Urine metabolites

Calculation of ID using biological monitoring techniques requires the knowledge of the pharmacokinetics of the parent pesticide in laboratory animals. This will allow the use of the parent or its urine metabolite(s) to calculate the total amount of the parent that had been absorbed through the skin of the test subject. The amount of the residue in the urine should be corrected for any molecular weight differences between the parent and its urine metabolite(s) and also corrected for daily urine excretion volumes based on creatinine analysis of the urine samples. 

Dray J, Dray F, Tiller F, Ulman A (1972) Hydrolysis of urine metabolites of different steroid hormons by b-glucuronidase of Escherichia coli. Ann Inst Pasteur 123 853-857... 

Fig. 1.38 LC separation with radioactivity detection of an urine sample. The response of the various peaks is directly proportional to the amount of metabolites present in the sample. Peaks HU1-HU3 human urine metabolites.

Sepai, 0., Schtitze, D., Heinrich, U., Hoymann, H.G, Henschler, D. Sabbioni, G. (1995b) Hemoglobin adducts and urine metabolites of 4,4 -methylenedianiline after 4,4 -methylene-diphenyl diisocyanate exposure of rats. Chem.-biol. Interact, 97, 185-198... 

Of other applications to biological samples we can cite the determination of urine metabolites of androst-5-en-17-ones [324], Some saturated substrates did not separate from their unsaturated analogues on OV-17 and therefore preliminary epoxidation with m-chloroperbenzoic acid was used in order to resolve them. Simpson [325] analysed corticosteroids in rat muscles and also reported mass spectra of their derivatives. Berthou... 

Nyeki A, Buclin T, Biollaz J, Decosterd LA (2002) NAT2 and CYP1A2 phenotyping with caffeine head-to-head comparison of AFMU vs. AAMU in the urine metabolite ratios. Br J Clin Pharmacol 55 62-67... 

Disposition in the Body. Rapidly absorbed after oral administration. It is extensively metabolised, less than 5% of a dose being excreted unchanged in the urine metabolites include des-methylnefopam and its A-glucuronide, and nefopam A-oxide. About 87% of a dose is excreted in the urine and about 8% in the faeces in 5 days. 

These 16 compounds identified in urine mostly by HPLC/ICPMS include the compound 102 plus 15 other selenium metabolites (Table 18). For many of these, the assignments have been made on very little evidence and require confirmation before the compounds can be accepted as typical urine metabolites [216, 217]. Some, such as methylselenol, have already been retracted by their discoverers. Selenosugar 95 is now firmly established as a major urinary metabolite when selenium is administered, and it is also a constituent of natural urine. There have also been reports of selenosugar 94 and selenosugar 96 as minor constituents. Selenite appears to be a common minor metabolite in normal urine. 

Oral administration of 100, 200, or 400 g pureed strawberries corresponded with 15,30, or 60 imol anthocyanin, respectively. The urine metabolites of strawberry anthocyanins were collected 24 h after each anthocyanin administration and the urine samples were analyzed. 

Levarterenol (I) is metabolized in man by the action of two enzymes, monoamine oxidase (MAO) and catechol 0-methyl transferase (COMT). Deamination and 0-methylation leads to a number of urine metabolites. 

Figure 9.2. Tentative metabolism of PBO in the mouse. L. liver metabolite U, urine metabolite.

Levels of the chlorpyrifos urine metabolite were found to be significantly correlated with chlorpyrifos concentrations in air and dust [135]. 

H 24 N-CH3 O-B-glucuronide Man (urine). Metabolite of oxaprotallne. 100 Wz Anomeric H 360 ttiz 4.95 (3=8 Hz) 400 Miz Other assignments CO3OO also made. 

Design a wash step that will selectively elute the interferences from the solid phase and retain the analyte. An example is the removal of urine metabolites from a cation-exchange sorbent with methanol while retaining a drug that is sorbed by cation exchange. Many metabolites in urine are organic anions and are easily removed from the sample by a methanol wash. 

Exposure Levels in Humans. No data are available regarding the levels of PAHs in body tissues or fluids for populations living near hazardous waste sites. PAHs and their metabolites can be measured in the urine of exposed individuals. In workers exposed to PAHs, the PAH metabolite 1-hydroxypyrene has been detected in the urine at concentrations of 0-40 pg/g creatinine (Jongeneelen et al. 1985). No correlation was found between occupational exposure levels and urine levels, so it is not known whether urine metabolites could be detected following exposure to low levels of PAHs (as might be expected to occur in individuals living in the vicinity of hazardous waste sites). 

Metabolic, nutritional and toxicological aspects of 160-163 Se were studied. The transport of Se within the organism and the urine metabolites observed were different, depending on the form of Se administred. Rapid and efficient incorporation of Se into SeP in the liver and excretion into the plasma followed by the slow and steady incorporation of Se into GPx in the kidneys and excretion into the plasma described. The formation of Se-methyl-/V-acetylselenohexosa-mine in liver and its excretion via urine were reported. The mechanisms underlying the interaction between Se and mercuric ions in the bloodstream were explained by the formation of a ternary complex, [(HgSe) ], -selenoprotein P... 

Pan, Z. et al., Principal component analysis of urine metabolites detected by NMR and DESI-MS in patients with inborn errors of metabolism, Anal. Bioanal. Chem., 387, 539, 2006. 

Abstract Metabolism and kinetic studies have shown that the overall elimination of ETBE and MTBE from blood in volunteers was multiphasic, (two or four phases in the case of ETBE and two or three phases for MTBE). The half-lives varied in different experiments and ranged from a few minutes for early phases up to a terminal half-life of 33 h in one experiment each with ETBE and MTBE. The kinetic data obtained from experiments with rats exposed to ETBE are restricted to a statement that the apparent half-life of elimination of ETBE from blood is about 0.8 h, but it is not clear if this only refers to an initial half-life. Some guidance may be possible from the known behaviour of MTBE. Its elimination from rat blood appears to be biphasic, with an initial half-life of less than 1 h and second half-lives ranging from 37 h to 92 h (reviewed in McGregor 2006). Elimination occurs in exhaled air (mainly unchanged ethers) and urine (metabolites). 

Urine proteins Urine enzymes Urine metabolites ... 

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