| Background: ischemic stroke is major cause of death and leading cause of disability wordwhile. It is very important of neuroprotective therapy in ischemic stroke. However, the clinical trials of Neuroprotective effect have had limited success. One of the reasons for the failure of trials of neuroprotection in ischemic stroke may be only concerned about gray matter protection and the lack of white matter protection. It has been confirmed that injury of cerebral white matter is a major cause of functional disability in srtoke, and moreover, white matter can be damaged even by brief ischemia. The treatment of acupuncture on injured cerebral axon has proven some efficacy in clinical practice. It is unknown whether acupuncture produces therapeutical effect by protection on injured cerebral myelin in ischemic stroke.Purpose: Establish focal cerebral ischemia-reperfusion model in rats, and study on protective effect of acupuncture on injured cerebral myelin in ischemic stroke rats.Methods: (1) 141 adult clean male Sprague-Dawley rats (body weight, 250-300g) were employed in the study, which were randomly divided into 5 groups including normal (N, n=12), sham-operated (C, n=21), ischemia-reperfusion model (non-acupuncture group, C+, n=36), early acupuncture (E2, n=36) and late acupuncture (E3, n=36) groups by random digits table. (2) Focal cerebral ischemia-reperfusion model was established by middle cerebral artery occlusion (MCAO) on the right side with modified thread embolism method. Xingnao kaiqiao needling method was applied for treatment of E2 and E3 groups on different time after ischemia. E2 group received the first acupuncture treatment when ischemia continued for 30 min. E3 group received the first acupuncture treatment while reperfusion came true by pulling out the thread after ischemia keeping for 2 h. The rats of N, C+, C. groups didn't receive acupuncture treatment, only fixed with rat clamp for the same time as acupuncture group. (3) The content of serum myelin basic protein (MBP), neurological assessment, remyelination of ischemic focus and expression of MBP gene were observed continuously by using the methods of ELISA, Neurologic functional impairment scores, Pal-Weigert's myelin staining, Semiquantitative RT-PCR and Real-time fluorescent quantitative PCR (FQ-PCR) in all groups before operation and on 1 d,3 d,5 d,7 d after operation respectively. (4) In addition, 2.5 h after operation was also added as an observing point in order to compare functional recovery of acupuncture group with non-acupuncture group better.Results: (1) Compared with 0 h, which is before operation, the content of serum MBP in non-acupuncture (C+) group was increased obviously (P<0.05), reaching peak (54.287±3.170 vs 1.447±0.079) on 3rd day; neurological functional impairment scores descended slowly (P<0.05), and the score was 2.8±0.447 at 2.5h and 2.2±0.447 on 3rd day; massive demyelination happened and slow remyelination could be also observed in the internal capsule (IC); expression of ischemic focus MBP mRNA rose gradually, the data on 7th day was (1.03±0.023 vs 0.52±0.016) (P<0.05) by RT-PCR method and (6.96±0.111 vs 1.22±0.424) (P<0.05) by FQ-PCR method. (2) Compared with non-acupuncture group, at other appointed time except 0 h, the content of serum MBP of acupuncture group was much lower (P<0.05), and the peak was 13.838±1.094 in early acupuncture group and 18.946±3.387 in late acupuncture group; neurological impairment scores descended faster, both scores of E2 and that of E3 groups were 1.6±0.548 on 3rd day (P<0.05); the extent of demyelination in IC lessened distinctly and remyelination was apparent; expression of ischemic focus MBP mRNA rose rapidly (P<0.05), the data of E2 group on 7th day was (1.95±0.0241 vs 1.03±0.023) by RT-PCR and (17.90±0.258 vs 6.96±0.111) by FQ-PCR, the data of E3 group on 7th day was (1.45±0.071 vs 1.03±0.023) by RT-PCR and (13.13±0.263 vs 6.96±0.111) by FQ-PCR. (3) Compared with E3 group, the content of serum MBP in E2 group reached peak on 5th day, and in E3 group reached on 3rd day; neurological impairment scores descended faster, the difference(0.6±0.548 vs 1.2±0.447) between E2 and E3 group on 7th day was significant statistically (P<0.05), but the difference (0.8±0.447 vs 1.2±0.447) between E3 and non-acupuncture group at the same time was not significant statistically (P>0.05); demyelination in IC seemed less on 1st d in E2 group; the expression of ischemic focus MBP mRNA rose higher and faster in the E2 group (P<0.05), the data on 7th day was (17.90±0.258 vs 13.13±0.263) by FQ-PCR. Conclusions: These results suggest:(1) The operation of establishing MCAO model with modified thread become easier to succeed by improving the method of making focal cerebral ischemia-reperfusion model.(2) Ischemia injury may activate cerebral plasticity potential in some degree.(3) Acupuncture could affect dynamic variation of the content of serum MBP in ischemic stroke rats.(4) The neuroprotective effect of acupuncture on injured cerebral myelin in ischemic stroke rats exists. The acupuncture treatment could make for neurological functional recovery by stimulating transcription of MBP gene obviously, increasing the synthesis of MBP and promoting remyelination of the ischemic focus.(5) Acupuncture treatment begins earlier and the neuroprotective effect on myelin is larger after focal cerebral ischemia.(6) In view of some aspects of serology, morphology and neurological impairment scores and gene transcription level, it showed that acupuncture has neuroprotective effect on injured cerebral myelin in ischemic stroke in our study, but we still need more research to verify it further.
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