Metergoline as a selective 5-hydroxytryptamine antagonist in the cerebral cortex.

In rats anaesthetized with a mixture of methoxyflurane, nitrous oxide, and oxygen, the depressant actions on the cerebral cortical neurones of iotophoretically applied 5-hydroxytryptamine (5-HT) but not of noradrenaline, histamine, AMP Ca2+, and gamma-aminobutyric acid were antagonized by metergoline. These observations indicate that metergoline may be a selective 5-HT antagonist in the cerebral cortex.