Simultaneous measurement of plasma protein extravasation and carotid vascular resistance in the rat.

Stimulation of the right trigeminal ganglion in pentobarbital anaesthetised rats increased mean arterial blood pressure and decreased right carotid vascular resistance but had no effect on left carotid vascular resistance. Sumatriptan (0.3 mg/kg i.v.) pretreatment did not significantly affect basal levels or stimulation induced changes in blood pressure or carotid vascular resistance. Trigeminal stimulation produced plasma protein extravasation (measured using a fluorescent marker) into the dura mater on the ipsilateral side which was significantly reduced by sumatriptan. These studies show that sumatriptan can reduce plasma protein extravasation while having no measurable effect on total carotid blood flow.