ABSTRACT
A fully automated method for the specific assessment of oestriol-16-glucuronide in urine is described. "On-line" sample preparation, including enrichment, pre-purification, focusing and injection, is combined with automated high-performance liquid chromatographic separation and fluorimetric quantification. Losses of oestriol-16-glucuronide throughout the total procedure are negligible. Thus, external calibration is feasible for quantification. Coefficients of variation are 4.44% (n = 12) for intra- and 7.85% (n = 9) for interassay variability. Assay sensitivity is 430 nmol/l. The excretion rates of oestriol-16-glucuronide relative to creatinine were estimated in 85 pregnancy urines. These oestriol-16-glucuronide estimates correlated well with those of total urinary oestriol, determined by high-performance liquid chromatography after acid hydrolysis (r = 0.957). The reference ranges of oestriol-16-glucuronide for the different weeks of gestation were evaluated. Unlike the determination of total oestriol, the present method does not need an hydrolysis step. The method is therefore well suited for the biochemical monitoring of fetal well-being under emergency conditions.
Subject(s)
Estriol/analogs & derivatives , Estrogens, Conjugated (USP)/urine , Chromatography, High Pressure Liquid/methods , Estriol/urine , Female , Humans , Male , Pregnancy , Spectrometry, FluorescenceABSTRACT
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)