Changes in brain catecholamine metabolism during bromocriptine treatment in polycystic ovary syndrome

The role of dopaminomimetic drugs on the brain catecholamine metabolism in the neuroendocrine regulation of the polycystic ovary syndrome (PCO) was investigated. We measured, besides peptide hormones and sex steroids, urinary dopamine (DA), norepinephrine, epinephrine, vanillylmandelic acid, homovanillic acid (HVA), 3,4-dihydroxyphenylacetic acid (DOPAC) and total 3-methoxy-4-hydroxyphenylglycol (MHPG) levels by high-performance liquid chromatography with electrochemical detector in 10 women with PCO before and during long-term bromocriptine (BRC) administration. HVA and DOPAC concentrations were significantly lower (p < 0.001) in PCO patients compared with 12 control subjects in the early follicular phase, whereas MHPG concentrations were significantly higher (p < 0.01) in PCO patients. During BRC administration, HVA, DOPAC and MHPG levels increased significantly (p < 0.01 for HVA and DOPAC, and p < 0.05) for MHPG), prolactin levels dropped markedly (p < 0.01), whereas luteinizing hormone levels did not change (p = NS). These data show (1) a reduced DA activity in PCO which may be normalizable under BRC treatment, but also (2) no major effects of DA metabolism on the inappropriate gonadotropin secretion of the syndrome.