The major urinary metabolite of the pineal hormone melatonin, 6-hydroxymelatonin is being quantified by a gas chromatographic-mass spectrometric method. Urinary excretion rates of this metabolite are being used to determine the possible role of the pineal gland in human biology. Collaborative studies on the effect of various drugs on melatonin secretion are in progress - tricyclic antidepressants, monamine oxidase inhibitors, and a serotonin reuptake blocker. Other collaborative studies include an effort to measure melatonin changes during the seasonal estrus cycle in monkeys; demonstration of the neural pathway ennervating the pineal gland in rats; and the correlation between plasma melatonin, cerebrospinal fluid melatonin and urinary 6-hydroxymelatonin in humans.
