Meeting Abstract
143.1 Monday, Jan. 7 Anemia amplifies postprandial cardiac hypertrophy in Burmese pythons SLAY, C.E.*; ENOK, S.; HICKS, J.W.; WANG, T.; University of California, Irvine; University of Aarhus, Aarhus, Denmark; University of California, Irvine; University of Aarhus, Aarhus, Denmark cslay@uci.edu
Burmese pythons (Python molarus) are intermittent feeders, capable of surviving prolonged fasts punctuated by periods of voracious feeding. The postprandial period in P. molarus is characterized by a rapid and significant increase in metabolic rate and a several-fold increase in oxygen consumption. Tasked with meeting elevated O2 demand during digestion, the heart may enlarge by as much as 40% within 48 hours, though the “trigger” and universality of this response remain unclear. We hypothesize that this postprandial cardiac hypertrophy is triggered by a mismatch between oxygen demands and oxygen delivery. To test this hypothesis, we reduced the oxygen transport capacity of pythons by halving arterial blood oxygen levels (anemia). Animals were then fed meals equivalent to 25% body mass. 48 hours after feeding occurred, heart rate and blood pressure data were collected, all animals were sacrificed, and visceral organs were dissected. Fed anemic snakes experienced a 125% increase in heart rate and fed control snakes exhibited a 78% increase above fasted controls. Gastrointestinal hypertrophies occurred in both controls and anemic animals, however only fed anemic animals exhibited a significant postprandial cardiac hypertrophy (a 38% increase in ventricular mass over fasted controls animals). These results support our hypothesis that a mismatch between oxygen demand and oxygen delivery may serve as the upstream stimulus for postprandial cardiac hypertrophy in Burmese pythons. Funding was provided by the Danish Research Council to TW and NSF grant IOS 0922756 to JWH. CES would like to acknowledge support from an NSF Graduate Research Fellowship and a SICB FGST.
