离体豚鼠耳蜗灌流一氧化氮供体对耳蜗组织中环磷酸鸟苷含量的影响

Effect of in Vitro Nitric Oxide Donor Perfusion on cGMP Content in Guinea Pig Cochlea

目的 通过对离体的豚鼠耳蜗即刻灌流一氧化氮供体 (DEA -NO)及可溶性鸟苷酸环化酶 (sGC)抑制剂 (ODQ) ,来改变耳蜗组织中环磷酸鸟苷 (cGMP)含量 ,以便进一步研究一氧化氮 /环磷酸鸟苷 (NO/cGMP)途径在耳蜗中的调节作用。方法 2 4只纯种白色雄性豚鼠完全随机分为三组 ,分别灌流人工外淋巴基础液、DEA -NO/人工外淋巴基础溶液、ODQ +DEA -NO/人工外淋巴基础溶液 ,收集耳蜗组织标本 ;用放射免疫的方法测定耳蜗组织中cGMP的含量。结果 向离体耳蜗中灌注 1mMDEA -NO溶液可以引起耳蜗组织中cGMP含量的显著增加 ,先灌注ODQ ,后灌注 1mMDEA -NO ,耳蜗组织中cGMP合成量明显少于单独灌注 1mMDEA -NO ,但仍高于对照组。结论 对离体的豚鼠耳蜗即刻灌流一氧化氮供体 (DEA -NO)及可溶性鸟苷酸环化酶 (sGC)抑制剂 (ODQ) ,可以作用于NO/cGMP途径 ,改变耳蜗组织中cGMP含量 ,同时用放射免疫测定耳蜗组织中cGMP含量的方法是可行的。

Objective To further study the physiological effect of the NO/cGMP pathway in the inner ear,to observe the changes of cGMP content in the cochlear tissue through perfusing DEA-NO(a NO donor) and ODQ(an inhibiter of soluble guanylyl cyclase)in vitro. Methods 24 pure albino male guinea pigs were randomly divided into three groups and the freshly dissected cochleae were perfused with artificial perilymph basal solution (APL), DEA-NO/APL and ODQ/APL separately. The cochleae were collected and the content of cGMP in the cochlear tissue was measured by radio-immunity assay method. Results The content of cGMP inereased markedly after perfusion with 1 mM DEA-NO while cGMP level decreased markedly in the group perfused with ODQ, the second group, but it was still considerably higher than that of the control group. Conclusion The cGMP concentration in the cochlear tissue can be changed by perfusing DEA-NO and ODQ into newly dissected cochlea. The method of assessing cGMP content in the inner ear by redio-immunity is feasible.