Prolactin response to d-fenfluramine in postmenopausal women on and off ERT: comparison with young women

Estrogen is thought to have an impact on both psychological well being and cognitive function. The biological basis to this is not fully understood, b ut may involve estrogen's interactions with central serotonergic (5-HT) sys tems. Therefore, we studied the effect of long-term estrogen hormone replac ement therapy (ERT) on central 5-HT tone in healthy postmenopausal women an d made comparisons with young women. Prolactin (PRL) responses to the speci fic 5-HT releasing and re-uptake inhibiting agent, d-fenfluramine, were mea sured in three groups of healthy women: 11 young, 11 postmenopausal on long -term ERT, and 11 postmenopausal ERT naive. PRL responses were significantl y decreased in ERT naive women compared to young healthy women. In contrast , PRL responses were not different between estrogen-treated and young women . Overall, there was a significant relationship between older age and lower PRL responsivity. These results suggest that central 5-HT tone is reduced in healthy postmenopausal women who are ERT naive, but not in postmenopausa l women who have received prolonged estrogen treatment. Estrogen may modula te age-related changes in 5-HT tone. This may partly explain why estrogen c an decrease vulnerability to mood disorders and cognitive changes in postme nopausal women. (C) 2001 Elsevier Science Ltd. All rights reserved.