[Changes of Histology and Ultrastructure of Otopoint "stomach" Area in Rabbits with Chronic Gastritis].

OBJECTIVE:To observe the histological and ultrastructural changes of the otopoint "Stomach" (MA-IC) area in chronic gastritis rabbits so as to provide a foundation for auricular acupoint diagnosis and treatment.METHODS:A total of 20 New Zealand rabbits (half male and half female) were randomly and equally divided into control and model groups. The chronic gastritis model was established by gavage of 5% sodium salicylate each day for 5 weeks, while the rabbits of the control group received gavage of clear water at the same volume. Morphological changes of the tissues of gastric mucosa, otopoint "Stomach" and auricular control point were observed under light microscope after staining with hematoxylin-eosin (H.E.), and given scores (0-3 points) according to the levels of inflammatory cells. The ultrastructural changes of the otopoint "Stomach" tissue were observed under transmission electronic microscope (TEM).RESULTS:H.E. staining revealed smoothness of the gastric smooth muscle with no or a few of inflammatory cells in the control group, and appearance of gastric mucosal hemorrhage and erosion, slightly disordered epithelial glands and infiltration of a large number of lymphocytes in the mucosal layer with some clustered lymphocyte aggregation foci in the model group. The pathological score of gastric mucous in the model group was significantly higher than that in the control group (P<0.01). Under light microscope, no obvious changes were observed in the skin of the otopoint "Stomach" of the control group and the control point of the model group, whereas hyperplasia and abscission in the epidermic cuticle and spinous layer and basal layer, dermal tissue and inflammatory cell infiltration were observed in the otopoint "Stomach" of the model group. Results of TEM observation showed no significant changes in the ultrastructure of the otopoint "Stomach" in the control group, and swollen and vacuolated epidermal keratinocyte mitochondria, reduced keratin filament aggregation, widened local cell space, unclear desmosome structure, activation of the dermal fibroblasts, and an increase of the myelinated nerve mitochondria in the "Stomach" region in the model group.CONCLUSION:The otopoint "Stomach" tissue has structural damage and hyperplasia in chronic gastritis rabbits, suggesting a special correlation between the otopoint "Stomach" and gastric tissue, hence, providing a morphological basis for otopoint diagnosis and treatment.