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)

The UHF fraction from NIL 8 hamster embryo fibroblasts contains the LETS protein and several other major proteins. It exhibits three enzymatic activities in significant amounts: 5'-nucleotidase, alkaline phosphatase, and galactosyl transferase. The latter two appear to be different from the membrane-bound enzymes. This fraction is heavily stained with ruthenium red, a dye specific for the cell coat in intact cells. A comparable fraction from hamster sarcoma virus-transformed cells exhibits a similar overall protein composition but lacks at least three major proteins, including the LETS protein. Compared to NIL 8 cells, the distribution of alkaline phosphatase in fractions from these cells is different, and the level of galactosyl transferase in the UHF is much reduced.
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PMID:Cell surface coat of hamster fibroblasts. 29 62

A new procedure for the purification of plasma membranes of Dictyostelium discoideum is described. Cells are broken by vigorously stirring in the presence of glass beads, and plasma membranes are isolated by equilibrium sucrose density centrifugation. The purified membranes are considerably enriched in alkaline phosphatase and 5'-nucleotidase and contain very low levels of succinate dehydrogenase and NADPH-cytochrome c reductase. The purified membranes contain relatively high levels of phospholipid, sterol and carbohydrate. They appear as a relatively homogeneous population of membrane vesicles in the electron microscope. This new method of purification is compared to previously published procedures which have been found to be unsuitable for our purposes.
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PMID:The purification and characterization of Dictyostelium discoideum plasma membranes. 40 46

A histochemical and autoradiographic study of the lining intestinal epithelium of the snake Xenodon merremii is reported. The absorptive cells present neutral polysaccharides, arginine, tyrosine, tryptophan, cysteine, alkaline phosphatase, acid phosphatase, ATPase, AMPase, esterase and RNA. There are histochemical differences between the goblet cells of the small and of the large intestine. Whereas in the former predominates the neutral polysaccharides and are found arginine, tyrosine, tryptophan and cysteine, in the latter predominates the sulfated polysaccharides (confirmed by the uptake of radioactive sulfur) and no amino acids were found.
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PMID:Histochemical (polysaccharides, proteins, nucleic acids and enzymes) and autoradiographic (incorporation of 35S labelled sodium sulfate) study of the epithelial intestinal cells of Xenodon merremii Wagler, 1824 (Ophidia). 40 42

The overall transport of bile salts across the hepatocyte is characterized as a carrier-mediated process whose rate-limiting step is biliary secretion. Specific bile salt binding proteins have been identified in liver surface membrane fractions and were postulated to represent the initial interaction in bile salt translocation across both the sinusoidal and canalicular membranes. To test this hypothesis, cycloheximide was administered to rats to inhibit hepatic protein synthesis. 16 h after cycloheximide administration [14C]leucine incorporation into hepatic protein was inhibited by 93% at 1 h and 47% at 12 h. However, values of liver function tests were not increased, although serum albumin, serum alanine amino-transferase, and alkaline phosphatase were significantly decreased. Light and electron microscopy did not demonstrate necrosis or fat accumulation. The latter demonstrated minimal disorganization of rough endoplasmic reticulum and occasional lamellar whorls. 16 h after cycloheximide administration bile salt independent bile flow, basal bile salt excretion, and basal bile flow were unaltered, but the maximum bile salt transport capacity was reduced to 62% of control and 24 h later to 38%. Decreased bile salt transport was reversible, for it returned to control values after 48 h, when hepatic protein synthesis was also normal. Maximum bromosulfophthalein (BSP) transport, on the other hand, was reduced after 16 h to only 85% of control. Both bile salt and BPS maximum transport capacities decreased with time during inhibition of protein synthesis, apparently following first order kinetics. It was estimated that their half-lives are 20 h for bile salt transport and 55 h for BSP transport. These different turnover rates suggest that cycloheximide does not decrease active transport through generalized hepatic dysfunction or alteration of high energy sources possibly required for transport. The maximum number of [14C]cholic acid binding sites in liver surface membrane fractions was determined by an ultrafiltration assay. They were reduced to 68% of control after 16 h of cycloheximide and to 25% after 24 h. This reduction in the number of binding sites is apparently selective, for the activities of the liver surface membrane enzymes (Na+-K+)ATPase, Mg++-ATPase, and 5'-nucleotidase were not significantly changed. The associated alterations in bile salt transport and the maximum number of binding sites after cycloheximide administration suggests that these receptors may be the bile salt carriers.
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PMID:Regulation of hepatic transport of bile salt. Effect of protein synthesis inhibition on excretion of bile salts and their binding to liver surface membrane fractions. 43 30

A pattern of results is reported which was found to be common among patients who had intrahepatic cholestasis (IHC) which was rarely found in patients with other hepatic conditions. The pattern was recognized from over 1000 cases suspected of hepatobiliary disease. 29 were diagnosed with IHC, and excluding 4, 25 revealed the following etiological pattern: chlorpromazine (12 patients); pregnancy and oral contraceptive use (8); and other (5). As opposed to patients with acute and chronic hepatic disease, IHC sufferers had relatively normal values for immunoglobulins and antibody titers. A disproportionate elevation of serum bilirubin vis-a-vis serum enzymatic activities separated potential IHC cases into intra- and extrahepatic cholestasis. The following factorial evaluations were useful in distinguishing hepatic disease states: 1) when the sum of the activities of serum alkaline phosphatase, 5'-nucleotidase, aspartate and alanine amiotransferases, and isocitrate dehydrogenase was divided by the serum bilirubin concentration, there was good resolution of the distinction between patients with IHC and those with primary biliary cirrhosis, early and late viral hepatitis, cholelithiasis, and pancreatic and bile duct cancers. 2) Resolution was also achieved when the numerator included alkaline phosphatase, 5'-nucleotidase, and aspartate aminotransferase, but not when alkaline phosphatase alone, or alkaline phosphatase combined with 5'-nucleotidase, was used. The essential lesion in IHC is an excretory defect.
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PMID:Biochemical features of intrahepatic cholestasis. 45 73

Tissue wet weight as well as total protein content, 5'-nucleotidase activity, alkaline phosphatase activity and Ca2+ accumulation associated with a plasma membrane fraction isolated from spontaneous hypertensive rats (SHR) and rats with deoxycorticosterone (DOC) induced hypertension were investigated. Enhanced alkaline phosphatase activity and reduced ATP-dependent Ca2+ accumulation preceded the development of hypertension in SHR and these effects were reversed by DOC withdrawal followed by lowering of blood pressure in DOC hypertension. Increased arterial tissue wet weight and 5'-nucleotidase occurred only at the later stage of hypertension in SHR and the increased tissue wet weight was not reversed by DOC withdrawal in DOC hypertension. These observations suggest that enhanced alkaline phosphatase and reduced ATP-dependent Ca2+ uptake may play a significant role in initiating hypertension, while increased arterial wet weight and 5'-nucleotidase activities may participate in the maintenance of hypertension.
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PMID:Abnormal biochemistry of vascular smooth muscle plasma membrane as an important factor in the initiation and maintenance of hypertension in rats. 50 50

When liver cells were dispersed with collagenase, their 5'-nucleotidase activity decreased to half the initial level, but it increased to the original level again on culture of the cells for a few days. The activity of another membrane enzyme, alkaline phosphatase, did not decrease on dispersion of the cells, but it increased about 10-fold on culture of the cells. These inductions did not require any hormone, but the effects were greater at a high cell density. These enzymes are located in both the plasma membranes and the cytoplasm, but the enzymes in these two locations can be distinguished by differences in their pH optima, substrate specificities, and susceptibilities to inhibitors. The increases were found to be due to increases in the activity of only the enzymes in the plasma membranes. The increases in enzyme activities were inhibited by actinomycin D, cycloheximide, and puromycin. The activities of leucine aminopeptidase and aminopeptidase B, other membrane enzymes, remained constant during dispersion and culture of the cells. These results show that enzymes in the cell membranes are affected in different ways by cell dispersion with collagenase and subsequent culture of the cells.
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PMID:Biochemical studies on liver functions in primary cultured hepatocytes of adult rats. III. Changes of enzyme activities on cell membranes during culture. 52 39

The epitheloid modified walls of helicine arteries are built of tightly arranged specialized smooth muscle cells (epitheloid cells). They are polygonal in shape, but do not branch out. The number of myofilaments is markedly reduced, whereas cell organelles are well developed (mitochondria, Golgi regions, rough endoplasmic reticulum). Myofilaments are gathered to bundles with no orientation as to their direction. Regular dense patches and attachment zones do occur. The cell surface is provided with caveolae (surface vesicles) and a basal lamina. Where epitheloid cells are joined together, they share a single basal lamina in common. In circumscribed regions basal lamina material is completely absent, and the cell membranes approach to form a 150 A gap (paired cells). Endothelial cells are rich in cytoplasmic filaments and show only a few transport vesicles. In particular areas a basal lamina is absent, and epitheloid cells and endothelial cells are joined together leaving a 200 A wide cleft. Fluorescence histochemistry shows that helicine arteries are provided with an extremely dense network of adrenergic nerves located at the medio-adventitial border. Epitheloid cells, like ordinary vascular smooth muscle cells, show a postive ATPase reaction, but lack any histochemically demonstrable 5'-nucleotidase activity. Endothelial cells in helicine arteries react on unspecific alkaline phosphatase, while the endothelium of deep arteries and of the cavernous spaces does not.
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PMID:Morphology and histochemistry of helicine arteries in the corpora cavernosa penis of mice. 59 4

After partial hepatoectomy of the rat normal liver a maximum three-fold increase in the activity of alkaline phosphatase is observed in the blood serum, on the second-third day, and by the 14th day becomes almost normal; the activity of adenosine desaminase, AMP-aminohydrolase and 5'-nucleotidase becomes 30-60% as high for one-two days. The activity of the alkaline phosphatase in the liver becomes four times as high and reaches normalcy by the sixth day. The activity of adenosine desaminase and AMP-aminohydrolase increases to a less extent for a fortnight. The activity of 5'-nucleotidase decreases in the first day, then rises and a fortnight later becomes normal. After partial hepatoectomy of the liver injured with deoxicholic acid the activity of all the enzymes in blood serum anr a longer period of time; in the 5'-nucleotidase activity there is no initial drop and its earlier subsequent increase is observed.
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PMID:[Enzyme activity in the regeneration process after partial hepatectomy of normal liver and that injured with deoxycholic acid]. 66 48

1. Fragments (2-20 mg wet wt.) of closed needle-biopsy specimens from human liver were disrupted in iso-osmotic sucrose and subjected to low-speed centrifugation. The supernatant was layered on a linear sucrose-density gradient in the Beaufay small-volume automatic zonal rotor. The following organelles, with equilibrium densities (g/ml) and principal marker enzyme shown in parentheses, were resolved: plasma membrane (1.12-1.14; 5'-nucleotidase); lysosomes (1.15-1.20; N-acetyl-beta-glucosaminidase); mitochondria (1.20; malate dehydrogenase); endoplasmic reticulum (1.17-1.21; neutral alpha-glucosidase); peroxisomes (1.22-1.24; catalase). 2. The distribution of particulate alkaline phosphatase and, to a lesser degree, leucine 2-naphthylamidase followed that of 5'-nucleotidase. gamma-Glutamyltransferase was associated with membranes of significantly higher equilibrium density than was 5'-nucleotidase. 3. The distribution of 12 acid hydrolases was determined in the density-gradient fractions. beta-Glucosidase had a predominantly cytosolic localization, but the other enzymes showed a broad distribution of activity throughout the gradient. Evidence was presented for two populations of lysosomes with equilibrium densities of 1.15 and 1.20 g/ml, but containing differing amounts of each enzyme. Further evidence of lysosomal heterogeneity was demonstrated by studying the distribution of isoenzymes of hexosaminidase and of acid phosphatase. 4. The resolving power of the centrifugation procedure can be further enhanced with membrane perturbants. Digitonin (0.12 mM) selectively disrupted lysosomes, markedly increased the equilibrium density of plasma-membrane components and lowered the density of the endoplasmic reticulum, but did not affect the mitochondria or peroxisomes. Pyrophosphate (15 mM) selectively lowered the equilibrium density of the endoplasmic reticulum.
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PMID:Analytical subcellular fractionation of needle-biopsy specimens from human liver. 70 96


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