Please use this identifier to cite or link to this item: https://une.intersearch.com.au/unejspui/handle/1959.11/586
Title: High activity antioxidant enzymes protect flying-fox haemoglobin against damage: an evolutionary adaptation for flight?
Contributor(s): Reinke, N (author); O'Brien, GM (author)
Publication Date: 2006
DOI: 10.1007/s00360-006-0094-7
Handle Link: https://hdl.handle.net/1959.11/586
Abstract: Flying-foxes are better able to defend haemoglobin against autoxidation than non-volant mammals such as sheep. When challenged with the common physiological oxidant, hydrogen peroxide, haemolysates of flying-fox red blood cells (RBC) were far less susceptible to methaemoglobin formation than sheep. Challenge with 1-acetyl-2-phenylhydrazine (APH) caused only half as much methaemoglobin formation in flying-fox as in ovine haemolysates. When intact cells were challenged with phenazine methosulfate (PMS), flying-fox RBC partially reversed the oxidant damage, and reduced methaemoglobin from 40 to 20% over 2 h incubation, while ovine methaemoglobin remained at 40%. This reflected flying-fox cells' capacity to replenish GSH fast enough that it did not deplete beyond 50%, while ovine RBC GSH was depleted to around 20%. The greater capacity of flying-foxes to defend haemoglobin against oxidant damage may be explained in part by antioxidant enzymes catalase, superoxide dismutase and cytochrome-b 5 reductase having two- to four-fold higher activity than in sheep (P < 0.001). Further, their capacity to limit GSH depletion to 50% and reduce methaemoglobin (in the presence of glucose), despite ongoing exposure to PMS may result from having ten-fold higher activity of G6PD and 6PGD than sheep (P < 0.001), indicating the presence of a very efficient pentose phosphate pathway in flying-foxes.
Publication Type: Journal Article
Source of Publication: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology, 176(8), p. 729-737
Publisher: Springer
Place of Publication: Heidelberg, Germany
ISSN: 0174-1578
Field of Research (FOR): 060104 Cell Metabolism
Peer Reviewed: Yes
HERDC Category Description: C1 Refereed Article in a Scholarly Journal
Statistics to Oct 2018: Visitors: 132
Views: 132
Downloads: 0
Appears in Collections:Journal Article

Files in This Item:
1 files
File SizeFormat 
Show full item record

SCOPUSTM   
Citations

3
checked on Nov 26, 2018

Page view(s)

24
checked on Dec 29, 2018
Google Media

Google ScholarTM

Check

Altmetric


Items in Research UNE are protected by copyright, with all rights reserved, unless otherwise indicated.