咪唑安定、丙泊酚对下丘脑室旁核去甲肾上腺素释放和心率变异性影响

Effect of Midazolam and Propofol on noradrenaline release in hypothdalamic paraventricular and HRV

目的探讨丙泊酚和咪唑安定对下丘脑室旁核(paraventricular nuclei,PVN)中去甲肾上腺素(noradrenaline,NE)释放及其与心率变异性(heart rate variability,HRV)关系。方法成年雄性新西兰兔24只,随机分为两组。P组:丙泊酚2 mg/kg;M组:咪唑安定0.2 mg/kg;药物均在30 s内缓慢静脉单次注射。清醒24 h后,P组以丙泊酚150μg.kg-1.min-1,咪唑安定15μg.kg-1.min-1静脉缓慢连续推注。以立体神经定位技术穿刺PVN,以推挽灌流技术洗脱NE递质。以高效液相色谱法(high performance liquid chromatography,HPLC)测定样品中NE含量。体表固定导联同步测定每组各时段HRV,并分析低频部分(low frequency,LF)、高频部分(high frequency,HF)、LF/HF比值。结果各组中NE和HRV参数基础值之间差异无显著性(P>0.05)。丙泊酚2 mg/kg单次静脉注射NE和LF、LF/HF较基础值显著降低(P<0.05)。咪唑安定0.2 mg/kg单次静脉注射和15μg.kg-1.min-1连续静脉滴注NE和LF、LF/HF较基础值显著降低(P<0.05)。丙泊酚2 mg/kg单次静脉注射较咪唑安定0.2 mg/kg单次静脉注射,NE和LF、LF/HF显著降低(P<0.05)。两种药物对于HF都没有影响。结论咪唑安定和丙泊酚都有较强的交感神经抑制作用,其中丙泊酚的抑制作用与剂量有关,单次注射丙泊酚交感抑制较咪唑安定更强。

Objective To study the effect of Midazolam and Propofol on noradrenaline（NE） release in hypothdalamic paraventricular nuclei（PVN） and heart rate variability（HRV）.Methods Twenty-four rabbits were randomly divided into two groups.Propofol 2 mg/kg was given in group P,Midazolam 0.2 mg/kg was given in group M.The drugs were injected into vein by bolus in 30 s.Twenty-four hours after wake,the experiment was done again with Propofol 150 μg/（kg·min）-1 and Midazolam 15 μg/（kg·min）-1 by inject continuity using pump.PVN was punctured stereotactically.The push-pull perfusion technique was used to detect the release of NE from PVN in rabbit.NE concentration in the drainage was measured by HPLC.The perfusion needle was inserted surgically under the direction of the three-dimensional cerebral nucleus locating system.HRV was detected by the lead fixed in body surface.Low frequency（LF）,high frequency（HF） and LF/HF were analyzed.Results There were no difference in the baseline of NE and HRV in two groups.Compared with control group,NE in PVN and LF,LF/HF in HRV were inhibited by Propofol 2 mg/kg,Midazolam 0.2 mg/kg with bolus injection and Midazolam 15 μg/（kg·min）-1 injection with pump（P〈0.05）.Compared with Midazolam,NE in PVN and LF,LF/HF in HRV were inhibited by Propofol 2 mg/kg with bolus injection.There were no differences in HF of HRV in all groups.Conclusion Propofol and Midazolam can inhibit NE released from PVN and LF,LF/HF in HRV.It shows that Medazolam and Propofol can inhibit the function of sympathetic nerve.And the inhibitory effect of Propofol was dose depended.The effect of Propofol is stronger than Medazolam with bolus injection.