Fatty acids and cholesterol in the liver cell nuclei of hibernating Yakutian ground squirrels.

The content of neutral lipids in tissue homogenates and liver cell nuclei of hibernating Yakutian ground squirrels was studied. In homogenates, hibernation increases the content of fatty acids and reduces the content of glycerides and cholesterol. When studying the liver cell nuclei of torpid winter ground squirrels, we detected a twofold increase in the content of fatty acids, cholesterol, and monoglycerides as compared to the "summer" ground squirrels.

Phospholipids of liver cell nuclei during hibernation of Yakutian ground squirrel.

In hibernating Yakutian ground squirrels S. undulatus, the content of total phospholipids in the nuclei of liver increased by 40% compared to that in animals in summer. In torpid state, the amount of sphingomyelin increased almost 8 times; phosphatidylserine, 7 times; and cardiolipin, 4 times.

[Lipids in nuclei of neocortex neurons and glia under CNS-syndrome in rats].

The effect of a local exposure of rat heads to X-ray radiation at a dose of 200 Gy on the number of phospho- lipids and neutral lipids in the nuclear fraction ofneocortex neurons and glia has been investigated A decrease in the amount ofphosphatidylinositol and an increase in sphingomyelin in neuronal nuclei occurred 2 h after irradiation at the time of repair of locomotive disorders. The amount of phosphatidylcholine and phosphati- dylinositol dropped, and the amount of sphingomyelin and cholesterol increased in the nuclei ofglial cells of the neocortex. Sphingomyelin, phosphatidylinositol, phosphatidylcholine and cholesterol of neuronal nuclei are involved in the dynamics of the CNS syndrome in mammals.

Lipids in mammalian hibernation and artificial hypobiosis.

Membrane lipids-phospholipids, fatty acids, and cholesterol-participate in thermal adaptation of ectotherms (bacteria, amphibians, reptiles, fishes) mainly via changes in membrane viscosity caused by the degree of fatty acids unsaturation, cholesterol/phospholipids ratio, and phospholipid composition. Studies of thermal adaptation of endotherms (mammals and birds) revealed the regulatory role of lipids in hibernation. Cholesterol and fatty acids participate in regulation of the parameters of torpor, gene expression, and activity of enzymes of lipid metabolism.