中枢内啡肽对等长收缩运动时心血管反应的调控意义

Regulation of central endogenous opioids on cardiovascular responses to isometric exercise

目的 研究电刺激等长收缩运动 (IE)时的中枢内啡肽 (EOPs)对心血管反应的调控机制。方法 成年健康杂种犬 2 0只 ,体质量 ( 11± 1.8)kg ,浅麻醉下以感应电刺激腓肠肌产生最大IE ,包括单侧IE(UIE)和双侧IE(DIE)。测定心率、血压、肺毛细血管楔嵌压、肺动脉压、中心静脉压、心输出量、每搏输出量。采用放射免疫法同批测定血浆及脑脊液中亮氨酸脑啡肽 (LEK )、β 内啡肽 ( β END)、强啡肽 (DYN)含量。结果 ①UIE与DIE时心率、血压、心输出量、血浆及脑脊液LEK、β END、DYN均明显增加 ( P <0 .0 1) ,每搏输出量明显下降 (P <0 .0 1) ;②UIE与DIE相比各血流动力学指标以及血浆LEK、β END、DYN净增量差异无显著性 (P >0 .0 5 ) ;③DIE时脑脊液LEK ,β END ,DYN净增量显著高于UIE( P <0 .0 1)。结论 中枢EOPs对等长收缩运动时心血管反应的调控起重要作用。

Objective To explore effect of central endogenous opioids (EOPs) regulation of hemodynamic responses to faradism stimulation induced isometric exercise (IE). Methods Twenty adult healthy dogs ,body mass (11± 1.8 ) kg, performed maximal IE in the unilateral(UIE) and dicateral (DIE) induced by faradism stimulation. Heart rate (HR), blood pressure (BP), pulmonary capillary wedge pressure (PCWP), pulmonary artery pressure (PBP), central vein pressure (CVP), cardiac output (CO), stroke volume (SV) were measured. Radioimmunoassay was employed to analyze leu enkephalin (LEK), β endorphin (β END) and dynaphin (DYN) in plasma and cerebrospinal fluid. Results ①During UIE and DIE, HR, BP, CO increased (P< 0.01 ), while SV reduced significantly (P< 0.01 ). Plasma and cerebrospinal fluid EOPs increased significantly (P< 0.01 ). ② The net increase of all hemodynamic parameters as well as plasma LEK, β END and DYN was insignificantly different between UIE and DIE (P> 0.05 ). ③The net increase of LEK, β END and DYN in cerebrospinal fluid was all significantly higher during DIE than that during UIE (P< 0.01 ). Conclusions Central EOPs is important in regulation of cardiovascular response to IE.