RESUMO
The neuroendocrine effects of the 5-HT receptor agonist, sumatriptan (6 mg subcutaneously), were studied in 11 healthy male subjects using a placebo-controlled, cross-over design. Compared to placebo, sumatriptan significantly lowered levels of plasma prolactin but increased those of plasma growth hormone. There was no effect on plasma cortisol concentrations. The neuroendocrine effects of sumatriptan differ from those of previously described 5-HT-receptor agonists, and may be a consequence of selective activation of 5-HT1D or 5-HT1B receptors. However, the present data cannot exclude the possibility that the neuroendocrine changes reflect nonspecific stress responses or changes in pituitary blood flow.
Assuntos
Sistemas Neurossecretores/efeitos dos fármacos , Sumatriptana/farmacologia , Adulto , Método Duplo-Cego , Hormônio do Crescimento/sangue , Humanos , Hidrocortisona/sangue , Masculino , Prolactina/sangue , Sumatriptana/efeitos adversosRESUMO
We studied the effect of the tricyclic antidepressant lofepramine (140-210 mg daily for 16 days) on 5-hydroxytryptamine 1A (5-HT1A) receptor sensitivity in healthy volunteers, using a buspirone neuroendocrine challenge paradigm (30 mg orally). We also studied the effect of lofepramine on platelet 5-HT content and sleep architecture. Lofepramine treatment did not alter the hypothermic, endocrine or amnesic effects of buspirone but significantly lowered platelet 5-HT content and decreased rapid eye movement sleep. Our findings suggest that at clinically used doses, lofepramine inhibits the uptake of 5-HT and produces changes in sleep architecture characteristic of tricyclic antidepressants. However, lofepramine does not appear to alter the sensitivity of 5-HT1A receptors.
