Imipramine receptor binding and serotonin uptake in platelets of women with premenstrual changes

Gonadal hormones are believed to be involved in the pathophysiology of premenstrual changes (PMC) possibly through their interaction with neurotransmitter systems in the brain. The serotonergic system, an important central modulator of mood and behavior which is involved in the pathophysiology of affective disorders has been suggested to play a role in the genesis of dysphoric PMC. Blood platelet serotonin (5-HT) uptake and imipramine (IMI) binding have been shown to share similarities with serotonergic mechanisms in the brain thus enabling the study of serotonergic mechanisms. In this study, we report on platelet 5-HT uptake and IMI receptor binding which were simultaneously studied in women with PMC. Subjects with PMC showed a large interindividual variability with no consistent typical pattern or change during the late symptomatic as compared to the early nonsymptomatic luteal phase. Their IMI receptor binding, however, was lower compared to controls already during the early luteal phase before they developed symptoms and was similar during the symptomatic phase. This might suggest a preexistent vulnerability to the development of dysphoric PMC that might be related to impaired gonadal hormone modulation of the serotonergic system.