Vitamin C Transporter Gene SLC23A1 Polymorphisms and Fasting Plasma Ascorbate

2007 ◽  
Vol 21 (5) ◽  
Author(s):  
Leah Cahill ◽  
Bénédicte Fontaine‐Bisson ◽  
Ahmed El‐Sohemy
Keyword(s):  
Vitamin C ◽  
Transporter Gene ◽  
Fasting Plasma ◽  
Plasma Ascorbate

scholarly journals Erythrocyte Ascorbate Is a Potential Indicator of Steady-State Plasma Ascorbate Concentrations in Healthy Non-Fasting Individuals

Nutrients ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 418 ◽  
Author(s):  
Juliet M. Pullar ◽  
Susannah Dunham ◽  
Gabi U. Dachs ◽  
Margreet C. M. Vissers ◽  
Anitra C. Carr
Keyword(s):  
Steady State ◽  
Vitamin C ◽  
Plasma Levels ◽  
Normal Diet ◽  
Plasma Vitamin ◽  
Stable Measure ◽  
Fasting Plasma ◽  
Plasma Ascorbate ◽  
Ascorbate Uptake ◽  
State Plasma

Plasma vitamin C concentrations fluctuate in response to recent dietary intake; therefore levels are typically determined in the fasting state. Erythrocyte ascorbate concentrations have been shown to be similar to plasma levels, but little is known about the kinetics of ascorbate accumulation in these cells. In this study, we investigated ascorbate uptake into erythrocytes after dietary supplementation with vitamin C and compared it to changes in plasma ascorbate concentrations. Seven individuals with baseline fasting plasma vitamin C concentrations ≥ 50 µmol/L were depleted of vitamin C-containing foods and drinks for one week, and then supplemented with 250 mg vitamin C/day in addition to resuming their normal diet. Fasting or steady-state plasma ascorbate concentrations declined to almost half of their baseline concentration over the week of vitamin C depletion, and then returned to saturation within two days of beginning supplementation. Erythrocyte ascorbate concentrations exhibited a very similar profile to plasma levels, with values ~76% of plasma, and a strong linear correlation (r = 0.89, p < 0.0001). Using a pharmacokinetic study design in six individuals with baseline fasting plasma vitamin C concentrations ≥50 µmol/L, we also showed that, unlike plasma, which peaked between 2 and 4 h following ingestion of 200 mg of vitamin C, erythrocyte ascorbate concentrations did not change in the six hours after supplementation. The data from these two intervention studies indicate that erythrocyte ascorbate concentration provides a stable measure of steady-state plasma ascorbate status and could be used to monitor ascorbate status in healthy non-fasting individuals.

scholarly journals 191 Effects of injectable vitamin C at weaning and prior to transit on growth performance and immune function of beef steers

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 152-153
Author(s):  
Aubree M Beenken ◽  
Erin L Deters ◽  
Colten W Dornbach ◽  
Stephanie L Hansen ◽  
Joshua C McCann ◽  
...  
Keyword(s):  
Vitamin C ◽  
Growth Performance ◽  
Repeated Measures ◽  
Fixed Effects ◽  
Average Daily Gain ◽  
Experimental Unit ◽  
Beef Steers ◽  
Diarrhea Virus ◽  
Plasma Ascorbate ◽  
Antibody Titers

Abstract Ninety-one early-weaned (65 ± 11 d) Angus steers (92 ± 4 kg) were blocked by age to a 2 × 2 factorial examining effects of injectable vitamin C (VC) at weaning and/or prior to transport to the feedlot on antibody titers and growth performance. Injections (20 mL/steer) of VC (250 mg sodium ascorbate/mL) or saline (SAL) were given at time of weaning on d 0 (WEAN) and/or prior to a 6 hr trucking event to a feedlot on d 49 (TRANS). Steers were given booster vaccinations on d 0. Steers were weighed on d 0, 1, 14, 48, 49, 64, 106, and 107. Blood was collected (12 steers/treatment) on d 0, 1, 2, 14, 49 (pre- and post-transit), 50, and 51. Data were analyzed via Proc-Mixed of SAS (experimental unit = steer; n = 22–23/treatment) with fixed effects of block, WEAN, TRANS, and WEAN × TRANS. Plasma ascorbate concentrations for weaning (d 0, 1, and 2) and transit (d 49-pre-trucking, 49-post-trucking, 50, and 51) were analyzed as repeated measures (repeated effect = day). Plasma ascorbate concentrations were greater on d 1 and 2 for steers that received VC at weaning (VC = 19.6, SAL = 8.8 ± 1.26 µM; WEAN × day P &lt; 0.01). Similarly, ascorbate concentrations were greater on d 49 post-trucking, 50, and 51 for steers that received VC pre-transit (TRANS × day P = 0.01). Treatments did not affect bodyweight or average daily gain throughout the trial (P &gt; 0.32). There were no effects of treatment on serum Bovine Viral Diarrhea Virus type 2 antibody titers on d 14 or 51 (P &gt; 0.33). An injection of VC administered to early weaned beef steers at weaning or pre-transit increases plasma ascorbate concentrations but does not improve growth performance or antibody response to vaccination booster.

Metabolic Interrelationship between Vitamin B12 and Ascorbic Acid in Pernicious Anemia

Blood ◽  
1968 ◽  
Vol 31 (1) ◽  
pp. 55-65 ◽  
Author(s):  
SIGMUND BENHAM KAHN ◽  
ISADORE BRODSKY ◽  
Sandra A. Fein
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Vitamin B12 ◽  
Pernicious Anemia ◽  
Vitamin B12 Deficiency ◽  
Biochemical Index ◽  
Plasma Ascorbate ◽  
B12 Deficiency ◽  
Future Work

Abstract An interrelationship between vitamin C and vitamin B12 was studied in three patients with vitamin B12 deficiency associated with pernicious anemia. Subnormal plasma ascorbate concentrations were found prior to therapy confirming previous observations. Following vitamin B12 administration and utilizing methylmalonate (MMA) excretion as a biochemical index of vitamin B12 deficiency, low plasma ascorbate concentrations persisted until MMA excretion was abolished. In two patients, RBC vitamin B12 activity was also serially measured in order to evaluate its sensitivity as an index of vitamin B12 stores when compared to MMA excretion. The data demonstrate that in these two vitamin B12-deficient patients undergoing slow repletion therapy, RBC vitamin B12 activity returns to normal before MMA excretion is abolished. Whether continued MMA excretion in these patients indicates a greater sensitivity of MMA excretion as an index of deficiency of vitamin B12 stores than does RBC vitamin B12 activity remains to be answered by future work.

Antioxidant Status of Patients on Peritoneal Dialysis: Associations with Inflammation and Glycoxidative Stress

2009 ◽  
Vol 29 (1) ◽  
pp. 89-101 ◽  
Author(s):  
Isabella Sundl ◽  
Johannes M. Roob ◽  
Andreas Meinitzer ◽  
Beate Tiran ◽  
Gholamali Khoschsorur ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Vitamin C ◽  
Interleukin 6 ◽  
Antioxidant Status ◽  
Low Dose ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Chronic Inflammatory Response ◽  
Plasma Ascorbate ◽  
High Doses

Background Patients on peritoneal dialysis (PD) frequently exhibit oxidant–antioxidant imbalance, advanced glycation end-product overload, and subclinical inflammation but the interrelations between these pathophysiological changes have not been fully elucidated. Subjects and Methods To study possible associations, a cross-sectional study of antioxidant status, glycoxidative stress, and inflammation, using HPLC and ELISA methods, was undertaken in 37 PD patients and age- and sex-matched healthy controls. Results Plasma ascorbate concentrations were low in patients not taking at least low-dose vitamin C supplements. In patients taking vitamin C supplements, there was a positive relation between ascorbate and pentosidine concentrations. Vitamin E and carotenoid concentrations were comparable between patients and controls, while lycopene and lutein/zeaxanthin concentrations were lower. Interleukin-6, C-reactive protein (CRP), and pentosidine concentrations were elevated in PD patients. β–Cryptoxanthin, lycopene, and lutein/zeaxanthin concentrations were inversely related to interleukin-6 concentrations. β–Cryptoxanthin concentrations were also inversely related to CRP concentrations. Pentosidine showed a low dialysate-to-plasma ratio, indicating low peritoneal clearance. Pentosidine concentrations increased with duration of PD therapy, while α– and β–carotene concentrations decreased. Malondialdehyde concentrations were elevated compared to controls but remained within the normal range. Retinol concentrations decreased with PD therapy and were inversely related to interleukin-6 and CRP concentrations. Conclusions Low-dose vitamin C supplements and a carotenoid-rich diet should be recommended for PD patients to maintain normal antioxidant status and efficiently counteract the chronic inflammatory response, rather than high doses of vitamin C, which could play a role as a precursor of pentosidine.

scholarly journals Low Vitamin C Status in Patients with Cancer Is Associated with Patient and Tumor Characteristics

Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2338 ◽  
Author(s):  
Rebecca White ◽  
Maria Nonis ◽  
John F. Pearson ◽  
Eleanor Burgess ◽  
Helen R. Morrin ◽  
...  
Keyword(s):  
Cancer Therapy ◽  
Vitamin C ◽  
Human Health ◽  
Cancer Patients ◽  
Vital Role ◽  
Tumor Characteristics ◽  
Patients With Cancer ◽  
Plasma Ascorbate ◽  
Number Of Patients ◽  
Low Levels

Vitamin C (ascorbate) acts as an antioxidant and enzyme cofactor, and plays a vital role in human health. Vitamin C status can be affected by illness, with low levels being associated with disease due to accelerated turnover. However, robust data on the ascorbate status of patients with cancer are sparse. This study aimed to accurately measure ascorbate concentrations in plasma from patients with cancer, and determine associations with patient or tumor characteristics. We recruited 150 fasting patients with cancer (of 199 total recruited) from two cohorts, either prior to cancer surgery or during cancer chemo- or immunotherapy. A significant number of patients with cancer had inadequate plasma ascorbate concentrations. Low plasma status was more prevalent in patients undergoing cancer therapy. Ascorbate status was higher in women than in men, and exercising patients had higher levels than sedentary patients. Our study may prompt increased vigilance of ascorbate status in cancer patients.

scholarly journals Stable isotope-labelled vitamin C as a probe for vitamin C absorption by human subjects

2004 ◽  
Vol 91 (5) ◽  
pp. 699-705 ◽  
Author(s):  
Christopher J. Bates ◽  
Kerry S. Jones ◽  
Leslie J. C. Bluck
Keyword(s):  
Stable Isotope ◽  
Vitamin C ◽  
Peak Plasma ◽  
Human Subjects ◽  
Total Concentration ◽  
Grape Juice ◽  
Isotope Enrichment ◽  
Factors Affecting ◽  
Plasma Ascorbate ◽  
Red Grape

Factors affecting absorption of physiological doses of vitamin C in man have not been widely studied, partly because few suitable tools exist to distinguish recently absorbed vitamin C from endogenous vitamin. Stable isotope-labelled vitamin C provides such a tool. Fifteen healthy non-smoking subjects aged 26–59 years were studied. Each received 30 mg L-[1-13C]ascorbic acid orally on two occasions, 3–4 weeks apart. The ascorbate was given alone or with Fe (100 mg as ferrous fumarate) or with red grape juice, which is rich in polyphenols. Blood was collected at frequent intervals for 1 h, and then each hour for a further 3 h. Total concentration of vitamin C was measured fluorometrically and its 13C-isotope enrichment was measured by GC–MS after conversion to volatile trimethylsilyl esters. Peak plasma enrichment occurred within 25–50 min. No kinetic variables were significantly altered by the iron fumarate supplement. Grape juice attenuated vitamin C absorption, reaching significance at the 20 min time point. There were weak correlations between isotope enrichment and body weight or endogenous ascorbate concentration. The increment in total plasma ascorbate was smaller if calculated from isotope enrichment than from vitamin C concentration increase. The dilution pool was much larger than the plasma ascorbate pool. Further studies are needed to resolve these paradoxes. Stable isotope-labelled ascorbate is potentially useful for measurement of vitamin C absorption by human subjects.

Plasma ascorbate levels and inhibition of the antioxidant activity of caeruloplasmin

1991 ◽  
Vol 81 (3) ◽  
pp. 413-417 ◽  
Author(s):  
John M. C. Gutteridge
Keyword(s):  
Antioxidant Activity ◽  
Vitamin C ◽  
Membrane Lipids ◽  
Molar Ratio ◽  
Iron Salt ◽  
Ferrous Ions ◽  
Oral Supplementation ◽  
Plasma Ascorbate ◽  
Ferroxidase Activity

1. The copper-containing protein caeruloplasmin has several oxidase activities. 2. Its ability to catalyse the oxidation of ferrous ions to the ferric state (ferroxidase activity) makes it an important antioxidant in vivo. 3. Recent reports have suggested that oral supplementation with vitamin C can inhibit the oxidase activities of caeruloplasmin. 4. As expected, damage to DNA and membrane lipids was stimulated by mixtures of iron salt and ascorbate, and this damage could be inhibited by caeruloplasmin provided the molar ratio of ascorbate to caeruloplasmin was kept sufficiently low. 5. When the molar ratio of ascorbate to caeruloplasmin was greater than 200 substantial loss of ferroxidase antioxidant activity occurred. 6. It is unlikely, however, that oral supplementation with vitamin C can raise plasma levels sufficiently to inhibit caeruloplasmin activity in vivo.

scholarly journals Erythrocyte Cytochrome b Reductase 1 Protein Levels and Structure in Sickle Cell Patients

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3654-3654
Author(s):  
Richard Kulmacz ◽  
Hamidreza Farzaneh ◽  
Kathryn L McElhinney ◽  
Jose M. Rodriguez ◽  
Nicole C. Thomason ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Vitamin C ◽  
Sickle Cell ◽  
Dose Response ◽  
Healthy Controls ◽  
Rbc Membrane ◽  
Coomassie Blue ◽  
Plasma Ascorbate ◽  
Sds Page ◽  
And Control

Abstract In humans, vitamin C (ascorbic acid) is required as substrate or cofactor in a number of important cellular processes. Patients with sickle cell disease (SCD) often are deficient in vitamin C and thus potentially adversely affected. A major determinant of the cellular availability of ascorbate is the plasma level of the vitamin. This reflects the balance between dietary supply, uptake by tissues, excretion, oxidative reactions in the plasma, and RBC dependent recycling or irreversible decomposition of oxidized ascorbate. The mechanisms for depressed plasma ascorbate levels in SCD patients have not been identified, and the effectiveness and safety of dietary ascorbate supplements have not been established. As RBC dysfunction is central to SCD, we have focused on the possibility that SCD patients' RBC membranes have an altered level, structure or function of CYBRD1, a key enzyme in recycling oxidized plasma ascorbate (Fig. 1A). Materials and methods: Blood samples were collected in EDTA tubes from adult SCD patients at routine ambulatory clinic visits and from healthy African American adults. Protocols were approved by institutional review. RBC were isolated by centrifugation and lysed in hypotonic buffer; membranes were isolated by centrifugation and stored at -80 C. Electrophoretic and western blot analyses: RBC membrane proteins were separated by SDS-PAGE, stained with Coomassie Blue and analyzed by densitometry to quantitate total membrane protein (standard: BSA). Alternatively, separated proteins were transferred to nitrocellulose or PVDF and probed with antibodies against CYBRD1. Immunoreactive bands were visualized colorimetrically and quantitated by densitometry (standard: recombinant human CYBRD1 (rCYBRD1)). Mass spectroscopic analyses: CYBRD1 was extracted from RBC membranes with dodecyl maltoside, and further enriched by immunoprecipitation. The immunopurified mixture was separated by SDS-PAGE and stained with Coomassie Blue. Gel pieces containing the CYBRD1 monomers were subjected to in-gel digestion and MS analysis of the tryptic peptides. Results and conclusions: Detailed dose-response analyses found unsuspected positively cooperative behavior between 0 and ~2 ng CYBRD1 in both rCYBRD1 and RBC membrane samples. This invalidated calculations of RBC CYBRD1 content based on linear response to rCYBRD1. However, selected RBC membrane samples were routinely included as quality controls on many blots. Further, the dose-response curves for RBC membrane samples had a consistent shape that fit a simple saturable model with an x-axis offset parameter. It was thus possible to estimate the CYBRD1 content for 36 of the RBC samples using one of them (V7) as reference (Fig. 1B). This permitted our ongoing comparison of CYBRD1 content in patients and controls, and in SCD subtypes. RBC CYBRD1 content in 4 homozygous SCD subjects sampled at 5 regular clinic visits changed little over 7-9 months (averages: 0.32 ± 0.05; 0.25 ± 0.05; 0.41 ± 0.04; and 0.37 ± 0.04 ng CYBRD1/µg RBC membrane protein). This suggests that patients' RBC CYBRD1 contents are relatively stable despite the short RBC half-life, and that a single sampling is sufficient for cross sectional studies. There was no significant difference in CYBRD1 level among ambulatory HbSC (N=6) and HbSS (N=8) patientsand healthy controls (N=8)(Fig. 1C, top). However, there were notable differences in CYBRD1 protein modification, with significantly less modification in CYBRD1 from HbSS patients than either HbSC patients or healthy controls (Fig. 1C, bottom). Similar isoform banding patterns are seen for patient and control CYBRD1 with antibodies against either the N- and C-terminal peptides (Fig. 1D). Retention of epitopes at both ends of CYBRD1 in the isoforms argues against differential proteolysis being involved. The mass spectrometric analyses found extensive oxidative modification of multiple methionine residues, but similar patterns were seen in RBC CYBRD1 from an SCD patient and a healthy control. Phosphorylation was found at multiple sites in residues 200-285 of CYBRD1 from both patient and control, but the fraction phosphorylated appeared much too low to account for the large proportion of CYBRD1 in individual isoforms. Thus, the structural basis for the isoforms' differential gel mobility remains to be identified. Support: American Heart Association, 16GRNT29170013 (R. Kulmacz); NIH 5T35DK007676 (B. Kone) Disclosures No relevant conflicts of interest to declare.

Vitamin C metabolites, independent of smoking status, significantly enhance leukocyte, but not plasma ascorbate concentrations

2008 ◽  
Vol 25 (10) ◽  
pp. 995-1009 ◽  
Author(s):  
Mark A. Moyad ◽  
Maile A. Combs ◽  
Angelica S. Vrablic ◽  
Janet Velasquez ◽  
Benilda Turner ◽  
...  
Keyword(s):  
Vitamin C ◽  
Smoking Status ◽  
Plasma Ascorbate

scholarly journals Vitamin C protects against chronic social isolation stress-induced weight gain and depressive-like behavior in adult male rats

2020 ◽  
Vol 54 (4) ◽  
pp. 266-274
Author(s):  
Alireza Najaf Dulabi ◽  
Zeinab Shakerin ◽  
Nasrin Mehranfard ◽  
Maedeh Ghasemi
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Vitamin C ◽  
Social Isolation ◽  
Male Rats ◽  
Fasting Plasma ◽  
Male Wistar Rats ◽  
Glandular Cells ◽  
In Cis ◽  
Ghrelin Secretion

Abstract Objective. Considering the importance of ghrelin in stress-induced hyperphagia and a role of antioxidants in decreasing body weight, in the present study, the effect of vitamin C (VitC) on ghrelin secretion and food intake following chronic social isolation (CIS) was evaluated in rats. Methods. Thirty two male Wistar rats (200–220g) were randomly divided into: control, VitC, CIS, and CIS + VitC groups. Animals received VitC (500 mg/kg/day)/saline by gavage for 3 weeks. For 24 h cumulative and post 18–20 h fasting food intake, fasting plasma ghrelin level, and body weight were measured. Gastric histopathology was also evaluated. Results. Results showed a marked increase in fasting plasma ghrelin and food intake in stressed rats compared to controls. VitC prevented the increases in stressed rats. Histological assessment indicated a positive effect of VitC on gastric glandular cells compared to control, an effect that might partially be a reason of significant increase of plasma ghrelin levels in VitC rats. Elevated plasma ghrelin in VitC group was even higher than that one in stressed group, whereas there were no significant changes in the food intake. Assessment of the percentage of changes in body weight during 21 days showed a significant increase in stressed rats compared to controls. Vitamin C treatment prevented this increase. Stressed rats also displayed depression-like behavior as indicated by sucrose test, whereas VitC ameliorated it. Conclusions. The data of the present study indicate that VitC may overcome ghrelin-induced hyperphagia and improve the abnormal feeding and depressive behavior in CIS rats.

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