Changes in plasma catecholamine levels after insula damage in experimental stroke.

The effect of permanent occlusion of the left middle cerebral artery (MCA) on plasma catecholamine levels was investigated in chloralose-anesthetized cats. Two-5 h after occlusion of the MCA the plasma levels of norepinephrine, epinephrine and dopamine were significantly elevated (33%, 44% and 28%, respectively) compared to preocclusion levels only in animals in which the cerebral infarction involved the insular cortex. No significant changes were observed in plasma catecholamine levels in animals in which either the infarction did not involve the insula or in sham-stroked animals. These data suggest that withdrawal of inhibitory inputs from the insula on central cardiovascular regulating centers after stroke results in an increase in the activity of the sympathoadrenal system.