1 results for Phillips, ARJ

  • Birds and longevity: Does flight driven aerobicity provide an oxidative sink?

    Hickey, Anthony; J??llig, M; Aitken, Jacqueline; Loomes, Kerry; Hauber, ME; Phillips, ARJ (2012-04)

    Journal article
    The University of Auckland Library

    Birds generally age slower and live longer than similar sized mammals. For birds this occurs despite elevated blood glucose levels that for mammals would in part de???ne them as diabetic. However these data were acquired in respiration states that have little resemblance to conditions in healthy tissues and mitochondrial RS production is probably minimal in healthy animals. Indeed mitochondria probably act as net consumers rather than producers of RS. Here we propose that (1) if mitochondria are antioxidant systems, the greater mitochondrial mass in athletic species, such as birds, is advantageous as it should provide a substantial sink forRS.(2) The intense drive for aerobic performance and decreased body density to facilitate ???ight may explain the relative insensitivity of birds to insulin, as well as depressed insulin levels and apparent sensitization to glucagon. Glucagon also associates with the sirtuin protein family, most of which are associated with caloric restriction regulated pathways, mitochondrial biogenesis and life span extension. (3) We note that telomeres, which appear to be unusually long in birds, bind Sirtuins 2 and 4 and therefore may stabilize and protect nuclear DNA. Ultimately these ???ight driven responses may suppress somatic growth and protect DNA from oxidative damage that would otherwise lead to ageing and non-viral cancers.

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