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Effects of maximal static apnea on antioxidant defenses in trained free divers

Citation

Bulmer, A and Coombes, JS and Sharman, JE and Stewart, I, Effects of maximal static apnea on antioxidant defenses in trained free divers, Medicine and Science in Sports and Exercise, 40, (7) pp. 1307-1313. ISSN 0195-9131 (2008) [Refereed Article]

DOI: doi:10.1249/MSS.0b013e31816a7188

Abstract

Purpose: To investigate the effects of maximal static apnea on plasma antioxidant status, oxidative stress, and antioxidant enzyme activities in trained free divers. Methods: Blood was taken from apnea-trained (Tr) and control (Con) subjects at baseline (B) and after one (A1), three (A3), and five (A5) apneas. Trolox equivalent antioxidant capacity (TEAC), ferric reducing ability of plasma (FRAP), uric acid, and bilirubin assays assessed plasma antioxidant status and malondialdehyde (MDA) quantified the oxidative stress response. The activities of erythrocyte antioxidant enzymes Superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were determined at baseline and after the fifth apnea. Results: TEAC was significantly higher in divers versus controls after AI (P < 0.05). A group effect of SOD activity indicated higher activity throughout the protocol in Tr (mean SD; Con, 43.2 10.1 Ug Hb-1; Tr, 50.1 7.3 Ug Hb -1; P = 0.04). With no other group differences, the groups' data were combined. Apnea significantly increased SOD (B, 44.1 11.1 Ug Hb -1; A5, 48.1 7.5 Ug Hb-1; P < 0.05) and GPx activity (B, 60.5 14.9 Ug Hb-1; A5, 70.1 16.0 Ug Hb-1; P = 0.02); however, CAT activity decreased (B, 5.25 0.59 Umg Hb-1; A5, 5.00 0.53 Umg Hb-1; P = 0.03). MDA was unaffected by apnea (P = 0.32). Conclusions: Trained free divers have increased SOD activity during apnea; however, there is little difference in their antioxidant and oxidative stress responses compared with controls. In both groups, acute changes in antioxidant enzyme activities suggest that they may protect from excessive antioxidant depletion and oxidative stress during apnea.

Item Details

Item Type:Refereed Article
Research Division:Medical and Health Sciences
Research Group:Cardiorespiratory Medicine and Haematology
Research Field:Cardiology (incl. Cardiovascular Diseases)
Objective Division:Health
Objective Group:Clinical Health (Organs, Diseases and Abnormal Conditions)
Objective Field:Cardiovascular System and Diseases
Author:Sharman, JE (Professor James Sharman)
ID Code:61255
Year Published:2008
Web of Science® Times Cited:4
Deposited By:Menzies Institute for Medical Research
Deposited On:2010-03-02
Last Modified:2010-05-03
Downloads:0

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