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Updated: May 28, 2026
08:02
Fecal Glucocorticoid Analysis: Non-invasive Adrenal Monitoring in Equids
Published on: April 25, 2016
Elevated plasma corticosterone increases metabolic rate in a terrestrial salamander
Corina L Wack1, Sarah E DuRant, William A Hopkins
1Department of Biological Sciences, Duquesne University, Pittsburgh, PA 15282, USA. wackc@chowan.edu
Summary
Elevated glucocorticoid hormones (GCs) increase metabolism in red-legged salamanders. This study shows that corticosterone (CORT) directly boosts oxygen consumption, impacting amphibian energy expenditure.
Area of Science:
- Comparative Physiology
- Endocrinology
- Amphibian Biology
Background:
- Plasma glucocorticoid hormones (GCs) influence intermediary metabolism and whole-animal energy expenditure in vertebrates.
- Previous studies in fish, birds, and reptiles show conflicting results regarding GC effects on metabolic rate, often using non-physiological hormone levels.
- In red-legged salamanders, male courtship pheromones previously increased plasma corticosterone (CORT), suggesting a link to metabolic demands of courtship.
Purpose of the Study:
- To investigate the metabolic effects of physiologically relevant elevations in plasma CORT in male red-legged salamanders (Plethodon shermani).
- To determine if exogenous CORT application or male courtship pheromone affects oxygen consumption in this amphibian species.
Main Methods:
- Male red-legged salamanders were treated with either exogenous CORT, male courtship pheromone, or a vehicle control.
- Plasma CORT concentrations were measured to confirm physiological relevance of treatments.
- Oxygen consumption rates were measured to assess changes in whole-animal metabolic rate.
Main Results:
- Exogenous CORT application successfully elevated plasma CORT to physiologically relevant levels.
- CORT treatment significantly increased oxygen consumption rates for several hours post-treatment, resulting in a 12% increase in oxygen consumed over 2 hours.
- Male courtship pheromone did not affect plasma CORT levels or respiration rates in this study's cohort, potentially due to non-breeding condition.
Conclusions:
- This study provides the first evidence that elevated plasma CORT directly increases whole-animal metabolism in an amphibian.
- Physiologically relevant increases in CORT enhance metabolic rate, supporting its role in energy expenditure regulation in vertebrates.
- Further research is needed to understand the specific mechanisms and ecological implications of CORT-mediated metabolic adjustments in amphibians.
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