TY - JOUR
T1 - Corticosteroid-binding globulins
T2 - Lessons from biomedical research
AU - Breuner, Creagh W.
AU - Beyl, Hannah E.
AU - Malisch, Jessica L.
N1 - Publisher Copyright:
© 2020
PY - 2020/8/20
Y1 - 2020/8/20
N2 - Glucocorticoids (GCs) circulate in the plasma bound to corticosteroid-binding globulin (CBG). Plasma CBG may limit access of glucocorticoids to tissues (acting as a sponge: the free hormone hypothesis), or may solely serve as a transport molecule, releasing GCs to tissues as the plasma moves through capillaries (the total hormone hypothesis). Both biomedical (focused on human health) and comparative (focused on ecological and evolutionary relevance) studies have worked to incorporate CBG in glucocorticoid physiology, and to understand whether free or total hormone is the biologically active plasma fraction. The biomedical field, however, has been well ahead of the comparative physiologists, and have produced results that can inform comparative research when considering the import of total vs. free plasma hormone. In fact, biomedical studies have made impressive strides regarding the function of CBG in tissues as well as plasma; we, however, focus solely on the plasma functions in this review as this is the primary area of disagreement amongst comparative physiologists. Here we present 5 sets of biomedical studies across genomics, pharmacology, cell culture, whole animal research, and human medicine that strongly support a role for CBG limiting hormone access to tissue. We also discuss three areas of concern across comparative researchers. In contrast to former publications, we are not suggesting that all comparative studies in glucocorticoid physiology must measure CBG, or that only free corticosterone levels are valid. However, we propose that comparative physiologists be aware of biomedical results as they investigate glucocorticoids and interpret how total hormone may or may not impact behavior and physiology of free-living vertebrates.
AB - Glucocorticoids (GCs) circulate in the plasma bound to corticosteroid-binding globulin (CBG). Plasma CBG may limit access of glucocorticoids to tissues (acting as a sponge: the free hormone hypothesis), or may solely serve as a transport molecule, releasing GCs to tissues as the plasma moves through capillaries (the total hormone hypothesis). Both biomedical (focused on human health) and comparative (focused on ecological and evolutionary relevance) studies have worked to incorporate CBG in glucocorticoid physiology, and to understand whether free or total hormone is the biologically active plasma fraction. The biomedical field, however, has been well ahead of the comparative physiologists, and have produced results that can inform comparative research when considering the import of total vs. free plasma hormone. In fact, biomedical studies have made impressive strides regarding the function of CBG in tissues as well as plasma; we, however, focus solely on the plasma functions in this review as this is the primary area of disagreement amongst comparative physiologists. Here we present 5 sets of biomedical studies across genomics, pharmacology, cell culture, whole animal research, and human medicine that strongly support a role for CBG limiting hormone access to tissue. We also discuss three areas of concern across comparative researchers. In contrast to former publications, we are not suggesting that all comparative studies in glucocorticoid physiology must measure CBG, or that only free corticosterone levels are valid. However, we propose that comparative physiologists be aware of biomedical results as they investigate glucocorticoids and interpret how total hormone may or may not impact behavior and physiology of free-living vertebrates.
KW - CBG
KW - Corticosterone
KW - Cortisol
KW - Glucocorticoids
KW - Transcortin
UR - http://www.scopus.com/inward/record.url?scp=85086464840&partnerID=8YFLogxK
U2 - 10.1016/j.mce.2020.110857
DO - 10.1016/j.mce.2020.110857
M3 - Review article
C2 - 32437784
AN - SCOPUS:85086464840
SN - 0303-7207
VL - 514
JO - Molecular and Cellular Endocrinology
JF - Molecular and Cellular Endocrinology
M1 - 110857
ER -