Lipid changes in blood serum and tissues of the Egyptian Cobra “Naja haje haje” during the hibernation cycle

1.Total lipids, free fatty acids, triglycerides, phospholipids and total cholesterol in blood serum, liver, brain, cardiac and skeletal muscles of Naja haje haje were determined during the different phases of the hibernation cycle.2.A sharp decrease in the level of total lipids of blood serum and all tissues occurred during hibernation. Upon arousal, lipogenesis is commonly restored.3.Elevated concentrations of serum free fatty acids predominated in pre-hibernation and hibernation periods, while the tissues recorded highly significant declines during hibernation.4.Occurrence of marked decreases in triglycerides contents of serum and tissues except the cardiac muscles in the hibernation and arousal phases.5.Sharp increases in the phospholipid contents of blood and the selected tissues were recorded during hibernation. The level declined in both liver and cardiac muscles in arousing animals.6.Total cholesterol level was lowered in blood during hibernation. The cardiac muscles showed a highly significant decrease while liver, brain and skeletal muscles showed elevations in the same phase.