These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Evidence for ultra-short-loop feedback in ACTH-induced interrenal steroidogenesis in coho salmon: acute self-suppression of cortisol secretion in vitro.
    Author: Bradford CS, Fitzpatrick MS, Schreck CB.
    Journal: Gen Comp Endocrinol; 1992 Aug; 87(2):292-9. PubMed ID: 1327952.
    Abstract:
    Interrenal tissues from coho salmon (Oncorhynchus kisutch) were incubated in a defined medium under blood-gas atmosphere at 17 degrees. Rates of cortisol secretion by tissues incubated in media containing 50 mU/ml porcine-ACTH were initially much greater than those of resting tissues in hormone-free media, but after 3 to 6 hr returned to resting rates. The time course of cortisol accumulation in ACTH-containing media was the same when tissues were incubated in different volumes; the final concentrations of cortisol in these incubations were similar to each other and resembled peak in vivo concentrations in juvenile coho subjected to acute stress. Cortisol secretion rates of tissues sequentially transferred to fresh ACTH-containing media every 6 hr did not return to resting levels but remained elevated for at least 24 hr. Cortisol secretion in response to ACTH was attenuated or completely abolished in tissues incubated in media containing exogenous cortisol; this effect was reversible and dose-dependent. Our results suggest that in coho salmon, cortisol may exert ultra-short-loop negative feedback directly at the level of the interrenal gland to effect self-suppression.
    [Abstract] [Full Text] [Related] [New Search]