Acute effects of lithium on central dopamine and serotonin activity reflected by inhibition of prolactin and growth hormone secretion in the rat.

The acute administration of lithium chloride significantly inhibits both prolactin and growth hormone secretion in the rat. In terms of known neuroendocrine relationships this finding indicates that lithium administration alters both dopamine (DA) and serotonin (5-HT) activity in the hypothalamus. The data suggest that DA activity is increased (inhibiting prolactin release) and 5-HT activity is decreased (reducing growth hormone stimulation). The data are in agreement with fluorescent histological studies on the effects of chronic lithium administration and suggest that endocrine parameters may be used to provide neuropharmacological information about compounds which alter brain monoamine activity.