全麻药脊髓作用机制的研究进展.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,全麻药脊髓作用机制的研究进展,Advances in Studies of Actions of General Anesthetics on spinal cord,汪萌芽,皖南医学院细胞电生理研究室,第11,次全国高等麻醉学专业教育研讨会,2006.4.21-24.,合肥,前言,Introduction,全麻药作用机制的研究：,非特异性作用还是特异性作用？,作用在皮层还是脊髓？,作用在感觉系统还是运动系统？,作用在抑制系统还是兴奋系统？,作用机制：生物大分子？,前言,Introduction,脊髓是全麻药作用的重要部位：,最低肺泡有效浓度（,MAC,）：,给予致痛刺激时，一半病人或动物不出现躯体扭动或逃避反应，肺泡中吸入全麻药的浓度。,Rampil,（,1994,）：,横断脊髓并不影响大鼠的全麻药,MAC。,Antognini,等(1993),：,将异氟醚（,isoflurane,）,同时施加于脑和脊髓的,MAC,，,远低于单独施加于脑的,MAC。,Antognini,等（,2000,2001,）：异氟醚或异丙酚所致的暂时性记忆缺失和意识不清，是其作用于脊髓、脑干的上行激活系统所致。,前言,Introduction,全麻药脊髓作用的重要靶点：,脊髓神经元（背角神经元、腹角神经元等）的抑制作用。,突触传递（快、慢突触传递，兴奋性、抑制性突触传递等）的影响。,神经递质,-,受体系统。,离子通道系统。,跨膜信号转导系统。,基因表达系统。,前言,Introduction,脊髓运动神经元是全麻药作用的位点：,全麻药抑制伤害性反射 镇痛和制动:,是否含有运动神经元(,MN),的作用成分？,回返性,F,波：反映,a,-MN,的兴奋性;,顺行,M,波：反映,MN,神经纤维的传导性;,H,反射：反映,MN,环路的兴奋性。,King,和,Rampil,（1994）,在大鼠的实验表明，异氟醚呈剂量依赖性地抑制,F,波，即能降低大鼠脊髓,a,-,运动神经元的兴奋性；而对,M,波无影响，说明异氟醚并不影响动作电位在外周运动神经纤维上的传导，也不影响神经肌肉接头。,Isoflurane,浓度,Head:,头部（灌流）,Torso:,躯体（肺）,肌电图：,M：M,波,F：F,波,Antognini,等,1999,A&A,研究技术,Preparations and Methods,S1:,腹根(,VR);S2:,背根(,DR);S3:,腹外侧索(,VLF),麻醉浓度乙醇对运动神经元的作用,MN,的,快兴奋性突触后电位,(,EPSP),背根,-,快兴奋性突触后电流,(,DR-EPSC),APV-,敏感性,DR-EPSP,和谷氨酸反应,乙醇对,DR-EPSP,的抑制作用,乙醇对谷氨酸反应的抑制作用,without TTX,with TTX,乙醇对谷氨酸反应的抑制作用,乙醇对谷氨酸反应的抑制作用,乙醇对谷氨酸反应的抑制作用,Effects of,propofol,on electrophysiological properties of,motoneurons,in vitro.,（x,SD,）,Paired,t,test:*,P,0.05,vs,control,*,P,0.01,vs,control，#Action potentials of 7/10 all recorded MNS were nullified.,Control,Propofol（,mmol,/l）,n=19,0.1(,n=19),0.3(,n=15),1.0(,n=10),Resting potential (RP,mV),-64.24.7,-65.95.4,-66.04.2,-67.57.0,Membrane resistance(,Rm,M),56.221.4,57.423.0,51.021.0,43.215.5,Time constant(,ms),5.93.0,4.71.9,*,4.32.4,2.51.1,*,Action potential,#,Amplitude(Amp,mV),69.06.3,68.16.9,69.16.5,69.38.3,Threshold(TL,mV),-45.27.7,-43.68.7,-42.811.1,-31.011.8,*,Overshoot(OS,mV),4.93.7,2.66.2,2.94.6,9.08.2,Half-width(ms),1.50.5,2.01.6,1.91.4,1.71.1,Max L.slope(mV/ms),140.339.7,132.243.7,137.745.8,106.725.2,Max R.slope(mV/ms),-87.934.3,-80.023.2,-76.224.1,-60.020.0,异丙酚对,I-F,关系曲线的作用,异丙酚对,I-F,关系曲线的作用,异丙酚对,DR-EPSP,的作用,异丙酚对,MN,的,EPSP,的浓度依赖性抑制作用（,x,SD,）,Control,Propofol,（,mmol,/l）,n=9,0.1(,n=9),0.3(,n=9),1.0(,n=7),Latency(ms),2.81.0,3.11.1,3.11.3,Amplitude(Amp,mV),5.93.2,4.92.9,3.52.4*,*,Duration(ms),35.627.3,26.122.3*,13.35.7*,Area under curve(mV*ms),114.2105.8,75.669.9,29.05.7*,Half-width(ms),12.612.7,5.14.8,3.63.1,Max L.slope(mV/ms),15.710.2,20.016.8,20.713.2,Max R.slope(mV/ms),-16.912.2,-21.614.8*,-18.313.8,Paired,t,test：*,P,0.05,vs,control，*,P,0.01，*,EPSPs,were eliminated.,Bicuculline,对异丙酚作用的影响,Control,BMI,BMI+P 0.1,BMI+P 0.3,BMI+P 1,BMI+P 3,Wash,GABA,A,受体阻断后异丙酚对,MN,的,EPSP,的影响,（,x,SD,）,Control,Propofol,（,mmol,/l）,(n=6),0.1(,n=6),0.3(,n=6),1.0(,n=6),3.0(,n=5),Latency(ms),2.90.8,3.10.9,3.30.6,3.40.5,Amplitude(Amp,mV),5.93.3,6.23.1,5.32.9,3.31.4,*,*,Duration(ms),75.953.6,97.855.1,*,90.860.7,69.743.5,Area under curve(mV*ms),176.9130.1,177.695.9,200.7112.7,97.561.9,Half-width(ms),19.416.3,10.211.2,28.531.4,14.221.3,Max L.slope(mV/ms),4.63.4,4.53.4,4.03.1,3.71.3,Max R.slope(mV/ms),-3.62.3,-3.62.1,-4.33.6,-3.92.8,Paired,t,test：*,P,0.05,vs,control，*,P,0.01，*,EPSPs,were eliminated.,Strychnine,对,异丙酚作用的影响,Control,Str,Str,+P 0.1,Str,+P 1,Str,+P 0.3,Wash,异丙酚对,VLF-EPSP,的,抑制作用,Concentration-dependent inhibitory effects of,Propofol,on VLF-,EPSPs,of MN,in vitro,.(x S.D.）,(,n=10)0.1(n=10),0.3(n=9)#1.0(n=4)#,Control,propofol,(,mmol,/L),F-test among concentration groups:*,P,0.05，Paired,t,test,vs,control：,*,P,0.05，,*,P,0.01.#EPSP in one of 10 cells was eliminated,#,EPSPs,in 3 of 7 cells was eliminated.,Latency(ms),1.80.8,1.90.7,1.90.9,2.50.1,Amplitude(Amp,mV)*4.83.2,4.01.9,3.21.9,*,2.72.0,*,Duration(ms)*,46.316.3,44.520.8 30.618.6,*,34.00.3,Area under curve*62.443.6,49.426.6,30.220.0,*,22.810.6,*,Half-width(ms)*,7.84.6,6.33.6,3.45.4,*,0.50.8,*,Max l.slope(mV/ms)2.92.1,2.92.5,2.51.7,3.02.2,Max r.slope(mV/ms)-1.91.0,-1.90.8,-1.91.0,-0.50.8,_,异丙酚对,VLF-EPSP,的,抑制作用,异丙酚对,VLF-EPSP,的,抑制作用,Effects of,propofol,on VLF-EPSP in a MN of neonatal rat spinal cord slices in the presence of,bicuculline,(50,m,mol,/L).,Comparison of the,propofol,effects on DR-,EPSPs,and VLF-,EPSPs,in the same MN of neonatal rat spinal cord slices in the absence and presence of strychnine(,1.0,m,mol,/L),（,1.0,m,mol,/L）,Control,0.1,0.3,Propofol,(,mmol,/L),Wash,Strychnine,0.3,mmol,/L,Propofol,Wash,Strychnine,Strychnine,Effects of,propofol,on VLF-EPSP in a MN of neonatal rat spinal cord slices in the presence of,bicuculline,(30,m,mol,/L)and strychnine(1,m,mol/L).,RP was 63 mV,异丙酚对,GLU,反应的抑制作用,异丙酚对外源性谷氨酸反应的抑制作用,（,x,SD,）,Control,Propofol,（,mmol,/l）,(n=7),0.1(,n=7),0.3(,n=6),1.0(,n=6),Amplitude(Amp,mV),10.63.1,9.46.0,4.93.3,*,*,Duration(s),16.13.8,16.36.8,13.311.0,Area under curve(mV*s),75.339.4,51.949.1,25.416.8,*,Half-width(s),1.62.4,1.72.6,1.31.6,Max L.slope(mV/ms),1.81.6,2.73.4,0.50.4,Max R.slope(mV/ms),-2.21.5,-3.82.6,-1.61.2,Paired,t,test：*P0.05,vs,control，*,depolarizing responses were eliminated in all tested cells.,小结,麻醉浓度的乙醇对,MN,的,DR-EPSP,和,Glu,反应有抑制作用。,乙醇的作用在,TTX、,bicuculline,和,strychnine,预处理的情况下仍然存在，表明为直接作用。,乙醇对,GLU,受体的,AMPA,和,NMDA,亚型均有抑制作用。,异丙酚对,DR-EPSP、VLF-EPSP,和,Glu,反应也存在浓度依赖性抑制作用。,异丙酚对,GLU,受体的抑制，部分与,GABAA,受体和甘氨酸受体有关，高浓度有直接抑制作用。,异丙酚对,DR,和,VLF,刺激诱发,EPSP,抑制作用具有差异性,。,乙醇和异丙酚均对,MN,的,动作电位有抑制作用，表明对,MN,的钠离子通道等均有影响，相关离子通道也是作用的靶点之一。,致谢,合作者：,Joan J.,Kendig,(Stanford Univ.),Ira J.,Rampil,(UCSF),任双来、杨克春、韩小虎、陈永君、,程龙珍、汪丽娜,（,研究生）,科研基金：,国家自然科学基金(,30270366,),安徽省自然科学基金(,0,5,04,30,4,01,),安徽省人事厅人才专项基金,(2003),谢谢！,第11次全国高等麻醉学专业教育研讨会,2006.4.21-24.合肥,