Meeting Abstract
P3.44 Sunday, Jan. 6 Cardiac response to temperature in hyperoxia and normoxia in the grass shrimp, Palaemonetes pugio . MIKA, T.L.*; REIBER, C.L.; University of Nevada, Las Vegas; University of Nevada, Las Vegas mikat@unlv.nevada.edu
Poikilothermic animals experience a mismatch between oxygen supply and demand with increasing temperature. Thermal tolerance may be related to a failure of the cardiorespiratory system to deliver available oxygen. Animals placed in a hyperoxic environment had a higher CTmax than animals in a normoxic environment, suggesting a physical limitation in oxygen delivery. Analyses were performed on grass shrimp, Palaemonetes pugio, acclimated to 20° C exposed to a range of temperatures (5° – 40° C) in both normoxic and hyperoxic environments to determine response of the oxygen delivery system to this increased demand. Previous work investigated the ventilatory aspect of the delivery system. Current work investigates the cardiovascular aspect of the oxygen delivery system. Pressure-area loops are generated to provide estimates of stroke work, cardiac work, and myocardial oxygen consumption in both normoxic and hyperoxic conditions to determine how the system responds to reduced oxygen availability at extreme temperatures and if that response is altered in a hyperoxic environment.
