Effects of dopamine on cortical blood flow and somatosensory evoked potentials in the acute stages of cerebral ischemia.

Effects of intravenous infusion of dopamine on local cortical blood flow (CBF) and somatosensory evoked potentials (SEP) was evaluated using canine cerebral ischemia, which was produced by middle cerebral artery occlusion. CBF was monitored with a H2 clearance method and SEP. P1 to N1 peak to peak amplitude (V1) was recorded by stimulating the sciatic nerve on the contralateral side. CBF and SEP recovered at doses of 5 and 10 gamma, despite almost no increase of systemic arterial pressure. CBF and SEP were restored at doses of dopamine of 20 and 30 gamma, with an increase of mean systemic arterial pressure 5 to 15 mm Hg and similar results were obtained at doses of 25 gamma. Recovery of SEP was slight at extremely high doses of dopamine (65 gamma), despite a definite increase of mean systemic arterial pressure (MSAP) and CBF.