Evidence for the influence of vitamin C on age- and heat exposure-dependent deterioration of biochemical function in rat's liver and kidney

Age and heat exposure-dependent changes in antioxidant enzymes activities in rat's liver and brain mitochondria: role of alpha-tocopherol

To investigate the role of mitochondrial antioxidant capacity during increased susceptibility to heat accompanied by the aging, young and aged Wistar rats were exposed on heat for 60 min. After heat exposure, hepatic and brain mitochondria were isolated. Our results revealed changes in antioxidant enzyme activities in liver and brain mitochondria from young and to a greater extent in aged rats. Our measurements of MnSOD, GPx and GR activity indicate greater reactive oxygen species production from the mitochondria of aged heat exposed in comparison to young heat exposed rats. Also in the aged rats, the effect of alpha-tocopherol treatment in the prevention of oxidative stress occurred as a result of heat exposure, is less pronounced. Taken together, our data suggest that mitochondria in aged rats are more vulnerable and less able to prevent oxidative changes that occur in response to acute heat exposure.

L-2-oxothiazolidine-4-carboxylate influence on age- and heat exposure-dependent redox changes in rat's blood plasma

In the present study, we investigated both the age- and heat exposure-related redox changes of blood plasma by analyzing GSH, thiol status and carbonyl groups. Our results clearly indicated that the plasma redox balance shifted toward oxidation during both aging and acute heat exposure. To further confirm this age- and heat exposure-related redox shift, we quantified the changes in thiol content. The total thiol level was found to be significantly decreased in the aged group. A similar pattern can be explained by low levels of serum GSH in old rats compared to young rats. The significance of the present study are the data showing increased oxidative stress in plasma during aging, attributed to a decrease in major antioxidant components in serum. OTC treatment, in relation to C=O regarded as a marker of oxidative damage was probably much more effective in increasing of GSH synthesis than in prevention of protein oxidation.