It has been suggested that alterations in Na + ,K + -ATPase mediate the development of several aging-related pathologies, such as hypertension and diabetes. Thus, we evaluated Na + ,K + -ATPase function and H 2 O 2 production in the renal cortex and medulla of Wistar Kyoto (WKY) rats at 13, 52 and 91 weeks of age. Creatinine clearance, proteinuria, urinary excretion of Na + and K + and fractional excretion of Na + were also determined.The results show that at 91 weeks old WKY rats had increased creatinine clearance and did not have proteinuria. Despite aging having had no effect on urinary Na + excretion, urinary K + excretion was increased and fractional Na + excretion was decreased with age. In renal proximal tubules and isolated renal cortical cells, 91 weeks old rats had decreased Na + ,K + -ATPase activity when compared to 13 and 52 weeks old rats. In renal medulla, 91 weeks old rats had increased Na + ,K + -ATPase activity, paralleled by an increase in protein expression of α 1 -subunit of Na + ,K + -ATPase. In addition, renal H 2 O 2 production increased with age and at 91 weeks of age renal medulla H 2 O 2 production was significantly higher than renal cortex production.The present work demonstrates that although at 91 weeks of age WKY rats were able to maintain Na + homeostasis, aging was accompanied by alterations in renal Na + ,K + -ATPase function. The observed increase in oxidative stress may account, in part, for the observed changes. Possibly, altered Na + ,K + -ATPase renal function may precede the development of age-related pathologies and loss of renal function.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.