The Changes Of Olfactory Ensheathing Cells In A Rat Model Of Acute Rhinosinusitis

Part one The establishment of a rat model of acute rhinosinusitisObjective:To develop a rat model of acute rhinosinusitis by combination of Merocel sponge with Streptococcus pneumoniae.Methods:50 healthy SD rats were randomly divided into experimental group (40) and control group (10).The right noses of experimental group rats were inoculated with 0.1 milliliter Streptococcus pneumoniae and with the help of merocel strips and only equal sterilized saline in control group.Each 10 rats of the experimental groups were sacrificed in first week, second week, third week and fourth week after the inoculation respectively;and the control group rats were sacrificed in first week after the inoculation.Followed were the procedures taken to collect containing nasal cavity and sinuses samples from these animals to observed the severe degree of inflammatory pathology by HE staining program.Results:Various degrees of inflammatory pathology could be determined in the tissue samples of rhinosinusitis mucosa among all the rats in experimental group, with the thickness of epithelial became thinner during the pathology developing course. This kind of pathology began to appear in the first week and was most marked in the second week. But the inflammatory reaction decreased since the third week,and the mucous membrane almost completely recovered to normal in the fourth week. Compared with that of experimental group,there was no pathologieal change in the mucous membrane of the rats in the control group.Conclusion:Combination of Merocel sponge with streptococcus pneumoniae can establish acute bacterial rhinosinusitis model successfully and stably,providing foundation for further exploration of rhinosinusitis corresponding mechanism. Part Two The detection of olfactory function of the ratsObcetive:Explore the feasibility of useing buried food pellet test (buffed food pellet test, BFPT) to detect olfactory function in rats, and analyze whether there was some kind of changes of the olfaction between each group of the rats.Methods:100 healthy SD rats were randomly divided into experimental group (80) and control group (20).On the basis of the first part of the experiment, we adopt the method called"buffed food pellet test, BFPT",which was advanced by Nathan professor,to measure the rats'olfaction, and the time of every rat spending in finding out the food pellet was recorded and analyzed.More than 300s had the food pellet not been found as the reference standard for olfactory dysfunction in rats which was advanced by Linjing. Each 20 rats of the experimental groups were sacrificed in first week, second week, third week and fourth week after the inoculation respectively;and the control group rats were sacrificed in first week.Each rats was detected twice that was interval of 6h between the two detectiong.Results:Compared with the rats in the control group,all the rats in experimental group spent more time in searching the food pellet,with the second-week the longest. Furthermore,the time all overtake 300s during the first three weeks which means varying degrees olfactory dysfunction.Although less than 300s in fourth-week,it was yet more longer than contol group.And the difference between the control group and the experimental group was significant(P<0.01).Conclusions:BFPT combination with histopathology could increase the objectivity of experiment,could be acted as a mehtod to evaluate animals'olfactory function.Part Three The effects of acute rhinosinusitis on the mature olfactory receptor neuronsObjective:To observe the changes of mature ORNs in a rat model of acute rhinosinusitis. Methods:On the basis of the first part of the experiment, the method of immunofluorescence was employed to display the changes of the mature ORNs in the olfactory epithelium(OE). Each 20 rats of the experimental groups were sacrificed first week, second week, third week and fourth week after the inoculation respectively; and the control group rats were sacrificed in first week after the inoculation.Followed were the procedures taken to collect containing the nasal septum samples under anatomic microscope from these animals to detect OMP by immunofluorescence technique in order to analyze the changes of the maturity of the regenerate ORNs.Results:There were numerous mature ORNs in the OE of the control rats while the mature ORNs decreased in all of the experimental rats.This tendency of decrease began to appear from first-week and much more marked in the second week. But the ORNs increased since the third week,and almost completely recovered to normal in the fourth week.Conclusions:Acute rhinosinusitis could result mature ORNs apoptosis increased; meanwhile induced their regeneration increased.But inflammatory conditions was an obstacles to the maturity of the regenerate ORNsPart Four The effects of acute rhinosinusitis on the changes of olfactory ensheathing cellsObjective:To observe the changes of the olfactory ensheathing cells(OECs), providing foundation for further exploration of what role may OECs play in olfactory function and other diseases corresponding mechanism.Methods:On the basis of the third part of the experiment, the method of double labeling was employed to display the changes of OECs in the lamina propria olfactory epithelium(OE). Slices were double labeled by antibody of P75NTR and antibody of GFAP.The cells that were double labled by the antibody of of P75NTR and antibody of GFAP would be OECs.Results:There were numerous mature OECs in the lamina propria(LP) of the control rats while various degrees of reduction od OECs could be determined in the tissue samples of olfactory mucosa among all the rats in experimental group.At the same time, we found there were OECs in the OE in the process of inflammatory. This kind of change began to appear in the first week and was most marked in the second week. A litter of OECs could been detected in the third week while the OECs in the OE almost completely disappeared in the fourth week. Compared with that of experimental group,there were no changes of OECs in OE of the rats in the control group.Conclusions:Acute rhinosinusitis not only resulted ORNs apoptosis increased but also induced OECs decreased in a short time.But following OECs regeneration increased in the LP as well as in the OE and much more marked in the second week until the inflammation disappeared. It may remind that OECs played a significant role in the recovery of olfactory dysfunction...