TY - JOUR
T1 - Impaired adrenocortical response to stress by brown trout, Salmo trutta, living in metal-contaminated waters of the Eagle River, Colorado
AU - Norris, David O.
AU - Donahue, Sean
AU - Dores, Robert M.
AU - Lee, Jennifer K.
AU - Maldonado, Tammy A.
AU - Ruth, Tina
AU - Woodling, John D.
N1 - Funding Information:
Discussions of these data with numerous colleagues were especially helpful in the preparation of the manuscript, especially Richard E. Jones and Carl B. Schreck. This work was supported in part by grants from UROP, the Undergraduate Research Opportunities Program, University of Colorado at Boulder (to S.D.); NSF IBN 9104707 (R.M.D.); and the USFWS Federal Aid Project F-84-R-9. Some of these data were reported as part of undergraduate honors theses at the University of Colorado by S.D. and J.K.L. Special thanks go to several students and faculty (especially James Reed, Edmund Clark, Earl Larson, and Yong Tang) and to many members of the Colorado Division of Wildlife (especially Barb Horn, Lori Martin, and Jake Bennett) for their assistance and cooperation in field collections as well as Stephen Brinkman for the metal analyses.
PY - 1999/1
Y1 - 1999/1
N2 - Brown trout, Salmo trutta, were collected from two sites contaminated with cadmium (Cd) and zinc (Zn) and one uncontaminated site. These fish were subjected to a continuous confinement stressor in wire cages placed in the river (moderate stress) or in 5-gal. plastic buckets on land (severe stress). Plasma cortisol and corticotropin (ACTH) were determined for fish in buckets by radioimmunoassay after 0, 1, 3, 12, or 24 h of confinement. Plasma cortisol and ACTH levels of brown trout from both contaminated and uncontaminated sites initially were the same and increased with time. However, the rise in plasma cortisol was delayed significantly in fish residing in contaminated sites, even though ACTH secretion initially was elevated compared with control trout. Furthermore, secretion of cortisol and ACTH by these fish declined significantly between 3 and 24 h of confinement. Fish from the uncontaminated site responded more rapidly to confinement with increased cortisol secretion and elevated levels of ACTH and continued to exhibit elevated levels of both hormones up to 24 h of confinement. Caged fish examined after 0, 3, 12, and 24 h of confinement exhibited similar plasma cortisol responses regardless of previous exposure to metals. These results suggest that the overall response to severe, short-term confinement stress by the hypothalamo-pituitary-adrenocortical axis of fish chronically exposed to Cd and Zn was depressed and that these fish could not sustain the stress response as readily as fish living in uncontaminated water.
AB - Brown trout, Salmo trutta, were collected from two sites contaminated with cadmium (Cd) and zinc (Zn) and one uncontaminated site. These fish were subjected to a continuous confinement stressor in wire cages placed in the river (moderate stress) or in 5-gal. plastic buckets on land (severe stress). Plasma cortisol and corticotropin (ACTH) were determined for fish in buckets by radioimmunoassay after 0, 1, 3, 12, or 24 h of confinement. Plasma cortisol and ACTH levels of brown trout from both contaminated and uncontaminated sites initially were the same and increased with time. However, the rise in plasma cortisol was delayed significantly in fish residing in contaminated sites, even though ACTH secretion initially was elevated compared with control trout. Furthermore, secretion of cortisol and ACTH by these fish declined significantly between 3 and 24 h of confinement. Fish from the uncontaminated site responded more rapidly to confinement with increased cortisol secretion and elevated levels of ACTH and continued to exhibit elevated levels of both hormones up to 24 h of confinement. Caged fish examined after 0, 3, 12, and 24 h of confinement exhibited similar plasma cortisol responses regardless of previous exposure to metals. These results suggest that the overall response to severe, short-term confinement stress by the hypothalamo-pituitary-adrenocortical axis of fish chronically exposed to Cd and Zn was depressed and that these fish could not sustain the stress response as readily as fish living in uncontaminated water.
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U2 - 10.1006/gcen.1998.7177
DO - 10.1006/gcen.1998.7177
M3 - Article
C2 - 9882538
AN - SCOPUS:0032932496
SN - 0016-6480
VL - 113
SP - 1
EP - 8
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
IS - 1
ER -