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RECORD NUMBER: 15 OF 33

OLS Field Name OLS Field Data
Main Title Dose-Dependent Effect of Prenatal Dexamethasone Treatment on beta-Adrenergic Receptor Coupling to Ornithine Decarboxylase and Cyclic AMP.
Author Bian, X. P. ; Seidler, F. J. ; Bartolome, J. ; Kavlock, R. J. ; Bartolome, M. ;
CORP Author Duke Univ. Medical Center, Durham, NC. Dept. of Pharmacology.;Health Effects Research Lab., Research Triangle Park, NC.;Public Health Service, Rockville, MD.
Publisher c1990
Year Published 1990
Report Number EPA-R-813769 ;PHS-HD-09713; EPA/600/J-90/523;
Stock Number PB91-211409
Additional Subjects Dexamethasone ; Beta adrenergic receptors ; Adenosine cyclic monophosphate ; Ornithine decarboxylase ; Heart ; Kidney ; Isoproterenol ; Animal pregnancy ; Rats ; Dose-response relationships ; Reprints ;
Holdings
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Status
NTIS  PB91-211409 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 11/26/1991
Collation 8p
Abstract
Glucocorticoids regulate the coupling of beta-adrenergic receptors to cell function. In the current study, the potential role of these agents in the development of adrenergic responses was evaluated in the offspring of pregnant rats given 0.8 mg/kg of dexamethasone on gestational days 17, 18 and 19. The authors examined the postnatal development of beta-receptors coupling to ornithine decarboxylase in heart and kidney throughout neonatal life into young adulthood; this enzyme is involved in transduction of neural signals controlling cellular replication and differentiation. Dexamethasone exposure perturbed the basal pattern of cardiac ornithine decarboxylase activity and attenuated the response of the enzyme in both heart and kidney to acute challenge with the beta-agonist, isoproterenol. Subsensitivity persisted into the postweaning period. This dosage regimen of dexamethasone also suppressed renal cyclic AMP responses to isoproterenol, but exposure to a lower dose (0.2 mg/kg) enhanced the response. Thus, although low doses of glucocorticoids foster development of the coupling of beta-receptors to cellular transduction mechanisms, higher doses such as those used to stimulate lung function may lastingly obtund adrenergic sensitivity.