Does high-dose ascorbic acid accelerate renal failure?

V M Reznik; W R Griswold; M R Brams; S A Mendoza

doi:10.1056/nejm198006193022512

Home/Archive/PubMed

PubMed · 7374700

Does high-dose ascorbic acid accelerate renal failure?

V M Reznik·W R Griswold·M R Brams·S A Mendoza

View original source ↗Export metadata ↓

Abstract

The source did not provide an abstract. Follow the original record for more information.

Explore related subjects

Ascorbic Acid Female Humans Infant Kidney Failure, Chronic Nephrotic Syndrome Case Reports Letter

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

V M Reznik, W R Griswold, M R Brams, S A Mendoza. 1980-06-19. Does high-dose ascorbic acid accelerate renal failure?. https://doi.org/10.1056/nejm198006193022512

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2024

Effect of light on ascorbic acid biosynthesis and bioinformatics analysis of related genes in Chinese chives.

Ascorbic acid (AsA) is an essential nutritional component and powerful antioxidant in vegetables, and in plants, AsA levels are regulated by light. AsA levels in the leaves of Chinese chive (Allium tuberosum Rottler ex Spr), a popular vegetable, are poorly understood. Thus, this study was performed to assess the influence of light on AsA biosynthesis in chive and select related genes (AtuGGP1 and AtuGME1); in addition, bioinformatic analyses and gene expression level assays were performed. The biological information obtained for AtuGGP1 and AtuGME1 was analysed with several tools, including NCBI, DNAMAN, and MEGA11. After different light treatments were performed, the Chive AsA content and AtuGGP1 and AtuGME1 expression levels were determined. These results suggest that 1) compared with natural light, continuous darkness inhibited AsA synthesis in chives. 2) The amino acid sequences of AtuGGP1 and AtuGME1 are very similar to those of other plants. 3) The trends observed for the expression levels of AtuGGP1 and AtuGME1 were consistent with the AsA content observed in chives. Hence, we speculated that light controls AsA biosynthesis in chives by regulating AtuGGP1 and AtuGME1 expression. This study provided impactful and informative evidence regarding the functions of GGP and GME in chives.

Ascorbic Acid↗

PubMed2001

Reaction of tetrahydrobiopterin with superoxide: EPR-kinetic analysis and characterization of the pteridine radical.

It has been shown that BH(4) ameliorates endothelial dysfunction associated with conditions such as hypertension, cigarette smoking, and diabetes. This effect has been proposed to be due to a superoxide scavenging activity of BH(4). To examine this possibility we determined the rate constant for the reaction between BH(4) and superoxide using electron paramagnetic resonance (EPR) spin trapping competition experiments with 5-diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide (DEPMPO). We calculated a rate constant for the reaction between BH(4) and superoxide of 3.9 +/- 0.2 x 10(5) M(-1)s(-1) at pH 7.4 and room temperature. This result suggests that superoxide scavenging by BH(4) is not a major reaction in vivo. HPLC product analysis showed that 7,8-BH(2) and pterin are the stable products generated from the reaction. The formation of BH(4) cation radical (BH(4)(*+)) was demonstrated by direct EPR only under acidic conditions. Isotopic substitution experiments demonstrated that the BH(4)(*+) is mainly delocalized on the pyrazine ring of BH(4). In parallel experiments, we investigated the effect of ascorbate on 7,8-BH(2) reduction and eNOS activity. We demonstrated that ascorbate does not reduce 7,8-BH(2) to BH(4), nor does it stimulate nitric oxide release from eNOS incubated with 7,8-BH(2). In conclusion, it is likely that BH(4)-dependent inhibition of superoxide formation from eNOS is the mechanism that better explains the antioxidant effects of BH(4) in the vasculature.

Ascorbic Acid↗

PubMed2001

Influence of plasma glutathione levels on radiation mucositis.

PURPOSE: To test the hypothesis that there is a link between plasma glutathione (GSH) or other antioxidants (uric acid, ascorbate) and the severity of radiation mucositis following radiation treatment of tumors of the head and neck. PATIENTS AND METHODS: Patients with carcinomas of the head-and-neck region were treated with the continuous hyperfractionated accelerated radiotherapy (CHART) regimen (54 Gy in 36 fractions over 12 days). Samples of blood plasma were analyzed for GSH, cysteine, urate, and ascorbate by high-pressure liquid chromatography. Patients were graded for dysphagia and requirement for analgesics. The areas under the curves of scores over 2-6 weeks following treatment were computed, and Spearman's rank-correlation coefficient was used to test for an association between plasma GSH levels (or those of other antioxidants) and mucositis. RESULTS: The pretreatment plasma GSH level in 18 patients scored in the study was 1.0 +/- 0.7 M. Analysis of these and the dysphagia scores produced a correlation coefficient of 0.22 (confidence interval -0.28, 0.61; p = 0.39). No correlation was seen between mucositis severity and other measures of plasma antioxidants: cysteine (7.6 +/- 1.7 M), cysteine + GSH (8.6 +/- 1.9 M), uric acid (317 +/- 86 M), ascorbate (29 +/- 20 M), or whole-blood GSH concentrations (1,010 +/- 239 M). CONCLUSION: The measurements of approximately micromolar levels of plasma GSH, or about 10 M cysteine + GSH (almost all of the total nonprotein thiols), are consistent with most other published data for either healthy adults or cancer patients; however, the values reported in an earlier study, suggesting a link between GSH and mucositis, are much higher. The hypothesis of a possible link between radiation mucositis and plasma-free (nonprotein) thiols was not supported.

Ascorbic Acid↗