脑室注射脑源性神经营养因子对新生大鼠缺氧缺血性脑损伤的影响

EFFECTS OF INTRACEREBROVENTRICULAR INJECTION OF BDNF ON HYPOXIC ISCHEMIC ENCEPHALOPATHY IN NEONATAL RATS

为探讨脑源性神经营养因子 (BDNF)对新生大鼠缺氧缺血性脑损伤的影响 ,以 7天龄大鼠一侧结扎颈总动脉联合低氧吸入形成缺氧缺血性脑损伤模型 ,伤后向脑室注射不同剂量 (0 2、0 5和 2 0 μg)BDNF ,观察对脑水肿、脑内脂质过氧化物 (MDA)水平和细胞凋亡的影响。结果表明 ,给药后 2 4h0 5 μg组脑水肿程度显著降低 ;左脑MDA含量 2 0 μg组显著高于单纯损伤组和 0 5 μg组 ;3种不同剂量BDNF组细胞凋亡不同程度降低 ,其中 0 2 μg和 0 5 μg组降低更明显。提示BDNF对缺氧缺血性脑损伤后的皮层和海马具有显著的保护作用 。

To explore the effects of brain derived neurotrophic factor (BDNF) on hypoxic ischemic encephalopathy in neonatal rats,0 2, 0 5 or 2 0μg of BDNF was injected into cerebroventricles of 7d neonatal Sprague Dawley rats with hypoxic ischemic encephalopathy by ligation of left common carotid artery and 2 5h inhalation of humidified 8% O 2 +92% N 2 at 37℃. Its effects on brain edema, levels of malondialehyde (MDA) and neuronal apoptosis at the left cortex and hippocampus were observed. The results showed that brain edema was markedly alleviated in 0 5μg group compared to the vehicle group 24h after BDNF injection. Levels of MDA in the left hemisphere in 2 0μg group were significantly higher than those in either vehicle group or 0 5μg group. Neuronal apoptosis decreased to a different extent in the three groups while obviously in both 0 2μg and 0 5μg groups. It is suggested that BDNF exerts a prominent protective effect on hypoxic ischemic encephalopathy in neonatal rats, but this effect is lowered when overdose is injected.