Objective To assess the effects of level changes of 5-hydroxytryptamine (5-HT) and dopamine (DA) in cerebral microvasculature on occurrence of secondary damage in traumatic brain injury in rats.

    Methods The level changes of 5-HT and DA in the cerebral microvasculature were determined with high performance liquid chromatography using electrochemical detector (HPLC-ECD).

    Results The levels of 5-HT and DA in the cerebral microvasculature were significantly elevated 30 minutes after brain injury (P?.01) and gradually decreased and were lower than the control level 48 to 72 hours postinjury. The water content of brain tissue was significantly increased 30 minutes postinjury and came down to the control level 168 hours after injury.

     ......