血小板生长因子对缺氧缺血性脑损伤新生鼠脑细胞凋亡率和血清神经元特异性烯醇化酶的影响

目的 研究血小板源性生长因子(platelet derived growth factor,PDGF)对缺氧缺血性脑损伤(hypoxic-ischemic brain damage,HIBD)的新生鼠神经细胞凋亡率及血清神经元特异性烯醇化酶(neuron-specific enolase,NSE)浓度的影响,进而探讨其对HIBD的神经保护作用. 方法 7日龄新生Wistar大鼠48只制备HIBD模型,并分为PDGF治疗组和生理盐水对照组,每组各24只.另取24只为假手术组.治疗组在缺氧缺血后即刻给PDGF-BB 50 ng/kg腹腔注射.对照组和假手术组腹腔注射等体积的生理盐水.每组于处置后12、24和72 h随机取8只处死,留血清标本,酶联免疫吸附法检测大鼠血清标本NSE浓度；取右侧大脑组织制备脑细胞悬液,双染法流式细胞仪检测脑细胞凋亡率.采用单因素方差分析及q检验进行统计学分析. 结果 (1)脑细胞凋亡率:治疗组(6.09±0.70)％、(9.67±1.52)％和(14.15±1.52)％]和对照组(8.00±1.10)％、(11.45±2.42)％和(22.90±2.03)％]3个时点的脑细胞凋亡率均较假手术组(2.11±0.54)％、(2.34±0.46)％和(2.21±0.49)％]显著增加(P均＜0.01或＜0.05),治疗组较对照组各时点脑细胞凋亡率均明显降低(P均＜0.01或＜0.05),3组大鼠在12、24、72 h时的组间比较差异均有统计学意义(F=39.01、66.60、194.20,P均＜0.01).(2)血清NSE浓度:各时点对照组(10.04±0.19) μg/L、(9.33±0.15)μg/L和(8.36±0.16)μg/L]和治疗组(8.43±0.17)μg/L、(6.73±0.16) μg/L和(6.12±0.13)μg/L]较假手术组(4.22±0.53)μg/L、(3.96±0.60) μg/L和(3.59±0.55) μg/L]NSE浓度增加(P均＜0.01),治疗组较对照组各时点NSE浓度降低(P均＜0.01),3组大鼠在12、24、72h组间比较差异均有统计学意义(F=371.25、245.61、236.22,P均＜0.01). 结论 PDGF能抑制新生大鼠HIBD后神经细胞凋亡及降低血清NSE浓度,对HIBD新生大鼠有神经保护作用.

Effects of platelet derived growth factor on brain cell apoptosis rate and serum neuron-specific enolase after hypoxic-ischemic brain damage in neonatal rats

Objective To investigate the effects of platelet derived growth factor (PDGF) on brain cell apoptosis rate and serum neuron-specific enolase (NSE) concentration after hypoxic-ischemic brain damage (HIBD) in neonatal rats. Methods Forty-eight HIBD models of 7-day old neonatal Wistar rats were established and then divided into two groups randomly:PDGF group and normal saline control group (n =24 in each).Another 24 neonatal Wistar rats were taken into the sham operation group.The treatment group received intraperitoneal injection of PDGF-BB (50 ng/kg) once,while the other two groups received normal saline at the same time.In each group,rats were randomly sacrificed immediately at 12,24 and 72 hours after injection (n=8).The serum of rats were reserved for NSE concentration determination by enzyme linked immunosorbent assay,and the right brains of the sacrificed rats were used to prepare brain cell suspension for neurocyte apoptosis rate examination by flow cytometry.Mono-variate analysis and q-test were performed for statistical analysis. Results (1) The brain cell apoptotic rates of treatment group (6.09 ± 0.70)％,(9.67 ± 1.52) ％ and (14.15±1.52)％] and control group (8.00± 1.10)％,(11.45±2.42)％ and (22.90±2.03) ％] were significantly increased compared to that of sham group (2.11 ± 0.54)％,(2.34 ±0.46)％ and (2.21±0.49)％] at all time points (all P＜0.01 or ＜0.05),the apoptotic rate of treatment group was lower than that of control group (P＜0.01 or ＜0.05).Statistical differences were found among the three groups at 12,24 and 72 hours (F =39.01,66.60 and 194.20respectively; P＜0.01).(2) Serum NSE concentration was significantly increased in the treatment group (8.43 ± 0.17) μg/L,(6.73 ± 0.16) μg/L and (6.12 ± 0.13) μg/L] and control group (10.04±0.19) μg/L,(9.33 0.15) μg/L and (8.36 ± 0.16) μg/L] than in the sham group (4.22±0.53) μg/L,(3.96±0.60) μg/L and (3.59±0.55) μg/L] at all time points,and it was significantly lower in treatment group than in control group (P＜ 0.01).Statistical difference was found among three groups at 12,24 and 72 hours (F=371.25,245.61 and 236.22 respectively,P＜0.01). Conclusions PDGF might have neuroprotective effect,which could inhibit apoptosis of neural cells and decrease the serum NSE concentration.