Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The human colon cancer cell line Caco-2 undergoes spontaneous enterocytic differentiation during growth, and expresses a number of brush-border-membrane-associated hydrolases typical of a differentiated phenotype. Among these are alkaline phosphatase, dipeptidyl peptidase IV and sucrase-isomaltase (sucrase, EC 3.2.1.48). Neutral endopeptidase 24.11 [EC 3.4.24.11, neprilysin (NEP)] is another abundant protease of normal enterocytes but its presence in Caco-2 cells has not been fully documented yet. In this paper, we show that Caco-2 cell extracts hydrolyse tritiated [D-Ala2Leu5]enkephalin with a Km of 180 microM, very close to the value obtained for the NEP present in the rabbit kidney (118 microM). Western-blot analysis of brush-border membranes purified from post-confluent cells revealed a protein with an apparent molecular mass of 94000 Da similar to that of the rabbit kidney NEP. The amount of enzyme in cell extracts increased as a function of the age of the culture, indicating that NEP expression is correlated with the degree of cell differentiation as is also the case for sucrase and dipeptidylpeptidase IV (DPP-IV). Binding of a radiolabelled antibody to Caco-2 cell monolayers grown on semi-permeable filters indicated that 95% of NEP molecules present at the cell surface are on the apical side. Immunocytochemical and flow cytometric analysis of intact and permeabilized cells were also used to investigate the presence of NEP and DPP-IV at the surface of Caco-2 cells. Whereas DPP-IV staining appeared to be homogeneous throughout the entire cell population, NEP-related fluorescence exhibited a bimodal distribution which indicates an uneven expression of the protein at the cell surface. Permeabilization of monolayers with saponin before staining restored a labelling pattern for NEP similar to the one obtained for DPP-IV. This suggests that although DPP-IV and NEP follow similar patterns of expression when enzymic activities are measured on whole-cell extracts, targeting of these brush-border proteins to the cell surface appears to be regulated in different ways.
 ...
PMID:Polarized distribution of neutral endopeptidase 24.11 at the cell surface of cultured human intestinal epithelial Caco-2 cells. 136 26

Effects in vitro of 1,25-dihydroxycholecalciferol (1,25-(OH)2D3) on alkaline phosphatase (PAL), gamma-glutamyltransferase (gamma-GT) and acid phosphatase (PAC) activities were investigated on renal cortex from hypophysectomized rats. In these animals the biosynthesis of 1,25-(OH)2D3 and the specific activities of kidney PAL and gamma-GT were decreased. The course of these effects was determined from 45 min to 8 h. In the presence of 1,25-(OH)2D3 (2 x 10(-6) M) a delayed (5h) but simultaneous stimulation of the three enzymes was observed. It reached a maximum at 6h and disappeared at 8h. The dose-response relation was studied at 6h. In the presence of 1,25-(OH)2D3 (5 x 10(-7) M), the three enzymes were activated. The effect was maximal at 10(-6) M; it was +22% for PAL, +17% and +15% respectively for gamma-GT and PAC compared with controls. Cycloheximide suppressed the induction of PAL but not of gamma-GT activity. The effects of the secosteroid on renal enzymes seems to be a pharmacological more than a physiological one.
 ...
PMID:[In vitro effects of 1,25-dihydroxycholecalciferol on alkaline phosphatase and gamma-glutamyltransferase activity in hypophysectomized rats]. 169 95

The effects of 24R,25-dihydroxyvitamin D3 (24,25-(OH)2D3 on alkaline phosphatase (PAL), gamma-glutamyltransferase (GGT) and acid phosphatase (PAC) activities were investigated on renal cortex slices of hypophysectomized rats. Indeed after hypophysectomy renal 24,25-(OH)2D3 production was increased and renal PAL and GGT activities were decreased. After 5h incubation with physiological concentrations (0.1-10 nM) of 24,25-(OH)2D3 significant increases of PAL and GGT activities were produced. The maximum stimulation obtained with 1 nM was +23% for PAL and +26% for GGT as compared to controls. PAC was not modified. The time course of these effects was studied from 45 min to 8 h. In the presence of 24,25-(OH)2D3 (1 nM), delayed (3h) stimulation of PAL and GGT appeared. It reached the maximal value after 6h, +37% for PAL and +30% for GGT and persisted again at 8h. Cycloheximide added to incubation medium with steroid inhibited the stimulating effect on PAL only. Actinomycin D suppressed the induction of both enzymes, indicating that the observed actions of 24,25-(OH)2D3 depend on protein synthesis whose responsible mechanisms were different. These protein synthesis inhibitors did not modified enzymatic activities. Physiological significance of these renal effects is to be clarified.
 ...
PMID:[In vitro effects of 24R,25-dihydroxyvitamin D3 on alkaline phosphatase and gamma-glutamyltransferase in the kidney of hypophysectomized rats]. 171 64

Problems encountered in attempts to purify mevalonate-5-diphosphate decarboxylase from rat liver are addressed. These are the quantitative, facile separation of [14C]isopentenol in the radiochemical assay (2) the instability of the enzyme activity and (3) the very low activity in rat liver. The assay was modified by using Sep Pac C18 filters to bind and release [14C]isopentenol. Authentic isopentenol was quantitated by absorbance at 210 nm wavelength and the extinction coefficient estimated to be epsilon m = 3.26 X 10(3). Recovery of authentic isopentenol from aqueous solution after binding and elution into methanol was quantitative from 10-100 nmols. Recovery of [14C]ispentenol from assay mixtures using 2-[14C]mevalonate-5-diphosphate and alkaline phosphatase to hydrolyze phosphate was quantitative using Sep Pac filter but not using petroleum ether extraction. Enzyme activity was stabilized by phenylmethylsulfonyl fluoride, aprotinin and leupeptin and was stable at -73 degrees C for 3 months. Activity of the decarboxylase was increased by 5-fold after feeding young rats 2.5% cholestyramine for ten days to four weeks.
 ...
PMID:Modification of the radiochemical assay of rat liver mevalonate-5-diphosphate decarboxylase and induction and stabilization of the activity. 176 97

The hepatoma-specific band of serum gamma-glutamyl transferase II (GGT II) and other three markers were evaluated in 77 patients with primary hepatocellular carcinoma (PHC). The positive rate of GGT II (87%) was much higher than that of the increased alpha-fetoprotein (AFP greater than or equal to 400 ng/ml, 54.5%), the increased alpha-1-antitrypsin (AAT greater than or equal to 400 mg/dl, 64.9%) and alkaline phosphatase isoenzyme I (ALP I, 13.0%). In patients with AFP less than 400 ng/ml, the positive rate of GGT II was 95.2%, higher than that of ALP I (22.8%) and AAT (60.0%). The positive rate of GGT II was positively correlated to the volume of PHC (r = 0.324, P less than 0.05), but even in patients with small PHC (less than or equal to 65 cm3), the positive rate of GGT II (78.6%) was higher than that of AFP (50.0%) and AAT (28.6%). The ALP I positivity was only seen in patients with larger PHC. Follow-up study showed that GGT II, like AFP, might occur before liver tumor could be detected by B-mode ultrasonography and computerized tomography. Therefore, GGT II is a valuable marker of PHC, especially in patients whose AFP was negative or slightly increased; GGT II may be useful for relatively early diagnosis of PHC.
 ...
PMID:Reappraisal of diagnostic significance of a hepatoma-specific band of serum gamma-glutamyl transferase. 197 81

The density of selected enzymes in the goblet cells of the mucous membrane of the small intestine was studied in a group of 12 gnotobiotic piglets experimentally infected with the coccidium Isospora suis one day after parturition (DPP), using the Vickers M-786 scanning and integrating microdensity meter. At an infecting dose of 100,000 oocysts of I. suis, the histochemistry of the goblet cells of the mucous membrane of the piglets changed significantly in the period of 4 to 10 days after infection (DPI). Increases occur in the density of non-specific esterase (EC. 3.1.1.1.) and acid phosphatase (EC. 3.13.2.). The density of acid and neutral muco-substances declines and the densities of alkaline phosphatase (EC. 3.1.3.1.) and aminopeptidase M (EC. 3.4.11.2) are significantly high. The goblet cells of the mid and posterior parts of jejunum are very similar in their histochemistry in the experimentally infected gnotobiotic piglets. In the duodenum and ileum the histochemical picture of the goblet cells shows no substantial difference from the data recorded in the goblet cells of the mucous membrane of the small intestine of the four control piglets at an age of two to seven days.
 ...
PMID:[Density of selected enzymes in the goblet cells of the small intestine in piglets experimentally infected with the coccidium Isospora suis]. 197 31

In the thymus of normally fed pregnant rats the plasma membrane enzymes dipeptidyl peptidase IV (DPP IV) and alkaline phosphatase (alP) were found in cortical and medullary lymphocytes (thymocytes). Plasma membrane aminopeptidase A (APA) and adenosine monophosphate hydrolysing phosphatase (AMPP) were present in cortical reticular cells. In medullary reticular cells, aminopeptidase M (APM), gamma-glutamyl transferase (GGT), adenosine triphosphate (ATPP) and thiamine pyrophosphate (TPPP) cleaving phosphatases were detected. Medullary reticular cells did not contain APA. Lysosomal DPP I and II, acid phosphatase, acid beta-D-galactosidase, beta-D-N-acetyl-glucosaminidase, beta-D-glucuronidase and non-specific esterases occurred especially in macrophages at the corticomedullary junction. The 21-day-old fetal thymus showed a similar reaction pattern as the maternal organ except for APA which was absent before birth. After treatment of the pregnant rats with valproic acid (VPA), salicylic acid (SA), streptozotocin (ST) and retinoic acid (RA) APA showed an increase in activity in the thymic cortex. In addition, ST and RA induced AMPP, ATPP and TPPP activity in cortical reticular cells up to the same pattern as in medullary reticular cells. After ethanol (ET) administration severe damages occurred. The thymic cortex was free of DPP IV-positive lymphocytes; the medullary reticular cells showed reduced or no GGT and occasionally an increased APM activity. Dexamethasone (DEXA) given to normal or zinc-deficient rats produced the most severe lesions; thymocytes with DPP IV activity were completely absent in the cortex and medulla. In Zn-deficient pregnant rats similar alterations were observed as after ET.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Enzymatic and morphological response of the thymus to drugs in normal and zinc-deficient pregnant rats and their fetuses. 295 24

Cis-dichlorodiammine platinum (CDDP) has recently been introduced for the treatment of human malignancies. CDDP belongs to the group of heavy metals and has nephrotoxicity, whose side effects limit the dose that can be used in patients. The urinary excretion of lactate dehydrogenase (LDH), gamma-glutamyl transpeptidase (gamma-GTP), alkaline phosphatase (ALP), arylamidase (AA) activity and beta 2-microglobulin was determined in ovarian cancer patients receiving sequential combination chemotherapy with CDDP, adriamycin (ADM) and cyclophosphamide (CPA) (PAC chemotherapy) to evaluate the sensitivity of these indices for acute renal tubular damage and compared with the change in serum BUN, Cr and Ccr values. Increases in enzyme excretion after PAC chemotherapy were more often noticed and the urinary enzyme activity varied up to the 10.4-fold of the control, while serum BUN, Cr and Ccr values remained almost within normal limits. Enzyme excretion returned almost to the normal value in one week. A comparison between the urinary enzyme excretion especially AA value and serum BUN, Cr and Ccr values indicated that the serial determination of the urinary AA excretion pattern is more useful in detecting CDDP-induced nephrotoxicity than that of serum BUN, Cr and Ccr values.
 ...
PMID:[Cisplatin and ovarian carcinoma--early detection of cisplatin-induced nephrotoxicity]. 404 May 42

Two newly established murine monoclonal antibodies (MAbs), OVS1 and OVS2, to human ovarian mucinous cystadenocarcinoma were further characterized for diagnostic efficacy. The specific SA-1 antigen, purified from the tumor extract was identified as a glycoprotein of 29 kDa. A double determinant biotinstreptavidin alkaline phosphatase immunoassay system, containing OVS1 and OVS2 MAbs was used to determine the SA-1 levels in serum. The OVS1 MAb was used as a first antibody because of its high specificity of 96% while OVS2 MAb, with a lower specificity of 8% but greater sensitivity of 78%, was chosen as a second antibody. Matched sera of 64 healthy controls and 90 patients with definite diagnoses of 25 benign diseases, 14 nonovarian cancer and 51 ovarian cancer, were simultaneously measured together with CA 125 values. At cut-off levels of 220 and 360 units/ml, the SA-1 test showed 63% and 43% positive rates respectively in all types of ovarian cancer, compared to 65% and 57% positive rates for CA 125 at cut-off levels of 35 and 60 units/ml, respectively. Sensitivity for SA-1 at 220 units/ml cut-off level in mucinous ovarian cancer was 75% and increased significantly to 85% when the test was combined with CA 125 at 35 units/ml cut-off level. Furthermore, The combination of both tests significantly increased the positive rates to 86% in all types of early stage ovarian cancer.(ABSTRACT TRUNCATED AT 250 WORDS)
Asian Pac J Allergy Immunol 1995 Jun
PMID:Establishment of OVS1 and OVS2 monoclonal antibodies recognizing human ovarian mucinous cystadenocarcinoma. 748 44

Only four established odontoblast-like cell lines have been reported in the literature (1-6). Of the four, only two synthesize dentin-specific proteins. These studies report that the cell line MO6-G3 synthesizes phosphophoryn (DPP), dentin sialoprotein (DSP) and dentin matrix protein-1 (DMP-1) while MDPC-23 synthesizes DSP, but not DMP-1. The objective of the present study was to determine whether polyclonal antibodies to rat DSP and DPP would label odontoblasts on microscopic sections of day-19 fetal mouse incisor odontoblasts as well as cultured cells of the MDPC-23 cell line. The spontaneously immortalized MDPC-23 cell line was derived from fetal mouse molar papillae, made continuous by the 3T6 method and cloned by dilution. These cultures have been passaged 77 times after cloning, form multilayered nodules, and have high alkaline phosphatase activity. The data show positive reactivity in odontoblasts in 19-d mouse fetal incisors as well as in cultures of MDPC-23 cells by fluorescence and confocal microscopy. In addition, these cultures were characterized by phase microscopy and scanning and transmission electron microscopy. These findings suggest that MDPC-23 cells are of the odontoblast lineage.
 ...
PMID:Dentin-specific proteins in MDPC-23 cell line. 954 Dec 35


1 2 3 4 5 Next >>