Document Detail

The effect of chronic cortisol elevation on urea metabolism and excretion in the rainbow trout (Oncorhynchus mykiss).
MedLine Citation:
PMID:  14586635     Owner:  NLM     Status:  MEDLINE    
The objective of this study was to investigate the possible involvement of cortisol in controlling urea metabolism and excretion in the ammoniotelic rainbow trout (Oncorhynchus mykiss). Trout fitted with dorsal aortic and internal urinary catheters received either no implant (control), or were implanted with coconut oil (sham), cortisol in coconut oil, RU486, a glucocorticoid receptor blocker, in coconut oil, or cortisol+RU486 in coconut oil, and monitored over 72 h. Rainbow trout treated with cortisol (+/- RU486) had similarly elevated plasma cortisol concentrations that were six fold greater than in control and sham fish. Elevated circulating cortisol concentrations caused a three-fold rise in plasma and urine urea concentrations, which was blocked by RU486. Similarly, a positive correlation between plasma cortisol and plasma urea concentrations was observed in fish treated with cortisol alone but not in fish treated with cortisol+RU486. Cortisol treatment caused an elevation in branchial (two fold higher) and urinary (three fold higher) excretion rates of urea compared to sham-implanted fish, which was prevented by treatment with RU486. However, as branchial and renal clearance were unaffected, there appears to be no stimulation or inhibition of urea excretion mechanisms in the gill or kidney separate from effects due to changes in plasma urea concentrations. Thus, cortisol and glucocorticoid receptors appear to be involved in the regulation of endogenous urea production but not in the control of urea excretory mechanisms in the ammoniotelic trout.
M D McDonald; C M Wood
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't     Date:  2003-10-28
Journal Detail:
Title:  Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology     Volume:  174     ISSN:  0174-1578     ISO Abbreviation:  J. Comp. Physiol. B, Biochem. Syst. Environ. Physiol.     Publication Date:  2004 Jan 
Date Detail:
Created Date:  2004-01-21     Completed Date:  2004-09-30     Revised Date:  2009-06-08    
Medline Journal Info:
Nlm Unique ID:  8413200     Medline TA:  J Comp Physiol B     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  71-81     Citation Subset:  IM    
McMaster University, Department of Biology, Hamilton, Ontario, L8S 4K1, Canada.
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MeSH Terms
Ammonia / metabolism
Drug Implants
Hydrocortisone / blood,  metabolism*
Kidney / metabolism*
Nitrogen / metabolism
Oncorhynchus mykiss / metabolism*
Receptors, Glucocorticoid / metabolism
Urea / blood,  metabolism*,  urine
Reg. No./Substance:
0/Drug Implants; 0/Receptors, Glucocorticoid; 50-23-7/Hydrocortisone; 57-13-6/Urea; 7664-41-7/Ammonia; 7727-37-9/Nitrogen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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