Latoni J, Shivapuja B, Seidman M D, Quirk W S
Department of Otolaryngology, Wayne State University, Detroit, Michigan, USA.
Acta Otolaryngol. 1996 May;116(3):388-94. doi: 10.3109/00016489609137862.
The etiology of noise-induced hearing loss is poorly understood despite years of clinical experience and experimental investigations. One potential mechanism which may contribute to noise-induced temporary threshold shifts (TTS) are vascular pathologies in the microcirculation of the cochlea. Several studies have demonstrated histologic evidence of reduced cochlear blood flow following noise exposure. Recent studies utilizing intravital microscopy (IVM) complement these histologic studies and furthermore demonstrate localized ischemia during noise exposure. The purpose of the current study was to attempt to maintain cochlear blood flow during noise exposure by treating with pentoxifylline, a xanthine derivative which promotes blood flow in capillary beds. The possibility that preserved cochlear microcirculation with pentoxifylline treatment attenuates noise-induced TTS was also examined in this study. The results show treatment with pentoxifylline maintains cochlear microcirculation as assessed by continuous red blood cell movement through capillaries. Pentoxifylline treatment did not prevent vasoconstriction or increased permeability often observed in the cochlear microvasculature during noise. Treatment with this drug reduced noise-induced TTS.
尽管有多年的临床经验和实验研究，但噪声性听力损失的病因仍未得到充分了解。一种可能导致噪声性暂时性阈移（TTS）的潜在机制是耳蜗微循环中的血管病变。多项研究已证明噪声暴露后耳蜗血流量减少的组织学证据。最近利用活体显微镜检查（IVM）的研究补充了这些组织学研究，并且进一步证明了噪声暴露期间的局部缺血。本研究的目的是尝试通过使用己酮可可碱进行治疗来在噪声暴露期间维持耳蜗血流量，己酮可可碱是一种可促进毛细血管床中血流的黄嘌呤衍生物。本研究还考察了己酮可可碱治疗保持耳蜗微循环从而减轻噪声性TTS的可能性。结果表明，通过连续的红细胞在毛细血管中的移动评估，己酮可可碱治疗可维持耳蜗微循环。己酮可可碱治疗并不能预防噪声期间耳蜗微血管中经常观察到的血管收缩或通透性增加。用这种药物治疗可降低噪声性TTS。
