Authors : Rebecca J. Adcock , Henry G. Kattesh , Mary P. Roberts , Arnold M. Saxton and Jeffery A. Carroll
Abstract: The relationship between plasma free cortisol and the free cortisol index (FCI, the ratio of cortisol to CBG) was evaluated in eight 8-wk old pigs over a 24 h period and in response to administration of saline or ACTH. A high (p<0.001) correlation was found between actual free cortisol and the FCI in both saline (r = 0.73) and ACTH (r = 0.85) treated pigs. A diurnal rhythm was apparent for total cortisol, free cortisol, percent free cortisol, pCBG and the FCI. Total cortisol (p<0.05), free cortisol (p<0.05) and the FCI (p<0.01) were elevated during the first four h following administration of ACTH. Concentrations of pCBG differed (p<0.001) over time and were higher (p<0.01) for ACTH treated pigs over the 24 h period. The results from this study affirm the contention that FCI is a suitable estimate of free cortisol in swine.
Rebecca J. Adcock , Henry G. Kattesh , Mary P. Roberts , Arnold M. Saxton and Jeffery A. Carroll , 2006. Relationships Between Plasma Cortisol, Corticosteroid-binding Globulin (CBG) and The Free Cortisol Index (FCI) In Pigs Over A 24 h Period . Journal of Animal and Veterinary Advances, 5: 85-91.