EFFECT OF GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR AND GRANULOCYTE-COLONY-STIMULATING FACTOR ON MELATONIN SECRETION IN RATS - IN-VIVO AND IN-VITRO STUDIES

The study was performed in order to clarify whether granulocyte-macrop hage colony stimulating factor (GM-CSF) and granulocyte colony stimula ting factor (G-CSF) affect melatonin production and release. We have f ound that both factors (GM-CSF at doses of 10.0 and 100.0 mu g/kg, and G-CSF at doses of 1.0, 10.0, and 100.0 mu g/kg) stimulate melatonin s ecretion in rats in vivo. Positive correlations between tested doses o f GM-CSF and G-CSF and plasma melatonin levels were observed (P < 0.01 ). Moreover, GM-CSF at doses of 2.0 and 20.0 ng/ml activated in vitro the pineal gland to melatonin release (P < 0.05) in a dose-dependent m anner.