Stanek B, Schwarz M, Zimpfer M, Raberger G
Br J Anaesth. 1980 Mar;52(3):305-11. doi: 10.1093/bja/52.3.305.
Anaesthetized dogs (pentobarbitone 25 mg kg-1 + 3 mg kg-1 h-1) with a Teflon catheter inserted to the femoral artery for pressure and heart rate measurement and blood sampling were studied. Extradural puncture was carried out at L7--S1 under x-ray control and 2% lignocaine (1 ml min-1) infused for approximately 10 min. During extradural block a decrease in arterial pressure was accompanied by a simultaneous decrease in plasma noradrenaline concentration (NA) and a compensatory increase in plasma renin activity (PRA), which became significant 15 min after commencing the block when the arterial pressure was at the minimum. Dihydroergotamine (DHE) led to a rapid reversal of the hypotension with no change in heart rate and a decrease in PRA. Hypovolaemia (blood loss 5 ml kg-1) was induced before and during block, respectively, in two further experimental groups. Increased NA and PRA were found under hypovolaemia without extradural block, but only PRA increased with hypovolaemia and a block. The effects of DHE in the later studies were comparable to those observed in the initial study.
研究对象为麻醉犬（戊巴比妥25mg/kg + 3mg/kg·h⁻¹），已插入聚四氟乙烯导管至股动脉以测量血压和心率并采集血样。在X线控制下于L7 - S1进行硬膜外穿刺，并以2%利多卡因（1ml/min）输注约10分钟。在硬膜外阻滞期间，动脉压下降的同时血浆去甲肾上腺素浓度（NA）降低，血浆肾素活性（PRA）代偿性升高，当动脉压降至最低时，在阻滞开始15分钟后这种变化变得显著。双氢麦角胺（DHE）可迅速逆转低血压，心率无变化，PRA降低。另外两个实验组分别在阻滞前和阻滞期间诱导低血容量（失血5ml/kg）。在无硬膜外阻滞的低血容量情况下，NA和PRA升高，但在低血容量合并阻滞时只有PRA升高。后期研究中DHE的作用与初始研究中观察到的作用相当。
