| Objective: This study aimed to observe the effect of local mild hypothermia(LMH)on neural dysfunction scores(NDS),morphology changes surrounding hematoma,neuron-specific enolase(NSE)and s-100? concentration changes in serum after acute intracerebral hemorrhage(ICH)in rats,explore the possible mechanisms of LMH on the protection of nervous function to appraise their value in the early diagnosis of brain injury and relation with clinical outcome,in order to provide more evidence for the clinical treatment of LMH.Method:(1)According to the random number table method,60 male SD rats were divided into 3 groups: sham operation group,homoeothermy on ICH group,LMH on ICH group,n=20;every group was averagely divided into four group as 6h,1d,3d,7d subgroup.(2)Autologous blood was injected into the basal ganglia in the homoeothermy group and the LMH group after narcosis.30 minutes later,a right head cooling therapeutic instrument was introduced into the LMH group immediately after the injection.(3)The success of ICH model was estimated by performing the neural behavioral scores of rats in each group at 6h,1d,3d,7d after operation.(4)6h group rats were continually cooled 3h,while other group rats were continually cooled 3h in the fixed time every day.The timbal temperature was used to represent the brain temperature and maintained between 32 ?and 33?.The homoeothermy group and sham operation group didn't receive LMH and their timbal temperature was maintained between 36 and 3? 7?.(5) After injected, using the Garcia's score method to evaluate neural dysfunction defect of the 3 groups at each time.(6) Then the rats were killed to get blood from blood vessels of the neck to detect NSE and s-100? with enzyme linked immunosorbent assay(ELISA) method after ICH 6h, 1d, 3d, 7d. The coronal slides of cerebral tissue were stained by hematoxylin-eosin.(7) All statistical analyses were performed by SPSS 17.0. Significance was set at p<0.05. Result:(1) Garcia's score showed neurological deficit occurred after ICH and the symptoms reached a peak at 3d. NDS of sham operation group were higher than other 2 groups(p<0.05); neurological deficits of LMH on ICH group were higher than homoeothermy group(p<0.05).(2) Brain tissue morphology changes surrounding hematoma: in sham operation group, structure of brain tissue was complete. Their nucleus and cytoplasm were uniform. In homoeothermy ICH group, nerve cells around the hematoma were edematous. A large number of red blood cells and a few inflammatory cells were visible at 6h, 1d. Then their necrosis, nuclear condensation, the decrease of red blood cells, the increase of inflammatory cells and a few glial cell proliferations were observed at 3d. The brain neurons of edema and inflammatory cells obviously decreased and glial cells increased at 7d. In LMH on ICH group, the expression was similar in homoeothermy ICH group at 6h, 1d. The swelling range of nerve cell necrosis were less than the homoeothermy intracerebral hemorrhage group and still visible a few inflammation cell infiltration and proliferation of glial cells at 3d, 7d.(3) There was significant difference between operation group and sham operation group of the serum NSE and s-100? concentrations after ICH at each time in rats(p<0.05). The operation group in group 3d NSE and s-100? concentrations were the highest in the same group at each time(p<0.05). Compared with homoeothermy on ICH group, the NSE and s-100? concentrations in serum in the LMH on ICH group were statistically significant(p<0.05).(4)NSE concentration changes in serum with NDS showed negative correlation at each time(p<0.05). S-100? protein concentration changes in serum with NDS showed negative correlation at each time(p<0.05). NSE concentration changes in serum with s-100? protein showed positive correlation at each time(p<0.05). Conclusion:(1) Autologous blood injection without anticoagulant rat caudate nucleus model of ICH is accurate location, reproducible and high success rate.(2) NSE and s-100? protein levels are negatively correlated with neurological function after ICH. They can comprehensively evaluate the severity of the brain damage after ICH.(3) LMH on brain damage following ICH makes an important impact on therapy. It helps mitigate neural defect and improve prognosis. Its protective mechanism may relate to reduce NSE and s-100? protein concentrations. |
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