Meeting Abstract

105.4  Thursday, Jan. 7  Effects of Dehydration on Cardiovascular Development in Alligator mississippiensis TATE, K*; SWART, J; EME, J; CONLON, JM; CROSSLEY II, DA; U N Dakota; U N Dakota; U. Cal, Irvine; United Arab Emirates Univ; U N Dakota kevin.tate@und.edu

Dehydration can have a significant impact on reptilian development. Embryos of the American alligator (Alligator mississippiensis), may be particularly susceptible to dehydration during drought episodes due to the nesting strategies. The potential for dehydration is exacerbated by the permeability of Alligator eggs. Our previous work demonstrates that periods of acute dehydration result in an irreversible loss of egg water; however, its impact on function needs further characterization. Therefore we subjected alligator eggs to acute drying events (20% total egg mass loss) during the first two-thirds of incubation to achieve two goals: understand the impact on cardiovascular (CV) development and determine the haematological response to these events. Blood volume (BV) and haematological parameters were determined at 70% & 90% of development. Further, the CV response to the vasoactive peptide Angiotensin II (Ang II) was used to assess the impact on CV function. BV estimations indicate that dehydrated embryos maintained BV, despite a significant decrease in embryo and egg mass. Ion composition (K⁺, Cl^–, Na⁺) of the blood and hematocrit, as well as heart, and kidney mass increased in dehydrated embryos, compared to controls. Dehydrated embryos also showed a relative bradycardia and hypertension. However the hypertensive response to Ang II in control and dehydrated embryos appeared similar. The data indicate that dehydrated embryos maintain BV while allowing ionic concentrations to rise, responses which are coupled to an increased heart and kidney mass suggesting an increase in functional capacity for these organs. Project was supported by a NSF career award to D.A.C IBN# IOS-0845741