RESUMO
BACKGROUND: Acupuncture in Chinese traditional medicine improves capacity of brain on resisting injury and accelerates injury repair in treatment of ischemic brain injury.OBJECTIVE: To observe the expressions of cerebral nerve growth factor (NGF) and choline acetyltransferase after simultaneous stimulation with electroacupuncture on Baihui (GV 20) and Dazhui (GV 14) so as to probe into the protection of electroacupuncture on hypoxia-ischemia brain injury.DESIGN: Randomized controlled experiment.SETTING: Department of Life Science in Zhengzhou Normal High Training School.MATERIALS: The experiment was performed in Human Anatomy Department of Basic Medical College of Zhengzhou University, in which, 50 cleangrade neonatal Wistar rats of 7 days old were employed and randomized into sham-operation group (10 rats), model control (20 rats) and electroacupuncture group (20 rats). Hypoxia cabin was self-made with constant pressure, 40 cm ×50 cm×60 cm in size, with two small holes of 2 cm ×2 cm for each to connect with the external. Soda lime was used to absorb moisture and CO2 in the cabin.The model was not prepared in sham-operation group. In model control and electroacupuncture group, hypoxia-ischemia model was set up. After modeling, the rats in two groups were recovered for 1 to 4 hours at room temperature; afterwards, hypoxia management was performed. The rats were placed in hypoxia cabin with constant pressure at constant temperature of 37 ℃, inputting O2 8 mL/L and mixed gas 920 mL/L, 1.5 L/minute; 2hours later, the rats were returned back to female rats for lactation continuously. In electroacupuncture group, on the 2nd day after modeling, a filiform needle of one cun was used to insert Baihui (GV 20) (midpoint of parietal bone) subcutaneously and Dazhui (GV 14) (between C7 and T1, on the midline of back). Electric stimulation was done simultaneously on two points with continuous wave, 16 Hz in frequency, 10V in intensity, retaining for 10 minutes, once per day, 10 days made 1 course, totally two courses at interval of 2 days. In model control, no any treatment was given group, 22 days after hypoxia and ischemia, the rats were anesthetized and sacrificed and brain tissue on the left side was collected to prepare paraffin slices. Immune positive cell was counted on slices of each group under optic microscope. For evaluation on the function of brain nerve cell, hippocampus was selected to count the positive cells of choline acetyltransferase. On each brain slice, 5 visual fields were randomized to calculate the average of positive cells. For evaluation on injury repair of nerve tissue, cortex and hippocampus were selected to count positive cells of cerebral NGF. The method was same as the above.MAIN OUTCOME MEASURES: Immune positive cell expressions of choline acetyltransferase and cerebral NGF in brain tissue after electric stimulation in neonatal rats.ferase in brain hippocampus: Compared with sham-operation group, that in model control was lower remarkably, but, there was no obvious change in electroacupuncture group [(24.46±8.24), (13.96±7.62), (25.54±5.05) pcs/visual field, P ＜ 0.05, P ＞ 0.05]; that in electroacupuncture group was of cerebral NGF in cerebral cortex and hippocampus: Compared with sham-operation group, that in both model control and electroacupuncture was increased remarkably [(14.14±6.11), (24.49±8.31), (31.35±9.92) pcs/visual field, P ＜ 0.05; (13.42±5.56), (21.93±5.12), (27.63±7.15) pcs/visual field, P ＜ 0.05], of which, that in electroacupuncture group was higher than model control (P ＜ 0.05).CONCLUSION: Electroacupuncture stimulates central cholinergic nerve system into positive active state in hypoxia-ischemia animals, increases cerebral nerve growth factor in quantity and enhances nerve repair of hypoxia-ischemia animals.