OBJECTIVES: Acupuncture has been known to be effective in ischemia, and glutamate excitotoxicity is an important factor for the neuronal cell death. We examined the effect of acupuncture on glutamate level in the ischemic stroke model. METHODS: A global ischemia was induced using the method of 11-vessel occlusion in rat. Rats were randomly divided into two groups: the control group (n=5, with 11-vessel occlusion) and the acupuncture group (n=5, with 11-vessel occlusion + acupuncture). The extracellular glutamate level was assessed using an intracerebral biosensor system measuring 256 samples per second. Simultaneously, the cerebral blood flow was measured and the electroencephalogram data were recorded. The time schedule of the experiment was as follows: 10 minutes of baseline measurement, 10 minutes of occlusion and 30 minutes of follow-up monitoring. Acupuncture stimulation was applied to the acupuncture points GB34 (Yangneungcheon) and GB39 (Hyeonjong) during the occlusion period. RESULTS: In the control group, the extracellular glutamate level was changed as 135.19 +/- 23.76 microM (mean +/- standard deviation) from the baseline level. However, this increase was suppressed in the acupuncture group (72.20 +/- 27.15 microM, p<0.01 versus the control group). The changes of cerebral blood flow and electroencephalogram were not significantly different between the groups. DISCUSSION: This result suggests that the effect of acupuncture might be closely associated with modulation of the brain glutamate release in the ischemic condition.

OBJECTIVES: Acupuncture has been known to be effective in ischemia, and glutamate excitotoxicity is an important factor for the neuronal cell death. We examined the effect of acupuncture on glutamate level in the ischemic stroke model. METHODS: A global ischemia was induced using the method of 11-vessel occlusion in rat. Rats were randomly divided into two groups: the control group (n=5, with 11-vessel occlusion) and the acupuncture group (n=5, with 11-vessel occlusion + acupuncture). The extracellular glutamate level was assessed using an intracerebral biosensor system measuring 256 samples per second. Simultaneously, the cerebral blood flow was measured and the electroencephalogram data were recorded. The time schedule of the experiment was as follows: 10 minutes of baseline measurement, 10 minutes of occlusion and 30 minutes of follow-up monitoring. Acupuncture stimulation was applied to the acupuncture points GB34 (Yangneungcheon) and GB39 (Hyeonjong) during the occlusion period. RESULTS: In the control group, the extracellular glutamate level was changed as 135.19 +/- 23.76 microM (mean +/- standard deviation) from the baseline level. However, this increase was suppressed in the acupuncture group (72.20 +/- 27.15 microM, p<0.01 versus the control group). The changes of cerebral blood flow and electroencephalogram were not significantly different between the groups. DISCUSSION: This result suggests that the effect of acupuncture might be closely associated with modulation of the brain glutamate release in the ischemic condition.

We hypothesize that one mechanism of the anti-epileptic effect of the ketogenic diet is to alter brain handling of glutamate. According to this formulation, in ketotic brain astrocyte metabolism is more active, resulting in enhanced conversion of glutamate to glutamine. This allows for: (a) more efficient removal of glutamate, the most important excitatory neurotransmitter; and (b) more efficient conversion of glutamine to GABA, the major inhibitory neurotransmitter.

Low-intensity swimming training, started at an early age, was undertaken to observe glycemic control in hypothalamic obese mice produced by neonatal monosodium l-glutamate (MSG) treatment. Although swimming exercises by weaning pups inhibited hypothalamic obesity onset and recovered sympathoadrenal axis activity, this event was not observed when exercise training is applied to young adult mice. However, the mechanisms producing this improved metabolism are still not fully understood. Current work verifies whether, besides reducing fat tissue accumulation, low-intensity swimming in MSG-weaned mice also improves glycemic control. Although MSG and control mice swam for 15 min/day, 3 days a week, from the weaning stage up to 90 days old, sedentary MSG and normal mice did not exercise at all. After 14 h of fasting, animals were killed at 90 days of age. Retroperitonial fat accumulation was measured to estimate obesity. Fasting blood glucose and insulin concentrations were also measured. Mice were also submitted to ipGTT. MSG obese mice showed fasting hyperglycemia, hyperinsulinemia, and glucose intolerance and insulin resistance. However, the exercise was able to block MSG treatment effects. Higher total cholesterol and triglycerides observed in MSG mice were normalized by exercise after weaning. Exercised MSG animals had higher HDLc than the sedentary group. Data suggest that early exercise training maintains normoglycemia, insulin tissue sensitivity, and normal lipid profile in mice programmed to develop metabolic syndrome.