Kocsis B, Fedina L, Pasztor E
Department of Physiology, National Institute of Neurosurgery, Budapest, Hungary.
J Appl Physiol (1985). 1991 May;70(5):2181-7. doi: 10.1152/jappl.1991.70.5.2181.
The performance of the sympathetic nervous system during sustained moderate cerebral ischemia (CI) was examined in the present study. For this purpose, a Cushing response was elicited repeatedly during incomplete global CI in anesthetized artificially ventilated cats after vagotomy and baroreceptor denervation. In control animals without CI, sympathetic activity in response to brief elevation of intracranial pressure (ICP) showed a well-repeatable two-phase reaction. During CI there was a progressive deterioration of background sympathetic nerve discharge (SND) over a period of 30 min. SND response to repeated elevation of ICP was initially similar to control response but later with progression of CI was seriously changed. 1) Instead of the usual hyperactivation, sympathetic nerve activity was depressed during intracranial hypertension. 2) The characteristic desynchronized activity either appeared later during the reperfusion period or remained absent. The progressive loss of SND response to raised ICP in developed CI was compared with the changes seen in experiments in which repeated ICP elevations were superimposed on asphyxia. These findings suggest that the sympathetic component of the Cushing reaction strongly depends on the actual state of brain stem autonomic circuits and may be seriously altered in pathological situations involving ischemic brain injury.
本研究检测了持续性中度脑缺血（CI）期间交感神经系统的表现。为此，在切断迷走神经和去神经支配的麻醉人工通气猫的不完全全脑缺血期间，反复引发库欣反应。在无CI的对照动物中，对短暂颅内压（ICP）升高的交感神经活动表现出良好的可重复性双相反应。在CI期间，背景交感神经放电（SND）在30分钟内逐渐恶化。对ICP反复升高的SND反应最初与对照反应相似，但随着CI的进展后来发生了严重变化。1） 在颅内高压期间，交感神经活动不是通常的过度激活，而是受到抑制。2） 特征性的去同步化活动要么在再灌注期后期出现，要么仍然不存在。将发展性CI中对升高ICP的SND反应的逐渐丧失与在反复ICP升高叠加在窒息上的实验中观察到的变化进行比较。这些发现表明，库欣反应的交感神经成分强烈依赖于脑干自主神经回路的实际状态，并且在涉及缺血性脑损伤的病理情况下可能会发生严重改变。
