Objective: To investigate the effects of dopamine on olfactory function and inflammatory injury of olfactory bulb in mice with allergic rhinitis (AR). Methods: AR mouse model was established by using ovalbumin (OVA), and the mice were divided into two groups: olfactory dysfunction (OD) group and without OD group through buried food pellet test (BFPT). The OD mice were randomly divided into 2 groups, and OVA combined with dopamine (3, 6, 9 and 12 days, respectively) or OVA combined with an equal amount of PBS (the same treatment time) was administered nasally. The olfactory function of mice was evaluated by BFPT. The number of eosinophils and goblet cells in the nasal mucosa were detected by HE and PAS staining. Western blotting, immunohistochemistry or immunofluorescence were used to detect the expression of olfactory marker protein (OMP) in olfactory epithelium, the important rate-limiting enzyme tyrosine hydroxylase (TH) of dopamine, and the marker proteins glial fibrillary acidic protein (GFAP) and CD11b of glial cell in the olfactory bulb. TUNEL staining was used to detect the damage of the olfactory bulb. SPSS 26.0 software was used for statistical analysis. Results: AR mice with OD had AR pathological characteristics. Compared with AR mice without OD, the expression of OMP in olfactory epithelium of AR mice with OD was reduced (F=26.09, P<0.05), the expression of GFAP and CD11b in the olfactory bulb was increased (F value was 38.95 and 71.71, respectively, both P<0.05), and the expression of TH in the olfactory bulb was decreased (F=77.00, P<0.05). Nasal administration of dopamine could shorten the time of food globule detection in mice to a certain extent, down-regulate the expression of GFAP and CD11b in the olfactory bulb (F value was 6.55 and 46.11, respectively, both P<0.05), and reduce the number of apoptotic cells in the olfactory bulb (F=25.64, P<0.05). But dopamine had no significant effect on the number of eosinophils and goblet cells in nasal mucosa (F value was 36.26 and 19.38, respectively, both P>0.05), and had no significant effect on the expression of OMP in the olfactory epithelium (F=55.27, P>0.05). Conclusion: Dopamine can improve olfactory function in mice with AR to a certain extent, possibly because of inhibiting the activation of glial cells in olfactory bulb and reducing the apoptotic injury of olfactory bulb cells.
目的： 研究多巴胺对变应性鼻炎（AR）小鼠嗅觉功能和嗅球炎性损伤的影响。 方法： 利用卵清蛋白（OVA）构建AR小鼠模型，通过埋藏食物小球实验将其分为有嗅觉障碍（olfactory dysfunction，OD）组和无OD组。选择OD小鼠，再将其随机分为2组，分别经鼻给予OVA联合多巴胺（时间分别为第3、6、9、12 d）或OVA联合等量的磷酸盐缓冲液（相同处理时间）。采用埋藏食物小球实验评估小鼠嗅觉功能。HE和PAS染色后观察鼻黏膜嗜酸粒细胞、杯状细胞的数量，蛋白免疫印迹、免疫组织化学或免疫荧光法检测小鼠嗅黏膜嗅觉标志蛋白（olfactory marker protein，OMP）的表达，以及嗅球中多巴胺重要的限速酶酪氨酸羟化酶（tyrosine hydroxylase，TH）和胶质细胞标志蛋白胶质纤维酸性蛋白（glial fibrillary acidic protein，GFAP）、CD11b的表达。TUNEL染色检测嗅球的损伤情况。采用SPSS 26.0软件进行统计学分析。 结果： AR伴OD小鼠鼻黏膜具有AR的组织病理学特征。与AR不伴OD小鼠相比，AR伴OD小鼠嗅黏膜OMP的表达减少（F=26.09，P<0.05），嗅球中GFAP和CD11b的表达增加（F值分别为38.95和71.71，P值均<0.05），嗅球中TH表达减少（F=77.00，P<0.05）。经鼻给予多巴胺可在一定程度上缩短小鼠发现食物小球时间，与对照模型组相比，多巴胺可下调嗅球中GFAP和CD11b的表达（F值分别为6.54和46.11，P值均<0.05），减少嗅球中凋亡细胞数量（F=25.64，P<0.05），但对鼻黏膜嗜酸粒细胞和杯状细胞数量无显著影响（F值分别为36.26和19.38，P值均>0.05），对嗅黏膜OMP的表达亦无显著影响（F=55.27，P>0.05）。 结论： 多巴胺可在一定程度上改善AR小鼠嗅觉功能，可能原因是抑制嗅球中胶质细胞的激活，减少嗅球细胞的凋亡损伤。.