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Journal ArticleDOI

Estimation of dehydroascorbic acid in blood of diabetic patients

01 Oct 1979-Analytical Biochemistry (Academic Press)-Vol. 98, Iss: 2, pp 368-374
TL;DR: The DHA from diabetic blood has been isolated as the 2,4-dinitrophenylhydrazone derivative and identified by thin-layer chromatography and spectrophotometry.
About: This article is published in Analytical Biochemistry.The article was published on 1979-10-01. It has received 77 citations till now. The article focuses on the topics: Dehydroascorbic acid & Ascorbic acid.
Citations
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Journal ArticleDOI
TL;DR: The discovery that pentosidine can form not only from pentoses but also from hexoses and ascorbate raises major new questions concerning biochemical pathways of the Maillard reaction in vivo.

465 citations

Journal ArticleDOI
TL;DR: GLUT1 and GLUT3 isoforms are the specific glucose transporter isoforms which mediate DHA transport and subsequent accumulation of AA according to Xenopus laevis oocyte expression system studies.

431 citations

Journal ArticleDOI
TL;DR: In this paper, the intake of antioxidants was studied for its ability to predict type 2 diabetes in a cohort of 2,285 men and 2,019 women 40-69 years of age and free of diabetes at baseline (1967-1972).
Abstract: OBJECTIVE —The intake of antioxidants was studied for its ability to predict type 2 diabetes. RESEARCH DESIGN AND METHODS —A cohort of 2,285 men and 2,019 women 40–69 years of age and free of diabetes at baseline (1967–1972) was studied. Food consumption during the previous year was estimated using a dietary history interview. The intake of vitamin C, four tocopherols, four tocotrienols, and six carotenoids was calculated. During a 23-year follow-up, a total of 164 male and 219 female incident cases occurred. RESULTS —Vitamin E intake was significantly associated with a reduced risk of type 2 diabetes. The relative risk (RR) of type 2 diabetes between the extreme quartiles of the intake was 0.69 (95% CI 0.51–0.94, P for trend = 0.003). Intakes of α-tocopherol, γ-tocopherol, δ-tocopherol, and β-tocotrienol were inversely related to a risk of type 2 diabetes. Among single carotenoids, β-cryptoxanthin intake was significantly associated with a reduced risk of type 2 diabetes (RR 0.58, 95% CI 0.44–0.78, P CONCLUSIONS —This study supports the hypothesis that development of type 2 diabetes may be reduced by the intake of antioxidants in the diet.

380 citations

Journal ArticleDOI
01 Oct 1992-Diabetes
TL;DR: Immunohistochemical localization studies revealed that pyrraline is found predominantly in the sclerosed extracellular matrix of glomerular and arteriolar renal tissues from both diabetic and aged nondiabetic individuals, suggesting that molecular damage by advanced Maillard reaction products may be a common mechanism in their development.
Abstract: Recent progress in structure elucidation of products of the advanced Maillard reaction now allows probing specifically for the role of this reaction in the pathogenesis of age- and diabetes-related complications. Pyrraline is a glucose-derived advanced glycation end product against which polyclonal and monoclonal antibodies have been raised. Immunohistochemical localization studies revealed that pyrraline is found predominantly in the sclerosed extracellular matrix of glomerular and arteriolar renal tissues from both diabetic and aged nondiabetic individuals. Pentosidine and carboxymethyllysine are Maillard end products derived from both glucose and ascorbate. In addition, pentosidine can be formed from several other sugars under oxidative conditions, and in vitro studies suggest that a common intermediate involving a pentose is a necessary precursor molecule. The highest levels of these advanced Maillard products are generally found in the extracellular matrix, but these products are also present in lens proteins and in proteins with a fast turnover such as plasma proteins. Diabetes, and especially uremia, greatly catalyzes pentosidine formation. Both conditions are characterized by accelerated cataractogenesis, atherosclerosis, and neuropathy, suggesting that molecular damage by advanced Maillard reaction products may be a common mechanism in their development.

313 citations

Journal ArticleDOI
01 Oct 1992-Diabetes
TL;DR: A high correlation betweenpentosidine levels and long-wave collagen-linked fluorescence also was observed, suggesting that pentosidine is a generalized marker of accelerated tissue modification by the advanced glycosylation/Maillard reaction, which is enhanced in IDDM patients with severe complications.
Abstract: Pentosidine is an advanced glycosylation end product and protein cross-link that results from the reaction of pentoses with proteins. Recent data indicate that long-term glycation of proteins with glucose also leads to pentosidine formation through sugar fragmentation. In this study, the relationship between the severity of diabetic complications and pentosidine formation was investigated in collagen from skin-punch biopsies from 25 nondiabetic control subjects and 41 IDDM patients with diabetes duration >17 yr. Pentosidine was significantly elevated in all IDDM patients versus control subjects ( P P P P P P P P > 0.05). A high correlation between pentosidine levels and long-wave collagen-linked fluorescence also was observed, suggesting that pentosidine is a generalized marker of accelerated tissue modification by the advanced glycosylation/Maillard reaction, which is enhanced in IDDM patients with severe complications.

300 citations


Cites background from "Estimation of dehydroascorbic acid ..."

  • ...Favoring this possibility is the discovery of elevated dehydroascorbate levels in the plasma of diabetic individuals (23-25)....

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References
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Book
01 Jan 1963
TL;DR: Methods of enzymatic analysis, Methods of enzymes analysis, the authors, Methods of enzyme analysis, enzymatics, methods of enzymes, and methods of analysis, method of enzymes.
Abstract: Methods of enzymatic analysis , Methods of enzymatic analysis , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

18,100 citations

Journal ArticleDOI
TL;DR: Using the in vitro method, the ascorbic acid synthesizing abilities of different species of animals in the phylogenetic tree are examined, and the results are given below.
Abstract: The requirement of ascorbic acid (vitamin C ) is a common property of living organisms, and it has long been considered that all animals except the guinea pig, monkey, and man can synthesize this vitamin. The classic method for determining the ability of an animal to synthesize ascorbic acid is to feed it a scorbutogenic diet for a prolonged period and to observe the appearance of the scurvy syndrome. Obviously, the method is laborious and time-consuming. Also, the onset of the scorbutic syndrome depends on the ascorbic-acid-retention capacity of the animal. For example, whereas the guinea pigs can be made scorbutic in about 3 weeks, it takes 3 to 4 months to produce scurvy in man. Since the discovery of the technique for studying ascorbic acid synthesir in vitro,1-8 the task has become much simpler. In this technique, the tissue homogenates or the subcellular fractions are incubated with precursors of ascorbic acid and the amount of the vitamin formed is estimated. Using the in vitro method, we have examined the ascorbic acid synthesizing abilities of different species of animals in the phylogenetic tree, and the results are given below.

331 citations

Journal ArticleDOI
TL;DR: Methods for determinations of vitamin C dehydro-Z-ascorbic (DHA), DHA, and DKA in the presence of each other are reported, indicating that these derivatives are identical substances.

268 citations

Journal ArticleDOI
TL;DR: An account is given of a new method, based on the two findings that homocysteine rapidly reduces dehydroascorbic acid at pH 7 0, and that under certain simple conditions 2:6-dichlorophenolindophenol can be used to estimate ascorbic acid in the presence of homocy steine without interference from the latter compound.
Abstract: Two main methods are in current use for the estimation of dehydroascorbic acid. In the one, developed by Roe and his colleagues (Roe & Kuether, 1943; Roe, Mills, Oesterling & Damron, 1948), the dehydroascorbic acid is condensed with 2:4-dinitrophenylhydrazine and the product treated with sulphuric acid to give a red colour, the intensity of which is measured photoelectrically. In a second technique (Tillmans, Hirsch & Siebert, 1932; Eekelen, Emmerie, Josephy & Wolff, 1933; Bessey, 1938), dehydroascorbic acid is measured as acorbic acid after reduction with hydrogen sulphide and removal of excess of reductant. Disadvantages are associated with both methods; they are nonspecific for dehydroascorbic acid, timeand labourconsuming, and in the method involving reduction with hydrogen sulphide it may be difficult to ensure the removal ofexcess ofreductant before estimating the ascorbic acid formed with 2:6-dichlorophenolindophenol. In this paper an account is given ofanew method, based on the two findings that homocysteine rapidly reduces dehydroascorbic acid at pH 7 0, and that under certain simple conditions 2:6-dichlorophenolindophenol can be used to estimate ascorbic acid in the presence of homocysteine without interference from the latter compound.

124 citations