INDEX urinary metabolites

Finkle et al. (46) have established a GC/MS reference data system for the identification of drugs of abuse. The data include phenethylamine derivatives, opiate and synthetic narcotics, barbiturates, and urinary metabolites. These data have been established for use with the gas chromatographic retention time index previously developed. 

This is the major urinary metabolite of progesterone. It can be measured in urine as an index of placental function in pregnant females, and to detect ovulation in non-pregnant females (see progesterone). It can be measured by gas chromatography, radioimmunoassay or chemical means (by its reaction with sulphuric acid following its isolation by column chromatography). 

From metabolic studies, an isotopic caffeine breath test has been developed that detects impaired liver function using the quantitative formation of labeled carbon dioxide as an index. From the urinary excretion of an acetylated uracil metabolite, human acet-ylator phenotype can be easily identified and the analysis of the ratio of the urinary concentrations of other metabolites represents a sensitive test to determine the hepatic enzymatic activities of xanthine oxidase and microsomal 3-methyl demethylation, 7-methyl demethylation, and 8-hydroxylation. Quantitative analyses of paraxanthine urinary metabolites may be used as a biomarker of caffeine intake. Fecal excretion is a minor elimination route, with recovery of only 2-5% of the ingested dose. 

In a study of workers engaged in synthesizing or otherwise handling p-dichlorobenzene, it was concluded that urinary excretion of 2,5-dichlorophenol (a metabolite of p-dichlorobenzene) can serve as an index of exposure."... 

Estriol (estra-1,3,5(10)-trien-3,16-a,17-8 -triol) is the major estrogen metabolite found in the urine. It is excreted in the form of its conjugate with glucuronic acid. The determination of this steroid as an index of placental function has become one of the most widely used endocrine determinations. As pregnancy progresses, the excretion increases and reaches very high levels near term. In abnormal fetoplacental function, the levels of estriol will fall in some cases. The fall is usually progressive, and, because of this, serial determinations of urinary estriol must be carried out. The drop in estriol can be taken as evidence of placental insufficiency, and close watch by the physician is indicated, as a continued drop may necessitate Cesarean section to save the life of the infant. 

Phenotypic trait measures based solely on the urinary excretion of 6-hydroxychlorzoxazone have also been reported based on the amount of metabolite excreted in zero to eight hours (278), or a hydroxylation index approach (279), or estimating the elimination half-life of the metabolite (280). However, the validity of these approaches is highly questionable, so they have not been widely applied. 

The plasma concentration of the biotin does not provide a sensitive index of stams, at least partly because there is increased renal reabsorption of the vitamin as intake falls. Urinary excretion of biotin and its metabolites is more sensitive, but may be confounded by changes in biotin excretion caused by glucocorticoid hormones (McMahon, 2002). There are three sensitive markers of stams (Mock, 1999) ... 

In addition to plasma melatonin levels, urine-excreted melatonin metabolite 6-sulfatoxymelatonin is easy to determine. Indeed, higher melatonin excretion in the first morning urine was 16% higher in women with higher quartile vegetable intake in comparison to those with lower quartile intake [100]. Moreover, nutrition habits and lifestyle have also been correlated with melatonin [101]. A statistically inverse relation was found between age, smoking, and body mass index, on one hand, and urinary 6-sulfatoxymelatonin [102]. 

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