[Different shifts in the plasma corticosterone content depending on the dose and administration route of melatonin]

The changes in plasma corticosterone levels were studied when the pineal hormone melatonin was administered in various doses and by routes in rat experiments. Its single administration in a median (1 mg/kg) and high (10 mg/kg) doses caused enhanced corticosteroid secretion. On the contrary, there were lover blood levels of corticosterone when melatonin was chronically used in a low dose of 0.1 mg/kg. The value of inhibitory pineal-adrenocortical relationships was studied for melatonin pharmacology.