摘要
目的观察缺血预适应是否通过腺苷受体,诱导蛋白激酶Cα(protein kinase Cα,PKCα)、蛋白激酶Cε(protein kinase Cε,PKCε)活化和失血性休克大鼠血管反应性和钙敏感性保护。方法采用高效液相色谱法测定缺血预适应过程中腺苷浓度变化;采用western blot技术,观察A1、A2A、A2B、A3腺苷受体(A1、A2A、A2B、A3adenosine receptor,A1R、A2AR、A2BR、A3R)抑制剂对缺血预适应诱导PKCα和PKCε表达和转位的影响;采用离体微血管环张力测定技术,观察腺苷受体抑制剂对缺血预适应诱导失血性休克血管反应性和钙敏感性保护作用的影响。结果 (1)休克2小时后血浆腺苷浓度较正常对照组显著增高,5%失血量预适应可进一步增高休克后的血浆腺苷浓度,以在休克前30分钟缺血预适应组的腺苷浓度最高(P<0.01);(2)5%失血量休克前30分钟预适应可促进PKCα和PKCε由胞浆向胞膜的转位(P<0.01),A1R拮抗剂可显著抑制缺血预适应导致的PKCα和PKCε的转位,使PKCα的胞膜/胞浆部分比值分别由1.071回降至0.583,使PKCε的胞膜/胞浆部分比值由1.280回降至0.606(P<0.01),A2AR、A2BR和A3R拮抗剂没有明显作用;(3)5%失血量休克前30分钟预适应可诱导血管反应性和钙敏感性的保护作用(P<0.01),A1R拮抗剂可以显著抑制其保护作用,使去甲肾上腺素(norepinephrine,NE)和Ca2+的最大收缩力(Emax)分别降低59.3%和53.4%(P<0.01),A2AR、A2BR、A3R拮抗剂均无显著抑制作用。结论缺血预适应通过A1R,诱导PKCα和PKCε活化和失血性休克大鼠血管反应性和钙敏感性的保护。
Objective To observe the role of adenosine receptor in the ischemia preconditioning-induced activation of protein kinase Cα（PKCα）,protein kinase Cε（PKCε） and protection of vascular reactivity and calcium sensitivity after hemorrhagic shock in rats.Methods The changes of adenosine concentration after ischemia preconditioning were measured using high performance liquid chromatogram（HPLC） system.The effects of A1,A2A,A2B and A3 adenosine receptor（A1R,A2AR,A2BR and A3R） inhibitors on the protein expression and translocation of PKCα and PKCε induced by ischemia preconditioning were measured via western blot,and the effects of A1R,A2AR,A2BR and A3R inhibitors on the protection of vascular reactivity and calcium sensitivity after hemorrhagic shock-induced by ischemia preconditioning were measured via isolated organ perfusion system.Results（1） The adenosine concentration was significantly increased after 2 hours shock comparing with normal control.Ischemia preconditioning could further increase the adenosine concentration after shock,and the adenosine concentration of 5% hemorrhage applied at 30 minutes before shock group was the highest（P0.01）.（2） Ischemia preconditioning（5% hemorrhage applied at 30 minutes before shock） could promote the translocation of PKCα and PKCε from cytoplasm to membrane（P0.01）,which was inhibited by A1R inhibitor.The ratio of PKCα protein expression in membrane to that in cytoplasm was decreased from 1.071 to 0.583,and the ratio of PKCε protein expression in membrane to that in cytoplasm was decreased from 1.280 to 0.606（P0.01）.A2AR,A2BR and A3R inhibitors had no effects.（3） Ischemia preconditioning（5% hemorrhage applied at 30 minutes before shock） could induce the protection of vascular reactivity and calcium sensitivity after hemorrhagic shock,which was also inhibited by A1R inhibitor.The Emax of NE and Ca2＋ were decreased by 59.3% and 53.4% respectively（P0.01）.A2AR,A2BR and A3R inhibitors had no effects.Conclusion Ischemia preconditioning could induce the activation of PKCα,PKCε and the protection of vascular reactivity and calcium sensitivity after hemorrhagic shock in rats through A1R.
出处
《创伤外科杂志》
2010年第5期443-447,共5页
Journal of Traumatic Surgery
基金
国家重大基础研究计划项目973项目(2005CB522601)
国家杰出青年科学基金(30625037)
关键词
失血性休克
缺血
血管反应性
钙敏感性
腺苷受体
hemorrhagic shock
ischemia
vascular reactivity
calcium sensitivity
adenosine receptor
