title: 20-Dihydroisomers of cortisol and cortisone in human urine: excretion rates under different physiological conditions.
abstract: The urinary excretion rates of free cortisol and cortisone as well as of their 20-dihydroisomers have been studied in normal subjects under different physiological or pharmacological conditions. For the estimation of steroid excretion rates, a fully automated, liquid-chromatographic method was used. In normal subjects, the median steroid excretion rates of free cortisol, cortisone, 20-alpha-dihydrocortisol, 20-beta-dihydrocortisol, 20-alpha-dihydrocortisone and 20-beta-dihydrocortisone were 6.7, 8.0, 9.8, 5.2, 5.7 and 1.3 mumol/mol creatinine. The excretion rates measured at three different intervals of the day followed a circadian rhythm similar to that known for the cortisol secreting activity of the adrenal gland. After adrenal stimulation by i.v. application of 250 micrograms of tetracosactide hexaacetate, (Synacthen, corticotropin beta 1-24) excretion of urinary cortisol was significantly higher than those of the other steroids. During a 24 h infusion of corticotropin beta 1-24, the excretion rates of cortisol and its C-20 reduced isomers increased to a significantly greater extent than those of cortisone and its C-20 reduced isomers. During a four-hour infusion of hydrocortisone, the relative increase of cortisol excretion was greater than that of the other steroids. During a five-hour infusion of metyrapone at different dosages, the excretion of all steroids decreased in a dose-dependent manner. The present data indicate that the 20-dihydroisomers of cortisol and cortisone in human urine primarily originate from the peripheral metabolism of cortisol rather than from adrenal secretion.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D002940:Circadian Rhythm; D003348:Cortisone / Q000652:urine*; D003366:Cosyntropin / Q000494:pharmacology; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology / Q000652:urine*; D007536:Isomerism; D007700:Kinetics; D008297:Male; D008797:Metyrapone / Q000494:pharmacology
chemical_list: D003366:Cosyntropin; D003348:Cortisone; D006854:Hydrocortisone; D008797:Metyrapone