The effect of the chronic administration of D-amphetamine upon circadian changes in amino acids in the pineal and pituitary glands of the rat.

The formation of dansyl derivatives of amino acids, 5-hydroxyindoleacetic acid and histamine, and their separation on polyamide plates provided a reliable and sensitive method for studying circadian changes in single pineal and pituitary glands of the rat. There appears to be no correlation between the circadian changes in concentrations of these substances in the pineal and pituitary glands. Chronically administered D-amphetamine altered the circadian rhythms of five amino acids in the pituitary, including the putative transmitters taurine, glycine, and glutamate; in the pineal gland only the rhythmical changes of lysine and 5-hydroxyindoleacetic acid were affected.