Regulation of glial cell line-derived neurotrophic factor expression by electroacupuncture after transient focal cerebral ischemia

The present study was designed to investigate whether electroacupuncture (E A) is able to regulate glial cell line-derived neurotrophic factor (GDNF) e xpression following transient middle cerebral artery occlusion (MCAO) using reverse transcriptase polymerase chain reaction and immunohistochemistry i n rats. The results indicate that after 2 h MCAO, GDNF mRNA and immunoreact ivity profoundly increased in peri-infarct cerebral cortex, with peaks at 2 h after reperfusion, then declined dramatically at 12 and 24 h after reper fusion. Although EA given immediatelly after MCAO couldn't elevate the peak s of GDNF expression, it obviously raised the GDNF mRNA and immunoreactivit y levels at 12 h after reperfusion, delayed the declining trends of GDNF mR NA and immunoreactivity levels. These results suggest that EA could upregul ate GDNF expression after ischemic insult, elongating the duration of upreg ulated GDNF expression. This may be one of the mechanisms of EA anti-ischem ic injury by augmenting endogenous protective mechanism.