Liposomes obtained from bovine brain cortex phospholipids (BC-PL), which display several effects on brain function in mice, have been administered intravenously (200 mg) to healthy subjects at various times before diagnostic lumbar puncture. HVA and 5-HIAA concentrations in CSF have been evaluated with the aim of assessing changes of monoamines metabolism. An increase of HVA occurs after 2 hours from BC-PL administration, reaching its peak after 6--7 hours. The finding is interpreted as an index of an increased turnover of brain DA. 5-HIAA changes are less impressive and a smaller increase of the metabolite is observed. They cannot correctly be related to brain changes of serotonin metabolism, since 5-HIAA originates also from the spinal cord. No effects are observed on the secretion of prolactin, but somatotropin increases sharply between 2 and 7 hours from treatment, suggesting the possibility of an activation of the dopaminergic pathway, stimulating STH secretion.