Progress towards development of an ELISA for quantifying avian CBG

Abstract

Corticosterone (CORT) is the avian equivalent to mammalian cortisol, one of the stress hormones expressed as part of the acute stress response. The biochemical response to environmental stressors is highly conserved amongst vertebrates, allowing for use of avian models in mammalian stress research. Corticosterone binding globulin (CBG) is a carrier protein for CORT which binds ~80% of CORT in the bloodstream. Current research indicates that only unbound CORT is active, suggesting that CBG acts as a regulator as well as a carrier of CORT. CBG declines under chronic stress which would correlate with higher levels of free CORT during the acute stress response. There are also studies which indicate that the CBG‐CORT complex has a biological role separate from CORT delivery or inactivation, and studies which indicate that unbound CBG can play a role in cell signaling pathways independent of CORT binding. There is evidence in humans that the CBG‐CORT complex can increase expression of cyclic adenosine monophosphate, but it is unknown if it has the same effect in birds. Routine quantification of CBG could lead to a more clear definition surrounding its role in the stress response and clarify some of its other biological functions. This project reports on the progress of refining an avian CBG enzyme linked immunosorbent assay (ELISA) using a novel CBG antibody against zebra finch (Taeniopygia guttata), and developing a standard for use in the ELISA for quantifying CBG. The current accepted technique for quantifying CBG is a radioactive assay which is not accessible to all researchers, highlighting the necessity of development of an ELISA to be an easier, safer, and more accessible method for quantificationThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.