title: Age and breeding effort as sources of individual variability in oxidative stress markers in a bird species.
abstract: Oxidative stress is the imbalance between the production of pro-oxidant substances and the level of antioxidant defenses, which leads to oxidative damage. It has been proposed that senescence is the result of accumulated oxidative damage throughout life. In birds, the sources of individual variability in oxidative stress are still poorly understood. Among these sources, age, as related to senescence, should be particularly relevant. Furthermore, recent findings suggest that breeding effort may also deeply influence susceptibility to oxidative stress. However, there is still no evidence of a link between breeding effort and oxidative damage in any vertebrate. Here we analyzed 288 captive red-legged partridges (Alectoris rufa) across a wide age range (i.e., 1-8 yr old), thus including potentially senescent birds. In spite of limitations due to the cross-sectional approach, results revealed that old birds produced less offspring and endured higher levels of oxidized glutathione and peroxidized lipids in erythrocytes than did middle-aged individuals. Old birds also showed higher plasma total antioxidant status and uric acid levels than did younger birds, but lower amounts of circulating carotenoids. Furthermore, hatching success was negatively correlated to lipid peroxidation in females but not in males, supporting the hypothesis that breeding effort promotes oxidative damage.
authors.affiliation: Instituto de Investigación en Recursos Cinegéticos (Consejo Superior de Investigaciones Científicas, Universidad de Castilla-La Mancha, Junta de Communidades de Castilla-La Mancha), Ronda de Toledo, s/n. 13071, Ciudad Real, Spain. carlos.alonso@uclm.es
authors.forename: Carlos
authors.initials: C
authors.lastname: Alonso-Alvarez
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Pérez-Rodríguez
authors.forename: Jesus T
authors.initials: JT
authors.lastname: García
authors.forename: Javier
authors.initials: J
authors.lastname: Viñuela
authors.forename: Rafael
authors.initials: R
authors.lastname: Mateo
mesh_terms: D000367:Age Factors; D000375:Aging / Q000502:physiology*; D000818:Animals; D002338:Carotenoids / Q000097:blood; D003430:Cross-Sectional Studies; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D046094:Galliformes / Q000097:blood / Q000502:physiology*; D019803:Glutathione Disulfide / Q000097:blood; D016014:Linear Models; D008054:Lipid Peroxides / Q000097:blood; D008297:Male; D010058:Oviposition / Q000502:physiology; D018384:Oxidative Stress / Q000502:physiology*; D012098:Reproduction / Q000502:physiology*; D014527:Uric Acid / Q000097:blood
chemical_list: D008054:Lipid Peroxides; D014527:Uric Acid; D002338:Carotenoids; D019803:Glutathione Disulfide