Meeting Abstract

74.3  Monday, Jan. 6 08:30  Differential vascular perfusion in response to bouts of acute hypoxic exposure in embryonic American alligators. KOHL, ZF*; ELSEY, RM; CROSSLEY II, DA; University of North Texas; Louisiana Department of Wildlife and Fisheries; University of North Texas zac.f.kohl@gmail.com

American alligators develop in mound nests and are subject to environmental challenges such as reduced oxygen levels from which they cannot escape. The central focus of our research group is to understand the modifications in cardiovascular function to persist through those environmental insults. Previously we have focused on embryonic blood pressure and heart rate responses to acute and chronic hypoxia, documenting the ontogeny of cardiovascular regulation and function. However our understanding of preferential vascular perfusion during bouts of reduced oxygen is limited. Here, we assess the capacity of embryonic alligators to regulate blood flow distribution using microsphere distribution technique. Blood flow distribution was measured in normoxia and acute 10% hypoxia in embryos at 70 and 90% of age incubated in normoxia or chronic hypoxia. The regulatory capacity was assessed via pharmalogical manipulation with the nitric oxide synthase inhibitor L-NAME or the alpha-receptor blockade agent phentolamine. Treatment with L-NAME resulted in an acute sustained hypertension while alpha blockade resulted in the opposite response. The patterns of blood flow distribution will be discussed.