Meeting Abstract

P2.171  Thursday, Jan. 5  Exogenous corticosterone elevates metabolic rate in an amphibian PETERSON, J.D.*; RILEY, K.L.; APPEL, A.; MENDONCA, M.T.; Auburn University; Troy University, Montgomery; Auburn University; Auburn University; Auburn University peterj1@auburn.edu

The vertebrate stress response is a suite of physiological changes that help organisms cope with environmental perturbations. One component of the stress response is the hypothalamic-pituitary-adrenal (interenal) axis, which secretes glucocorticoids to modulate the organism’s energetic response to a stressor. Acute glucocorticoid secretion functions in freeing energy stores, increasing metabolism, and reducing non-immediate energy consuming processes. However, chronic elevated glucocorticoid secretion results in an increased resting metabolic rate that can potentially lead to weight loss and unsustainable tissue catabolism. Although this effect has been documented in several vertebrate groups, there are no studies verifying it in amphibians. However, given recent global population declines, this is the very group to explore the relation between environmental stressors, chronically elevated baseline levels of corticosterone and their effect on metabolic rate, body condition, and tissue catabolism. We treated Litoria caerulea with exogenous glucocorticoids (400ug/20ul DMSO), which mimicked elevated baseline levels. Treated individuals consumed significantly more oxygen than those treated with vehicle (p=0.0002), representing a 1.8 fold increase in oxygen consumption. Time course of elevated oxygen consumption and effects on baseline plasma corticosterone will also be discussed.