神经生长因子对新生大鼠缺氧缺血性脑损伤的保护作用

目的：研究神经生长因子(NGF)对新生大鼠缺氧缺血性脑损伤(HIBD)的保护作用。方法：将新生7日龄SD大鼠40只随机分为NGF治疗组(n=16)，对照组(n=16)和假手术组(n=8)，缺氧缺血(HI)后即刻腹腔注射100 U NGF或等量生理盐水(假手术组不注射)，然后观察NGF对HIBD模型鼠的体重增长、脑组织病理及超微结构改变的影响，并用TUNEL法原位标记DNA片段，观察NGF对HIBD后脑细胞凋亡的影响。结果：NGF治疗组体重增长(4.16±0.24) g明显高于对照组(2.86±0.17) g，(P<0.01)；TUNEL检测结果，HIBD后24 h治疗组左侧海马和皮质凋亡细胞数(分别为199.75±19.61，182.75±19.12)明显低于对照组(分别为285.50±32.67，271.00±28.36)(P<0.01)；HIBD后48 h治疗组左侧海马、皮质凋亡细胞数(分别为77.75±15.76，82.50±19.15)亦明显低于对照组(分别为106.50±16.96，122.75±16.56)(P<0.01)。结论：外源性NGF对HIBD后脑细胞凋亡可能具有一定的保护作用。

Protective Effects of Nerve Growth Factoron Hypoxic-ischemic Brain Damage in Neonatal Rats

Objective　To explore the protective effects of nerve growth factor (NGF) on hypoxic-ischemic brain damage (HIBD) in neonatal rats. Methods　Forty 7-day postnatal rats were randomly divided into NGF-treated (n=16), control (n=16) and sham surgery groups (n=8). Immediately after hypoxic-ischemic (HI) injury, 100 U NGF or normal saline solution was injected intraperitoneally; the sham surgery group was not injected. The effects on body weights, macro- and microscopical changes were then assessed. The effect on apoptosis of neurons was observed by terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labelling (TUNEL) staining. Results　The increased body weight in the NGF treated-group was significantly higher than that in the control group ［(4.16±0.24) g and (2.86±0.17) g, respectively (P<0.01)］. The average number of positive cells in the left hippocampus and cortex in the NGF-treated group at 24 h after HIBD were much lower than those in the control group (199.75±19.61 vs 285.50±32.67, 182.75±19.12 vs 271.00±28.36, respectively, P<0.01). At 48 h after HIBD, they were also much lower than those in the control group (77.75±15.76 vs 106.50±16.96; 82.50±19.15 vs 122.75±16.56, respectively, P<0.01). Conclusions　It is suggested that intraperitoneal administration on NGF has protective effects on neuronal apoptosis associated with hypoxic-ischemic injury.