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Title: Examining the Effects of Chronic Selenium Exposure on Traditionally Used Stress Parameters in Juvenile American Alligators (Alligator mississippiensis)

Journal Article · · Archives of Environmental Contamination and Toxicology
ORCiD logo [1];  [2];  [3];  [4];  [5];  [2]
  1. Auburn Univ., AL (United States); Univ. of Georgia, Athens, GA (United States); Univ. of Georgia, Aiken, SC (United States)
  2. Univ. of Georgia, Aiken, SC (United States)
  3. Auburn Univ., AL (United States)
  4. Univ. of Florida, Gainesville, FL (United States)
  5. Univ. of Georgia, Athens, GA (United States)

Environmental contaminants, such as the trace element selenium (Se), are a continuing concern to species worldwide due to their potential pathophysiological effects, including their influence on the stress response mediated through glucocorticoids (GCs; stress hormones). Environmental concentrations of Se are increasing due to anthropogenic activities, including the incomplete combustion of coal and subsequent disposal of coal combustion wastes. However, most studies examining how Se affects GCs have been focused on lower trophic organisms. The objectives of this study were to investigate the effects of long-term Se exposure on traditionally used stress parameters and to identify which of these parameters best indicate Se accumulation in liver and kidney of the American alligator (Alligator mississippiensis), a top trophic carnivore found in the southeastern United States and known to inhabit Se-containing areas. Alligators were divided into three dietary treatments and fed prey spiked with 1000 or 2000 ppm selenomethionine (SeMet) or deionized water (control treatment) for 7 weeks. Following the 7-week treatment protocol, blood and tissue samples were obtained to measure plasma corticosterone (CORT; the main crocodilian GC), tail scute CORT, the ratio of peripheral blood heterophils (H) to lymphocytes (L) as H/L ratio, and body condition. To evaluate which parameter best indicated Se accumulation in the liver and kidney, principal component and discriminant analyses were performed. The only parameter significantly correlated with liver and kidney Se concentrations was scute CORT. Furthermore, our results suggest that measurement of CORT in tail scutes, when compared to plasma CORT, H/L ratios, and body condition, is the best indicator of Se-exposure and accumulation in crocodilians.

Research Organization:
Savannah River Site (SRS), Aiken, SC (United States). Savannah River Ecology Lab. (SREL)
Sponsoring Organization:
USDOE
Grant/Contract Number:
FC09-07SR22506
OSTI ID:
1821182
Journal Information:
Archives of Environmental Contamination and Toxicology, Vol. 77, Issue 1; ISSN 0090-4341
Publisher:
SpringerCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 11 works
Citation information provided by
Web of Science

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