Effects of 5-hydroxytryptamine, fluoxetine and chlorimipramine on reflex bradycardia in rats

In the urethane-anaesthetized rat, increasing 5-hydroxytryptaminergic receptor activity or functional 5-HT in brain with either the specific inhibitors of 5-HT reuptake (e.g. fluoxetine and chlorimipramine) or the 5-HT itself greatly reduced the reflex bradycardia induced by the systemically administered adrenaline. The data indicate that activation of central 5-HT-ergic receptors tends to inhibit reflex bradycardia.