Determination of the percentage of free cortisol in plasma in the dog by ultrafiltration/dialysis.
The current methods for measurement of free cortisol are hampered by methodological drawbacks including large sample requirement, length of the procedure, and overestimation or underestimation of free cortisol. We report a technique combining ultrafiltration and dialysis, which could largely overcome these drawbacks, for measurement of the per cent free cortisol in plasma in the dog. This is a modification of the method of Hammond et al. for the determination of sex steroids in man. We found a good positive correlation (rs = 0.87) with equilibrium dialysis, which is considered the golden standard in free cortisol measurements. The 2.5th and 97.5th percentiles of values of free cortisol measured in plasma of 40 healthy household dogs were 5-20 nmol/l or 5.1-11.7% of the total cortisol concentration.
Meyer
H P
HP
Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands.
Rothuizen
J
J
D000302:Adrenal Cortex / Q000378:metabolism; D000818:Animals; D002498:Centrifugation; D004285:Dogs / Q000097:blood*; D005260:Female; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D006435:Renal Dialysis / Q000379:methods; D013696:Temperature; D013997:Time Factors; D014462:Ultrafiltration / Q000379:methods
D006854:Hydrocortisone