Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 30, 2006
Publication Date: October 15, 2006
Citation: Sweazea, K.L., McMurtry, J.P., Elsey, R.M., Braun, E.J. 2006. Comparison of avian and reptilian glucose and ketone body levels [abstract]. The Physiologist. Abstract 24.10
By mammalian standards birds are insulin resistant and they have very high plasma glucose and fatty acid levels. In addition, birds preferentially utilize fatty acids for energy as opposed to the less efficient carbohydrate stores. As a close non-avian vertebrate relative, the levels of various substrates in alligator (Alligator mississippiensis) plasma were compared to Mourning dove (Zenaidura macroura) to determine whether hyperglycemia and high fatty acid utilization were conserved across species. Plasma glucose concentrations in doves (419±25.6 mg/dl) were five times that observed in alligators (76.87±5.66 mg/dl), which were similar to mammalian values. This difference may have evolved as birds draw on large amounts of fatty acids to sustain flight resulting in insulin resistance and hyperglycemia. Concentrations of ketone bodies were not significantly different between doves and alligators suggesting similar utilization of fatty acids, although triglyceride levels in birds (148.6±29.5 mg/dl) were four times that observed in previous studies of juvenile alligators but were undetectable in the present study of adult alligators. This increase in ketone bodies, along with decreased triglycerides, is also observed in mammals on a low carbohydrate diet, which is similar to the carnivorous diet of alligators.