[The orientation and its significance of water channel protein in the mouse inner ear].

OBJECTIVE: To examine the distribution of various subtypes of water channel protein (aquaporin, Aqp) in various structures of the mouse inner ear. METHODS: Thirty mice with white color were used in this study and were cardiacally perfused. The temporal bones were taken out and were processed and sectioned by paraffin-embedded technique. The sections were labeled with fluorescent antibody by immunohistochemical method. The distribution of Aqp1, 3, 4, 5, 7, 9 were confirmed in the inner ear of mouse. RESULTS: The constant and clear fluorescent reaction could be observed in the inner ear tissue with the first antibody concentration of 1:200 for Aqp-1 and 1:100 for Aqp-3, 7, 9. But the reaction of Aqp-4 and 5 could not be found with the concentration of 1:50, even 1:30. Aqp-1 was labeled in the round window membrane, spiral ligament, endolymphatic sac and duct, utricle and saccule and the wall of inner ear blood vessel; Aqp-3 in the spiral limb, vestibular lip, internal and external sulci, basilar membrane and basilar membrane crest, endolymphatic sac and duct, membranous semicircular canal and utricle and saccular macula; Aqp-7 in the stria vascularis, basilar membrane, Reissner's membrane, utricle and saccule and their maculae; Aqp-9 in the spiral limb, vestibular lip internal and external sulci, Reissner's membrane, membranous semicircular canal, saccule and its macula. CONCLUSION: Aqp-1, 3, 7, 9 were extensively distributed in various tissues of mouse inner ear. Their distribution sites and reaction degree were different, and mainly located in the structures related to the endolymph.