The effect of hibernation on the positional distribution of ethanolamineglycerophospholipid fatty acids in hamster brain membranes.

Microsomal and myelin membrane fractions were prepared from the brains of warm-adapted (room temperature) and hibernating Syrian Hamsters (Mesocricetus auratus). Ethanolamineglycerophospholipids were isolated and subjected to a fractionation scheme to separate the fatty acids of the plasmenylethanolamine and the phosphatidylethanolamine 1 and 2 positions. The major changes in microsomal phosphatidylethanolamine with hibernation were relative increases in 18:1 at the 1 position and 20:4(n-6) in the 2 position. In myelin, 18:1 increased and 18:0 decreased at the 1 position while the 2 position showed an increase in 16:0 and a decrease in 22:6(n-3). Plasmenylethanolamine fatty acids also changed in microsomes and myelin although the magnitudes were not as great and confined to longer chain fatty acids. In both membranes, fatty acid alterations were position-specific, and no new types of fatty acids were introduced at any position.