title: Effect of acute stress on plasma beta-corticosterone, estradiol-17 beta and testosterone concentrations in juvenile American alligators collected from three sites within the Kissimmee-Everglades drainage basin in Florida (USA).
abstract: The effect of acute stress on plasma beta-corticosterone (B), testosterone (T) and estradiol-17beta (E2) concentrations in juvenile alligators collected from sites with varying sediment contaminants was examined in this study. Dramatic increases in plasma B concentrations were observed in alligators from all of the sites after 2 h of capture although females from the intermediate contaminant site exhibited a significantly lower percentage increase in B than females from the other two sites. Males from the site with the highest contaminant levels exhibited elevated initial B concentrations relative to the other sites. This pattern was not observed after 2 h of restraint. Females from the highest contaminant site exhibited depressed initial T when compared to the other sites although this pattern was not observed after 2 h of restraint. Neither E2 nor T decreased after 2 h in females, whereas T concentrations decreased in all males over the same time period. The variance associated with these endpoints was also examined to determine whether it could serve as a more sensitive marker for perturbations of the endocrine system and stress response. Females from the higher and intermediate contaminant sites exhibited the lowest and highest standard errors (respectively) associated with 2 h plasma B concentrations with no differences among mean concentrations suggesting a perturbation of the stress response in these animals that was not detected by examining the means. We concluded that the environmental contaminants could be acting as stressors, leading to the observed differences.
authors.affiliation: Department of Zoology, University of Florida, P.O. Box 118525, Gainesville, FL 32611-8525, USA. mgunderson@zoo.ufl.edu
authors.forename: M P
authors.initials: MP
authors.lastname: Gunderson
authors.forename: S A E
authors.initials: SA
authors.lastname: Kools
authors.forename: M R
authors.initials: MR
authors.lastname: Milnes
authors.forename: L J
authors.initials: LJ
authors.lastname: Guillette
mesh_terms: D000208:Acute Disease; D000367:Age Factors; D000489:Alligators and Crocodiles / Q000097:blood*; D000818:Animals; D003345:Corticosterone / Q000097:blood*; D004958:Estradiol / Q000097:blood*; D005260:Female; D005431:Florida; D008297:Male; D013312:Stress, Physiological / Q000097:blood*; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone; D004958:Estradiol; D003345:Corticosterone