In order to demonstrate the suggested failure of the serotoninergic system in human obesity and to evaluate the role of central serotoninergic activity in prolactin (PRL) and thyroid stimulating hormone (TSH) release in this condition, 13 euthyroid obese and 9 healthy women of normal weight were studied. A TRH test (200 μg i.v.) was performed before and after administration of fenfluramine (FF) 60 mg b.d. for 14 days. In the controls, FF did not modify the expected significant increase in PRL induced by TRH. In obese patients, however, the PRL levels was significantly increased after TRH but the increase was less than in the controls. After FF, the PRL response to TRH was larger than in the pretreatment phase, with values similar to those observed in normal subjects. In neither group FF did change the TSH-stimulating effect of TRH, but the hormonal response in obese patients was greater than in the controls. The restoration of the responsiveness of PRL to TRH after central serotoninergic stimulation confirms the hypothesis that a failure of the serotoninergic system may occur in human obesity. Since FF does not interfere with the secretory pattern of basal and stimulated TSH in normal or obese patients, the serotoninergic system does not seem to play a major role in the control of TSH secretion.
Effects of fenfluramine on prolactin and thyrotropin stimulating hormone response to thyrotropin-releasing hormone in obese and in normal women
BERNINI, GIAMPAOLO;MONZANI, FABIO;
1990-01-01
Abstract
In order to demonstrate the suggested failure of the serotoninergic system in human obesity and to evaluate the role of central serotoninergic activity in prolactin (PRL) and thyroid stimulating hormone (TSH) release in this condition, 13 euthyroid obese and 9 healthy women of normal weight were studied. A TRH test (200 μg i.v.) was performed before and after administration of fenfluramine (FF) 60 mg b.d. for 14 days. In the controls, FF did not modify the expected significant increase in PRL induced by TRH. In obese patients, however, the PRL levels was significantly increased after TRH but the increase was less than in the controls. After FF, the PRL response to TRH was larger than in the pretreatment phase, with values similar to those observed in normal subjects. In neither group FF did change the TSH-stimulating effect of TRH, but the hormonal response in obese patients was greater than in the controls. The restoration of the responsiveness of PRL to TRH after central serotoninergic stimulation confirms the hypothesis that a failure of the serotoninergic system may occur in human obesity. Since FF does not interfere with the secretory pattern of basal and stimulated TSH in normal or obese patients, the serotoninergic system does not seem to play a major role in the control of TSH secretion.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
