Real time monitoring of extracellular glutamate release in rat ischemia model treated by traditional acupuncture

It is generally thought that cerebral ischemia is associated with extracellular concentrations of the excitatory amino acids. Stroke, one of leading causes of death and long-lasting disabilities, in acupuncture medicine field has been treated with acupuncture in Korea, which is known as a physiological therapeutic modality. Real time quantitative measurement of glutamate would be very helpful for evaluation brain injury during or after surgery, as well as validation of the instantaneous effect of acupuncture. For in-vivo glutamate measurements, we prepared the eleven vessel occlusion (11VO) in rat model. Changes in cerebral cortical blood flow were monitored by laser-Doppler flowmetry simultaneously with cortical glutamate levels by amperometric biosensor. A ten minute 11VO cerebral ischemia was initiated by pulling the snares on the common carotid arteries (CCAs) and the external carotid arteries (ECAs). Acupuncture at the acupoints of bilateral GB34 and GB39 based on the classical literature, was conducted during the ischemic period for 10 min. In comparison with the acupuncture and non-acupuncture group, peak concentration and the area under the curve(AUC) of glutamate release showed statistically significant difference between two groups. It is considered that the decrease of extracellular glutamate level in treated group is attributed to neuroprotective effect by acupuncture.