Ozcan Cengiz, Görür Kemal, Cinel Leyla, Talas Derya Umit, Unal Murat, Cinel Ismail
Department of Otorhinolaryngology, School of Medicine, Mersin University, Mersin, Turkey.
Int J Pediatr Otorhinolaryngol. 2002 May 15;63(3):179-84. doi: 10.1016/s0165-5876(01)00640-1.
Myringosclerosis often occurs in patients in whom ventilation tube insertion and tympanoplasty procedures are performed. Recent studies have revealed a relationship between the development of myringosclerosis and oxygen-derived free radicals, and some investigations have demonstrated that free radical scavengers prevent the development of myringosclerosis. N-acetylcysteine is a well-known anti-oxidant and anti-inflammatory agent. In this study, we aimed to investigate the preventive effect of N-acetylcysteine on myringosclerosis in myringotomized rat tympanic membranes.
Twenty Sprague-Dawley rats were bilaterally myringotomized and divided into four groups. Group 1 received no treatment, group 2 was treated with topical saline solution in Spongostan, group 3 received topical 0.6 mg N-acetylcysteine in Spongostan and group 4 received 1.2 mg N-acetylcysteine in Spongostan daily for 12 days. Tympanic membranes were examined by otomicroscopy on day 12. Then, the membranes were harvested and evaluated histologically by light microscopy.
The tympanic membranes of groups 1 and 2 (saline and non-treated) showed extensive occurrence of myringosclerosis, whereas groups 3 and 4 (treated with N-acetylcysteine) showed lesser occurrence of myringosclerosis in otomicroscopic evaluation (P<0.01). Under light microscopic examination, lamina propria of pars tensa was found thicker in groups 3 and 4 when compared with groups 1 and 2. There was no significant difference between groups 3 and 4 (P: 0.30).
Topically applied N-acetylcysteine was found to be effective in the prevention of sclerotic lesions in myringotomized rat tympanic membranes.
鼓膜硬化症常发生于接受通气管插入术和鼓室成形术的患者。近期研究揭示了鼓膜硬化症的发展与氧衍生自由基之间的关系，并且一些调查表明自由基清除剂可预防鼓膜硬化症的发展。N-乙酰半胱氨酸是一种知名的抗氧化剂和抗炎剂。在本研究中，我们旨在调查N-乙酰半胱氨酸对鼓膜切开术大鼠鼓膜中鼓膜硬化症的预防作用。
20只Sprague-Dawley大鼠双侧鼓膜切开，并分为四组。第1组不接受治疗，第2组用明胶海绵中的局部生理盐水溶液治疗，第3组在明胶海绵中接受局部0.6mg N-乙酰半胱氨酸治疗，第4组在明胶海绵中每天接受1.2mg N-乙酰半胱氨酸治疗，持续12天。在第12天通过耳显微镜检查鼓膜。然后，收集鼓膜并通过光学显微镜进行组织学评估。
第1组和第2组（生理盐水组和未治疗组）的鼓膜在耳显微镜评估中显示出广泛的鼓膜硬化症发生，而第3组和第4组（用N-乙酰半胱氨酸治疗）显示出较少的鼓膜硬化症发生（P<0.01）。在光学显微镜检查下，与第1组和第2组相比，第3组和第4组的紧张部固有层更厚。第3组和第4组之间没有显著差异（P：0.30）。
发现局部应用N-乙酰半胱氨酸可有效预防鼓膜切开术大鼠鼓膜中的硬化性病变。
