Bunc G, Kovacic S, Strnad S
Department of Neurosurgery, Maribor Teaching Hospital, Slovenia.
Wien Klin Wochenschr. 2000 Jun 16;112(12):533-9.
The objective of this study was to establish whether the exclusion of the effect of the sympathetic nervous system prevents vasospasm of cerebral arteries after experimental subarachnoid haemorrhage in rabbits.
The effect of sympathetic exclusion on vasospasm was studied in 29 New Zealand rabbits under conditions similar to human subarachnoid haemorrhage: 1. The activity of the sympathetic nervous system was excluded only after subarachnoid haemorrhage. 2. The effect of this exclusion was evaluated on the eighth day after subarachnoid haemorrhage. 3. The single haemorrhage model of experimental subarachnoid haemorrhage was chosen. Four groups of rabbits were investigated. The control group A comprised rabbits without subarachnoid haemorrhage; group B consisted of those with subarachnoid haemorrhage (1 ml autologous blood/kg BW suboccipitally into the cisterna magna); group C included those with subarachnoid haemorrhage and pharmacological sympathetic exclusion by the alpha blocker phenoxybenzamine, and group D was composed of those with subarachnoid haemorrhage and operative sympathetic exclusion by cervical gangliectomy. Changes in the basilar arteries of rabbits were evaluated by computer image analysis, using histologic specimens of vessel walls. A new measuring procedure was developed to assess the intensity of vasospasm; the method has a corrugation coefficient that expresses changes in intimal corrugation.
Comparison of control group A and group B in regard of vessel intima corrugation showed significantly less corrugated intima in group A (P = 0.0042). In comparison with group B, corrugation of the vessel intima in group C was less intense after sympathetic exclusion by phenoxybenzamine following subarachnoid haemorrhage (P = 0.00012). In comparison with group B, a reduced corrugation was also found in group D after sympathetic exclusion by upper cervical gangliectomy following subarachnoid haemorrhage (P = 0.0026).
The results of the study suggest that exclusion of sympathetic nervous system activity in rabbits prevents vasospasm in circumstances similar to subarachnoid haemorrhage in man. Thus, the sympathetic nervous system could play a critical role in the development of vasospasm in subarachnoid haemorrhage.
本研究的目的是确定排除交感神经系统的影响是否能预防兔实验性蛛网膜下腔出血后大脑动脉的血管痉挛。
在29只新西兰兔身上研究了交感神经阻断对血管痉挛的影响，实验条件与人蛛网膜下腔出血相似：1. 仅在蛛网膜下腔出血后排除交感神经系统的活性。2. 在蛛网膜下腔出血后第8天评估这种阻断的效果。3. 选择实验性蛛网膜下腔出血的单次出血模型。对四组兔进行了研究。对照组A包括未发生蛛网膜下腔出血的兔；B组由发生蛛网膜下腔出血的兔组成（枕下向小脑延髓池注入1ml自体血/kg体重）；C组包括发生蛛网膜下腔出血并通过α受体阻滞剂酚苄明进行药理学交感神经阻断的兔，D组由发生蛛网膜下腔出血并通过颈神经节切除术进行手术交感神经阻断的兔组成。使用血管壁组织学标本，通过计算机图像分析评估兔基底动脉的变化。开发了一种新的测量程序来评估血管痉挛的强度；该方法有一个表示内膜皱襞变化的皱襞系数。
对照组A和B组血管内膜皱襞的比较显示，A组内膜皱襞明显较少（P = 0.0042）。与B组相比，蛛网膜下腔出血后通过酚苄明进行交感神经阻断后，C组血管内膜的皱襞程度较轻（P = 0.00012）。与B组相比，蛛网膜下腔出血后通过上颈神经节切除术进行交感神经阻断后，D组也发现皱襞减少（P = 0.0026）。
研究结果表明，在与人类蛛网膜下腔出血相似的情况下，兔交感神经系统活性的阻断可预防血管痉挛。因此，交感神经系统可能在蛛网膜下腔出血后血管痉挛的发生中起关键作用。
