius. 2. Oral infection with small numbers of N. dubius larvae caused villus height, crypt depth and enterocyte migration rate to increase in the mouse jejunum. None of these effects occurred in ileal tissue. 3. Lactase activity also increased in jejunal, but not ileal, tissue of infected mice. This increase was associated with a doubling of the rate at which activity appeared in the brush-border membrane of enterocytes during migration over the basal regions of jejunal villi. Alkaline phosphatase activity in jejunal tissue remained unchanged in infected mice. 4. Attention is drawn to the fact that this is the first occasion when crypt cell hyperplasia has been found to be positively correlated with an increase in lactase activity and a decrease in cytotoxic/suppressor T-cells. Further work is needed to establish the primary cause of these effects.
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PMID:Intestinal infection with Nematospiroides dubius selectively increases lactase expression by mouse jejunal enterocytes. 250 31

110 children suffering from malabsorption underwent several biopsies of the gut to confirm coeliac disease (CD) following the ESPGAN criteria. We studied the values for alkaline phosphatase (AP) in the intestinal mucosa after gluten challenge. In 42 patients the after challenge biopsy was normal, thus excluding coeliac disease. In 68 children the mucosa was severely damaged confirming CD. In all biopsy specimens lactase, invertase, maltase and alkaline phosphatase were measured. We found a good correlation between PA values and severity of mucosal damage, showing that measurement of PA in the mucosa is helpful in assessing the degree of mucosal atrophy in children suffering from malabsorption.
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PMID:[Alkaline phosphatase in the intestinal mucosa of children with the malabsorption syndrome]. 250 30

To assess correlations between cellular differentiation and enzymatic maturation in the developing rat colon, tissue from fetal, suckling, weanling, and adult rats was analyzed by electron microscopy and assayed for lactase, alkaline phosphatase, and sodium-potassium-stimulated adenosine triphosphatase activities. The proximal and distal colon were analyzed independently at all ages. All three enzymes were detected in the fetal colon when the cells were highly undifferentiated. Postnatally, significant regional differences in cellular ultrastructure appeared, only some of which were directly paralleled by enzymatic changes. Each enzyme had a distinct region-specific developmental pattern. Lactase and sodium-potassium-stimulated adenosine triphosphatase were significantly enhanced at birth, decreasing to adult levels by 15 days postnatal. Regional differences were present, but the patterns were similar. These patterns did not parallel the increase in microvillar height and number and basolateral interdigitations of the surface columnar cells, the structural correlates of lactase, and sodium-potassium-stimulated adenosine triphosphatase, respectively. In contrast, developmental changes in alkaline phosphatase activity paralleled structural maturation, at least in part. The activity levels in the distal colon did not change significantly with age and few major structural changes were noted. In the proximal colon, activity increased markedly after birth, and after 10 days decreased rapidly to adult levels, a pattern that coincided with the transient appearance of villi and specialized cells with apical tubules and vesicles known to have alkaline phosphatase activity. The results show age- and region-related changes in cellular ultrastructure and enzymatic activities, only some of which appear to be directly correlated.
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PMID:Structural and enzymatic changes during colonic maturation in the fetal and suckling rat. 254 5

The activities of intestinal brush border membrane (BBM) enzymes alkaline phosphatase, maltase, lactase, sucrase, gamma-glutamyl transpeptidase and leucine aminopeptidase were determined in intestinal homogenates and purified BBMs from control, heat-stable and heat-labile enterotoxin treated mice. The activities of all the enzymes except lactase were decreased significantly (p less than 0.01) in homogenates while increased significantly (p less than 0.001) in BBMs of experimental groups as compared to controls. Calmodulin activities were increased significantly (p less than 0.01) as compared to control in heat-stable enterotoxin treated mice but remained unaltered in heat-labile enterotoxin treated mice. DNA contents of intestinal homogenates were decreased in experimental groups demonstrating the decrease in cell number in these groups. The altered BBM enzyme activities could not be attributed to changes in calmodulin activities. The increase in enzyme activities in BBMs may reflect a compensatory phenomenon in the remaining cells.
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PMID:Effect of heat-stable and heat-labile enterotoxins of Escherichia coli on intestinal brush border membrane enzymes of mice. 257 May 78

Oral administration of antiulcerogenic drug ranitidine significantly inhibits glucose and amino acid uptake in small intestinal segments. It also inhibits activities of brush border membrane disaccharidases and alkaline phosphatase but increases the activity of leucine aminopeptidase. Kinetic analysis reveals noncompetitive and mixed type of inhibition for disaccharidases and alkaline phosphatase, respectively. In vitro addition of the drug to membrane preparation shows similar type of results as seen in vivo with the inhibition constant (ki) for sucrase, lactase, maltase and alkaline phosphatase as 12.5, 5, 11.5 and 19.5 mM, respectively.
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PMID:Effect of antiulcerogenic drug, ranitidine, on intestinal absorption and digestive functions in mice. 263 81

In a retrospective study, jejunal mucosal disaccharidase and alkaline phosphatase activities have been investigated in 40 controls and patients with proven celiac sprue (n = 26), lactase deficiency (n = 26), osteoporosis or osteomalacia (n = 16), chronic pancreatitis (n = 12), giardiasis (n = 7), or Crohn's disease (n = 7). Apart from a nonselective reduction of mucosal enzyme activities in the sprue syndrome and a selective reduction of lactase activity in the patients with primary lactase deficiency, assays of mucosal disaccharidases revealed only inconstant or slight deviations from the control group and were not of diagnostic significance for any of the above-mentioned disorders. Isolated forms of enzyme deficiencies other than lactase deficiency, such as sucrase-isomaltase or trehalase deficiency were not present among 168 investigations carried out from 1972-1982. It is concluded that assay of small intestinal disaccharidase or alkaline phosphatase activities does not expand the diagnostic impact of morphological examination of small bowel biopsy specimens and modern noninvasive methods for the detection of carbohydrate malabsorption. Thus, the method does not appear a necessary or relevant investigation in routine clinical practice.
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PMID:Is the assay of disaccharidase activity in small bowel mucosal biopsy relevant for clinical gastroenterologists? 274 34

The effects of Gossypol acetic acid (10 mg/kg b. wt. daily for 15 days), an experimental male antifertility agent and its subsequent withdrawal for another 15 days, on the structure and functions of the rat small intestinal tract have been investigated. Gossypol feeding causes a reduction in body weight and intestinal weight, length, protein, and nucleic acid contents. A 27%-50% reduction in the uptake of glucose, alanine, leucine, and calcium is observed after Gossypol feeding which is found to be reversible after 15 days of withdrawal of the drug. Gossypol also causes a significant reduction in the activities of sucrase, lactase, maltase and alkaline phosphatase in the intestinal homogenates as well as in the purified brush border membrane of the microvillus. A decrease in the maximum of apparent enzyme velocity and no change in the substrate affinity constant in these digestive hydrolases are observed on Gossypol treatment. It also causes a shift in the transition temperature in these enzymes and predictably changes the energy of activation both below and above the temperature of transition, although the Arrhenius expression of the temperature dependence still shows proximity, non-linearity, and is parallel to the control group. These changes are reversed on withdrawal of the drug and during the subsequent recovery period. Recovery experiments also show near identical values in kinetic parameters (Kt and Jmax) of 14C-glucose uptake in jejunal segments both in the presence and absence of Na+ ions. Also, no difference is observed between the control and recovery groups with respect to body and intestinal weight, intestinal length, and DNA, RNA, protein, lactate dehydrogenase and glucose-6-phosphate phosphohydrolase values in the intestinal homogenates. Phospholipid, cholesterol and sialic acid levels in both the groups also show nearly identical values. Molecular mechanism of the effects of Gossypol on brush border membrane-bound enzyme/carrier molecules operation is discussed in view of the kinetic and thermodynamic data obtained.
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PMID:Reversibility of the effects of gossypol acetic acid, an antispermatogenic/antifertility agent on the intestinal structure and functions of male albino rats. 274 9

Actinomycin D, at a dose of 0.25 micrograms/g body wt, produced slight increases in intestinal enzymatic activity on hamsters. At a high dose (1.5 micrograms/g body wt), actinomycin D produced inhibition of lactase activity, whereas maltase, sucrase and alkaline phosphatase activity decreased in males and increased in females. Cycloheximide (1.5 micrograms/g body wt), produced no changes in enzymatic activity. In the male and female hamster, the different actions of the antibiotic can be explained by the variations in the cortisol release produced by stress.
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PMID:Actinomycin D and cycloheximide actions on activity of some intestinal enzymes of adult hamster. 286 61

The fetal and postnatal activity patterns of different hydrolytic enzymes (alkaline phosphatase, gamma-glutamyltransferase, trehalase, maltase, glucoamylase, lactase, and sucrase) have been examined in mouse renal homogenates. Alkaline phosphatase and gamma-glutamyltransferase activities presented approximately similar changes. They increased from 18 days of gestation up to 30 days after birth. These activities showed marked increases during the 3rd and 4th postnatal weeks. A similar important rise was observed for trehalase activity at the end of the suckling period. Maltase activity increased gradually after birth. Traces of lactase, sucrase, and glucoamylase activities were detected at each developmental stage.
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PMID:[Activity of renal hydrolases in pre- and postnatal development of mice]. 286 26


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