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Circadian cortisol secretion and circadian adrenal responses to ACTH are maintained in dexamethasone suppressed capuchin monkeys ( Cebus apella )
Author(s) -
TorresFarfan Claudia,
Valenzuela Francisco J.,
Ebensperger Renato,
Méndez Natalia,
Campino Carmen,
Richter Hans G.,
Valenzuela Guillermo J.,
SerónFerré María
Publication year - 2008
Publication title -
american journal of primatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.988
H-Index - 81
eISSN - 1098-2345
pISSN - 0275-2565
DOI - 10.1002/ajp.20461
Subject(s) - circadian rhythm , endocrinology , medicine , dexamethasone , adrenocorticotropic hormone , glucocorticoid , circadian clock , hydrocortisone , adrenal gland , rhythm , adrenal cortex , cebidae , biology , hormone , ecology
We tested the hypothesis that the capuchin monkey adrenal ( Cebus apella ) gland has oscillatory properties that are independent of adrenocorticotropic hormone (ACTH) by exploring under ACTH suppression by dexamethasone: (i) maintenance of a circadian rhythm of plasma cortisol and (ii) clock time dependency of plasma cortisol response to exogenous ACTH. The capuchin monkey had a clear ACTH and plasma cortisol rhythm. Dexamethasone treatment resulted in low non‐rhythmic ACTH levels and decreased cortisol to 1/10 of control values; nevertheless, the circadian rhythm of plasma cortisol persisted. We found that cortisol response to exogenous ACTH was clock time‐dependent. The maximal response to ACTH occurred at the acrophase of the cortisol rhythm (0800 h). These results suggest that the capuchin monkey adrenal cortex may possess intrinsic oscillatory properties that participate in the circadian rhythm of adrenal cortisol secretion and in the circadian cortisol response to ACTH. Am. J. Primatol. 70:93–100, 2008. © 2007 Wiley‐Liss, Inc.