Peripheral dopamine metabolism in polycystic ovary syndrome

It has been proposed that a relative dopamine deficiency or an increased sensitivity of the gonadotrope to dopamine may explain the elevated luteinizing hormone (LH) levels characteristic of polycystic ovary syndrome. To study one aspect of this issue, that of peripheral dopamine metabolism in polycystic ovary syndrome, we measured the conversion of dopamine to norepinephrine after intravenous dopamine infusions in women with polycystic ovary syndrome and in matched controls. In addition, we measured urinary metabolites of dopamine and norepinephrine, which reflect in part central catecholamine turnover, after daily ingestion of L-dopa with carbidopa, which increases brain dopamine levels. After dopamine infusion in women with polycystic ovary syndrome and in matched controls, steady state levels of plasma dopamine, norepinephrine, and the ratio of dopamine/norepinephrine were similar in the two groups. Similarly, urinary metabolites of dopamine, norepinephrine, and their ratios were not different in patients and controls after L-dopa with carbidopa. We suggest that no major alterations in dopamine metabolism exist in these patients with polycystic ovary syndrome.