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Title: Characterization and quantification of corticosteroid-binding globulin in a southern toad, Bufo terrestris, exposed to coal-combustion-waste

Abstract

Corticosteroid-binding globulin (CBG) is a plasma protein that binds corticosterone and may regulate access of hormone to tissues. The role of CBG during a stress response is not clear. In this study, southern toads, Bufo terrestris, were exposed to a chronic pollutant (coal-combustion-waste), to determine changes in CBG and free corticosterone levels. Since toads exposed to chronic pollutants in previous studies did not exhibit the predicted changes in metabolic rate and mass, but did experience a significant elevation in total corticosterone, we hypothesized that CBG would likewise increase and thus, mitigate the effects of a chronic (i.e. 2 months) pollutant stressor. To conduct this study, we first characterized the properties of CBG in southern toads. After characterization, we monitored the changes in CBG, total corticosterone, and free corticosterone in male toads that were exposed to either coal-combustion-waste or control conditions. CBG increased in all groups throughout the experiment. Total corticosterone, on the other hand, was only significantly elevated at four weeks of exposure to coal-combustion-waste. The increase in CBG did not parallel the increase in total corticosterone; as a result, free corticosterone levels were not buffered by CBG, but showed a peak at four weeks similar to total corticosterone. Thismore » finding indicates that, in this species, CBG may not provide a protective mechanism during long-term pollution exposure.« less

Authors:
; ; ;  [1]
  1. Auburn University, Auburn, AL (USA). Dept. of Biological Science
Publication Date:
OSTI Identifier:
20923887
Resource Type:
Journal Article
Resource Relation:
Journal Name: General and Comparative Endocrinology; Journal Volume: 152; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; AMPHIBIANS; FROGS; ASHES; FLY ASH; COAL; BIOCHEMISTRY; GLOBULINS; BIOLOGICAL EFFECTS; HORMONES; WATER POLLUTION; STEROIDS; METALS

Citation Formats

Ward, C.K., Fontes, C., Breuner, C.W., and Mendonca, M.T. Characterization and quantification of corticosteroid-binding globulin in a southern toad, Bufo terrestris, exposed to coal-combustion-waste. United States: N. p., 2007. Web. doi:10.1016/j.ygcen.2007.02.031.
Ward, C.K., Fontes, C., Breuner, C.W., & Mendonca, M.T. Characterization and quantification of corticosteroid-binding globulin in a southern toad, Bufo terrestris, exposed to coal-combustion-waste. United States. doi:10.1016/j.ygcen.2007.02.031.
Ward, C.K., Fontes, C., Breuner, C.W., and Mendonca, M.T. Tue . "Characterization and quantification of corticosteroid-binding globulin in a southern toad, Bufo terrestris, exposed to coal-combustion-waste". United States. doi:10.1016/j.ygcen.2007.02.031.
@article{osti_20923887,
title = {Characterization and quantification of corticosteroid-binding globulin in a southern toad, Bufo terrestris, exposed to coal-combustion-waste},
author = {Ward, C.K. and Fontes, C. and Breuner, C.W. and Mendonca, M.T.},
abstractNote = {Corticosteroid-binding globulin (CBG) is a plasma protein that binds corticosterone and may regulate access of hormone to tissues. The role of CBG during a stress response is not clear. In this study, southern toads, Bufo terrestris, were exposed to a chronic pollutant (coal-combustion-waste), to determine changes in CBG and free corticosterone levels. Since toads exposed to chronic pollutants in previous studies did not exhibit the predicted changes in metabolic rate and mass, but did experience a significant elevation in total corticosterone, we hypothesized that CBG would likewise increase and thus, mitigate the effects of a chronic (i.e. 2 months) pollutant stressor. To conduct this study, we first characterized the properties of CBG in southern toads. After characterization, we monitored the changes in CBG, total corticosterone, and free corticosterone in male toads that were exposed to either coal-combustion-waste or control conditions. CBG increased in all groups throughout the experiment. Total corticosterone, on the other hand, was only significantly elevated at four weeks of exposure to coal-combustion-waste. The increase in CBG did not parallel the increase in total corticosterone; as a result, free corticosterone levels were not buffered by CBG, but showed a peak at four weeks similar to total corticosterone. This finding indicates that, in this species, CBG may not provide a protective mechanism during long-term pollution exposure.},
doi = {10.1016/j.ygcen.2007.02.031},
journal = {General and Comparative Endocrinology},
number = 1,
volume = 152,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}