Meeting Abstract
Ectothermic organisms, such as reptiles, rely on the external environment for regulating internal temperatures necessary for vital physiological processes. When faced with environmental challenges, temperature may differentially affect how allostatic mediators (e.g., glucocorticoid hormones) are released to mediate energy allocation for handling stressors. Subsequent differences in energy mobilization and circulating metabolites during a stress response may ultimately influence self-maintenance processes such as immunity. The aims of this research were to determine how stress sensitivity varies with diurnal temperatures in the Plateau Side-blotched Lizard (Uta stansburiana uniformis) and to assess the potential implications for immune function. Both baseline and stress-induced levels of glucocorticoids (corticosterone) and energy metabolites (glucose) were compared to body temperature and the thermal environment. Variation in innate immune function (bactericidal ability) was then compared to both temperature and physiological parameters at baseline and stress-induced levels. Stress reactivity via glucocorticoid release positively corresponded with body and environmental temperatures, although glucose release did not. Bactericidal ability subsequent to a stressor negatively corresponded with body temperature and glucocorticoid release. Such findings provide further insight on how stress sensitivity and self-maintenance can vary across the thermal environment, posing potential fitness consequences for an ectothermic organism.
