Evidence for a physiological reduction in brain dopamine but not norepinephrine metabolism during the preovulatory phase in normal women.
To investigate the role of brain catecholamine (CA) activity in the mechanisms related to physiological ovulatory function, we used high-performance liquid chromatography with electrochemical detector to measure the levels of urinary dopamine (DA), norepinephrine (NE), epinephrine (E), vanillylmandelic acid (VMA), homovanillic acid (HVA), 3,4-dihydroxyphenylacetic acid (DOPAC), and total 3-methoxy-4-hydroxy-phenylglycol (MHPG) in a group of 12 normal women during both the early follicular and pre-ovulatory phases of the menstrual cycle. The mean (+/- SEM) concentrations of HVA and DOPAC were significantly lower (P less than 0.001) during the pre-ovulatory phase than during the early follicular phase, whereas those of DA, NE, E, VMA and total MHPG were unaltered. A significant negative correlation between urinary HVA and plasma LH (r = -0.70, P less than 0.01) was also found during the pre-ovulatory period, whereas no significant negative correlations were found between urinary HVA and plasma PRL, progesterone and oestradiol. These data show: 1) reduced brain DA activity and 2) unchanged brain NE activity at the time of the midcycle surge in normal women, suggesting a physiological variation of the central DA metabolism in ovulatory function.
Paradisi
R
R
Institute of Reproductive Physiology and Pathology, University of Bologna, Italy.
Grossi
G
G
Venturoli
S
S
Capelli
M
M
Magrini
O
O
Porcu
E
E
Pasquali
R
R
Flamigni
C
C
D015102:3,4-Dihydroxyphenylacetic Acid / Q000652:urine; D000328:Adult; D001921:Brain / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D005498:Follicular Phase; D012739:Gonadal Steroid Hormones / Q000097:blood; D006719:Homovanillic Acid / Q000652:urine; D006801:Humans; D009638:Norepinephrine / Q000378:metabolism*; D010908:Pituitary Hormones, Anterior / Q000097:blood
D012739:Gonadal Steroid Hormones; D010908:Pituitary Hormones, Anterior; D015102:3,4-Dihydroxyphenylacetic Acid; D004298:Dopamine; D009638:Norepinephrine; D006719:Homovanillic Acid