Document Detail


Pretreatment with intravenous ascorbic acid preserves endothelial function during acute hyperglycaemia (R1).
MedLine Citation:
PMID:  15854139     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
1. Acute hyperglycaemia may impair endothelial function. Ascorbic acid (AA), administered intra-arterially, has been reported to improve endothelium-dependent vasodilatation during a forearm hyperglycaemic clamp. Using a randomized, double-blind, placebo-controlled, cross-over study, we investigated the potential for intravenous ascorbic acid to modify the endothelial response to acute systemic hyperglycaemia in humans. 2. Nine healthy male volunteers were recruited from the hospital staff. Endothelial function was determined by measuring the forearm blood flow responses to intrabrachial infusions of endothelium-dependent (ED) and endothelium-independent (EID) vasodilators. The endothelial function index (EFI) was derived from the ratio of ED and EID vasodilatation. Haemodynamic and endothelial function measurements were performed at baseline and then repeated 2 h after a systemic hyperglycaemic clamp (14 mmol/L). The subjects, studied on two separate occasions, were randomized to placebo or 2 g intravenous ascorbic acid prior to the initiation of hyperglycaemia. 3. After systemic hyperglycaemia with placebo pretreatment, the EFI fell from 1.08 +/- 0.21 to 0.74 +/- 0.13 (difference (95% confidence interval): 0.34 (0.20, 0.47); P < 0.001). When subjects were pretreated with ascorbic acid, the EFI was not affected by hyperglycaemia (1.11 +/- 0.21 to 1.12 +/- 0.17; P = 0.938). This difference between placebo and ascorbic acid was significant (P < 0.001). Plasma ascorbate concentrations decreased during hyperglycaemia and correlated directly with the reduction in the EFI (r = 0.798; P < 0.001). 4. Pretreatment with an intravenous bolus of ascorbic acid can prevent endothelial dysfunction during acute systemic hyperglycaemia. Therefore, ascorbic acid may have potential therapeutic use in clinical situations where acute hyperglycaemia may be a complication.
Authors:
Brian A Mullan; Ciaran N Ennis; Howard J P Fee; Ian S Young; David R McCance
Related Documents :
16425449 - Biochemical responses in leaves of two apple tree cultivars subjected to progressing dr...
2681119 - Effects of ascorbic acid on the antifungal action of amphotericin b.
9049009 - Evaluation of ascorbate and urate antioxidant capacity in human semen.
15091459 - The impact of so2 and so2 + ascorbic acid treatments on growth and partitioning of dry ...
12600959 - Certification of standard reference material 970, ascorbic acid in serum, and analysis ...
9799529 - Optimal conditions for the simultaneous ion-pairing hplc determination of l-ascorbic, d...
6031429 - Amino acid concentrations in rumen fluid.
18928419 - Trichotillomania: a case of response to valproic acid.
646179 - Percutaneous indirect lymphography with a new experimental contrast medium: a prelimina...
Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Clinical and experimental pharmacology & physiology     Volume:  32     ISSN:  0305-1870     ISO Abbreviation:  Clin. Exp. Pharmacol. Physiol.     Publication Date:    2005 May-Jun
Date Detail:
Created Date:  2005-04-27     Completed Date:  2006-01-17     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0425076     Medline TA:  Clin Exp Pharmacol Physiol     Country:  Australia    
Other Details:
Languages:  eng     Pagination:  340-5     Citation Subset:  IM    
Affiliation:
Department of Anaesthesia and Intensive Care Medicine, Queen's University Belfast, Belfast, Northern Ireland, UK. brian@mullan99.fsnet.co.uk
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Acute Disease
Adult
Analysis of Variance
Ascorbic Acid / administration & dosage*
Cross-Over Studies
Dose-Response Relationship, Drug
Double-Blind Method
Endothelium, Vascular / drug effects*,  physiology
Humans
Hyperglycemia / drug therapy*,  physiopathology
Infusions, Intravenous
Male
Chemical
Reg. No./Substance:
50-81-7/Ascorbic Acid

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Clarifying homologies in the mammalian cerebral cortex: the case of the third visual area (V3).
Next Document:  Euphorbia thymifolia suppresses herpes simplex virus-2 infection by directly inactivating virus infe...