Meeting Abstract

67.2  Thursday, Jan. 6  Examining the chronic and acute impacts of food intake on hydration state in the Gila monster, Heloderma suspectum WRIGHT, C.W.*; JACKSON, M.; DENARDO, D.; Arizona State University, Tempe christian.wright@asu.edu

Animals living in xeric environments must have strategies to cope with extended periods of limited water availability. One such strategy is to rely on preformed water to maintain water balance. As residents of the Sonoran Desert, Gila monsters, Heloderma suspectum, experience a hot, dry summer, and it has been previously shown that they cope with this challenging period by reducing surface activity and by using their urinary bladder as a water reservoir to buffer changes in their plasma osmolality. However, little is known about the extent to which preformed water in ingested meals contributes to their water balance. As such, we investigated the influence of a single meal on dehydration and rehydration rates, the acute impact of a meal on plasma osmolality at various stages of hydration (isoosmotic, moderate, and severe dehydration), and how meal type (rat pups vs. chicken egg contents) affects these parameters. We measured hydration state and water flux using plasma osmolality and deuterium oxide, respectively. We found that a single meal has no impact on the rate of dehydration nor does it aid in the recovery from severe dehydration. Additional results about the acute impacts of a meal on plasma osmolality at various stages of hydration are currently being analyzed and will be presented.