瘦素对新生期大鼠惊厥性脑损伤的保护作用及对海马CB-D28k表达的影响

Protective effect of leptin on seizure brain injury in neonatal rats and its effect on expression of CB-D28k in hippocampus

目的探讨瘦素急性期干预对新生期大鼠惊厥性脑损伤的神经保护作用及海马组织CB-D28k表达的影响。方法采用随机数字表法将7日龄SD大鼠分为四组,即单纯对照组、瘦素对照组(Leptin组)、单纯惊厥组(RS组)及瘦素干预组(RS+Leptin组)。RS组和RS+Leptin组大鼠应用三氟乙醚诱导惊厥持续状态,连续7d。Leptin组和RS+Leptin组于每日惊厥后1h腹腔给予瘦素4mg/kg,连续干预7d(P7~P13)。于P14天,即末次惊厥后24h,每组随机取5只,取海马组织,采用蛋白免疫印迹技术(Western blot)检测海马CB-D28k的表达,采用实时PCR技术检测海马CB-D28kmRNA的表达。每组余10只于P33进行避暗测试。结果四组大鼠错误次数和潜伏期组间差异有统计学意义(F=5.471,F=13.775,P<0.05),RS组大鼠较对照组错误次数明显增多(次:1.40±0.52vs.0.80±0.42,P<0.05),RS+Leptin组大鼠较RS组错误次数明显减少(次:0.60±0.52vs.1.40±0.52,P<0.05);RS组大鼠较对照组潜伏期明显缩短(s:92.01±22.78vs.154.97±23.65,P<0.05),RS+Leptin组大鼠较RS组潜伏期明显延长(s:142.42±21.85vs.92.01±22.78,P<0.05)。CB-D28k及mRNA在四组大鼠海马组织中表达差异有统计学意义(F=26.963,F=24.420,P<0.05);与对照组比较,RS组海马组织CB-D28k及mRNA的表达量明显减少(1.29±0.20vs.0.44±0.09,1.08±0.16vs.0.49±0.10,P<0.05);与RS组比较,RS+Leptin组海马组织CB-D28k及mRNA的表达量明显增加(0.44±0.09vs.1.22±0.21,0.49±0.10vs.0.93±0.09,P<0.05)。结论急性期瘦素干预对新生期大鼠惊厥所致神经行为损伤具有神经保护作用,其作用机制可能与调节海马组织CB-D28k表达有关。

Objective To investigate the neuroprotective effect of leptin intervention in the acute phase on brain injury and on the expression of CB-D28k in hippocampus in seizure neonatal rats.Methods Seven-day-old Sprague-Dawley rats were randomly divided into 4 groups blank control group(Control group),Leptin control group(Leptin group),simple seizure group(RS)and Leptin intervention group(RS + Leptin group).The rats in the seizure group and the Leptin intervention group were treated with trifluoroether to induce seizure for 30 minutes for 7 days.The Leptin control group and the Leptin intervention group were received Leptin 4 mg/kg intraperitoneally after 1 hour of daily seizure.On the 14 day(24 hours after the last seizure),5 rats in each group were randomly sacrificed and hippocampus were taken.Western blot was used to evaluate the expression of CB-D28k in hippocampus.Real-time reverse-transcription polymerase chain reactions(RT-PCRs)were used to detect the expression of CB-D28k mRNA in hippocampus.The neurobehavioral test was performed on P33 in each group.Results There were significant differences in the number of error among the four groups,with it in the RS group significantly more increaser than in the control group(F=5.471,F=13.775,P<0.05).Compared with the control group,the latency of the RS group was significantly shorter(times:1.40 ±0.52 vs.0.80 ± 0.42,P<0.05);compared with the RS group,the latency of RS + Leptin group was significantly longer(times:0.60 ± 0.52 vs.1.40 ± 0.52,P<0.05).The expression of CB-D28k and mRNA in the seizure group was significantly decreased compared with the control group(0.44 ± 0.09 vs.1.29 ± 0.20,0.49 ±0.10 vs.1.08 ± 0.16,P<0.05),and the expression of CB-D28k and mRNA in the RS + Leptin group was significantly increased compared with RS group(0.44 ±0.09 vs.1.22 ± 0.21,0.49 ± 0.10 vs.0.93 ± 0.09,P<0.05).Conclusion The acute phase intervention of Leptin has neuroprotective effects on neurobehavioral injury induced by seizure in neonatal rats,and its mechanism may be related to the regulation of CB-D28k expression in hippocampus.