Antioxidant responses to variations of oxygen by the Harderian gland of different species of the superspecies Spalax ehrenbergi

The subterranean blind mole rats of the superspecies Spalax ehrenbergi (Nehring, 1898) have developed several strategies to cope with changing concentrations of underground oxygen. Such an atmosphere induces the generation of reactive oxygen species that can cause oxidative damage without proper control. To understand how S. ehrenbergi appear to be able to counteract the free radicals and avoid oxidative damage, we studied the oxidative status of the Harderian gland (an organ particularly vulnerable to oxidative stress in many rodents) in two species of the superspecies S. ehrenbergi (Spalax galili and Spalax judaei) under different oxygen concentration levels, paying special attention to the antioxidant defences developed by these animals and the resulting macromolecular damage. The results presented herein reinforce the idea that S. ehrenbergi deal better with hypoxic conditions than other rodents by regulating the activity of its antioxidant enzymes. Moreover, S. galili is better adapted to hypoxic conditions, whereas S. judaei appears to be better adapted to hyperoxic conditions.