【摘要】：目的： 建立未成熟大鼠腦白質(zhì)損傷（white matter damage,WMD）動物模型，觀察促紅細胞生成素（Erythropoietin，EPO）對2日齡缺血性腦白質(zhì)損傷大鼠腦細胞髓鞘堿性蛋白（MBP）表達及遠期學(xué)習(xí)記憶能力的影響，探討EPO對未成熟大鼠腦白質(zhì)損傷后神經(jīng)保護作用的可能機制。 方法： 將2日齡未成熟新生大鼠隨機分為正常對照組即假手術(shù)組（Sham，n=36）、模型組(BCAO，n=36)、EPO治療組(EPO，n=36)。采用雙側(cè)頸總動脈結(jié)扎術(shù)（Bilateral carotid artery occlusion，BCAO）建立缺血性腦白質(zhì)損傷動物模型。對照組只分離雙側(cè)頸總動脈，但不結(jié)扎。EPO治療組于BCAO后即刻給予腹腔注射EPO（5000u/Kg），對照組、BCAO組注射等體積生理鹽水。三組大鼠于術(shù)后24h、48h、72h和7d、14d、35d分別測量體重、腦重，HE染色觀察腦組織病理形態(tài)學(xué)改變，免疫組化染色檢測腦組織MBP蛋白的表達。術(shù)后72h采用干濕法測定腦含水量；術(shù)后35天采用Morris水迷宮試驗、跳臺試驗、閉暗試驗進行神經(jīng)行為學(xué)檢測，觀察EPO治療對腦白質(zhì)損傷未成熟新生大鼠體重、腦重、腦含水量、早期神經(jīng)行為、腦組織病理形態(tài)學(xué)、學(xué)習(xí)記憶能力及MBP蛋白表達的影響。 結(jié)果： （1）模型組大鼠體重、腦重增長不良，各時間點EPO治療組大鼠體重、腦重增長明顯高于模型組，與模型組比較差異有顯著性（P＜0.05）；各時間點EPO治療組大鼠體重、腦重與假手術(shù)組無顯著性差異（P＞0.05）。 （2）模型組腦組織含水量明顯高于假手術(shù)組（P＜0.05），EPO治療后腦組織含水量明顯低于模型組（P＜0.05）。 （3）HE染色模型組大鼠出現(xiàn)腦室周圍白質(zhì)損傷，光鏡下表現(xiàn)為腦室周圍白質(zhì)細胞腫脹、囊性壞死、組織疏松；EPO治療組腦白質(zhì)細胞腫脹、囊性壞死等病理形態(tài)學(xué)改變較模型組減輕，具有凋亡特征的神經(jīng)細胞明顯減少。假手術(shù)組腦組織未見異常。 （4）術(shù)后24h、48h、72h三組大鼠MBP平均積分光密度比較差異無顯著性意義（P＞0.05）；術(shù)后7d模型組大鼠MBP積分光密度與對照組、治療組比較均明顯降低，差異有顯著性意義（P＜0.05）；EPO治療后MBP積分光密度較模型組增高，與假手術(shù)組比較差異無顯著性（P＞0.05）；術(shù)后14d、35d差異更為顯著。 （5）35日齡時，模型組大鼠自主活動減少，反應(yīng)遲鈍，靈活性降低，Morris水迷宮試驗、閉暗試驗、跳臺試驗的結(jié)果均差于對照組和治療組，差異有顯著性（P＜0.05）。EPO治療后大鼠學(xué)習(xí)、記憶能力明顯改善。 結(jié)論： 成功建立了2日齡未成熟新生大鼠腦白質(zhì)損傷動物模型；在此基礎(chǔ)上，應(yīng)用EPO干預(yù)治療腦白質(zhì)損傷未成熟新生大鼠，可明顯減輕腦白質(zhì)損傷大鼠腦水腫，促進體重、腦重增長，降低早期神經(jīng)行為異常發(fā)生率，減少細胞凋亡，，進一步證實外源性EPO可提高大鼠學(xué)習(xí)、記憶能力，推測可能與促進未成熟新生大鼠腦白質(zhì)MBP蛋白表達，減少少突膠質(zhì)細胞凋亡有關(guān)，為臨床應(yīng)用EPO治療早產(chǎn)兒腦損傷提供了實驗依據(jù)。
[Abstract]:Objective:
To investigate the effects of erythropoietin (EPO) on the expression of myelin basic protein (MBP) and long-term learning and memory ability in brain cells of 2-day-old rats with ischemic brain white matter damage (WMD), and to explore the neuroprotective effect of EPO on immature rats after WMD. The possible mechanism.
Method:
Two-day-old immature neonatal rats were randomly divided into sham operation group (Sham, n = 36), model group (BCAO, n = 36) and EPO treatment group (EPO, n = 36). Bilateral carotid artery occlusion (BCAO) was used to establish an animal model of ischemic white matter injury. EPO (5000u/Kg) was injected into the abdominal cavity immediately after BCAO in the treatment group, and the same volume of normal saline was injected into the control group and the BCAO group. The body weight and brain weight were measured 24 hours, 48 hours, 72 hours, 7 days, 14 days and 35 days after BCAO. The pathological changes of brain tissue were observed by HE staining, and the expression of MBP protein was detected by immunohistochemical staining. The body weight, brain weight, brain water content, early neurobehavioral changes, histopathology, learning and memory ability and MBP protein expression in immature neonatal rats with white matter injury were observed by Morris water maze test, step-down test and dark test 35 days after operation.
Result:
(1) The weight and brain weight of rats in model group increased badly. The weight and brain weight of rats in EPO treatment group were significantly higher than those in model group at each time point (P < 0.05), and there was no significant difference between EPO treatment group and sham operation group at each time point (P > 0.05).
(2) The water content of brain tissue in model group was significantly higher than that in sham operation group (P < 0.05). The water content of brain tissue after EPO treatment was significantly lower than that in model group (P < 0.05).
(3) HE staining model group showed periventricular white matter injury, light microscopy showed that periventricular white matter cells swelling, cystic necrosis, tissue loosening; EPO treatment group white matter cells swelling, cystic necrosis and other pathological changes than the model group alleviated, neurons with apoptotic characteristics were significantly reduced. Often.
(4) There was no significant difference in the mean integral optical density of MBP among the three groups 24 hours, 48 hours and 72 hours after operation (P > 0.05); the integral optical density of MBP in the model group was significantly lower than that in the control group 7 days after operation (P < 0.05); the integral optical density of MBP after EPO treatment was higher than that in the model group, and the difference was significant (P < 0.05). There was no significant difference (P > 0.05), and the difference between 14d and 35d was more significant.
(5) At the age of 35 days, the autonomic activity of rats in the model group decreased, the response was slow and the flexibility was reduced. The results of Morris water maze test, dark test and step-down test were worse than those in the control group and the treatment group, and the difference was significant (P < 0.05). After EPO treatment, the learning and memory abilities of rats were significantly improved.
Conclusion:
The animal model of brain white matter injury in 2-day-old immature neonatal rats was successfully established. On this basis, EPO intervention in the treatment of brain white matter injury in immature neonatal rats can significantly reduce brain edema, promote body weight, brain weight growth, reduce the incidence of early neurobehavioral abnormalities, reduce cell apoptosis, and further confirm the exogenous. Sexual EPO can improve the learning and memory abilities of rats, which may be related to the promotion of MBP protein expression in the white matter of immature neonatal rats and the reduction of oligodendrocyte apoptosis, providing experimental basis for clinical application of EPO in the treatment of brain injury of premature infants.
【學(xué)位授予單位】：安徽醫(yī)科大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2012
【分類號】：R722.1

【參考文獻】

相關(guān)期刊論文 前10條

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本文編號：2245910