The effect of hibernation on lipids of the liver mitochondrial fraction in the Yakut ground squirrel Spermophilus undulatus

Abstract

We demonstrated that the level of phospholipids in the liver mitochondrial fraction is increased by 60% during the winter hibernation season in the Yakut ground squirrel S. undulatus; the phospholipid composition in sleeping animals is characterized by an increase in phosphatidylethanolamine compared with summer animals. A sharp increase in the level of cholesterol, as well as fatty acid, monoglycerides, and diglycerides was found in the mitochondrial fraction of hibernating ground squirrels in relation to summer ground squirrels. Functional changes during hibernation concern the level of phosphatidylserine (the growth in sleeping animals compared with active animals). Seasonal modification of the lipid composition of the liver mitochondria (particularly, an increase in the level of cholesterol) can play a role in the resistance of mitochondria to the seasonal increase in the level of fatty acids in the liver. Lipids of the liver mitochondrial fraction are involved in the ground squirrel adaptation to the hibernation season.