Measurement of free glucocorticoids: quantifying corticosteroid binding capacity and its variation within and among mammal and bird species.

ABSTRACT: Plasma glucocorticoid (CORT) levels are one measure of stress in wildlife and give us insight into natural processes relevant to conservation issues. Many studies use total CORT concentrations to draw conclusions about animals' stress state and response to their environment. However, the blood of tetrapods contains corticosteroid-binding globulin (CBG), which strongly binds most circulating CORT. Only free CORT (CORT not bound by CBG) leaves the circulation and exerts biological effects on CORT-sensitive tissues. Measuring free CORT concentrations provides insight to an animal's stress response that cannot be revealed by simply measuring total CORT. To calculate free CORT concentrations in plasma or serum samples, one needs three measurements: the binding affinity of CBG for CORT (which va

SUBMITTER: Delehanty B 

PROVIDER: S-EPMC7476546 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature