SummaryThe influence of gonadal steroids on central dopaminergic function was assessed by measuring concentrations of the dopamine metabolite homovanillic acid (HVA) in cerebrospinal fluid (CSF) in humans and monkeys. CSF HVA and 5-hydroxyindoleacetic acid (5-HIAA) concentrations were measured by high performance liquid chromatography with electrochemical detection. Thirteen intact adult female monkeys (Macaca fascicularis) and six ovariectomized monkeys had a lumbar puncture to collect CSF. Ovariectomized monkeys had higher HVA concentrations in their CSF while 5-HIAA levels remained unchanged. In a second experiment, 40 human subjects were divided into six groups as follows: I, women with menses; II, menopaused or ovariectomized women taking estrogens; III, hysterectomized women of unknown hormonal status; IV, menopaused or ovariectomized women; V, women taking dopaminergic drugs or showing signs of parkinsonism; VI, men. CSF was collected by lumbar puncture. 5-HIAA levels were constant. Hysterectomized (III) as well as menopaused or ovariectomized (IV) women had significantly (p < 0.05) higher CSF HVA concentrations compared to men. While women in group IV were older, those in group III were of the same age as the men. These results provide further evidence for the role of endogenous ovarian factors as modulators of central dopaminergic activity.