Journal
GENERAL AND COMPARATIVE ENDOCRINOLOGY
Volume 136, Issue 3, Pages 371-381Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.ygcen.2004.01.016
Keywords
Eumetopias jubatus; Steller sea lion; cortisol; corticosterone; fecal glucocorticoids; ACTH; adrenal glands; hormones; stress
Categories
Ask authors/readers for more resources
Fecal corticosterone concentrations, measured via radio immuno assay (RIA), were validated as a method to monitor adrenal function in Steller sea lion physiology. Quantification of adrenal response to an acute stressor and relevance of data produced by developed methodologies was determined through physiological challenge with exogenous administration of adrenocorticotropic hormone (ACTH) to captive adult, reproductively intact, Steller sea lions of both sexes (n = 3, 1 male, 2 female) during seasonal molt. Following ACTH administration, serial blood and fecal samples were collected and analyzed by RIA to determine adrenal response. Storage regimens and weather exposure were examined to establish external impact on fecal corticosterone concentrations. High-pressure liquid chromatography (HPLC) of both serum and feces of Steller sea lions was employed to explore potential gender-based differences extant in either sample media. ACTH challenges produced >3-fold increases in serum cortisol concentrations which were reflected in >18-fold increases in fecal corticosterone concentrations post-injection at 3.25 and 32 h, respectively, and fecal corticosterone concentrations returned to baseline 52 It post-injection. Neither outdoor exposure to weather nor variation in duration and temperature of freezer storage impacted fecal corticosterone concentrations. HPLC of individual fecal samples produced eluate immunoreactivity profiles that differed consistently with both sex and age class. Techniques developed herein effectively detected physiologically relevant corticosterone data in Steller sea lion feces, unaffected by conditions likely to be encountered with field collection samples. Additionally, results quantify an acute response to ACTH and provide methodology for examining chronically heightened adrenal activity in Steller sea lions. (C) 2004 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available