摘要目的 探讨大鼠蛛网膜下腔出血(SAH)后早期脑损伤(EBI)中脑源性神经营养因子(BDNF)及其酪氨酸激酶受体B(TrkB)的表达情况及其作用. 方法 将56只雄性SD大鼠按随机数字表法分为假手术组和SAH组(n=28),后者应用颈内动脉线栓穿刺法建立SAH模型.分别于术后24 h和72 h进行神经功能评分、测定脑组织含水量并应用免疫组化染色和ELISA法检测脑皮质BDNF和TrkB的表达. 结果 术后24 h和72 h时,SAH组大鼠的神经功能评分和脑组织含水量均高于假手术组;SAH组大鼠的BDNF免疫组化染色评分[(1.33±0.52)分、(1.67±0.52)分]、表达水平[(12.11 ±0.44) mg/mL、(15.82±0.89) mg/mL]明显高于假手术组[(0.33±0.52)分、(0.17±0.41)分、(4.92±0.16) mg/mL、(4.93±0.20) mg/mL],差异均有统计学意义(P＜0.05);SAH组大鼠的TrkB免疫组化染色评分[(1.17±0.75)分、(2.00±0.00)分]、表达水平[(18.89±0.38) mg/mL、(25.18±0.68) mg/mL]明显高于假手术组[(0.17±0.41)分、(0.33±0.52)分、(8.52±0.41) mg/mL、(8.08±0.34) mg/mL],差异均有统计学意义(P＜0.05). 结论 大鼠SAH后BDNF及TrkB表达明显增加,可能在EBI中发挥着重要的保护作用.

abstractsObjective To observe the expressions of brain derived neurotrophic factor (BDNF) and tropomyosin-related kinase B (TrkB) in rats with early brain injury (EBI) after subarachnoid hemorrhage,and study the neuroprotective effects of BDNF and TrkB on EBI.Methods Male Sprague-Dawley rats (n=56),weighing 280-320 g,were randomly divided into sham-operated group and SAH group;SAH models were established by endovascular perforation ofinternal carotid artery.At 24 and 72 h after modeling,neurological scale scores were recorded;brain water content was measured;immunohistochemical staining and ELISA were used to observe the dynamical expressions of BDNF and TrkB in the brain.Results At 24 and 72 h after modeling,the neurological function scores and brain water content of SAH rats were higher than those of sham-operated group.The expression scores of BDNF in the SAH rats were 1.33±0.52 and 1.67±0.52,and the expression levels were (12.11±0.44) mg/mL and (15.82±0.89) mg/mL;the expression scores of TrkB were 1.17±0.75 and 2.00±0.00,and the expression levels were (18.89±0.38) mg/mL and (25.18±0.68) mg/mL.The expression scores of BDNF in the sham-operated group were 0.33±0.52 and 0.17±0.41,and the expression levels of BDNF in the sham-operated group was (4.92±0.16) mg/mL and (4.93±0.20) mg/mL;the expression scores of TrkB were 0.17±0.41 and 0.33±0.52,and the expression levels were (8.52±0.41) mg/mL and (8.08±0.34) mg/mL.There were significant differences in BDNF and TrkB expressions between the two groups at 24 and 72 h after modeling (P＜0.05).Conclusion The expressions of BDNF and TrkB increase significantly after SAH,and BDNF and TrkB play protective effect on EBI after SAH.