Glucocorticoid regulation of ornithine decarboxylase in the postnatal rat lung

摘要: Abstract Ornithine decarboxylase (ODC) is thought to play a critical role in pulmonary development. The purpose of this study was characterize the effects dexamethasone on ODC gene expression and enzyme activity lung rat pups. Subcutaneous administration (10 mg kg ) shown suppress 2-, 6- 10-day-old rats for as long 24 h after injection. In contrast, treatment stimulated liver indicating that inhibition tissue specific. Contrary expectation, glucocorticoid enhanced indicated by an increased accumulation mRNA transcripts. latter effect associated with heightened c-myc max mRNAs, encoded proteins which act transactivators gene. Dexamethasone did not alter levels “antizyme” (AZ), inducible protein specifically promotes degradation enzyme. However, lack AZ induction does necessarily mean mechanism decrease dexamethasone-treated animals. results obtained indicate glucocorticoids can downregulate activity, mediated post-transcriptional rather than transcriptional mechanisms. These findings are consistent idea endogenous important modulation early