Age-related changes in the activity and expression of manganese superoxide dismutase, and mitochondrial oxidant generation in female and male rats

Abstract

Objective: The aim of this study was to examine the age-and gender-related differences in peroxide production, manganese superoxide dismutase (MnSOD) activity and expression in liver mitochondria of Wistar rats at 12 and 24 months of age. Methods: The chemiluminometric method for peroxide production, fluorometric method for malondialdehyde (MDA) levels, cumene hydroperoxide assay for glutathione peroxidase (GPx), the nitroblue tetrazolium assay for MnSOD activity, and Western-blotting for MnSOD expression were used. Results: Mitochondrial peroxides are increased significantly in both genders as aging proceeded, and females exhibited more profound increment than the males. Mitochondrial SOD and GPx activities remained unaltered between 12 and 24 months of age, with no difference between two genders. The gender-and age-related differences were observed in MnSOD expression (p<0.01). The SOD activity per expressed enzyme protein was significantly decreased in 24-month-old animals of both genders (p<0.01). Female rats had a significantly lower ratio than their male counterparts (p<0.05). In females, the expression was not associated with the activity of MnSOD, while a positive correlation existed between these parameters in males (r=0.573, p=0.001). Enzyme expression was found to be significantly higher in female rats as compared to their male counterparts. Liver mitochondria are less prone to oxidative damage in female rats compared to males as observed at 12 and 24 months of age Conclusions: An involvement of factors other than estrogen seems to be relevant for the difference in the MnSOD activity and expression pattern between two genders. Key Words: oxidative stress, aging, gender differences, MnSOD, rat liver Conflict of interest: The authors declare that there is no conflict of interest. ÖZETAmaç: Çalışmamızda, 12 ve 24 aylık Wistar cinsi sıçanların karaciğer mitokondrilerinde yaş ve cinsiyet ile ilişkili olarak peroksit üretimi, mangan süperoksit dismutaz (MnSOD) aktivitesi ve ekspresyonundaki ortaya çıkan değişikliklerin incelenmesi amaçlanmıştır. Yöntemler: Peroksit üretimi kemilümünometrik, malondialdehit (MDA) düzeyi florometrik, glutatyon peroksidaz (GPx) kümen hidroperoksit, MnSOD aktivitesi nitroblue tetrazolium yöntemleri ile MnSOD ekspresyonu ise western blotting yöntemi ile ölçülmüştür. Bulgular: Her iki cinsiyette de yaş ilerledikçe SOD ve GPx aktivitelerinde anlamlı bir değişiklik oluşmadığı, mitokondriyal peroksit üretiminin ise anlamlı şekilde arttığı ve bu artışın dişi sıçanlarda daha belirgin olduğu saptanmıştır. MnSOD ekspresyonun da yaş ve cinsiyete bağlı olarak değişiklikler gösterdiği (p<0.01) ve eksprese edilen enzim proteini başına düşen enzim aktivitesinin 24 aylık sıçanlarda her iki cinsiyette de anlamlı olarak azalmakla birlikte (p<0.01) bu azalmanın dişi sıçanlarda erkek sıçanlara göre daha belirgin (p<0.05) olduğu görülmüştür. Erkek sıçanlarda MnSOD aktivitesi ile ekspresyonu arasında pozitif bir korelasyon (r=0.573, p=0.001) olduğu saptanmış, dişi sıçanlarda ise böyle bir il...

Antioxidant Expression Response to Free Radicals in Active Men and Women Fallowing to a Session Incremental Exercise; Numerical Relationship Between Antioxidants and Free Radicals

“…Our findings also showed that MnSOD enzyme gene expression had not significantly increased in active men, however, MnSOD gene expression changes were significant in women. These findings are consistent with those obtained by Ademoglu et al The investigators reported that MnSOD activity is higher in women than in men ( 39 ). Therefore, it is likely to indicate the higher influence of estrogen on MnSOD ( 37 ).…”

Superoxide Dismutase in Psychiatric Diseases

“…A significant negative correlation was obtained between SOD activity and the duration of the schizophrenic disease [32]. In an animal model it was shown (Wistar rats) that mitochondrial SOD and GPx activities remaind unaltered between 12 and 24 months Superoxide Dismutase in Psychiatric Diseases DOI: http://dx.doi.org/10.5772/intechopen.99847 of age, with no difference between two genders, while the gender and age-differences were observed in MnSOD expression [42]. Schizophrenic patients with tardive dyskinesia (TD) showed lower plasma MnSOD activity [43], CuZnSOD activity and total antioxidant status levels, but higher MDA levels than those without TD.…”