Changes in Brain Catecholamine Metabolism during Bromocriptine Treatment in Polycystic Ovary Syndrome

Abstract

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.

Peripheral catecholamine alterations in adolescents with polycystic ovary syndrome

“…A number of studies in adult PCO patients (Paradisi et al, 1989;Yoshino et al, 1992;Shoupe & Lobo, 1984) have also shown urinary levels of catecholamines and VMA within the control range but to our knowledge plasma levels of catecholamines or Dopa have not been reported previously in PCO. A number of studies in adult PCO patients (Paradisi et al, 1989;Yoshino et al, 1992;Shoupe & Lobo, 1984) have also shown urinary levels of catecholamines and VMA within the control range but to our knowledge plasma levels of catecholamines or Dopa have not been reported previously in PCO.…”

“…These findings were interpreted as supporting the suggestion of both decreased dopaminergic control of LH secretion and increased noradrenergic activity in hypothalamic GnRH neurons in PCO syndrome. (Paradisi et al, 1993;Yoshino et al, 1992;Shoupe & Lobo, 1984). Nevertheless, further research in the field has cast some doubts on these interpretations.…”

“…Altered central catecholamine metabolism leading to inappropriate gonadotrophin secretion has been suggested as a possible cause of PCO, even though contradictory data have been reported (Lobo et al, 1983). (Paradisi et al, 1993;Yoshino et al, 1992;Shoupe & Lobo, 1984). These findings were interpreted as supporting the suggestion of both decreased dopaminergic control of LH secretion and increased noradrenergic activity in hypothalamic GnRH neurons in PCO syndrome.…”

Impaired Cardiometabolic Effects of Bromocriptine in Men With Early‐Onset Androgenic Alopecia

“…[25][26][27] Beneficial effects of bromocriptine on glucose and lipid metabolism are mediated by an increase in dopaminergic tone within the central nervous system, 25 and this drug was also found to stimulate central dopaminergic transmission in women with polycystic ovary syndrome. 26 Interestingly, abnormalities in pituitary hormone secretion in polycystic ovary syndrome seem to be a consequence of relative central dopaminergic failure. 27 A similar failure may also occur in men with early-onset androgenic alopecia because their hormonal profile resembles that of women with polycystic ovary syndrome.…”

“…The obtained results may be also associated with a different effect of bromocriptine on insulin sensitivity, which was stronger in men with normal hair growth than in men with early‐onset androgenic alopecia, as well as correlating positively with the extent of changes in uric acid, hsCRP, fibrinogen, homocysteine, and UACR. Moreover, they may result from the impact on dopaminergic transmission 25–27 . Beneficial effects of bromocriptine on glucose and lipid metabolism are mediated by an increase in dopaminergic tone within the central nervous system, 25 and this drug was also found to stimulate central dopaminergic transmission in women with polycystic ovary syndrome 26 .…”