ObjectivesAntioxidative enzyme efficiency changes in some organs with age. However, no study has been conducted on age-related antioxidant enzyme changes in tongue. In the present study, the authors investigated the activities of four antioxidative enzymes and their protein expressions in the tongues of young and old Fischer 344 rats.MethodsAge-dependent changes in the enzyme activities of total superoxide dismutase (SOD), Mn-SOD, Cu/Zn-SOD, catalase (CAT), and glutathione peroxidase (GPx) were determined using chemical kits, and the protein expressions levels of these enzymes by Western blotting. The study was conducted using rats aged 7 months (the young group, n=8) and 22 months (the old group, n=8).ResultsTotal SOD, Cu/Zn-SOD, and GPx activities in the tongues of old rats were lower than in young rats, and similarly, corresponding protein expressions were downregulated in old rats. On the other hand, although the protein expressions of Mn-SOD and CAT were lower in old rats, their enzyme activities were not.ConclusionThe results of this study provide a possible mechanism for the tongue aging process, as in old Fischer 344 rats the antioxidant defense system was diminished with respect to enzyme activity levels and protein abundances.

Objectives Previously the authors reported age-related changes in the activities of anti-oxidative enzyme activities and protein expressions in the tongues of rats. Because more information is required about relations between aging and oxidative stress and anti-oxidative enzyme efficiency, the authors investigated differences between the expression of master regulator of anti-oxidative enzymes (nuclear factor erythroid 2-related factor 2 [Nrf2]), levels of reactive oxygen species (ROS), and mitochondrial structures in the tongues of young and aged Fischer 344 rats.Methods Age-dependent changes in Nrf2 protein and ROS were determined by Western blotting and using chemical kits, respectively. Tongue specimens were examined by electron microscopy. The study was conducted using rats aged 7 months (young, n=8) or 22 months (old, n=8).Results Nrf2 protein levels in the tongues of aged rats were lower than in young rats. ROS levels were higher in older rats and mitochondrial structural deficits were observed their tongues. Three young rats showed moderate mitochondrial degeneration, whereas profound degeneration with mitochondrial cristae disruption, swelling, rupture, or intramitochondrial vacuole formation was observed in all 8 old rats. Notably, mitochondrial rupture was observed in 5 old rats.Conclusion Antioxidant defense systems of old rats were compromised by Nrf2 deficiency, which could lead to the deleterious accumulation and release of ROS and probably mitochondrial structural deficits in aged tongue tissues.