Comparative analysis of mitochondrial fatty acids in the brain of avian species: an allometric study

GUTIÉRREZ AM; REBOREDO GR; MOSCA SM; CATALÁ A

Huerta Grande

Congreso; Primera Reunión Conjunta de Sociedades de Biología de la República Argentina,; 2007

Sociedades de Biología de la República Argentina

The acyl composition of tissue lipids varies in a systematic manner among species. Previous research has shown that tissue phospholipids from small mammals were more polyunsaturated than those from large mammal species, whilst the phospholipids from large mammals were more monounsaturated than those from small mammals. This relationship was present in all tissues examined (heart, liver, kidney and skeletal muscle) except the brain. The objective of this investigation was to examine the relationship between body size and mitochondrial fatty acid composition in the brain of manon, quail, pigeon, duck and goose. The fatty acid composition was determined in isolated mitochondria by gas-chromatography. The percentage of saturated fatty acids (SFAs) was significantly higher (r = 0.92; P< 0.05), whereas the percentage of monounsaturated fatty acids (MUFAs), mainly oleic acid (C18:1n9), was significantly lower in the larger birds (@ 15 % in goose vs 30 % in manon). The allometric exponents were 0.014 and 0.09 for SFAs and MUFAs, respectively. There were no statistically significant allometric trends for polyunsaturated fatty acid percentage (r = 0.30) and unsaturation index (r = 0.52). The brain of all birds studied had a high content of docosahexaenoic acid (22:6n3) (@ 12 %) and high level of double bonds (as indicated by the unsaturation index  @  150). These results show that: 1) brain mitochondria of small birds had higher content of monounsaturated and lower content of saturated fatty acids and 2) the brain of the avian species examined, similarly to other vertebrates, had consistently high levels of C22:6 n3, indicating a tissue specificity.