丙泊酚复合皮质酮对突触可塑性的影响

目的探讨丙泊酚复合皮质酮（CORT）对大鼠海马CA1区突触结构的影响。方法将48只Wistar大鼠随机分为对照组（A组）、丙泊酚组（B组）、CORT组（C组）及丙泊酚＋CORT组（D组）,各12例。对4组大鼠分别以0.9%氯化钠注射液10mL/kg、丙泊酚100mg/kg、CORT10mg/kg及丙泊酚100mg/kg＋CORT10mg/kg配方进行腹腔注射,连续用药6d,每天待大鼠清醒后0.5h,以Morris水迷宫检测大鼠空间学习记忆能力;第6天测试结束后,测定海马CA1区突触间隙的宽度、突触后致密物质厚度及突触活性区长度的变化。结果 Morris水迷宫训练3～5d,各组逃避潜伏期均比训练1～2d缩短,差异均有统计学意义（P〈0.05）;A组逃避潜伏期较其他3组短（P〈0.05）;与B及C组比较,D组逃避潜伏期延长（P〈0.05）。与A组比较,B、C及D组突触间隙的宽度、突触后致密物质厚度及突触活性区长度均减少（P〈0.05）,与B及C组比较,D组突触间隙的宽度、突触后致密物质厚度及突触活性区长度均减少（P〈0.05）。结论 100mg/kg丙泊酚或10mg/kgCORT多次注射均会影响大鼠的认知功能与突触结构,两药复合使用影响更大。

Combined effects of propofol and corticosterone on synaptic plasticity

Objecttive To investigate the combined effects of propofol and corticosterone on the synaptic plasticity in hippocampal CA1 region.Methods Forty-eight Wistar rats21days old,（50±2）g in weight）were randomly divided into 4 groups（12 in each group）：control group（group A）,propofol treated group（group B）,corticosterone treated group（group C）and propofol combined with corticosterone treated group（group D）,which were respectively received intraperitoneal injection of 10 ml/kg 0.9% sodium chloride solution,100mg/kg propofol,10 mg/kg corticosterone,or 100mg/kg propofol combined with 10mg/kg corticosterone for 6 consecutive days.All rats were tested for spatial learning and memory in Morris Waster Maze（MWM）everyday.On the 6th day after the MWM test was finished,the ultrastructure of synapses were observed with transmission electron microscope,including the width of synaptic cleft（SC）,the thickness of postsynaptic densities（PSD）and the length of synaptic active zone（SAZ）.Results The latency of escaping on the 3th,4th,5th day was significantly longer of group B,C,D than that of group A.The latency of rats were also longer on the 3th,4th,5th dayof group D than that of group B,C.The thickness of PSD,the width of SC and the length of SAZ were remarkably decreased of group B,C,D than that of group A.Compared with group B and C,the thickness of PSD,the length of SAZ and the width of SC decreased in group D.Conclusions Repeated propofol or corticosterone administration can reduce spatial learning and memory and change the synaptic structure.The combined application of propofol and corticosterone can aggravate this effect.