Antioxidant activity in Spalax ehrenbergi: a possible adaptation to underground stress.
The blind subterranean mole rat Spalax ehrenbergi superspecies has evolved adaptive strategies to cope with underground stress. Hypoxia is known to stimulate reactive oxygen species generation; however, mechanisms by which Spalax counteracts oxidative damage have not been investigated before. We studied in Spalax the oxidative status of the Harderian gland (HG), an organ which is particularly vulnerable to oxidative stress in many rodents. With regard to the sexual dimorphism found in this gland, differences between males and females were determined and compared to the surface-dwelling Syrian hamster. Our results show, for the first time, that Spalax exhibits remarkably low biomolecular damage, which implies the existence of physiological strategies to avoid oxidative damage under fluctuating O(2) and CO(2) levels existing in the mole rat's subterranean niche. Correspondingly, main antioxidant enzymes, such as superoxide dismutase (SOD), catalase, and glutathione reductase (GR), exhibited high activities in both genders; in particular, remarkably high levels were measured in SOD. SOD and GR activities showed statistically significant differences between sexes. Melatonin, an important circadian agent is also a very important antioxidant molecule and is synthesized in the Harderian glands (HGs) of Spalax. Therefore, the possible interaction between antioxidant enzymes and melatonin is suggested.
Department of Morphology and Cellular Biology, Faculty of Medicine, University of Oviedo, C/ Julián Clavería s/n, 33006 Oviedo, Spain.
Beatriz
B
Caballero
Cristina
C
Tomás-Zapico
Ignacio
I
Vega-Naredo
Verónica
V
Sierra
Delio
D
Tolivia
Rüdiger
R
Hardeland
María Josefa
MJ
Rodríguez-Colunga
Alma
A
Joel
Eviatar
E
Nevo
Aaron
A
Avivi
Ana
A
Coto-Montes
D000064:Acclimatization / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D006224:Cricetinae; D005260:Female; D005980:Glutathione Reductase / Q000378:metabolism; D006243:Harderian Gland / Q000201:enzymology*; D000860:Hypoxia / Q000201:enzymology / Q000503:physiopathology; D015227:Lipid Peroxidation / Q000502:physiology; D008297:Male; D008647:Mesocricetus; D019577:Mole Rats; D018384:Oxidative Stress / Q000502:physiology*; D050050:Protein Carbonylation / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012737:Sex Factors; D013045:Species Specificity; D013482:Superoxide Dismutase / Q000378:metabolism
D000975:Antioxidants; D017382:Reactive Oxygen Species; D002374:Catalase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase