Kinetics in serum and urinary excretion of ethyl sulfate and ethyl glucuronide after medium dose ethanol intake

Institute of Forensic Medicine, University Hospital Freiburg, Albertstrasse 9, 79104 Freiburg, Germany.
Deutsche Zeitschrift für die Gesamte Gerichtliche Medizin (Impact Factor: 2.6). 03/2008; 122(2):123-8. DOI: 10.1007/s00414-007-0180-8
Source: PubMed

ABSTRACT The direct ethanol metabolites, ethyl glucuronide (EtG) and ethyl sulfate (EtS), are of increasing importance for clinical and forensic applications, but there are only few studies on the kinetics of EtG in serum and none on EtS. In this study, 13 volunteers (social drinkers) drank ethanol in the form of white wine to reach a blood alcohol concentration of 0.51 +/- 0.17 g/kg, and blood and urine samples were analyzed for EtG and EtS simultaneously by chromatography-tandem mass spectrometry (LC-MS/MS). Mean peak serum EtG and EtS concentrations were 2.9 +/- 1.3 and 2.8 +/- 1.6 micromol/l, respectively, and were reached between 4.0 +/- 0.9 h after the start of drinking (3.0 +/- 0.5 h for EtS). The mean time differences between reaching maximum blood ethanol levels and serum metabolite levels were 2.3 +/- 0.9 h for EtG and 1.2 +/- 0.5 h for EtS. In the last blood samples collected (10-11 h after the start of drinking), 11 (of 13) volunteers were still positive for EtG in serum, whereas only 2 were positive for EtS. In the serum of one female person, no EtS was detectable at any time; however, it was excreted in the urine in (low) concentrations. Ethanol was detectable in the serum for up to 8.6 h after the start of drinking, whereas EtG and EtS were detectable up to more than 5.8 h (EtG) and 4.0 h (EtS), respectively. Mean peak urinary concentrations were 401 +/- 232 micromol/l for EtG and 266 +/- 153 micromol/l for EtS, and mean peak levels were reached 6.2 +/- 0.9 h (EtG) and 5.3 +/- 1.2 h (EtS) after the start of drinking. Maximum concentrations of EtG and EtS in serum showed a wide interindividual variation and could not be correlated to the maximum blood ethanol concentrations. Correlations (p < 0.001, Kendall's Tau b) were found when comparing pairs of parameters, but mostly involved areas under the curve (AUC) of metabolites or of ethanol; one correlation linked the peak concentrations of EtG and EtS in urine.

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    • "Some reports have indeed documented a high interindividual variability in EtG production (Halter et al., 2008; Paul et al., 2008). Halter et al. (2007) showed that the administration of a conventional dose of ethanol to 13 individuals resulted in highly variable (8-fold) maximum concentrations of serum EtG, and that EtG concentrations did not correlate with blood ethanol concentrations (Halter et al., 2008). This marked interindividual variability in EtG levels could be attributed to variable activities of UGTs involved in ethanol metabolism. "
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    ABSTRACT: Background: Ethylglucuronide (EtG) determination is increasingly used in clinical and forensic toxicology to document ethanol consumption. The enzymes involved in EtG production, as well as potential interactions with common drugs of abuse, have not been extensively studied. Methods: Activities of human liver (HLM), kidney (HKM) and intestinal (HIM) microsomes, as well as of twelve major human recombinant UDP-glucuronosyltransferases (UGTs), toward ethanol (50 and 500 mM) were evaluated in vitro using liquid chromatography-tandem mass spectrometry. Enzyme kinetic parameters were determined for pooled microsomes and recombinant UGTs with significant activity. Individual contributions of UGTs were estimated using the relative activity factor (RAF) approach, proposed for scaling activities obtained with cDNA-expressed enzymes to HLM. Interaction of morphine, codeine, lorazepam, oxazepam, nicotine, cotinine, cannabinol and cannabidiol (5, 10, 15 mg/L) with ethanol (1.15, 4.6, 11.5 g/L; i.e. 25, 100, 250 mM) glucuronidation was assessed using pooled HLM. Results: Ethanol glucuronidation intrinsic clearance (Cl(int)) was 4- and 12.7- times higher for HLM than for HKM and HIM, respectively. All recombinant UGTs, except UGT1A1, 1A6 and 1A10, produced EtG in detectable amounts. UGT1A9 and 2B7 were the most active enzymes, each accounting for 17% and 33% of HLM Cl(int), respectively. Only cannabinol and cannabidiol significantly affected ethanol glucuronidation. Cannabinol increased ethanol glucuronidation in a concentration-dependent manner, whereas cannabidiol significantly inhibited EtG formation in a non-competitive manner (IC(50)=1.17 mg/L; Ki=3.1 mg/L). Conclusions: UGT1A9 and 2B7 are the main enzymes involved in ethanol glucuronidation. In addition, our results suggest that cannabinol and cannabidiol could alter significantly ethanol glucuronidation.
    Drug metabolism and disposition: the biological fate of chemicals 12/2012; 41(3). DOI:10.1124/dmd.112.047878 · 3.33 Impact Factor
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    • "According to former investigations [24] [29] [30], the marker and ethanol concentrations did not show good analogy and vice versa. "
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    ABSTRACT: To clarify the circumstances of death, the degree of inebriation is of importance in many cases, but for several reasons the determination of the ethanol concentration in post-mortem samples can be challenging and the synopsis of ethanol and the direct consumption markers ethyl glucuronide (EtG) and ethyl sulphate (EtS) has proved to be useful. The use of a rather stable matrix like vitreous humor offers further advantages. The aim of this study was to determine the concentrations of ethanol and the biomarkers in the robust matrix of vitreous humor and to compare them with the respective levels in peripheral venous blood and urine. Samples of urine, blood from the femoral vein and vitreous humor were taken from 26 deceased with suspected ethanol consumption prior to death and analyzed for ethanol, EtS and EtG. In the urine samples creatinine was also determined. The personal data, the circumstances of death, the post-mortem interval and the information about ethanol consumption prior to death were recorded. EtG and EtS analysis in urine was performed by LC-ESI-MS/MS, creatinine concentration was determined using the Jaffé reaction and ethanol was detected by HS-GC-FID and by an ADH-based method. In general, the highest concentrations of the analytes were found in urine and showed statistical significance. The mean concentrations of EtG were 62.8mg/L (EtG100 206.5mg/L) in urine, 4.3mg/L in blood and 2.1mg/L in vitreous humor. EtS was found in the following mean concentrations: 54.6mg/L in urine (EtS100 123.1mg/L), 1.8mg/L in blood and 0.9mg/L in vitreous humor. Ethanol was detected in more vitreous humor samples (mean concentration 2.0g/kg) than in blood and urine (mean concentration 1.6g/kg and 2.1g/kg respectively). There was no correlation between the ethanol and the marker concentrations and no statistical conclusions could be drawn between the markers and matrices.
    Forensic science international 02/2011; 210(1-3):63-8. DOI:10.1016/j.forsciint.2011.01.036 · 2.12 Impact Factor
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    • "Data from a drinking experiment were taken from Halter et al. 2007 [17]: 13 volunteers (social drinkers) drank ethanol in the form of white wine (doses in the range of 28.8–64.8 g) and reached a blood alcohol concentration of 0.64 AE 0.21 g/L (0.52 AE 0.17 g/kg). "
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    ABSTRACT: For 12 volunteers of a drinking experiment the concentration-time-courses of ethyl sulfate (EtS) and ethanol were simulated and fitted to the experimental data. The concentration-time-courses were described with the same mathematical model as previously used for ethyl glucuronide (EtG). The kinetic model based on the following assumptions and simplifications: a velocity constant k(form) for the first order formation of ethyl sulfate from ethanol and an exponential elimination constant k(el). The mean values (and standard deviations) obtained for k(form) and k(el) were 0.00052 h(-1) (0.00014) and 0.561 h(-1) (0.131), respectively. Using the ranges of these parameters it is possible to calculate minimum and maximum serum concentrations of EtS based on stated ethanol doses and drinking times. The comparison of calculated and measured concentrations can prove the plausibility of alleged ethanol consumption and add evidence to the retrospective calculation of ethanol concentrations based on EtG concentrations.
    Forensic science international 11/2009; 194(1-3):34-8. DOI:10.1016/j.forsciint.2009.10.004 · 2.12 Impact Factor
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