摘要目的 观察大鼠急性鼻-鼻窦炎致嗅觉障碍模型中嗅黏膜微结构的变化情况,为进一步探索鼻-鼻窦炎对嗅觉功能影响的可能机制提供实验基础.方法 健康SD大鼠100只采用随机数字表法分为实验组(80只)和对照组(20只).实验组使用肺炎链球菌建立大鼠急性鼻-鼻窦炎动物模型,运用嗅觉功能行为学(食物小球埋藏法)检测实验模型的嗅觉功能,采用SPSS 13.0统计软件对该数据进行DunnettT3检验.分别于接种细菌后第1(A组)、2(B组)、3(C组)、4周(D组)各处死20只实验组大鼠;对照组(E组)大鼠未接种细菌且均于第1周处死.取包含鼻顶部嗅黏膜的鼻腔鼻窦黏膜组织,制作冰冻切片、采用免疫荧光技术观察嗅黏膜中成熟嗅感觉神经元和嗅鞘细胞的形态变化.结果 嗅觉功能行为学检测实验结果显示,A、B、C、D组大鼠找到食物小球的时间[分别为(402.9±9.3)、(453.7±7.3)、(351.9±8.9)、(278.7±8.1)s]均较对照组[(178.3±6.6)s]长,差异有统计学意义(P值均＜0.01).实验组嗅黏膜较对照组均有不同程度的成熟嗅感觉神经元数量减少及黏膜上皮层变薄倾向,尤以造模后第2周最为严重,至第4周时最轻.实验组大鼠嗅黏膜固有层嗅鞘细胞在出现短时间的减少后,自第2周起先于嗅感觉神经元出现数量增加.至第4周,固有层的嗅鞘细胞基本恢复正常.所有实验组动物嗅上皮均有少量嗅鞘细胞生长.结论 发生急性鼻-鼻窦炎时,嗅黏膜中成熟嗅感觉神经元和嗅鞘细胞均出现数量减少.但嗅鞘细胞先于嗅感觉神经元增多,并且嗅上皮亦出现少量嗅鞘细胞生长.

abstractsObjective To observe the microstructural changes of olfactory mucosa in rat model with acute rhinosinusitis leading to olfactory dysfunction,and to provide foundation for further exploration of corresponding mechanism.Methods On the basis of prior successfully established rat model of acute rhinosinusitis through inoculation with Streptococcus pneumoniae and with the help of merocel strips,one hundred healthy SD rats were randomly divided into experimental group (80) and control group (20).After inoculation,every 20 rats in the experimental groups were sacrificed in first week,second week,third week and fourth week respectively; and all rats in the control group were sacrificed in first week after the inoculation.Before the rats were sacrificed,the method called “buffed food pellet test,BFPT” was adopted,which was advanced by professor Nathan,to measure the rats’ olfaction,and the time of every rat spending in finding out the food pellet was recorded and analyzed.BFPT showed that the rats in experimental group spent (402.9±9.3),(453.7 ±7.3),(351.9±8.9),(278.7 ±8.1) s respectively in searching the food pellet,which were more than the rats in the control group[ ( 178.3 ±6.6) s].Then the olfactory mueosa was collected under anatomic microscope from all the rats to make frozen section and detect the changes of mature olfactory receptor neurons (ORN) and olfactory ensheathing cells (OEC) by immunofluorescence technique.Results The reduction of ORN in various degrees could be detected in the tissue samples of olfactory mucosa among all the rats in experimental group,with a tendency to become thinner in the thickness of epithelial lamina during the inflammation developing course.This kind of pathology was most marked in the second week and it gradually developed into the stage showing the lesion being the feeblest in the forth week following the beginning of modeling.Although the number of olfactory ensheathing cells appeared reduction in the first week following the beginning of modeling as well,it came to increase from the second week before olfactory receptor neurons and almost completely recovered to normal in the fourth week.In addition,some olfactory ensheathing cells could be detected in the tissue samples of olfactory mucosa among all the rats in experimental group.Conclusions Both mature olfactory sensory neurons and olfactory ensheathing cells appeared to reduction when sinonasal mucosa taken place acute rhinosinusitis.But the number of olfactory ensheathing cells increased faster than olfactory sensory neurons.In addition,some olfactory ensheathing cells could be detected in the olfactory epithelium.