Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.11.1.7 (peroxidase)
 65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Uric acid in serum was determined calorimetrically with a batch type microcalorimeter, by measuring the heat evolved during a coupled uricase/catalase enzymic reaction in tris(hydroxymethyl)aminomethane HCl buffer (pH 9.0 at 30 degrees C). Heat evolution and concentration are linearly related through the physiological range of serum uric acid concentrations and the method is free of interferences of the sort encountered with spectrophotometric methods. Precision and accuracy are good (CV, 2%) and the results correlate well with those obtained by a mechanized colorimetric uricase/peroxidase system.
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PMID:Calorimetric enzymic measurement of uric acid in serum. 83 82

A sensitive spectrofluorimetric micromethod for the determination of uric acid is presented together with its application to human and rat plasma. The method is based on the reactions or uricase and peroxidase coupled with p-hydroxyphenylacetic acid as a fluorophor. There is a very wide range of proportionality between the concentration of uric acid and the increase of fluorescence intensity. 10 ng of uric acid is still determinable. At most 25 mul of human or 50 mul of rat plasma is sufficient to obtain the accurate valve of endogenous plasma uric acid concentration. The uric acid levels of normal human and rat plasma measured by present method were within the ranges of concentrations previously reported. A comparative study of this method with a standard assay method is also presented.
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PMID:The enzymatic spectrofluorimetric determination of uric acid in microsamples of plasma by using p-hydroxyphenylacetic acid as a fluorophor. 100 Aug 45

The distribution of oestrogen-induced peroxidase in the resuspended 8000g pellet of rat uterine homogenates was examined by centrifugation in a sucrose density gradient. Within 10h of treatment with oestradiol, peroxidase activity was found in a region devoid of catalase or urate oxidase (peroxisomal markers) which did not overlap the fractions containing succinate dehydrogenase (mitochondrial marker) or acid phosphatase (lysosomal marker). The induced uterine enzyme was localized in reticular membrane-bound vesicles with isopycnic density of 1.28g/ml from which it could be released by treatment with detergent.
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PMID:Subcellular localization of oestrogen-induced uterine peroxidase. 100 53

An automatic micromethod is described for the estimation of plasma uric acid. The hydrogen peroxide formed when uric acid is oxidised by uricase, condenses by oxidation two molecules of p-hydroxyphenil-acetic acid in the presence of peroxidase. The product formed (dicarboxymethyl-5,5' dihydroxy-2,2' biphenyl) is fluorescent. This method permits one to estimate quantitites of uric acid of the order of 1 microng and permits measurement of uric acid in 50 microll of plasma. The values obtained for human plasma are compared to those supplied by a reductrimetric technique (SMA 12-60).
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PMID:[Automatic ultramicrotechnic for the determination of plasma uric acid]. 102 25

Administration of noramidopyrine or of noramidopyrine-methane-sulfonate interferes with the determination of blood uric acid by both the colorimetric method of Folin-Denis and an enzymatic uricase peroxidase method. This interference which is observed at least during the 24 hours following intravenous administration of noramidopyrine, results in either an increase (Folin-Denis) or a decrease (uricase) of the intensity of the final colour. The same effects are also observed in vitro when one adds noramidopyrine to an aqueous solution of uric acid. Existence of this interference should be taken into consideration especially in the diagnosis, the prognosis and the analgesic treatment of renal lithiasis.
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PMID:[Interference of noramidopyrin and its derivatives on the dosage of uric acid]. 118 Apr 17

A continuous flow method is described for the determination of uric acid in serum using uricase and peroxidase, with omicron-dianisidine as the chromogen. The method can be used with single channel systems and with the multichannel system SMA 12/60 (Technicon). The new method was compared with six other manual and mechanized methods for the dosage of uric acid, and the results were analyzed statistically. The results from all the enzymic methods showed a good correlation, whereas the "chemical oxidation" methods showed systematic deviations.
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PMID:[A mechanized enzymic method for the determination of uric acid (author's transl)]. 118 25

We describe an ultramicromethod for determination of uric acid by a manual procedure. Hydrogen peroxide, formed when uric acid is oxidized in the presence of uricase, oxidatively couples two molecules of p-hydroxyphenylacetic acid in the presence of peroxidase to produce a highly fluorescent compound. The specificity of the uricase reaction is retained, and the fluorometry results in a higher sensitivity (but a lower precision) than that obtained by applying spectrophotometric methods. As little as 50 ng of uric acid can be determined, and only 10 mul of plasma is required. Values obtained for human plasma are higher than those obtained by the spectrophotometric method.
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PMID:Ultramicromethod for determination of plasma uric acid. 127 25

We examined the possible effect of different bilirubin species, including unconjugated (Bu), sugar-conjugated (Bc), and authentic delta bilirubin (Bd) isolated from serum, on the direct enzymatic measurement of uric acid by using the uricase (EC 1.7.3.3) and peroxidase (EC 1.11.1.7) coupled reaction. Bc, isolated from human bile, produced the most interference with uric acid determination. Although the presence of human serum albumin reduced interference by Bu and Bc, albumin-bound Bc complex still produced greater interference than Bu. Interference with the peroxidase reaction by Bc covalently bound to serum albumin (Bd) was less than that by Bu. We examined this phenomenon by using serum-isolated Bd obtained by ammonium sulfate precipitation and ultrafiltration and by using commercially available ditaurobilirubin (DTB) and chemically synthesized Bd (via Woodward's reagent, WBd) as surrogates for bile-isolated Bc and natural Bd, respectively. DTB produced the same amount of interference as natural Bc, but the interference produced by DTB in the presence of serum albumin was not the same as that produced by natural Bc with albumin. Our synthetic Bd appears to be a reliable surrogate for natural Bd in testing for bilirubin interference.
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PMID:Effects of serum bilirubin on determination of uric acid by the uricase-peroxidase coupled reaction. 132 Apr 71

The estimation of serum urate by uricase/peroxidase procedures involving single point bichromatic absorbance monitoring gives inaccurate results with samples which are haemolysed, icteric or lipaemic. These inaccuracies can be greatly minimized by reducing the rate of chromogen formation and applying the assay in a kinetic mode.
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PMID:Adapting the uricase/peroxidase procedure for plasma urate to reduce interference due to haemolysis, icterus or lipaemia. 153 32

A manual enzymatic method is described for sensitive fluorometric determination of uric acid in human serum. This method is based on an enzymatic reaction with uricase to form hydrogen peroxide from uric acid and the following oxidation of o-phenylenediamine with peroxidase and hydrogen peroxide for the production of a fluorescence compound. The specificity and the selectivity in the method are due to the uricase reaction and the fluorometry, respectively. The formed fluorescence in the reaction mixture is measured at 410 nm (an excitation) and 550 nm (an emission). This enzymatic method can determine uric acid at 30-1000 microM, with a between-assay relative standard deviation of 4.35% or less. A good correlation is obtained between the present method and the colorimetric kit method.
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PMID:Use of the o-phenylenediamine fluorescence system in the enzymatic assay of serum uric acid. 180 95


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