title: Lactation Affects Isolated Mitochondria and Its Fatty Acid Composition but Has No Effect on Tissue Protein Oxidation, Lipid Peroxidation or DNA-Damage in Laboratory Mice.
abstract: Linking peak energy metabolism to lifespan and aging remains a major question especially when focusing on lactation in females. We studied, if and how lactation affects in vitro mitochondrial oxygen consumption and mitochondrial fatty acid composition. In addition, we assessed DNA damage, lipid peroxidation and protein carbonyls to extrapolate on oxidative stress in mothers. As model system we used C57BL/6NCrl mice and exposed lactating females to two ambient temperatures (15 °C and 22 °C) while they nursed their offspring until weaning. We found that state II and state IV respiration rates of liver mitochondria were significantly higher in the lactating animals than in non-lactating mice. Fatty acid composition of isolated liver and heart mitochondria differed between lactating and non-lactating mice with higher n-6, and lower n-3 polyunsaturated fatty acids in the lactating females. Surprisingly, lactation did not affect protein carbonyls, lipid peroxidation and DNA damage, nor did moderate cold exposure of 15 °C. We conclude that lactation increases rates of mitochondrial uncoupling and alters mitochondrial fatty acid composition thus supporting the "uncoupling to survive" hypothesis. Regarding oxidative stress, we found no impact of lactation and lower ambient temperature and contribute to growing evidence that there is no linear relationship between oxidative damage and lactation.
authors.affiliation: Research Institute of Wildlife Ecology, University of Veterinary Medicine, Savoyenstrasse 1, Vienna A-1160, Austria. teresa.valencak@vetmeduni.ac.at.|Institute of Physiology, Pathophysiology and Biophysics, University of Veterinary Medicine, Veterinärplatz 1, Vienna A-1210, Austria. teresa.valencak@vetmeduni.ac.at.
authors.forename: Teresa G
authors.initials: TG
authors.lastname: Valencak
authors.affiliation: Institute of Veterinary Public Health, University of Veterinary Medicine, Veterinärplatz 1, Vienna A-1210, Austria. Johannes.raith@vetmeduni.ac.at.
authors.forename: Johannes
authors.initials: J
authors.lastname: Raith
authors.affiliation: Institute of Pharmacology and Toxicology, University of Veterinary Medicine, Veterinärplatz 1, Vienna A-1210, Austria. katrin.staniek@vetmeduni.ac.at.
authors.forename: Katrin
authors.initials: K
authors.lastname: Staniek
authors.affiliation: Institute of Pharmacology and Toxicology, University of Veterinary Medicine, Veterinärplatz 1, Vienna A-1210, Austria. lars.gille@vetmeduni.ac.at.
authors.forename: Lars
authors.initials: L
authors.lastname: Gille
authors.affiliation: Institute of Physiology, Pathophysiology and Biophysics, University of Veterinary Medicine, Veterinärplatz 1, Vienna A-1210, Austria. alois.strasser@vetmeduni.ac.at.
authors.forename: Alois
authors.initials: A
authors.lastname: Strasser
keywords: C57BL/6NCrl; TBARS; comet assay; isolated mitochondria; lactation; mitochondrial fatty acid composition; oxygen consumption; protein oxidation