High levels of antioxidant enzymatic defence assure good protection against hypoxic stress in spontaneously diabetic rats

• Published in: The international journal of biochemistry & cell biology Vol. 38; no. 12; pp. 2196 - 2208
• Main Authors: Bonfigli, A., Colafarina, S., Falone, S., Di Giulio, C., Di Ilio, C., Amicarelli, F.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 2006
• Subjects: Animals; Antioxidant enzymes; Antioxidants - metabolism; BB rats; Caspase 3 - metabolism; Catalase - metabolism; Cell Hypoxia; Diabetes; Diabetes Mellitus - enzymology; Diabetes Mellitus - metabolism; Diabetes Mellitus - pathology; Glutathione Peroxidase - metabolism; Glutathione Reductase - metabolism; Glutathione Transferase - metabolism; Hypoxia; Lactoylglutathione Lyase - metabolism; Liver - enzymology; Lung - enzymology; NF-kappa B - metabolism; NF-κB; Rats; Rats, Wistar; Superoxide Dismutase - metabolism; Superoxide Dismutase-1; Thiolester Hydrolases - metabolism; Tumor Suppressor Protein p53 - metabolism; NF-κB; Hypoxia; Diabetes; BB rats; Antioxidant enzymes
• ISSN: 1357-2725; 1878-5875
• DOI: 10.1016/j.biocel.2006.06.011

Recent data from literature report that reactive oxygen species (ROS) seem to play a crucial role in the etiology of both types I and II diabetes. This may render diabetic individuals more prone to oxidative injury when challenged with hypoxic stress. It is in fact well known that many diabetic complications cause ischaemic episodes, with a consequent reduction in oxygen supply to various tissues and organs. To check this hypothesis, in this work we tested type I diabetic individuals’ antioxidant capability towards a hypoxic-mediated oxidative challenge. In particular, spontaneously diabetic and age-matched non-diabetic biobreeding (BB) Wistar rats were submitted to chronic normobaric hypoxia, and the response of antioxidant enzymes, as well as redox-sensitive transcription factor NF-κB and p53, were monitored. Results show that diabetic subjects present a dramatic enhancement in the major antioxidant enzymes activities, thus supporting the notion of diabetes-related changes in cellular redox status. This allows diabetic individuals to counteract hypoxia-mediated oxidative challenge better than the non-diabetic counterpart. Also the behaviour of both the redox-sensitive nuclear transcription factor NF-κB and p53 protein in response to hypoxic stimulation seems to support the hypothesis of a better ROS scavenging efficiency in diabetics under hypoxic conditions. In conclusion, high levels of antioxidant enzymatic defences in diabetic BB rats reflect a positive adaptive response able to assure an efficient protection not only against chronic, diabetes-mediated reactive oxygen species (ROS) overproduction, but also versus further oxidative damage.