Asai Y, Umemura K, Kohno Y, Uematsu T, Nakashima M
Department of Pharmacology, Hamamatsu University School of Medicine, Japan.
Eur Arch Otorhinolaryngol. 1993;250(5):292-6. doi: 10.1007/BF00186229.
A photochemical reaction between intravenous rose bengal and xenon light was used to induce a selective thrombus in the rat anterior inferior cerebellar artery (AICA). Compound action potentials (CAPs) were recorded by electrocochleography and cochlear blood flow (CBF) was monitored by laser Doppler flowmetry. Photothrombotic occlusion of the AICA caused inner ear ischemia to various degrees with or without alterations of the CAP. With use of this model we investigated the critical range of the CBF for preserving cochlear function, represented by the CAPs induced with 8 kHz half-wave of sinusoid at 100 dB SPL. Results then showed that a CBF range between 26.7% and 42.9% of baseline was somewhat critical for maintenance of cochlear function in an acute phase of ischemia. Pretreatment with heparin significantly delayed thrombotic occlusion of the AICA in a dose-dependent manner. Further use of our model for inner ear ischemia may be useful for studying pathophysiology and pharmacological therapy of cochlear disturbances subsequent to circulatory disorders.
静脉注射孟加拉玫瑰红与氙灯光之间的光化学反应被用于在大鼠小脑前下动脉（AICA）诱导形成选择性血栓。通过电耳蜗图记录复合动作电位（CAPs），并使用激光多普勒血流仪监测耳蜗血流（CBF）。AICA的光血栓性闭塞导致内耳不同程度的缺血，伴或不伴有CAP的改变。利用该模型，我们研究了以100 dB SPL的8 kHz正弦波半波诱发的CAPs所代表的、维持耳蜗功能的CBF临界范围。结果表明，在缺血急性期，CBF范围在基线的26.7%至42.9%之间对维持耳蜗功能较为关键。肝素预处理以剂量依赖的方式显著延迟了AICA的血栓性闭塞。进一步将我们的模型用于内耳缺血研究，可能有助于研究循环障碍后耳蜗功能紊乱的病理生理学和药物治疗。
