Effect of aquaporin 1 and 4 on masticatory muscles degeneration as a result of aging

Abstract

OBJECTIVE: The changes in the mouth structures due to aging cause some structural and functional changes by affecting masticatory muscles over time. The aim of this study was to evaluate the aging-related histopathologic changes and immunohistochemically assessed aquaporin 1 and 4 expressions on masseter and temporal muscles. MATERIAL AND METHODS: 14 Balb/c white mice (50-80 g) were used in this study. Group I consisted of young animals (2-month-individuals) (n = 7) and Group II consisted of older animals (18-month-old) (n = 7). After routine histological follow-ups were made, tissues were stained immunohistochemically for aquaporin 1 and aquaporin 4 as well as with hematoxylin-eosin. RESULTS: It was seen that while the masseter and temporalis muscle tissues showed a high immunoreactivity (+++) for aquaporin 1 and 4 in young mice, they showed a weak immunoreactivity (+) for aquaporin 1 and 4 in old mice (p = 0.001). In the H-score assessment, aquaporin 1 and 4 immunoreactivity was signifi cantly higher in young mice than in old mice (p = 0.002). CONCLUSIONS: Consequently, it was shown that degeneration of the masticatory muscles increased with aging and there was a decrease in intra- and intercellular exchange of substances because of changing aquaporin 1 and aquaporin 4 expressions.