Age-Related Changes in Plasma Corticosterone and Aldosterone Responses to Exogenous ACTH in the Rat
| Autor: | R. Brudieux, J. Rakotondrazafy, A. Ait-Chaoui |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Male
Aging medicine.medical_specialty Time Factors Aldosterone business.industry Endocrinology Diabetes and Metabolism Rats Inbred Strains Rats chemistry.chemical_compound Endocrinology chemistry Corticosterone Age related Internal medicine medicine Animals Cosyntropin Female Plasma corticosterone sense organs business |
| Zdroj: | Hormone Research. 43:181-187 |
| ISSN: | 1423-0046 0301-0163 |
| DOI: | 10.1159/000184275 |
| Popis: | Age related changes in the time courses of response of plasma corticosterone and aldosterone to exogenously applied ACTH were simultaneously studied in old (female and male) Long-Evans rats and compared to both young and adult pentobarbitone-anesthetized and dexamethasone-pretreated control rats. Acute intravenous injection of either 0.5 or 50.0 ng ACTH (1-24)/100 g body weight increased plasma concentrations of the two steroids with a similar time course in all groups of rats. However, we observed a significant age-related attenuation in the plasma corticosteroid response. Thus, in old as compared to young rats there was a decrease of approximately 45, 40 and 30% in plasma corticosterone levels respectively 8 min after the lower dose of ACTH in female and 45 min after the higher dose in female and male rats. Similarly, an attenuated (approximately -38%) response of plasma aldosterone levels, induced 45 min after the higher dose of ACTH, was observed both in old female and male rats. These results suggest that the previously reported age-related decreases of in vivo corticosterone and aldosterone secretion are, at least in part, due to a reduced capacity of adrenocortical cells for steroid biosynthesis and release in response to stimulation by ACTH. |
| Databáze: | OpenAIRE |
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