title: Defining, explaining and understanding hormesis.
abstract: A problem that hormesis has in being more scientifically accepted is (1) proving that only one mechanism accounts for both the 'beneficial' and 'toxic' parts of the biphasic dose-response curve and (2) giving substantial evidence against the interpretation that 'hormesis' is the sum of many different mechanisms which add up to either 'beneficial' or 'toxic' in two different parts of the dose-response curve. Hormesis may consist of a initial beneficial dose region where several mechanisms are operating (just for the sake of argument let us say 3 mechanisms) and the overall sum of these 3 mechanisms is 'beneficial' to the organism. At higher, toxic, doses, many more mechanisms are operating (just for the sake of argument let us say 8 mechanisms) and the sum of all these 8 mechanisms puts the organism in the 'toxic' part of the biphasic dose-response curve.
authors.affiliation: Environmental Carcinogenesis Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA. kitchin.kirk@epa.gov
authors.forename: K T
authors.initials: KT
authors.lastname: Kitchin
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D002869:Chromosome Aberrations / Q000187:drug effects / Q000528:radiation effects; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D006706:Homeostasis / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D006801:Humans; D008954:Models, Biological; D009369:Neoplasms / Q000209:etiology; D019055:No-Observed-Adverse-Effect Level; D011955:Receptors, Drug / Q000187:drug effects / Q000528:radiation effects; D012308:Risk Management
chemical_list: D011955:Receptors, Drug