Of Gansu Zokor Nasal Tissue Anatomy And Hypoxic Conditions, Immune Response Of Nasal Mucosa Containing Sp And Cgrp Fibers

Myospalax cansus is a subterranean rodents. It has to be faced with multiple pressures of survival due to living in the confined tunnel environment,and hypoxia is one of the pressures. Substance P (SP) and calcitonin gene-related peptide(CGRP) in primary sensory neurons are predominant signal substances to transmite sensory information. The change of SP and CGRP content within peptidergic nerve fibers in hypoxic condition shows how Myospalax cansus adapts to the harmful stimulus.In this paper, the nasal cavity of Myospalax cansus were studied by using histology and anatomical approach. We revealed the differences between Myospalax cansus and other rodents in the nasal cavity. Using immunohistochemical technique,the distributing density of SP-immunoreactive and CGRP-immunoreactive nerve fibers in the nasal mucosa was compared between normoxic and chronically hypoxic Myospalax cansus (10.5%O₂ for 8 hours everyday within 1 month) . We tried to find how Myospalax cansus adapts to hypoxic condition in the upper respiratory tract and drew the following conclusions:1. Be similar to other rodents, the nasal mucosa of Myospalax cansus is divided into the vestibular mucosa, respiratory mucosa and olfactory mucosa, and the epithelial cell type of the nasal mucous is also divided into squamous epithelium, transitonal epithelium ,respiratory epithelium and olfactory epithelium. From the outside to inside of the nasal mucous ,the epithelium is followed by basal lamina and lamina propria. The olfactory mucosa accouts for a large proportion of the nasal mucosa.It almost covers the majority of maxilloturbinate and half of the nasal septum, which features was adapted to well-developed sense of smell of Myospalax cansus. The goblet cell in respiratory mucosa can protect the epithelium from bacteria, viruses as result of secreting mucin, and it constitutes the first line of defense. But the goblet cells of respiratory mucosa in Myospalax cansus are few, which may be one of the reasons why the immunity of Myospalax cansus with reared in the laboratory is compromised.2. In nasal mucosa in hypoxic Myospalax cansus , the relative density of SP- and CGRP-immunoreactive nerve fibers was also higher than normoxic mucosa(p<0.05), but that did not reach very significant levels, In addition, in hypoxic Myospalax cansus nasal mucosa, the rate of increase of peptidergic nerves (be compared with Myospalax cansus in normoxic conditions) was significantly smaller than the SD rats, and has little difference between normxic and hypoixic conditions (the ratio of them was less than 1.5). It suggests that hypoxic environment has no greater impact on upper respiratory tract of Myospalax cansus. Thus, we thinked that the upper respiratory tract in Myospalax cansus was no highly sensitive to hypoxic entironment , which adated to the extremely living environment. However, in hypoxic trachea mucosa, lung mucosa ,the density change of peptidergic nerve fibers have been not studied. The hypoxic adptation in whole respiratory tract in Myospalax cansus has still been further researched.