Nycthemeral rhythm in adrenal responsiveness to ACTH

M. F. Dallman, W. C. Engeland, J. C. Rose

Research output: Contribution to journalArticle

193 Scopus citations

Abstract

Adrenal adenosine 3',5'-cyclic monophosphate (cAMP) and corticosterone responses to exogenous ACTH were found to be about 2.5 times greater in the evening (at lights off) than in the morning (at lights on) in rats. The rhythm in adrenal responsiveness to ACTH was found to persist in rats treated with dexamethasone 15 and 3 h before exogenous ACTH (in the presumed absence of a rhythm in endogenous ACTH). Treatment with p-chlorophenylalanine did not affect the daily rise in circulating ACTH levels but did abolish the rhythm in adrenal responsiveness to ACTH. The magnitude of the rhythm in adrenal responsiveness to ACTH is greater than the magnitude of the rhythm in ACTH. Because the rhythms are dissociable, we conclude that in vivo measurements of adrenal corticosteroid levels do not necessarily reflect ACTH levels.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume4
Issue number3
StatePublished - 1978

Fingerprint Dive into the research topics of 'Nycthemeral rhythm in adrenal responsiveness to ACTH'. Together they form a unique fingerprint.

  • Cite this