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)

Theophylline increases the synthesis of alkaline phosphatase in normal Hamster fibroblasts (activity X6 after 24 hours with theophylline 10-3 M). The enzymatic activity of these cells is inhibited by theophylline in vitro (80% inhibition in the presence of theophylline 10-3 M). The inhibition seems to be non competitive, since the apparent Km of the enzyme is not modified. This stimulator and inhibitor effect of theophylline is absent in Hamster fibroblasts transformed by SV 40 virus.
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PMID:[Stimulation of the synthesis and non-competitive inhibition of alkaline phosphatase by theophylline in normal hamster fibroblasts and absence of response in transformed fibroblasts]. 40 33

1. The effects of theophylline (1,3-dimethylxanthine) on alkaline phosphatase and 5'-nucleotidase activities of bovine milk fat globule membranes (MFGM) were examined. 2. Theophylline inhibited MFGM alkaline phosphatase in a concentration-dependent manner with 50% inhibition produced by 99 +/- 28 microM theophylline. 3. The 5'-nucleotidase activity was resistant to theophylline inhibition with 50% inhibition produced by 33.9 +/- 3.1 mM theophylline. 4. Theophylline was an uncompetitive inhibitor of MFGM alkaline phosphatase with a Ki of 126 +/- 15 microM. 5. The extent of theophylline inhibition of alkaline phosphatase activity was independent of the substrate utilized in the assay. 6. The effect of theophylline on bovine MFGM alkaline phosphatase was similar to theophylline effects on other mammalian alkaline phosphatases of liver/bone isoenzyme origin.
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PMID:Differential theophylline inhibition of alkaline phosphatase and 5'-nucleotidase of bovine milk fat globule membranes. 186 47

We selected various compounds [bromolevamisole, levamisole, cimetidine, L-homoarginine, 2,3,5,6-tetrahydroimidazo-(2,1-b)thiazole (IT), imidazole, theophylline] previously reported as inhibitors of alkaline phosphatase (ALP) and/or diamine oxidase (DAO) and studied their activity on concanavalin A (ConA)-induced mouse spleen cell lymphocyte proliferation. According to the Ki values, the decreasing order of potency for ALP inhibition was: bromolevamisole, levamisole, theophylline, cimetidine, IT, imidazole and L-homoarginine. The order of potency was different for DAO inhibition. Cimetidine was the most potent inhibitor of DAO, followed by bromolevamisole, levamisole, IT, imidazole and L-homoarginine. Theophylline had no inhibitory effect on DAO. We show that these compounds, except theophylline, enhance ConA-induced lymphocyte proliferation. Similarly, all the compounds except imidazole and theophylline, significantly inhibited ALP at concentrations which enhanced lymphocyte proliferation as measured by (3H)-thymidine uptake. DAO inhibition correlated with DNA synthesis only for IT and cimetidine. These observations suggest that ALP and DAO play a negative role in the proliferation process; however, the degree of enhancement of ConA-induced proliferation did not correlate strictly with the degree of ALP and DAO inhibition.
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PMID:Enhancement of mitogen-induced lymphocyte proliferation by some inhibitors of alkaline phosphatase and diamine oxidase. 250 82

Theophylline was measured with a Kodak Ektachem DTSC using its property of uncompetitive inhibition of alkaline phosphatase. Within- and between-batch reproducibility was satisfactory. Agreement with consensus mean values on quality assessment samples was good as was agreement on patients' samples with a high performance liquid chromatography reference method and an automated fluorescence polarisation immunoassay. At therapeutic theophylline concentrations, no interference was seen with caffeine, theobromine, 1,7-dimethylxanthine, 1,3-dimethyluric acid or 3-propylxanthine. 3-methylxanthine (a theophylline metabolite) gave a positive bias but the concentrations of this metabolite found in serum are such that the clinical significance of this finding is questionable. Salicylate at concentrations which might be found during therapy for paediatric rheumatoid arthritis also gave a positive bias.
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PMID:Theophylline assay on Kodak Ektachem DTSC--performance and interference by structurally-related compounds and salicylate. 276 72

Theophylline in serum was estimated by three methods. Two of them are based on high pressure liquid chromatography. A reversed phase method was chosen as reference method. Liquid chromatography on a straight phase was compared with this method. A third method was based on inhibiting alkaline phosphatase enzyme activity. Samples of test serum and patients' serum were analysed. The precision and accuracy of the methods were estimated by linear regression analysis. Some other aspects like duration of analysis and cost were also investigated. Generally, straight phase liquid chromatography was the method of choice because of its simplicity, high selectivity and relatively low cost.
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PMID:Determination of theophylline in serum by a simple enzyme method and by liquid chromatography. 406 71

Theophylline absorption and disposition of CF patients have not been systematically studied. To evaluate these factors in CF subjects, seven CF patients were fasted overnight and administered a dose of aminophylline liquid equivalent to 4 mg/kg of anhydrous theophylline. Liver function tests (SGOT, GGT, alkaline phosphatase) were normal in all seven patients. maximum serum theophylline concentrations occurred between 30 and 60 minutes post-dose in all subjects and ranged from 4.8 to 8.6 mcg/ml. These values are similar to those reported in non-CF subjects for a single 4 mg/kg oral dose. The mean serum half-life of 3.5 hours with a range of 1.2 to 5.0 hours is similar to that reported in non-CF populations. The authors conclude that theophylline elimination (half-lives) in CF patients with normal liver function is similar to those of normal and asthmatic patients. CF patients with clinical liver disease may have a decreased clearance and should be carefully monitored.
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PMID:Oral theophylline disposition in cystic fibrosis. 706 81

We have studied CFTR-Cl- channels in non-CF CAPAN-1 and in CFTR-transfected CFPAC-PLJ-CFTR-6 epithelial cells from human pancreas. Theophylline and IBMX induced the opening of cell-attached CFTR-Cl- channels. Theophylline, IBMX and the alkaline phosphatase (AP) inhibitor levamisole enhanced the activity of excised channels and reduced by 70-75% the apical membrane-associated APs activity. Okadaic acid had no effect on APs and channel activities. A polyclonal anti-alkaline phosphatase antibody (which detected apical APs) reduced APs activity and activated quiescent excised chloride channels. These results suggest that CFTR channels may be regulated by membrane-bound phosphatases.
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PMID:Possible regulation of CFTR-chloride channels by membrane-bound phosphatases in pancreatic duct cells. 768 97

Theophylline is an effective bronchodilatator used in the treatment of asthma which requires frequent control because of its narrow therapeutic index. Over the past decade much attention has been dedicated to the peculiar properties of the inner water pools of AOT (sodium 2-bishexyl-ethyl sulfosuccinate) microemulsions as enzyme microreactors, yet few analytical applications of the latter have been reported. We developed an original assay based on the uncompetitive inhibition by theophylline of the reaction catalyzed by alkaline phosphatase from bovine liver (E.C. 3.1.3.1) of the ELF-97 fluorogenic substrate in borate buffer 20 mM (pH 8.6)/AOT/iso-octane-ethyl acetate (95:5) at a temperature of 37 degrees C. Optimal activity of endogenous plasmatic alkaline phosphatase isoenzymes approximately pH 10.5, interfering activity of the serum are avoided. The assay is multiple point rate, monitoring the appearance of the photostable fluorescence emission of the reaction product (510-530 nm) out of the water pool. The influence of several parameters such as the amount of buffer (W(o)), the amount of alkaline phosphatase, sample volume (10-30 microl) [corrected], optimal run time (1-7 min) and the use of phosphorylating acceptor (2A2MP) are discussed. The method was compared to HPLC UV and TDx methods.
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PMID:Fluorimetric determination of theophylline in serum by inhibition of bovine alkaline phosphatase in AOT based water/in oil microemulsion. 991 59