RADIOIMMUNOASSAY OF CORTISONE IN SERUM, URINE, AND SALIVA TO ASSESS THE STATUS OF THE CORTISOL-CORTISONE SHUTTLE

We have developed a new assay for cortisone (E) in serum, saliva, and urine involving Celite(R) chromatography followed by RIA with I-125-la beled E and scintillation proximity assay. The chromatography step sep arates cortisol (F) from E, and in combination with their RIAs, permit s assessment of the status of the F-E shuttle. We report the results o f basal, postcorticotropin (ACTH), and postdexamethasone E and F conce ntrations and their circadian fluctuations in the serum, saliva, and u rine of healthy volunteers. The serum and urine F/E ratios were increa sed in patients with ectopic ACTH secretion, whereas in adrenal adenom a and Gushing disease only the urinary ratio was increased. In chronic renal insufficiency this ratio was increased in serum (23.5 +/- 3.9) but diminished in saliva (0.38 +/- 0.11), and in apparent mineralocort icoid excess the ratios were high in serum (44.3 +/- 9.3) and urine (5 .35 +/- 0.85) compared with those of healthy subjects (serum 9.8 +/- 3 .5, urine 0.52 +/- 0.29, saliva 0.52 +/- 0.29).