Meeting Abstract
51.4 Tuesday, Jan. 5 Dietary n-3 and n-6 polyunsaturated fatty acid supplementation alters heart phospholipid composition but does not affect lifespan VALENCAK, TG*; RUF, T; University of Veterinary Medicine Vienna; University of Veterinary Medicine Vienna teresa.valencak@vetmeduni.ac.at
Smaller mammals such as mice possess tissues containing more polyunsaturated fatty acids (PUFAs) while at the same time living shorter lives. These relationships have been combined in the ‘membrane pacemaker hypothesis of aging’, a recent extension of the widely accepted ‘oxidative stress’ hypothesis of aging. It suggests that membrane PUFA content might determine an animal’s lifespan. PUFAs in general, and certain long chain PUFAs in particular, are very prone to lipid peroxidation, which brings about a high rate of reactive oxygen species (ROS) production. We hypothesized that dietary supplementation of either n-3 or n-6 PUFAs might affect i) heart phospholipid composition and ii) lifespan of the animals because of the altered membrane composition and the thereby affected lipid peroxidation processes. Therefore, we kept 40 female laboratory mice from the C57BL/6 strain on three different diets (n-3 PUFA rich, n-6 PUFA rich, control) and assessed body weights, lifespan and heart phospholipid composition after the animals had died. We found that while heart phospholipid composition clearly differed between feeding groups, no influence on lifespan was detected. When relating certain fatty acid classes to the longevity of the mice however, we observed that the content of monounsaturated fatty acids was positively linked to lifespan. In other words, the eldest mice had the highest content of monounsaturated fatty acids in their heart phospholipids. We conclude that our dietary intervention, the addition of either n-3 or n-6 PUFAs did not affect lifespan of the animals. However, membrane phospholipid content of monounsaturated fatty acids was clearly related to longevity of the mice. Thus, further studies are needed to assess the role of monosaturated fatty acids on lifespan.
