Age-Related Decreases in Plasma Adrenocorticotropic Hormone, Corticosterone, and Aldosterone Responses to Exogenous Corticotropin-Releasing Hormone in the Rat
| Autor: | A. Ait Chaoui, R. Brudieux, J. Rakotondrazafy |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
endocrine system
Aging medicine.medical_specialty Corticotropin-Releasing Hormone medicine.drug_class Radioimmunoassay Adrenocorticotropic hormone chemistry.chemical_compound Corticotropin-releasing hormone Adrenocorticotropic Hormone Corticosterone Internal medicine medicine Animals Aldosterone Rats Endocrinology chemistry Mineralocorticoid Injections Intravenous Female Corticotropic cell Geriatrics and Gerontology hormones hormone substitutes and hormone antagonists Glucocorticoid Hormone medicine.drug |
| Zdroj: | Gerontology. 41:308-314 |
| ISSN: | 1423-0003 0304-324X |
| Popis: | Age-related changes in plasma adrenocorticotropic hormone (ACTH), corticosterone, and aldosterone responses to exogenous corticotropin-releasing hormone (CRH) were studied concomitantly in both old and adult Long-Evans female rats. All animals were pretreated with dexamethasone and pentobarbital anesthetized. An acute intravenous injection of 1 micrograms rat CRH/100 g body weight markedly increased the plasma concentrations of ACTH, corticosterone, and aldosterone--with similar temporal kinetics in the two groups of rats. However, the incremental CRH responses were significantly lower in old (approximately -70, -45-60, and -30-50%, respectively, for ACTH, corticosterone, and aldosterone) as compared with adult rats. Together with our recent findings, the present results suggest that the previously reported reduced secretion of corticosteroids in aged rats is due to both an impaired steroidogenetic capacity of adrenocortical cells to respond to ACTH and to a decreased ability of corticotropes to produce ACTH in response to CRH. |
| Databáze: | OpenAIRE |
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