[The role of the sympathetic nervous system and adrenals in hemodynamic changes after intracerebroventricular administration of 5-hydroxytryptamine in rats].

Recently, the role of the serotonergic nervous system has been implicated in blood pressure regulation and in the pathogenesis of hypertension. However, the effects of 5-hydroxytryptamine (5-HT) administration on hemodynamics have been notoriously inconsistent and the precise mechanism of the blood pressure regulation of the serotonergic nervous system has not been elucidated yet. In our previous study, we demonstrated that the intracerebroventricular (i.c.v.) administration of 5-HT in rats elicited consistent pressor response with concomitant increase in plasma norepinephrine and that the pressor response was abolished by systemic pretreatment of phenoxybenzamine or by serotonin receptor antagonist, methysergide. The purpose of this experiment is to investigate further the relationship between the sympathetic nervous system and the serotonergic nervous system.