Na+,K+-ATPase activity and subunit protein expression: Ontogeny and effects of exogenous and endogenous steroids on the cerebral cortex and renal cortex of sheep

Chang Ryul Kim, Grazyna B. Sadowska, Stephanie A. Newton, Maricruz Merino, Katherine H. Petersson, James F. Padbury, Barbara S. Stonestreet

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

We examined the effects of development, exogenous, and endogenous glucocorticoids on Na+,K+-ATPase activity and subunit protein expression in ovine cerebral cortices and renal cortices. Ewes at 60%, 80%, and 90% gestation, newborns, and adults received 4 dexamethasone or placebo injections. Cerebral cortex Na+,K+-ATPase activity was higher (P <.05) in placebo-treated newborns than fetuses of placebo-treated ewes and adults, α1-expression was higher at 90% gestation than the other ages; α2-expression was higher in newborns than fetuses; α3-expression was higher in newborns than 60% gestation; α1-expression was higher in newborns than the other ages, and α2-expression higher at 60% than 80% and 90% gestation, and in adults. Renal cortex Na+,K+-ATPase activity was higher in placebo-treated adults and newborns than fetuses. Cerebral cortex Na+,K+-ATPase activity was higher in dexamethasone- than placebo-treated adults, and α1-expression higher in fetuses of dexamethasone- than placebo-treated ewes at 60% and 80% gestation. Renal cortex Na+,K+-ATPase activity and α1-expression were higher in fetuses of dexamethasone- than placebo-treated ewes at each gestational age, and α1-expression was higher in fetuses of dexamethasone- than placebo-treated ewes at 90% gestation and in dexamethasone- than placebo-treated adults. Cerebral cortex Na+,K+-ATPase activity, α1-expression, α1-expression, and renal cortex α1-expression correlated directly with increases in fetal cortisol. In conclusion, Na +,K+-ATPase activity and subunit expression exhibit specific developmental patterns in brain and kidney; exogenous glucocorticoids regulate activity and subunit expression in brain and kidney at some ages; endogenous increases in fetal cortisol regulate cerebral Na+,K +-ATPase, but exogenous glucocorticoids have a greater effect on renal than cerebral Na+,K+-ATPase.

Original languageEnglish
Pages (from-to)359-373
Number of pages15
JournalReproductive Sciences
Volume18
Issue number4
DOIs
StatePublished - 2011 Apr 1

Keywords

  • K+-ATPase
  • Na+
  • brain
  • glucocorticoids
  • kidney

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