We examined the effect of estrogen replacement therapy (ERT) on plasma serotonin (5HT) and norepinephrine (NE) and their correlation with serum estradiol, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in 12 postmenopausal women. Plasma 5HT and NE, estrogen, progesterone, LH and FSH were examined every 4 days for 2 consecutive months (before and during ERT). Serotonin values were low (32.29±38.36 nmol/l) and showed an intrinsic spontaneous cyclicity with a nadir every 10-11 days. Plasma NE was similar to that observed during the follicular phase of the ovulatory cycle (1,216.8±503.4 pmol/l) and showed no cyclicity. ERT significantly increased mean (±SD) serum estrogen values (from 95.40±73.31 to 390.72±347.17 pmol/l, P = 0.0001), significantly decreased serum FSH (from 84.04±14.97 to 52.97±20.74 mIU/ml, P = 0.0001) and LH (from 35.35±13.82 mIU/ml to 29.69±16.46 mIU/ml, P = 0.03). Plasma 5HT levels showed a tendency to rise under the influence of ERT, but this increase was not statistically significant. Plasma NE decreased significantly from 1,216.8±503.4 to 994.1±353.89 pmol/l, P < 0.05. In conclusion, plasma serotonin in postmenopausal women has a 10-11 day cycle and is significantly lower than in the follicular phase of ovulating women. Plasma NE shows no cyclicity and is significantly decreased by ERT.
|Number of pages||5|
|Journal||Israel Journal of Medical Sciences|
|State||Published - Dec 1996|
- Estrogen replacement