Abstract
In vivo brain dialysis was applied to investigate the effects of cerebral ischemia on striatal dopaminergic neurons. Cerebral ischemia was induced in spontaneously hypertensive rats (SHR) by bilateral carotid artery ligation. Extracellular dopamine and 3.4-dihydroxyphenylacetic acid (DOPAC) were determined in the striatum of SHR during 20 min ischemia and 60 min recirculation. Striatal tissue contents of dopamine and DOPAC were also determined in sham-operated, 20 min ischemia and 20 min recirculation groups.
Dopamine in the perfusates increased remarkably to 241 times at 20 min ischemia and returned to the control level after 30 min recirculation. DOPAC decreased to 50% of the control at 20 min ischemia and increased to 211% after 40 min recirculation. Dopamine content in 20 min recirculation group increased by 9% compared with sham-operated group (p<0.05), although DOPAC was not different among the three groups.
These results indicate massive release of striatal dopamine in the acutely induced ischemic brain.
