[Melatonin: physiological and pathophysiological aspects and possible applications].

The number of indications for the medical use of melatonin is slowly increasing. Melatonin is produced by the pineal gland and is a key signal in the circadian rhythm of the body. Melatonin plays an obvious role in the pathophysiology and treatment of sleep disorders and jetlag. Recent research has also demonstrated its favourable effect on blood-pressure regulation. By analogy, melatonin may play a role in a variety of other circadian processes. However, research into the precise effects is still insufficient.