PLASMA CORTISONE MEASURED BY COMPETITIVE PROTEIN BINDING.
Final rept. Sep 68-Jan 69,
LOYOLA UNIV HINES ILL STRITCH SCHOOL OF MEDICINE
Pagination or Media Count:
Cortisone and cortisol were simultaneously measured in plasma by separating these compounds by paper chromatography and quantitating the eluted steroids by competitive protein-binding analysis. One milliliter of normal human plasma sufficed for cortisone estimation and 0.25 ml. for cortisol. Two different groups of normal young men had mean plasma cortisol levels of 8.6 and 7.8 micrograms100 ml. about 3 hours after arising, with cortisone levels averaging 2.1 and 1.7 micrograms100 ml., respectively. When the second group was given 40 units of ACTH gel, the plasma cortisol rose to a mean of 21.0 micrograms100 ml. and the cortisone to 3.1 micrograms100 ml. 2 hours after the injection. The cortisone, as a fraction of the cortisol, dropped from a mean of 22.4 to 15.3--a significant difference P.01--thus suggesting saturation of the 11-beta-hydroxysteroid dehydrogenase enzyme system at rapidly increasing levels of plasma cortisol. Author