"I. A FLUOROMETRIC COUPLED ENZYMATIC METHOD FOR THE DETERMINATION OF AD" by PATRICK STEPHEN MICHAEL. CAINES

Date of Award

1985

Publication Type

Doctoral Thesis

Degree Name

Ph.D.

Department

Chemistry and Biochemistry

Keywords

Chemistry, Biochemistry.

Rights

info:eu-repo/semantics/openAccess

Abstract

Part I. A new fluorometric, coupled, enzymatic method for the determination of adenosine triphosphate is described. The procedure uses the hexokinase reaction coupled with three other enzymes in a system of phosphorylation and double reduction to form NADPH. The NADPH is measured in a reaction catalyzed by diaphorase in which the nonfluorescent material, resazurin, is converted to the highly fluorescent compound, resorufin. This kinetic method can determine adenosine triphosphate at the picomole level. Intra- and inter-assay CV's were both less than 3% and recoveries were quantitative. No significant interference was observed from EDTA or heparin. Correlation with an established method was significant (r = 0.99). Adenosine triphosphate was measured in platelets. Mean ATP levels in the platelets of "normal" subjects were found to be 2.17 (+OR-) 0.76 nmol/10('8) platelets (14.22 (+OR-) 6.32 nmol/mg protein). Part II. A new procedure was developed for the determination of non-enzymatically glycated albumin (GA). Albumin was separated from serum or plasma using Sepharose-blue dextran affinity chromatography. The "fructosamine assay" was improved and used to determine GA. The stable ketoamine linkage in GA reduced 3-(4,5-dimethylthiazol-2-yl)-2,4-diphenyltetrazolium bromide (MTT) to a colored formazan. Optimum conditions for the assay were established using the simplex optimization technique. The reagent blank value was minimal and MTT had a 3-fold greater molar absorptivity than nitroblue tetrazolium used in the original "fructosamine assay". The assay was adapted for use in a centrifugal analyzer (Flexigem('tm)) and GA was used as the standard. The within and between run CV's were 4.6% and 8.5%, respectively. Recovery of GA was quantitative. The reference range for this method was 8.94 - 11.19% GA and normal and diabetic populations can be clearly discriminated (p < 0.005). Values obtained with this method correlate well with a thiobarbituric acid assay (r = 0.974) but not with those for glycated hemoglobin (r = 0.350). Source: Dissertation Abstracts International, Volume: 46-08, Section: B, page: 2649. Thesis (Ph.D.)--University of Windsor (Canada), 1985.

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