[Effect of long-term around the clock illumination on rabbit serum phospholipids]

This study was designed to investigate the effects of light on pineal gland function and phospholipids contents in the blood serum of rabbits. The level of melatonin in the blood serum was significantly reduced and endogenous rhythm of the melatonin secretion brok down under constant illumination conditions. Two-month treatment of rabbits with light led to a significant and short-term decrease of the phosphatidylethanolamine and phosphatidylinositol + phosphatidylserine levels in the serum. The contents of the other lipids under study (phosphatidylcholine, lysophosphatidylcholine and sphingomyelin) in blood increased later under 3-5 month-long constant illumination conditions. The results obtained demonstrate important role of pineal gland in the regulation of phospholipids metabolism.