The pineal regulation of the immune system: 40 years since the discovery.

The first observation on the relationship between the pineal gland and the immune system was done by the author of this paper in the late sixties and early seventies of the last century. After neonatal pinealectomy the thymus has been destroyed and wasting disease developed. Since that time a flood of experiments justified the observation and pointed to the prominent role of pineal in the regulation of the immune system. Melatonin, the hormone of the pineal gland stimulates immune processes acting to the immune cells' cytokine production, the haemopoiesis, and immune cell-target cell interactions. Melatonin receptors have been demonstrated and their localization and function were justified. Melatonin production by and melatonin receptors on (and in) the immune cells was proved. Melatonin agonists have been synthesized and the use of melatonin as adjuvant in the therapy of diseases connected to the immune system (cancers included) has been started. The paper summarizes the most important studies and discusses the interrelations of the data. The discussion points to the possibility of packed transport of the pineal hormone by the immune cells and to the adventages of local regulation by this transport.