[Effect of electroacupuncture on expression of gamma-glutamylcysteine synthetase protein and mRNA in cerebral cortex in rats with focal cerebral ischemia-reperfusion].

ABSTRACT

OBJECTIVE: To observe the effect of electroacupuncture (EA) of "Baihui" (GV 20) and "Dazhui" (GV 14) on the expression of gamma-glutamylcysteine synthetase (gamma-GCS) protein and gene in the cerebral cortex in rats with cerebral ischemia-reperfusion (CI/R) injury, so as to explore its molecular biological mechanism underlying anti-oxidative stress. METHODS: A total of 30 male Sprague-Dawley rats were randomized into sham operation (sham, n = 10), model (n = 10), and EA (n = 10) groups. CI/R model was established by right middle cerebral artery occlusion (modified Longa's thread occlusion method) for 2 hours and reperfusion for 24 hours. EA (3 Hz, 1-3 mA) was applied to "Dazhui" (GV 14) and "Baihui" (GV 20) for 30 min. gamma-GCS protein expression of the parietotemporal region of cerebral cortex was detected by immunohistochemistry and gamma-GCS heavy subunit (gamma-GCSh) mRNA and gamma-GCS light subunit (gamma-GCSI) mRNA expression levels were assayed by real-time quantitative polymerase chain reaction (RT-PCR). RESULTS: Compared with the sham group, the expression levels of gamma-GCS protein in the pyramidal cell layer of the cerebral cortical parietotemporal region, and y-GCSh mRNA and gamma-GCSI mRNA, and the number of gamma-GCS immuno-reaction positive cells had no remarkable changes in the model group (P > 0.05), while in comparison with the model group, the expression levels of cerebral cortical gamma-GCS protein, and gamma-GCSh mRNA and gamma-GCSI mRNA, and the number of gamma-GCS immuno-reaction positive cells were increased considerably in the EA group (P < 0.01, P < 0.05). CONCLUSION: EA of GV 20 and GV 14 can upregulate expression levels of gamma-GCS protein, gamma-GCSh mRNA and gamma-GCSI mRNA of the cerebral cortical parietotemporal region in CI/R rats, which may contribute to its effect in protecting cerebral cortical cells from injury by clearing away excessive oxygen free radicals.