Platelet serotonin content and plasma tryptophan in peri‐ and postmenopausal women: variations with plasma oestrogen levels and depressive symptoms

Abstract

Platelet serotonin content was measured by high pressure liquid chromatography in 56 peri and postmenopausal women, in order to study variations of this parameter with hormonal status and depressive mood symptoms. Clinical symptoms were assessed by a self-report depression symptom scale (CES-D of NIMH). Thirty-eight women with a score of 16 or more were considered as presenting depressive symptoms (mean score ± SD = 28·8 ± 10·5), while the others formed the control group (n= 18, score = 4·4 ± 4·2). Platelet serotonin contents were significantly lower in the ‘depressed’ group (0·302 ± 0·010 vs. 0·366 ± 0·020 nmol 10^-8 platelets, x̄+ SEM, P< 0·001 by Mann-Whitney U-test). In ‘depressed’ women who had been treated for one or more depressive episodes, platelet 5-HT contents (0·283 ± 0·023, n= 18, P-8 platelets did not differ significantly from controls but serotonin expressed in nmol ml^-1 of blood was slightly lower than control values (0·890 ± 0·085, n= 20 vs. 1·088 ± 0·090 nmol ml^-1, n= 18, P-1 showed lower LH values in ‘depressed’ than in ‘non-depressed’ women (19·6 ± 2·2, n= 23 vs. 26·1 ± 1·9 mIU ml^-1, n= 9, x̄± SEM, P<0·01). Variations in platelet 5-HT content did not appear to be secondary to alteration of plasma-free and total tryptophan since no modifications of these parameters were detected either with depressive symptoms or with plasma oestrogen concentrations.