二甲胺四环素对顺铂作用后耳蜗神经元中iNOS表达的影响

目的探讨二甲胺四环素对顺铂耳蜗神经元毒性的拮抗作用。方法体外培养出生3d的大鼠耳蜗基底膜,分别以顺铂以及顺铂联合二甲胺四环素作用耳蜗基底膜,应用免疫荧光染色方法观察螺旋神经节的变化及免疫蛋白印记方法检测iNOS蛋白表达情况。结果顺铂能够引起耳蜗神经元数目减少约30%,部分神经元形态变小并且不规则。预先应用二甲胺四环素,存活的耳蜗神经元数目明显多于单纯顺铂组;顺铂作用后耳蜗组织中的iNOS蛋白表达和NO含量明显增高(P<0.01),而联合应用二甲胺四环素,耳蜗组织中的iNOS蛋白表达和NO含量明显降低。结论二甲胺四环素可以通过抑制iNOS蛋白表达而减轻顺铂所致的耳蜗神经元损害。

Changes of cisplatin induced iNOS protein expression in cochlear cultures after treatment with minocycline

Objective To study the effects of cisplatin on the inducible nitric synthase (iNOS) protein expression in cochlear cultures after minocycline treatment.Methods The neonatal rats cochlear membrane was isolated and cultured in DMEM/F12 medium with 10% FBS.Cochlear cultures were treated with cisplatin or cisplatin combined with minocycline for 24h.Immunostaining of NF-200kD was used to identify and count surviving SGNs and Western Blot was used to detect the expression of iNOS protein in cochlear cultures.Results The number of surviving SGNs decreased approximately 30% following cisplatin treatment for 24h.Some SGN were smaller and out of shape.In minocycline pretreatment group,the number of surviving SGNs were significantly increased than only cisplatin treatment.Moreover the expression of iNOS protein and NO concentration were down-regulation.Conclusion Minocycline can protect against cisplatin ototoxicity through suppressly the expression of iNOS protein in cochleas.