Determination of the urinary cortisol production rate using (1,2,3,4-13C)cortisol. Isotope dilution analyses at very small enrichments

1987 ◽  
Vol 14 (2) ◽  
pp. 73-82 ◽  
Author(s):  
T. E. Chapman ◽  
G. P. B. Kraan ◽  
N. M. Drayer ◽  
G. T. Nagel ◽  
B. G. Wolthers
Keyword(s):  
Production Rate ◽  
Isotope Dilution ◽  
Urinary Cortisol

Cortisol production rate determined by radio gas-chromatography.

1977 ◽  
Vol 23 (3) ◽  
pp. 518-521 ◽  
Author(s):  
H J Derks ◽  
F A Muskiet ◽  
B G Wolthers ◽  
J H Thijssen ◽  
N M Drayer
Keyword(s):  
Production Rate ◽  
Chromatographic Method ◽  
Correlation Coefficients ◽  
Urinary Cortisol ◽  
Coefficients Of Variation ◽  
Specific Activities ◽  
Gas Chromatographic Method ◽  
Layer Chromatography ◽  
Cortisol Metabolites

Abstract We describe a ratio gas-chromatographic method for determination of cortisol production rate by measuring the isotope dilution of urinary cortisol metabolites. The method was calibrated by analyzing [3H]tetrahydrocortisol and [3H]tetrahydrocortisone of known specific activities. Results are reasonably well reproducible, the coefficients of variation ranging from 8-15% of allotetrahydrocortisol/tetrahydrocortisol and from 9-19% for tetrahydrocortisone. Correlation coefficients were 0.966 and 0.998 for tetrahydrocortisone and allotetrahydrocortisol/tetrahydrocortisol, respectively, when the method was compared with a method involving thin-layer chromatography and colorimetry. Only one chromatographic step is needed for both purification and quantitation, thus time and effort are saved.

VARIATION OF CORTISOL METABOLISM AS A CONTRIBUTING FACTOR TO DISCREPANCIES IN THE MEASUREMENT OF CORTISOL PRODUCTION RATE

1972 ◽  
Vol 70 (1) ◽  
pp. 89-96 ◽  
Author(s):  
M. J. Levell
Keyword(s):  
Production Rate ◽  
Isotope Dilution ◽  
Normal Subjects ◽  
Contributory Factor ◽  
Morning Dose ◽  
Production Rates ◽  
Evening Dose ◽  
Cortisol Metabolism

ABSTRACT Five normal subjects were given [14C] cortisol in the morning and [3H] cortisol in the evening, in both cases by mouth. The excretion of radioactivity in tetrahydrocortisol (THF) and tetrahydrocortisone (THE) was measured by a modified form of reverse isotope dilution. In 2 subjects, the ratio of isotopic THF/isotopic THE was higher after the evening dose than after the morning dose. In 1 subject the ratio decreased. In 2 subjects it did not change. Cortisol production rates calculated from THF were usually higher than those calculated from THE. The observed variations of metabolism were only a contributory factor to these discrepancies.

Sign in / Sign up

Export Citation Format

Share Document