Ontogenetic diurnal variation of adrenal responsiveness to ACTH and stressin rats

Citation
Amo. Leal et al., Ontogenetic diurnal variation of adrenal responsiveness to ACTH and stressin rats, HORMONE RES, 52(1), 1999, pp. 25-29
Citations number
24
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Endocrinology, Nutrition & Metabolism
Journal title
HORMONE RESEARCH
ISSN journal
0301-0163 → ACNP
Volume
52
Issue
1
Year of publication
1999
Pages
25 - 29
Database
ISI
SICI code
0301-0163(199907)52:1<25:ODVOAR>2.0.ZU;2-0
Abstract
We performed studies in 8-, 16-, 24-, 30 and 35-day-old Wistar rats at 8.00 h (AM) and 20.00 h (PM) to investigate the relationship between the diurna l variations of basal plasma corticosterone (compound B, CB) and its respon ses to ACTH and ether stress during the postnatal period. Basal plasma CB l evels increased at PM from 8 to 35 days of age a nd an AM-PM difference was observed at 16 days. Although an AM-PM difference in CB responsiveness to ACTH was detected only at 24 and 35 days, ACTH induced an increasingly high er CB response at PM than at AM from 8 to 35 days. A stress-induced CB resp onse was observed starting at 8 days of age and presented an age-dependent increase; however, no AM-PM difference was observed at any age. The stress- induced CB levels were higher than ACTH-induced CB values at all ages teste d except at PM in 8-day old rats, These data demonstrate that the basal CB levels and adrenal sensitivity to ACTH rise during the evening as a functio n of neonatal development. Copyright (C) 2000 S.Karger AG, Basel.