Meeting Abstract
When exposed to stressors, animals respond by secreting glucocorticoid hormones such as corticosterone (CORT), thus affecting a variety of physiological processes, including lipid metabolism. However, the factors regulating lipid metabolism, particularly during acute (i.e., short-term) stressors, are not well-characterized. To investigate one putative mechanism, we examined how expression of the enzyme heme oxygenase (HO), which primarily converts heme into biliverdin, changes during an acute stressor. Because HO also has links to decreased levels of triglycerides, we tested the hypothesis that an acute stressor increases HO expression, which would concomitantly decrease circulating lipid levels. House sparrow (Passer domesticus) nestlings exposed to a stressor had reduced circulating triglycerides consistent with an increase in rate of gluconeogenesis during an acute stressor. Concentrations of triglycerides were also negatively correlated with HO expression in the liver, which is consistent with mammalian studies. However, contrary to our predictions, exposure to a stressor did not affect HO expression, or biliverdin concentration in liver, spleen, or kidney. Overall, our results support a link between HO expression and triglyceride levels, though the molecular pathways connecting these two metrics still need to be elucidated.
