Abstracto

A low degree of fatty acid unsaturation protects against lipid peroxidation in mitochondria of different organs of gentoo penguin Pygoscelis papua

Monica Marmunti, Ana Mar�?�?�?�?�?�?�?­a Gutierrez, Diego Montalti, Mariana Gavazza, Alejandro Palacios

Lipid peroxidation is one of the main events induced by oxidative stress and is particularly active in those tissues whose membranes are rich in polyunsaturated fatty acids. The aim of the present study was examine fatty acid profiles and the susceptibility to lipid peroxidation in mitochondria obtained from liver and heart of Gentoo penguin Pygoscelis papua. When we analysed the fatty acid composition of Gentoo penguin we observed that the amount of saturated and unsaturated fatty acids obtained fromliver mitochondria was 53%and 45%, whereas in heartmitochondria was 40% and 60% respectively. In liver as in heart the predominant unsaturated fatty acid was C18:1n9. The polyunsaturated fatty acid percentages of mitochondria obtained from liver was 16% whereas in heart was 18%. The rate betweenC20:4n6/C18:2n6 in liver and heartmitochondria was 2.17 and 0.34 respectively. The mitochondria obtained from liver and heart is not susceptible to lipid peroxidation. The most interesting finding of our study is the low sensitivity to lipid peroxidation observed in both organs; this fact may be involved in the protection to oxidative stress observed in these organelles.