The role of pineal gland as the main pacemaker of biological rhythms in humans and animals is very important nowadays. It is known that ultrastructure of pinealocytes changes, subject circadian rhythms — at day time serotonin is synthesized, and at night — melatonin. In their numerous experimental studies scientists of Medical Biology and Genetics department of Bukovinian State Medical University pay much attention to melatonin, its unique and different properties are thoroughly studied today.
