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

Bulmer, Andrew C. and Coombes, Jeff S. and Sharman, James E. and Stewart, Ian B. (2008) 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

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 A1 (P G 0.05). A group effect of SOD activity indicated higher activity throughout the protocol in Tr (mean T SD; Con, 43.2 T 10.1 UIg Hbj1; Tr, 50.1 T 7.3 UIg Hbj1; P = 0.04). With no other group differences, the groups’ data were combined. Apnea significantly increased SOD (B, 44.1 T 11.1 UIg Hbj1; A5, 48.1 T 7.5 UIg Hbj1; P G 0.05) and GPx activity (B, 60.5 T 14.9 UIg Hbj1; A5, 70.1 T 16.0 UIg Hbj1; P = 0.02); however, CAT activity decreased (B, 5.25 T 0.59 UImg Hbj1; A5, 5.00 T 0.53 UImg Hbj1; 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.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Author version not held.
Depositing User: Ms Debbie White
Faculty / Department / School: Historic - Faculty of Sciences - Department of Biological and Physical Sciences
Date Deposited: 05 May 2010 13:00
Last Modified: 02 Jul 2013 23:52
Uncontrolled Keywords: enzymes; superoxide dismutase; glutathione peroxidase, catalase; hypoxia; breath hold
Fields of Research (FOR2008): 11 Medical and Health Sciences > 1106 Human Movement and Sports Science > 110602 Exercise Physiology
Socio-Economic Objective (SEO2008): E Expanding Knowledge > 97 Expanding Knowledge > 970111 Expanding Knowledge in the Medical and Health Sciences
Identification Number or DOI: doi: 10.1249/MSS.0b013e31816a7188
URI: http://eprints.usq.edu.au/id/eprint/7918

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