title: Free radical paradoxes.
abstract: Unlike bigger and more advanced animals, Caenorhabditis elegans does not generate NO, yet it was recently found that NO produced by chemical or biological sources exerts profound effects in that animal, leading to increased life span and thermotolerance. The biological source was Bacillus subtilis, a natural food for C. elegans. Yet once in the cell, NO might react with superoxide, leading to the production of the potentially toxic peroxynitrite. In this paper, a number of paradoxes that are involved in that situation are discussed. It is also argued that their solution might lead to a sizeable advancement of our knowledge of what constitutes oxidative stress and what role oxidative stress plays in the development of pathological processes and aging.
authors.affiliation: 8 Foxlair Court, Durham, NC 27712, USA. Electronic address: liochev@yahoo.com.
authors.forename: Stefan I
authors.initials: SI
authors.lastname: Liochev
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001412:Bacillus subtilis / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000378:metabolism*; D005609:Free Radicals; D009569:Nitric Oxide / Q000378:metabolism*; D018384:Oxidative Stress / Q000502:physiology*
chemical_list: D005609:Free Radicals; D009569:Nitric Oxide
keywords: Aging; B. subtilis; C. elegans; E. coli; Hydrogen peroxide; Nitric oxide; Peroxynitrite; ROS; SOD; Superoxide; Superoxide dismutase; reactive oxygen species; superoxide dismutases