Sex-dependent differences in the effects of aging on antioxidant defense mechanisms of rat liver

Rikans, Lora E.; Moore, Dennis; Snowden, Cynthia D.

doi:10.1016/0304-4165(91)90061-k

Cited by 106 publications

(43 citation statements)

References 34 publications

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“…CAT activities declined with age in male rat livers; however, we found a significant increase with age in female rat livers (Carrillo et al 1992a). Rikans et al (1991) also previously reported that there is no decline in SOD enzyme activities with age in rat livers. Interestingly, they also reported an agedependent decline in CAT activities in male rat livers, and conversely an age-dependent increase in female rat livers (Rikans et al 1991), as we ourselves found (Carrillo et al 1992a).…”

Section: An Altered Enzyme Hypothesis For Sodsupporting

confidence: 61%

“…Rikans et al (1991) also previously reported that there is no decline in SOD enzyme activities with age in rat livers. Interestingly, they also reported an agedependent decline in CAT activities in male rat livers, and conversely an age-dependent increase in female rat livers (Rikans et al 1991), as we ourselves found (Carrillo et al 1992a). I think when Gershon found a decrease in SOD activities in his rat liver, he never doubted that it was not true in other animal models, probably because he was also biased by the idea of J. Ek that everything is going down with age.…”

Section: An Altered Enzyme Hypothesis For Sodmentioning

confidence: 58%

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What really declines with age?

Kitani¹

2007

AGE

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In order to understand the basic mechanisms underlying the organismic aging process, considerable efforts have been devoted in the last half-century to biochemical (enzyme activity) alterations in specific tissues and organs of various organisms associated with aging. When a decline in enzyme activities with age has been found in a study, especially for key enzymes such as antioxidant enzymes, the results have often been interpreted as a cause for the aging of the entire body. Retrospectively, however, these changes turned out to be so variabledepending on species, strains and sexes of animalsthat the interpretation of these results in general terms of aging became invalid. Further, unlike the prediction for the whole human body, many enzyme activities in a vital organ, such as the liver, remained unchanged, as long as the old subjects remained healthy. However, enzyme activities in old animals and humans are often more susceptible to morbidities and frailties, which themselves are often accompanied by infections and malnutrition. Despite the rather stable enzyme functions in the liver with age, a distinct and progressive decline in the lateral diffusion coefficient of proteins of hepatocyte plasma membranes has been demonstrated by fluorescence recovery after photobleaching (FRAP), which was implicated as the cause for the decline of hepatocyte functions such as ouabain (and taurocholate) hepatic uptake and their eventual biliary excretion. Since a similar decline in protein diffusion coefficients was observed in brain and muscle cells, it is likely that these changes are occurring in common with many cell types of the body, thus causing a delay in transmembrane transport of endogenous and exogenous substances whose transports are mediated by membrane proteins. In attempts to prolong the life spans of animals other than by calorie restriction, but instead using deprenyl or tetrahydrocurcumin, works by the author and coworkers are introduced and discussed. Despite limited success along these lines thus far, further attempts are encouraged, primarily to understand the mechanisms underlying organismic aging processes and to find a practical way to prolong the health span of the elderly.

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Section: An Altered Enzyme Hypothesis For Sodsupporting

confidence: 61%

Section: An Altered Enzyme Hypothesis For Sodmentioning

confidence: 58%

What really declines with age?

Kitani¹

2007

AGE

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“…The GPx level of female rats was significantly higher than those of male rats. These results agree with previous finding within different sex and in aging age (10,16,18). According to Rao (18) the age-related changes in the activities of GPx were paralled by a similar change in the relative level of the mRNAs coding for this enzyme.…”

Section: Discussionsupporting

confidence: 92%

“…We also have a similar results in ageand sex-related changes with Rikans et a1. (16). According to Rikans et al (16), the effects of aging on antioxidant levels may also depend on the strain of the rats.…”

Section: Discussionmentioning

confidence: 99%

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The effects of exogenous glutathione on reduced glutathione level, glutathione peroxidase and glutathione reductase activities of rats with different ages and gender after whole-body Γ-irradiation

İnal

Akgün

Kahraman

2003

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Age-and gender-related changes on reduced glutathione (GSH) level, glutathione peroxidase (GPx) and glutathione reductase (GR) activities in the liver of rat exposed to different dose of whole-body g-ray irradiation were determined. In addition, the effect of administration of exogenous GSH on endogenous GSH levels, GPx and GR activities was investigated. For this aim, male and female rats aged 1 and 5 moths were divided into two groups as g-ray and g-ray+GSH. Both groups were again divided into four groups as irradiated with 2, 4, 6 and 8 Gy doses. GSH level and GPx activity did not change with age while GR activity was decreased with age. Gender-dependent changes in GPx and GR activities were observed, but GSH values were not affect by sex. GSH levels, GPx and GR activities were not obsewed dose-associated changes of g-irradiation. GSH level and GPx activity in the 8Gy group were increased by GSH. GR activities of old male rats were found to be increased by glutathione in the 6 and 8Gy groups. These results indicate that radiation and administration of exogenous GSH affect gender-and age-dependent GSH level, GPx and GR activities in the rats.

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