| Objective: In this study,the effects of different administration methods after administration of nerve growth factor(NGF)on the foraging time of a mouse model of olfactory dysfunction were compared by analyzing the efficacy of NGF combined with olfactory training.Method:(1)Experimental grouping: Forty-eight SPF BALB/c male mice aged 6-7 weeks were selected and divided into olfactory training combined with NGF atomization group(group A,n=19),olfactory training combined with NGF intramuscular injection group(group B,n=19),and a pure olfactory training group(group C,n=11)by random number table.Groups A and B were considered to be the experimental groups and group C was the control group.(2)To create an animal model of olfactory dysfunction,mice in groups A,B,and C were administered 3-methylindole(3-MI)at a concentration of 15 mg/ml and a dose of 150 mg/kg.(3)Intervention: The three groups of mice were administered four different water-soluble olfactories(rose essential oil,lemon essential oil,clove essential oil,and eucalyptol)via nasal nebulization inhalation(30 minutes/olfactory,2times/day)on the first day after modeling.In group A,based on olfactory training,the atomized concentration intramuscular was increased to 15 μg/ml,and the dose was adjusted to 45.5 μg/kg of NGF.On the basis of olfactory training,the injection concentration and dose of NGF for group B were increased to be the same as in group A.In both groups,NGF was administered once daily.No NGF drug intervention was performed in group C.A total of 28 days of training were performed for all groups.Foraging experiments were conducted before modeling and on the 7th,14 th,and 28 th day after.Recovery of the sense of smell of the mice was compared and analyzed according to the foraging time.After 4 weeks,the mice in each group were sacrificed to obtain the olfactory mucosa.The amount of olfactory marker protein(OMP)was detected by immunohistochemistry,and the recovery of olfactory function was further objectively evaluated from a morphological point of view.Result:(1)Comparison of foraging time: On days 7,14,and 28 after modeling,group A was statistically significant compared with the control group(P<0.05).The foraging time of group B was shorter than that of the control group on the 14 th and 28 th day,and P<0.05 compared with the control group only on the 28 th day.The foraging time of group A was shorter than that of group B on the 7th,14 th,and 28 th day.The difference between the A and B groups was only statistically significant on the 7th and 14 th day,P<0.05,and the difference was not statistically significant on the 28 th day,P=0.063.(2)Comparison of the number of OMP: The number of OMP-positive cells under the olfactory mucosa of mice in groups A and B was higher than that in the control group,P<0.05.The number of OMP-positive cells in group A was higher than that in group B,but the difference was not statistically significant,P>0.05.Conclusion: Atomization or intramuscular injection of NGF combined with olfactory training can better help restore olfactory function and can accelerate olfactory neuron repair and smell epithelial regeneration,in mice with olfactory dysfunction caused by3-MI.The onset of effect of nebulization was rapid compared with a slower onset of effect of the intramuscular injection. |
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