1
|
Weraduwage SM, Sahu A, Kulke M, Vermaas JV, Sharkey TD. Characterization of promoter elements of isoprene-responsive genes and the ability of isoprene to bind START domain transcription factors. PLANT DIRECT 2023; 7:e483. [PMID: 36742092 PMCID: PMC9889695 DOI: 10.1002/pld3.483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 01/12/2023] [Indexed: 06/18/2023]
Abstract
Isoprene has recently been proposed to be a signaling molecule that can enhance tolerance of both biotic and abiotic stress. Not all plants make isoprene, but all plants tested to date respond to isoprene. We hypothesized that isoprene interacts with existing signaling pathways rather than requiring novel mechanisms for its effect on plants. We analyzed the cis-regulatory elements (CREs) in promoters of isoprene-responsive genes and the corresponding transcription factors binding these promoter elements to obtain clues about the transcription factors and other proteins involved in isoprene signaling. Promoter regions of isoprene-responsive genes were characterized using the Arabidopsis cis-regulatory element database. CREs bind ARR1, Dof, DPBF, bHLH112, GATA factors, GT-1, MYB, and WRKY transcription factors, and light-responsive elements were overrepresented in promoters of isoprene-responsive genes; CBF-, HSF-, WUS-binding motifs were underrepresented. Transcription factors corresponding to CREs overrepresented in promoters of isoprene-responsive genes were mainly those important for stress responses: drought-, salt/osmotic-, oxidative-, herbivory/wounding and pathogen-stress. More than half of the isoprene-responsive genes contained at least one binding site for TFs of the class IV (homeodomain leucine zipper) HD-ZIP family, such as GL2, ATML1, PDF2, HDG11, ATHB17. While the HD-zipper-loop-zipper (ZLZ) domain binds to the L1 box of the promoter region, a special domain called the steroidogenic acute regulatory protein-related lipid transfer, or START domain, can bind ligands such as fatty acids (e.g., linolenic and linoleic acid). We tested whether isoprene might bind in such a START domain. Molecular simulations and modeling to test interactions between isoprene and a class IV HD-ZIP family START-domain-containing protein were carried out. Without membrane penetration by the HDG11 START domain, isoprene within the lipid bilayer was inaccessible to this domain, preventing protein interactions with membrane bound isoprene. The cross-talk between isoprene-mediated signaling and other growth regulator and stress signaling pathways, in terms of common CREs and transcription factors could enhance the stability of the isoprene emission trait when it evolves in a plant but so far it has not been possible to say what how isoprene is sensed to initiate signaling responses.
Collapse
Affiliation(s)
- Sarathi M Weraduwage
- MSU-DOE Plant Research Laboratory Michigan State University East Lansing Michigan USA
- Department of Biochemistry and Molecular Biology Michigan State University East Lansing Michigan USA
- Great Lakes Bioenergy Research Center Michigan State University East Lansing Michigan USA
| | - Abira Sahu
- MSU-DOE Plant Research Laboratory Michigan State University East Lansing Michigan USA
| | - Martin Kulke
- MSU-DOE Plant Research Laboratory Michigan State University East Lansing Michigan USA
- Department of Biochemistry and Molecular Biology Michigan State University East Lansing Michigan USA
| | - Josh V Vermaas
- MSU-DOE Plant Research Laboratory Michigan State University East Lansing Michigan USA
- Department of Biochemistry and Molecular Biology Michigan State University East Lansing Michigan USA
| | - Thomas D Sharkey
- MSU-DOE Plant Research Laboratory Michigan State University East Lansing Michigan USA
- Department of Biochemistry and Molecular Biology Michigan State University East Lansing Michigan USA
- Great Lakes Bioenergy Research Center Michigan State University East Lansing Michigan USA
- Plant Resilience Institute Michigan State University East Lansing Michigan USA
| |
Collapse
|
2
|
Trefz P, Obermeier J, Lehbrink R, Schubert JK, Miekisch W, Fischer DC. Exhaled volatile substances in children suffering from type 1 diabetes mellitus: results from a cross-sectional study. Sci Rep 2019; 9:15707. [PMID: 31673076 PMCID: PMC6823423 DOI: 10.1038/s41598-019-52165-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 10/10/2019] [Indexed: 02/06/2023] Open
Abstract
Monitoring metabolic adaptation to type 1 diabetes mellitus in children is challenging. Analysis of volatile organic compounds (VOCs) in exhaled breath is non-invasive and appears as a promising tool. However, data on breath VOC profiles in pediatric patients are limited. We conducted a cross-sectional study and applied quantitative analysis of exhaled VOCs in children suffering from type 1 diabetes mellitus (T1DM) (n = 53) and healthy controls (n = 60). Both groups were matched for sex and age. For breath gas analysis, a very sensitive direct mass spectrometric technique (PTR-TOF) was applied. The duration of disease, the mode of insulin application (continuous subcutaneous insulin infusion vs. multiple daily insulin injection) and long-term metabolic control were considered as classifiers in patients. The concentration of exhaled VOCs differed between T1DM patients and healthy children. In particular, T1DM patients exhaled significantly higher amounts of ethanol, isopropanol, dimethylsulfid, isoprene and pentanal compared to healthy controls (171, 1223, 19.6, 112 and 13.5 ppbV vs. 82.4, 784, 11.3, 49.6, and 5.30 ppbV). The most remarkable differences in concentrations were found in patients with poor metabolic control, i.e. those with a mean HbA1c above 8%. In conclusion, non-invasive breath testing may support the discovery of basic metabolic mechanisms and adaptation early in the progress of T1DM.
Collapse
Affiliation(s)
- Phillip Trefz
- Department of Anesthesiology and Intensive Care Medicine, Rostock Medical Breath Research Analytics and Technologies (ROMBAT), Rostock University Medical Centre, Rostock, Germany.
| | - Juliane Obermeier
- Department of Anesthesiology and Intensive Care Medicine, Rostock Medical Breath Research Analytics and Technologies (ROMBAT), Rostock University Medical Centre, Rostock, Germany
| | - Ruth Lehbrink
- Department of Pediatrics, Rostock University Medical Centre, Rostock, Germany
| | - Jochen K Schubert
- Department of Anesthesiology and Intensive Care Medicine, Rostock Medical Breath Research Analytics and Technologies (ROMBAT), Rostock University Medical Centre, Rostock, Germany
| | - Wolfram Miekisch
- Department of Anesthesiology and Intensive Care Medicine, Rostock Medical Breath Research Analytics and Technologies (ROMBAT), Rostock University Medical Centre, Rostock, Germany
| | | |
Collapse
|
3
|
Non-Invasive Assessment of Metabolic Adaptation in Paediatric Patients Suffering from Type 1 Diabetes Mellitus. J Clin Med 2019; 8:jcm8111797. [PMID: 31717811 PMCID: PMC6912469 DOI: 10.3390/jcm8111797] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/22/2019] [Accepted: 10/25/2019] [Indexed: 02/06/2023] Open
Abstract
An analysis of exhaled volatile organic compounds (VOC) may deliver systemic information quicker than available invasive techniques. Metabolic aberrations in pediatric type 1 diabetes (T1DM) are of high clinical importance and could be addressed via breathomics. Real-time breath analysis was combined with continuous glucose monitoring (CGM) and blood tests in children suffering from T1DM and age-matched healthy controls in a highly standardized setting. CGM and breath-resolved VOC analysis were performed every 5 minutes for 9 hours and blood was sampled at pre-defined time points. Per participant (n = 44) food intake and physical activity were identical and a total of 22 blood samples and 93 minutes of breath samples were investigated. The inter-individual variability of glucose, insulin, glucagon, leptin, and soluble leptin receptor relative to food intake differed distinctly between patients and controls. In T1DM patients, the exhaled amounts of acetone, 2-propanol, and pentanal correlated to glucose concentrations. Of note, the strength of these correlations strongly depended on the interval between food intake and breath sampling. Our data suggests that metabolic adaptation through postprandial hyperglycemia and related oxidative stress is immediately reflected in exhaled breath VOC concentrations. Clinical translations of our findings may enable point-of-care applicability of online breath analysis towards personalized medicine.
Collapse
|
4
|
Obermeier J, Trefz P, Happ J, Schubert JK, Staude H, Fischer DC, Miekisch W. Exhaled volatile substances mirror clinical conditions in pediatric chronic kidney disease. PLoS One 2017; 12:e0178745. [PMID: 28570715 PMCID: PMC5453591 DOI: 10.1371/journal.pone.0178745] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 05/02/2017] [Indexed: 12/12/2022] Open
Abstract
Monitoring metabolic adaptation to chronic kidney disease (CKD) early in the time course of the disease is challenging. As a non-invasive technique, analysis of exhaled breath profiles is especially attractive in children. Up to now, no reports on breath profiles in this patient cohort are available. 116 pediatric subjects suffering from mild-to-moderate CKD (n = 48) or having a functional renal transplant KTx (n = 8) and healthy controls (n = 60) matched for age and sex were investigated. Non-invasive quantitative analysis of exhaled breath profiles by means of a highly sensitive online mass spectrometric technique (PTR-ToF) was used. CKD stage, the underlying renal disease (HUS; glomerular diseases; abnormalities of kidney and urinary tract or polycystic kidney disease) and the presence of a functional renal transplant were considered as classifiers. Exhaled volatile organic compound (VOC) patterns differed between CKD/ KTx patients and healthy children. Amounts of ammonia, ethanol, isoprene, pentanal and heptanal were higher in patients compared to healthy controls (556, 146, 70.5, 9.3, and 5.4 ppbV vs. 284, 82.4, 49.6, 5.30, and 2.78 ppbV). Methylamine concentrations were lower in the patient group (6.5 vs 10.1 ppbV). These concentration differences were most pronounced in HUS and kidney transplanted patients. When patients were grouped with respect to degree of renal failure these differences could still be detected. Ammonia accumulated already in CKD stage 1, whereas alterations of isoprene (linked to cholesterol metabolism), pentanal and heptanal (linked to oxidative stress) concentrations were detectable in the breath of patients with CKD stage 2 to 4. Only weak associations between serum creatinine and exhaled VOCs were noted. Non-invasive breath testing may help to understand basic mechanisms and metabolic adaptation accompanying progression of CKD. Our results support the current notion that metabolic adaptation occurs early during the time course of CKD.
Collapse
Affiliation(s)
- Juliane Obermeier
- Department of Anesthesiology and Intensive Care Medicine, Rostock Medical Breath Research Analytics and Technologies (ROMBAT), University Medicine Rostock, Rostock, Germany
| | - Phillip Trefz
- Department of Anesthesiology and Intensive Care Medicine, Rostock Medical Breath Research Analytics and Technologies (ROMBAT), University Medicine Rostock, Rostock, Germany
| | - Josephine Happ
- Department of Anesthesiology and Intensive Care Medicine, Rostock Medical Breath Research Analytics and Technologies (ROMBAT), University Medicine Rostock, Rostock, Germany
| | - Jochen K. Schubert
- Department of Anesthesiology and Intensive Care Medicine, Rostock Medical Breath Research Analytics and Technologies (ROMBAT), University Medicine Rostock, Rostock, Germany
| | - Hagen Staude
- Department of Pediatrics, University Medicine Rostock, Rostock, Germany
| | | | - Wolfram Miekisch
- Department of Anesthesiology and Intensive Care Medicine, Rostock Medical Breath Research Analytics and Technologies (ROMBAT), University Medicine Rostock, Rostock, Germany
- * E-mail:
| |
Collapse
|
5
|
Kramer C, Mochalski P, Unterkofler K, Agapiou A, Ruzsanyi V, Liedl KR. Prediction of blood:air and fat:air partition coefficients of volatile organic compounds for the interpretation of data in breath gas analysis. J Breath Res 2016; 10:017103. [PMID: 26815030 PMCID: PMC4957668 DOI: 10.1088/1752-7155/10/1/017103] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In this article, a database of blood:air and fat:air partition coefficients (λ b:a and λ f:a) is reported for estimating 1678 volatile organic compounds recently reported to appear in the volatilome of the healthy human. For this purpose, a quantitative structure-property relationship (QSPR) approach was applied and a novel method for Henry's law constants prediction developed. A random forest model based on Molecular Operating Environment 2D (MOE2D) descriptors based on 2619 literature-reported Henry's constant values was built. The calculated Henry's law constants correlate very well (R(2) test = 0.967) with the available experimental data. Blood:air and fat:air partition coefficients were calculated according to the method proposed by Poulin and Krishnan using the estimated Henry's constant values. The obtained values correlate reasonably well with the experimentally determined ones for a test set of 90 VOCs (R(2) = 0.95). The provided data aim to fill in the literature data gap and further assist the interpretation of results in studies of the human volatilome.
Collapse
Affiliation(s)
- Christian Kramer
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 82, A-6020 Innsbruck, Austria. Present address: Fa. Hoffmann-La Roche Ltd, Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, Grenzacherstrasse 124, CH-4070 Basel, Switzerland
| | | | | | | | | | | |
Collapse
|
6
|
Development of an inhalation unit risk factor for isoprene. Regul Toxicol Pharmacol 2015; 73:712-25. [PMID: 26545327 DOI: 10.1016/j.yrtph.2015.10.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 10/28/2015] [Accepted: 10/29/2015] [Indexed: 11/22/2022]
Abstract
A unit risk factor (URF) was developed for isoprene based on evaluation of three animal studies with adequate data to perform dose-response modeling (NTP, 1994, 1999; Placke et al., 1996). Ultimately, the URF of 6.2E-08 per ppb (2.2E-08 per μg/m(3)) was based on the 95% lower confidence limit on the effective concentration corresponding to 10% extra risk for liver carcinoma in male B6C3F1 mice after incorporating appropriate adjustment factors for species differences in target tissue metabolite concentrations and inhalation dosimetry. The corresponding lifetime air concentration at the 1 in 100,000 no significant excess risk level is 160 ppb (450 μg/m(3)). This concentration is almost 4400 times lower than the lowest exposure level associated with statistically increased liver carcinoma in B6C3F1 mice in the key study (700 ppm in Placke et al., 1996) and is above typical isoprene breath concentrations reported in the scientific literature. Continuous lifetime environmental exposure to the 1 in 100,000 excess risk level of 160 ppb would be expected to raise the human blood isoprene area under the curve (AUC) less than one-third of the standard deviation of the endogenous mean blood AUC. The mean for ambient air monitoring sites in Texas (2005-2014) is approximately 0.13 ppb.
Collapse
|
7
|
Amann A, Costello BDL, Miekisch W, Schubert J, Buszewski B, Pleil J, Ratcliffe N, Risby T. The human volatilome: volatile organic compounds (VOCs) in exhaled breath, skin emanations, urine, feces and saliva. J Breath Res 2014; 8:034001. [PMID: 24946087 DOI: 10.1088/1752-7155/8/3/034001] [Citation(s) in RCA: 377] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Breath analysis is a young field of research with its roots in antiquity. Antoine Lavoisier discovered carbon dioxide in exhaled breath during the period 1777-1783, Wilhelm (Vilém) Petters discovered acetone in breath in 1857 and Johannes Müller reported the first quantitative measurements of acetone in 1898. A recent review reported 1765 volatile compounds appearing in exhaled breath, skin emanations, urine, saliva, human breast milk, blood and feces. For a large number of compounds, real-time analysis of exhaled breath or skin emanations has been performed, e.g., during exertion of effort on a stationary bicycle or during sleep. Volatile compounds in exhaled breath, which record historical exposure, are called the 'exposome'. Changes in biogenic volatile organic compound concentrations can be used to mirror metabolic or (patho)physiological processes in the whole body or blood concentrations of drugs (e.g. propofol) in clinical settings-even during artificial ventilation or during surgery. Also compounds released by bacterial strains like Pseudomonas aeruginosa or Streptococcus pneumonia could be very interesting. Methyl methacrylate (CAS 80-62-6), for example, was observed in the headspace of Streptococcus pneumonia in concentrations up to 1420 ppb. Fecal volatiles have been implicated in differentiating certain infectious bowel diseases such as Clostridium difficile, Campylobacter, Salmonella and Cholera. They have also been used to differentiate other non-infectious conditions such as irritable bowel syndrome and inflammatory bowel disease. In addition, alterations in urine volatiles have been used to detect urinary tract infections, bladder, prostate and other cancers. Peroxidation of lipids and other biomolecules by reactive oxygen species produce volatile compounds like ethane and 1-pentane. Noninvasive detection and therapeutic monitoring of oxidative stress would be highly desirable in autoimmunological, neurological, inflammatory diseases and cancer, but also during surgery and in intensive care units. The investigation of cell cultures opens up new possibilities for elucidation of the biochemical background of volatile compounds. In future studies, combined investigations of a particular compound with regard to human matrices such as breath, urine, saliva and cell culture investigations will lead to novel scientific progress in the field.
Collapse
Affiliation(s)
- Anton Amann
- Univ-Clinic for Anesthesia and Intensive Care, Innsbruck Medical University, Anichstr, 35, A-6020 Innsbruck, Austria. Breath Research Institute of the University of Innsbruck, Rathausplatz 4, A-6850 Dornbirn, Austria
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Amann A, Mochalski P, Ruzsanyi V, Broza YY, Haick H. Assessment of the exhalation kinetics of volatile cancer biomarkers based on their physicochemical properties. J Breath Res 2014; 8:016003. [PMID: 24566039 DOI: 10.1088/1752-7155/8/1/016003] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The current review provides an assessment of the exhalation kinetics of volatile organic compounds (VOCs) that have been linked with cancer. Towards this end, we evaluate various physicochemical properties, such as 'breath:air' and 'blood:fat' partition coefficients, of 112 VOCs that have been suggested over the past decade as potential markers of cancer. With these data, we show that the cancer VOC concentrations in the blood and in the fat span over 12 and 8 orders of magnitude, respectively, in order to provide a specific counterpart concentration in the exhaled breath (e.g., 1 ppb). This finding suggests that these 112 different compounds have different storage compartments in the body and that their exhalation kinetics depends on one or a combination of the following factors: (i) the VOC concentrations in different parts of the body; (ii) the VOC synthesis and metabolism rates; (iii) the partition coefficients between tissue(s), blood and air; and (iv) the VOCs' diffusion constants. Based on this analysis, we discuss how this knowledge allows modeling and simulating the behavior of a specific VOC under different sampling protocols (with and without exertion of effort). We end this review by a brief discussion on the potential role of these scenarios in screening and therapeutic monitoring of cancer.
Collapse
Affiliation(s)
- Anton Amann
- Breath Research Institute, Leopold-Franzens University of Innsbruck, 6850 Dornbirn, Austria. Department of Anesthesiology and Critical Care Medicine, Innsbruck Medical University, 6020 Innsbruck, Austria
| | | | | | | | | |
Collapse
|
9
|
Amann A, Miekisch W, Schubert J, Buszewski B, Ligor T, Jezierski T, Pleil J, Risby T. Analysis of exhaled breath for disease detection. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2014; 7:455-482. [PMID: 25014347 DOI: 10.1146/annurev-anchem-071213-020043] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Breath analysis is a young field of research with great clinical potential. As a result of this interest, researchers have developed new analytical techniques that permit real-time analysis of exhaled breath with breath-to-breath resolution in addition to the conventional central laboratory methods using gas chromatography-mass spectrometry. Breath tests are based on endogenously produced volatiles, metabolites of ingested precursors, metabolites produced by bacteria in the gut or the airways, or volatiles appearing after environmental exposure. The composition of exhaled breath may contain valuable information for patients presenting with asthma, renal and liver diseases, lung cancer, chronic obstructive pulmonary disease, inflammatory lung disease, or metabolic disorders. In addition, oxidative stress status may be monitored via volatile products of lipid peroxidation. Measurement of enzyme activity provides phenotypic information important in personalized medicine, whereas breath measurements provide insight into perturbations of the human exposome and can be interpreted as preclinical signals of adverse outcome pathways.
Collapse
Affiliation(s)
- Anton Amann
- Breath Research Institute of the University of Innsbruck, A-6850 Dornbirn, Austria;
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Spaněl P, Dryahina K, Smith D. A quantitative study of the influence of inhaled compounds on their concentrations in exhaled breath. J Breath Res 2013; 7:017106. [PMID: 23445832 DOI: 10.1088/1752-7155/7/1/017106] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Throughout the development of breath analysis research, there has been interest in how the concentrations of trace compounds in exhaled breath are related to their concentrations in the ambient inhaled air. In considering this, Phillips introduced the concept of 'alveolar gradient' and judged that the measured exhaled concentrations of volatile organic compounds should be diminished by an amount equal to their concentrations in the inhaled ambient air. The objective of the work described in this paper was to investigate this relationship quantitatively. Thus, experiments have been carried out in which inhaled air was polluted by seven compounds of interest in breath research, as given below, and exhaled breath has been analysed by SIFT-MS as the concentrations of these compounds in the inhaled air were reduced. The interesting result obtained is that all the exogenous compounds are partially retained in the exhaled breath and there are close linear relationships between the exhaled and inhaled air concentrations for all seven compounds. Thus, retention coefficients, a, have been derived for the following compounds: pentane, 0.76 ± 0.09; isoprene, 0.66 ± 0.04; acetone, 0.17 ± 0.03; ammonia, 0.70 ± 0.13, methanol, 0.29 ± 0.02; formaldehyde, 0.06 ± 0.03; deuterated water (HDO), 0.09 ± 0.02. From these data, correction to breath analyses for inhaled concentration can be described by coefficients specific to each compound, which can be close to 1 for hydrocarbons, as applied by Phillips, or around 0.1, meaning that inhaled concentrations of such compounds can essentially be neglected. A further deduction from the experimental data is that under conditions of the inhalation of clean air, the measured exhaled breath concentrations of those compounds should be increased by a factor of 1/(1 - a) to correspond to gaseous equilibrium with the compounds dissolved in the mixed venous blood entering the alveoli. Thus, for isoprene, this is a factor of 3, which we have confirmed experimentally by re-breathing experiments.
Collapse
Affiliation(s)
- Patrik Spaněl
- J Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejskova 3, Prague 8, Czech Republic.
| | | | | |
Collapse
|
11
|
Mochalski P, King J, Kupferthaler A, Unterkofler K, Hinterhuber H, Amann A. Human Blood and Plasma Partition Coefficients for C4-C8 n-alkanes, Isoalkanes, and 1-alkenes. Int J Toxicol 2012; 31:267-75. [DOI: 10.1177/1091581812442689] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Human blood:air and plasma:air partition coefficients for C4-C8 n-alkanes, isoalkanes, and 1-alkenes were determined using multiple headspace extraction coupled with solid phase microextraction and gas chromatography. Mean blood:air partition coefficients expressed in the form of dimensionless blood-to-air concentration ratio (g/mLb/g/mLa) were 0.183, 0.416, 1.08, 2.71, and 5.77 for C4-C8 n-alkanes; 0.079, 0.184, 0.473, 1.3, and 3.18 for C4-C8 isoalkanes; and 0.304, 0.589, 1.32, 3.5, and 7.01 for C4-C8 1-alkenes, respectively (n = 8). The reported partition coefficient values increased exponentially with boiling points, molecular weights, and the carbon atoms in the particle. The solubility of 1-alkenes in blood was higher than in plasma, whereas the blood:air and plasma:air partition coefficients of n-alkanes and isoalkanes did not differ significantly. Consequently, additional interactions of 1-alkenes with whole blood seem to occur. The presented findings are expected to be particularly useful for assessing the uptake, distribution, and elimination of hydrocarbons in human organism.
Collapse
Affiliation(s)
- Paweł Mochalski
- Breath Research Institute, Austrian Academy of Sciences, Rathausplatz 4, A-6850 Dornbirn, Austria
- Institute of Nuclear Physics PAN, Radzikowskiego 152, PL-31342 Kraków, Poland
| | - Julian King
- Breath Research Institute, Austrian Academy of Sciences, Rathausplatz 4, A-6850 Dornbirn, Austria
- Faculty of Mathematics, University of Vienna, Nordbergstr.15, A-1090 Wien, Austria,
| | - Alexander Kupferthaler
- Breath Research Institute, Austrian Academy of Sciences, Rathausplatz 4, A-6850 Dornbirn, Austria
| | - Karl Unterkofler
- Breath Research Institute, Austrian Academy of Sciences, Rathausplatz 4, A-6850 Dornbirn, Austria
| | - Hartmann Hinterhuber
- University Clinic for Psychiatry, Innsbruck Medical University, Anichstr. 35, A-6020 Innsbruck, Austria
| | - Anton Amann
- Breath Research Institute, Austrian Academy of Sciences, Rathausplatz 4, A-6850 Dornbirn, Austria
- University Clinic for Anesthesia, Innsbruck Medical University, Anichstr. 35, A-6020 Innsbruck, Austria
| |
Collapse
|
12
|
Quantitative Property-Property Relationship for Screening-Level Prediction of Intrinsic Clearance of Volatile Organic Chemicals in Rats and Its Integration within PBPK Models to Predict Inhalation Pharmacokinetics in Humans. J Toxicol 2012; 2012:286079. [PMID: 22685458 PMCID: PMC3364689 DOI: 10.1155/2012/286079] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 01/13/2012] [Accepted: 01/13/2012] [Indexed: 01/28/2023] Open
Abstract
The objectives of this study were (i) to develop a screening-level Quantitative property-property relationship (QPPR) for intrinsic clearance (CLint) obtained from in vivo animal studies and (ii) to incorporate it with human physiology in a PBPK model for predicting the inhalation pharmacokinetics of VOCs. CLint, calculated as the ratio of the in vivo Vmax (μmol/h/kg bw rat) to the Km (μM), was obtained for 26 VOCs from the literature. The QPPR model resulting from stepwise linear regression analysis passed the validation step (R2 = 0.8; leave-one-out cross-validation Q2 = 0.75) for CLint normalized to the phospholipid (PL) affinity of the VOCs. The QPPR facilitated the calculation of CLint (L PL/h/kg bw rat) from the input data on log Pow, log blood: water PC and ionization potential. The predictions of the QPPR as lower and upper bounds of the 95% mean confidence intervals (LMCI and UMCI, resp.) were then integrated within a human PBPK model. The ratio of the maximum (using LMCI for
CLint) to minimum (using UMCI for CLint) AUC predicted by the QPPR-PBPK model was 1.36 ± 0.4 and ranged from 1.06 (1,1-dichloroethylene) to 2.8 (isoprene). Overall, the integrated QPPR-PBPK modeling method developed in this study is a pragmatic way of characterizing the impact of the lack of knowledge of CLint in predicting human pharmacokinetics of VOCs, as well as the impact of prediction uncertainty of CLint on human pharmacokinetics of VOCs.
Collapse
|
13
|
Mochalski P, King J, Kupferthaler A, Unterkofler K, Hinterhuber H, Amann A. Measurement of isoprene solubility in water, human blood and plasma by multiple headspace extraction gas chromatography coupled with solid phase microextraction. J Breath Res 2011; 5:046010. [DOI: 10.1088/1752-7155/5/4/046010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
14
|
Phase-resolved real-time breath analysis during exercise by means of smart processing of PTR-MS data. Anal Bioanal Chem 2011; 401:2079-91. [PMID: 21706328 DOI: 10.1007/s00216-011-5173-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 05/30/2011] [Accepted: 06/08/2011] [Indexed: 10/18/2022]
|
15
|
Koc H, King J, Teschl G, Unterkofler K, Teschl S, Mochalski P, Hinterhuber H, Amann A. The role of mathematical modeling in VOC analysis using isoprene as a prototypic example. J Breath Res 2011; 5:037102. [DOI: 10.1088/1752-7155/5/3/037102] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
16
|
King J, Koc H, Unterkofler K, Mochalski P, Kupferthaler A, Teschl G, Teschl S, Hinterhuber H, Amann A. Physiological modeling of isoprene dynamics in exhaled breath. J Theor Biol 2010; 267:626-37. [PMID: 20869370 DOI: 10.1016/j.jtbi.2010.09.028] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 08/31/2010] [Accepted: 09/17/2010] [Indexed: 10/19/2022]
Abstract
Human breath contains a myriad of endogenous volatile organic compounds (VOCs) which are reflective of ongoing metabolic or physiological processes. While research into the diagnostic potential and general medical relevance of these trace gases is conducted on a considerable scale, little focus has been given so far to a sound analysis of the quantitative relationships between breath levels and the underlying systemic concentrations. This paper is devoted to a thorough modeling study of the end-tidal breath dynamics associated with isoprene, which serves as a paradigmatic example for the class of low-soluble, blood-borne VOCs. Real-time measurements of exhaled breath under an ergometer challenge reveal characteristic changes of isoprene output in response to variations in ventilation and perfusion. Here, a valid compartmental description of these profiles is developed. By comparison with experimental data it is inferred that the major part of breath isoprene variability during exercise conditions can be attributed to an increased fractional perfusion of potential storage and production sites, leading to higher levels of mixed venous blood concentrations at the onset of physical activity. In this context, various lines of supportive evidence for an extrahepatic tissue source of isoprene are presented. Our model is a first step towards new guidelines for the breath gas analysis of isoprene and is expected to aid further investigations regarding the exhalation, storage, transport and biotransformation processes associated with this important compound.
Collapse
Affiliation(s)
- Julian King
- Breath Research Institute, Austrian Academy of Sciences, Rathausplatz 4, A-6850 Dornbirn, Austria
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
King J, Mochalski P, Kupferthaler A, Unterkofler K, Koc H, Filipiak W, Teschl S, Hinterhuber H, Amann A. Dynamic profiles of volatile organic compounds in exhaled breath as determined by a coupled PTR-MS/GC-MS study. Physiol Meas 2010; 31:1169-84. [PMID: 20664160 DOI: 10.1088/0967-3334/31/9/008] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
18
|
Beauchamp J, Kirsch F, Buettner A. Real-time breath gas analysis for pharmacokinetics: monitoring exhaled breath by on-line proton-transfer-reaction mass spectrometry after ingestion of eucalyptol-containing capsules. J Breath Res 2010; 4:026006. [DOI: 10.1088/1752-7155/4/2/026006] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
19
|
Bajtarevic A, Ager C, Pienz M, Klieber M, Schwarz K, Ligor M, Ligor T, Filipiak W, Denz H, Fiegl M, Hilbe W, Weiss W, Lukas P, Jamnig H, Hackl M, Haidenberger A, Buszewski B, Miekisch W, Schubert J, Amann A. Noninvasive detection of lung cancer by analysis of exhaled breath. BMC Cancer 2009; 9:348. [PMID: 19788722 PMCID: PMC2761408 DOI: 10.1186/1471-2407-9-348] [Citation(s) in RCA: 356] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Accepted: 09/29/2009] [Indexed: 02/01/2023] Open
Abstract
Background Lung cancer is one of the leading causes of death in Europe and the western world. At present, diagnosis of lung cancer very often happens late in the course of the disease since inexpensive, non-invasive and sufficiently sensitive and specific screening methods are not available. Even though the CT diagnostic methods are good, it must be assured that "screening benefit outweighs risk, across all individuals screened, not only those with lung cancer". An early non-invasive diagnosis of lung cancer would improve prognosis and enlarge treatment options. Analysis of exhaled breath would be an ideal diagnostic method, since it is non-invasive and totally painless. Methods Exhaled breath and inhaled room air samples were analyzed using proton transfer reaction mass spectrometry (PTR-MS) and solid phase microextraction with subsequent gas chromatography mass spectrometry (SPME-GCMS). For the PTR-MS measurements, 220 lung cancer patients and 441 healthy volunteers were recruited. For the GCMS measurements, we collected samples from 65 lung cancer patients and 31 healthy volunteers. Lung cancer patients were in different disease stages and under treatment with different regimes. Mixed expiratory and indoor air samples were collected in Tedlar bags, and either analyzed directly by PTR-MS or transferred to glass vials and analyzed by gas chromatography mass spectrometry (GCMS). Only those measurements of compounds were considered, which showed at least a 15% higher concentration in exhaled breath than in indoor air. Compounds related to smoking behavior such as acetonitrile and benzene were not used to differentiate between lung cancer patients and healthy volunteers. Results Isoprene, acetone and methanol are compounds appearing in everybody's exhaled breath. These three main compounds of exhaled breath show slightly lower concentrations in lung cancer patients as compared to healthy volunteers (p < 0.01 for isoprene and acetone, p = 0.011 for methanol; PTR-MS measurements). A comparison of the GCMS-results of 65 lung cancer patients with those of 31 healthy volunteers revealed differences in concentration for more than 50 compounds. Sensitivity for detection of lung cancer patients based on presence of (one of) 4 different compounds not arising in exhaled breath of healthy volunteers was 52% with a specificity of 100%. Using 15 (or 21) different compounds for distinction, sensitivity was 71% (80%) with a specificity of 100%. Potential marker compounds are alcohols, aldehydes, ketones and hydrocarbons. Conclusion GCMS-SPME is a relatively insensitive method. Hence compounds not appearing in exhaled breath of healthy volunteers may be below the limit of detection (LOD). PTR-MS, on the other hand, does not need preconcentration and gives much more reliable quantitative results then GCMS-SPME. The shortcoming of PTR-MS is that it cannot identify compounds with certainty. Hence SPME-GCMS and PTR-MS complement each other, each method having its particular advantages and disadvantages. Exhaled breath analysis is promising to become a future non-invasive lung cancer screening method. In order to proceed towards this goal, precise identification of compounds observed in exhaled breath of lung cancer patients is necessary. Comparison with compounds released from lung cancer cell cultures, and additional information on exhaled breath composition in other cancer forms will be important.
Collapse
Affiliation(s)
- Amel Bajtarevic
- Department of Operative Medicine, Innsbruck Medical University, A-6020 Innsbruck, Austria.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Ligor M, Ligor T, Bajtarevic A, Ager C, Pienz M, Klieber M, Denz H, Fiegl M, Hilbe W, Weiss W, Lukas P, Jamnig H, Hackl M, Buszewski B, Miekisch W, Schubert J, Amann A. Determination of volatile organic compounds in exhaled breath of patients with lung cancer using solid phase microextraction and gas chromatography mass spectrometry. Clin Chem Lab Med 2009; 47:550-60. [PMID: 19397483 DOI: 10.1515/cclm.2009.133] [Citation(s) in RCA: 173] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
BACKGROUND Analysis of exhaled breath is a promising diagnostic method. Sampling of exhaled breath is non-invasive and can be performed as often as considered desirable. There are indications that the concentration and presence of certain of volatile compounds in exhaled breath of lung cancer patients is different from concentrations in healthy volunteers. This might lead to a future diagnostic test for lung cancer. METHODS Exhaled breath samples from 65 patients with different stages of lung cancer and undergoing different treatment regimes were analysed. Mixed expiratory and indoor air samples were collected. Solid phase microextraction (SPME) with carboxen/polydimethylsiloxane (CAR/PDMS) sorbent was applied. Compounds were analysed by means of gas chromatography (GC) and mass spectrometry (MS). RESULTS The method we used allowed identification with the spectral library of 103 compounds showing at least 15% higher concentration in exhaled breath than in inhaled air. Among those 103 compounds, 84 were confirmed by determination of the retention time using standards based on the respective pure compound. Approximately, one third of the compounds detected were hydrocarbons. We found aromatic hydrocarbons, alcohols, aldehydes, ketones, esters, ethers, sulfur compounds, nitrogen-containing compounds and halogenated compounds. Acetonitrile and benzene were two of 10 compounds which correlated with smoking behaviour. A comparison of results from cancer patients with those of 31 healthy volunteers revealed differences in the concentration and presence of certain compounds. The sensitivity for detection of lung cancer patients based on eight different compounds not seen in exhaled breath of healthy volunteers was 51% and the specificity was 100%. These eight potential markers for detection of lung cancer are 1-propanol, 2-butanone, 3-butyn-2-ol, benzaldehyde, 2-methyl-pentane, 3-methyl-pentane, n-pentane and n-hexane. CONCLUSIONS SPME is a relatively insensitive method and compounds not observed in exhaled breath may be present at a concentration lower than LOD. The main achievement of the present work is the validated identification of compounds observed in exhaled breath of lung cancer patients. This identification is indispensible for future work on the biochemical sources of these compounds and their metabolic pathways.
Collapse
Affiliation(s)
- Magdalena Ligor
- Department of Anaesthesiology and Critical Care Medicine, Innsbruck Medical University, Innsbruck, Austria
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
King J, Kupferthaler A, Unterkofler K, Koc H, Teschl S, Teschl G, Miekisch W, Schubert J, Hinterhuber H, Amann A. Isoprene and acetone concentration profiles during exercise on an ergometer. J Breath Res 2009; 3:027006. [PMID: 21383461 DOI: 10.1088/1752-7155/3/2/027006] [Citation(s) in RCA: 203] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
22
|
O'Hara ME, Clutton-Brock TH, Green S, Mayhew CA. Endogenous volatile organic compounds in breath and blood of healthy volunteers: examining breath analysis as a surrogate for blood measurements. J Breath Res 2009; 3:027005. [PMID: 21383460 DOI: 10.1088/1752-7155/3/2/027005] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
To investigate the premise that levels of endogenous volatile organic compounds (VOC) in breath reflect those in blood, the concentration of acetone and isoprene were measured in radial arterial blood, peripheral venous blood and breath samples from ten healthy volunteers. Coefficients of repeatability as a percentage of mean are less than 30% in breath but greater than 70% in blood. The volunteer-mean ratios of arterial to venous blood concentration are 1.4 (0.9-2.1) for acetone and 0.55 (0.3-1.0) for isoprene. Concentration in breath showed a significant inter-subject correlation with concentration in arterial blood (CAB) for acetone but not for isoprene. Arterial blood/breath ratios are 580 (280-1060) for acetone and 0.47 (0.22-0.77) for isoprene. The sample-mean blood/breath ratio was used to calculate an estimate of CAB and the standard deviation of this estimate was lower than that of arterial blood measured directly. For most subjects, estimated CAB was within uncertainty limits of the actual CAB. Owing to the poor repeatability of VOC concentrations from consecutive blood samples, and the capacitive effects of the lung, this study suggests that breath VOC measurements may provide a more consistent measure than blood measurements for investigating underlying physiological function or pathology within individuals.
Collapse
Affiliation(s)
- M E O'Hara
- School of Physics and Astronomy, University of Birmingham, Birmingham, B15 2TT, UK
| | | | | | | |
Collapse
|
23
|
Sprunger L, Gibbs J, Acree W, Abraham M. Correlation of Human and Animal Air-to-Blood Partition Coefficients With a Single Linear Free Energy Relationship Model. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/qsar.200860078] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
24
|
O'Hara ME, O'Hehir S, Green S, Mayhew CA. Development of a protocol to measure volatile organic compounds in human breath: a comparison of rebreathing and on-line single exhalations using proton transfer reaction mass spectrometry. Physiol Meas 2008; 29:309-30. [PMID: 18367807 DOI: 10.1088/0967-3334/29/3/003] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Analysis of volatile organic compounds (VOCs) on human breath has great potential as a non-invasive diagnostic technique. It is, therefore, surprising that no single, standard procedure has evolved for breath sampling. Here we present a novel repeated-cycle isothermal rebreathing method, where one cycle comprises five rebreaths, which could be adopted for breath analysis of VOCs. For demonstration purposes, we present measurements of three common breath VOCs: isoprene, acetone and methanol. Their concentrations measured in breath are shown to increase with number of rebreaths until a plateau value is reached by at least 20 rebreaths. The average ratio of plateau concentration to single mixed expired breath concentration was found to be 1.92 +/- 0.57 for isoprene, 1.25 +/- 0.13 for acetone and 1.12 +/- 0.12 for methanol (mean +/- standard deviation). Measurements from on-line single exhalations are presented which demonstrate a positive slope in the time-dependent expirograms of isoprene and acetone. The slope of the isoprene expirogram is persistently linear and the end-expired concentration of isoprene is highly variable in the same subject depending on the duration of exhalation. End-expired values of acetone are not as sensitive to the length of exhalation, and are the same to within measurement uncertainty for any duration of exhalation for any subject. It is concluded that uncontrolled single on-line exhalations are not suitable for the reliable measurement of isoprene in the breath and that rebreathing can be the basis of an easily tolerated protocol for the reliable collection of breath samples.
Collapse
Affiliation(s)
- M E O'Hara
- School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
| | | | | | | |
Collapse
|
25
|
Abraham MH, Ibrahim A, Acree WE. Air to liver partition coefficients for volatile organic compounds and blood to liver partition coefficients for volatile organic compounds and drugs. Eur J Med Chem 2007; 42:743-51. [PMID: 17292513 DOI: 10.1016/j.ejmech.2006.12.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Revised: 12/05/2006] [Accepted: 12/07/2006] [Indexed: 10/23/2022]
Abstract
Values of in vitro air to liver partition coefficients, K(liver), of VOCs have been collected from the literature. For 124 VOCs, application of the Abraham solvation equation to logK(liver) yielded a correlation equation with R(2)=0.927 and SD=0.26 log units. Combination of the logK(liver) values with logK(blood) values leads to in vitro blood to liver partition coefficients, as logP(liver) for VOCs; an Abraham solvation equation can correlate 125 such values with R(2)=0.583 and SD=0.23 log units. Values of in vivo logP(liver) for 85 drugs were collected, and were correlated with R(2)=0.522 and SD=0.42 log units. When the logP(liver) values for VOCs and drugs were combined, an Abraham solvation equation could correlate the 210 compounds with R(2)=0.544 and SD=0.32 log units. Division of the 210 compounds into a training set and a test set, each of 105 compounds, showed that the training equation could predict logP(liver) values with an average error of 0.05 and a standard deviation of 0.34 log units.
Collapse
Affiliation(s)
- Michael H Abraham
- Department of Chemistry, University College London, 20 Gordon Street, London, Middlesex WC1H OAJ, UK.
| | | | | |
Collapse
|
26
|
Feng S, Plunkett SE, Lam K, Kapur S, Muhammad R, Jin Y, Zimmermann M, Mendes P, Kinser R, Roethig HJ. A new method for estimating the retention of selected smoke constituents in the respiratory tract of smokers during cigarette smoking. Inhal Toxicol 2007; 19:169-79. [PMID: 17169864 DOI: 10.1080/08958370601052022] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This report describes a new method for estimating the retention of selected mainstream smoke constituents in the respiratory tract of adult smokers during cigarette smoking. Both particulate-phase (PP) constituents including nicotine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and N'-nitrosonornicotine (NNN), two tobacco-specific nitrosamines (TSNA), and gas-vapor-phase (GVP) constituents including carbon monoxide (CO), isoprene (IP), acetaldehyde (AA), and ethylene, were studied. To estimate the amounts of smoke constituents delivered during smoking, we used predetermined linear relationships between the measured cigarette filter solanesol content and machine-generated mainstream deliveries of these selected compounds. To determine the amounts of smoke constituents exhaled, the expired breath was directed through a Cambridge filter pad (CFP) attached to an infrared spectrometer. PP compounds were trapped on the CFP for later analysis and GVP compounds were analyzed in near real time. The smokers' respiratory parameters during smoking, such as inhalation/exhalation volume and time, were monitored using LifeShirt(R), a respiratory inductive plethysmography (RIP) device. The retention of each smoke constituent, expressed as a percentage, was then calculated as the difference between the amount delivered (estimated) and the amount exhaled relative to the amount delivered. We studied 16 adult male smokers who smoked cigarettes according to 3 predefined smoking patterns: no inhalation (pattern A), normal inhalation (pattern B), and deep inhalation (pattern C). For the three PP constituents, the mean retentions for pattern A ranged between 10 and 20%; and while the mean retentions of the two TSNAs were significantly higher for pattern C (84% for NNK and 97% for NNN) than those for pattern B (63% for NNK and 84% for NNN), the mean retentions of nicotine were basically the same between patterns B and C, which were both greater than 98%. For the GVP constituents, the retentions were similar between pattern B and pattern C, although different constituents were retained to different degrees (average values of 33%, 52%, 79%, and 99% for ethylene, IP, CO, and AA, respectively). The differences in the retention between different constituents could be interpreted in terms of each constituent's physical properties such as volatility and solubility. In conclusion, the method described is suitable for studying the retention of selected mainstream smoke constituents in the respiratory tract of smokers.
Collapse
Affiliation(s)
- Shixia Feng
- Philip Morris USA, Research Center, Richmond, Virginia 23234, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Abraham MH, Ibrahim A. Air to fat and blood to fat distribution of volatile organic compounds and drugs: Linear free energy analyses. Eur J Med Chem 2006; 41:1430-8. [PMID: 16996652 DOI: 10.1016/j.ejmech.2006.07.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Revised: 07/07/2006] [Accepted: 07/17/2006] [Indexed: 10/24/2022]
Abstract
Partition coefficients, K(fat), from air to human fat and to rat fat have been collected for 129 volatile organic compounds, VOCs. A linear free energy relationship, LFER, correlates the 129 values of log K(fat) with R(2)=0.958 and a standard deviation, S.D., of 0.194 log units. Use of training and test sets gives a predictive assessment of around 0.20 log units. Combination of log K(fat) with our previously listed values of log K(blood) enables blood/plasma to fat partition coefficients, as log P(fat), to be obtained for 126 VOCs. These values can be correlated with R(2)=0.847, S.D.=0.304 log units; the latter is also our assessment of the predictive capability of the LFER. Values of log P(fat) have been collected for 46 drugs, and can be fitted to an LFER with R(2)=0.811 and S.D.=0.355 log units. Unlike partition into brain or muscle, the data for VOCs and drugs cannot be combined. There are marked discrepancies for PCBs for which partition from blood/plasma into fat is very much less than that calculated from the data on VOCs or from the data on drugs.
Collapse
Affiliation(s)
- Michael H Abraham
- Department of Chemistry, University College London, London, Middlesex, UK.
| | | |
Collapse
|
28
|
Filser JG, Kessler W, Csanády GA. The "Tuebingen desiccator" system, a tool to study oxidative stress in vivo and inhalation toxicokinetics. Drug Metab Rev 2004; 36:787-803. [PMID: 15554247 DOI: 10.1081/dmr-200033492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The "Tuebingen desiccator," a gas-tight all-glass closed chamber system (CCS), has been established in Herbert Remmer's Institute of Toxicology, University of Tuebingen, to investigate the mechanisms underlying the exhalation of endogenous volatile hydrocarbons in rats under oxidative stress. Remmer and associates confirmed the former view that ethane and n-pentane were derived from polyunsaturated fatty acids, and they demonstrated that propane, n-butane and isobutane were released from amino acids. Hydrocarbons exhaled following acute ethanol treatment of rats resulted predominantly from ethanol-dependent inhibition of their metabolism and partly from oxidation of proteins. Exhalation of alkanes in carbon tetrachloride exposed rats did not reflect liver damage, which was, however, directly linked to the amount of carbon tetrachloride metabolized. As has first been shown in Herbert Remmer's institute by investigating the fate of inhaled vinyl chloride in rats, the CSS proved to be also an excellent tool for studying toxicokinetics of inhaled gaseous xenobiotics by means of gas uptake experiments. Based on results gained by such studies, it was recently demonstrated that knowledge of compound-specific physicochemical and species-specific physiological parameters are often sufficient to predict important toxicokinetic properties of inhaled chemicals such as tissue burdens at steady state. By means of the CCS, not only kinetics of a parent gaseous substance but also of gaseous metabolites can be investigated in vivo, as exemplified for ethylene oxide and 1, 2-epoxy-3-butene, metabolites of ethylene and 1,3-butadiene, respectively. Gas uptake studies in closed chamber systems are now worldwide used for determining toxicokinetic parameters relevant for physiological toxicokinetic modeling.
Collapse
Affiliation(s)
- Johannes G Filser
- Institute of Toxicology, GSF National Research Center for Environment and Health, Neuherberg, Germany
| | | | | |
Collapse
|
29
|
Karl T, Prazeller P, Mayr D, Jordan A, Rieder J, Fall R, Lindinger W. Human breath isoprene and its relation to blood cholesterol levels: new measurements and modeling. J Appl Physiol (1985) 2001; 91:762-70. [PMID: 11457792 DOI: 10.1152/jappl.2001.91.2.762] [Citation(s) in RCA: 190] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Numerous publications have described measurements of breath isoprene in humans, and there has been a hope that breath isoprene analyses could be a noninvasive diagnostic tool to assess blood cholesterol levels or cholesterol synthesis rate. However, significant analytic problems in breath isoprene analysis and variability in isoprene levels with age, exercise, diet, etc., have limited the usefulness of these measurements. Here, we have applied proton transfer reaction-mass spectrometry to this problem, allowing on-line detection of breath isoprene. We show that breath isoprene concentration increases within a few seconds after exercise is started as a result of a rapid increase in heart rate and then reaches a lower steady state when breath rate stabilizes. Additional experiments demonstrated that increases in heart rate associated with standing after reclining or sleeping are associated with increased breath isoprene concentrations. An isoprene gas-exchange model was developed and shows excellent fit to breath isoprene levels measured during exercise. In a preliminary experiment, we demonstrated that atorvastatin therapy leads to a decrease in serum cholesterol and low-density-lipoprotein levels and a parallel decrease in breath isoprene levels. This work suggests that there is constant endogenous production of isoprene during the day and night and reaffirms the possibility that breath isoprene can be a noninvasive marker of cholesterologenesis if care is taken to measure breath isoprene under standard conditions at constant heart rate.
Collapse
Affiliation(s)
- T Karl
- Institut für Ionenphysik, Universität Innsbruck, 6020 Innsbruck, Austria.
| | | | | | | | | | | | | |
Collapse
|
30
|
Csanády GA, Filser JG. Toxicokinetics of inhaled and endogenous isoprene in mice, rats, and humans. Chem Biol Interact 2001; 135-136:679-85. [PMID: 11397422 DOI: 10.1016/s0009-2797(01)00204-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Isoprene (IP) is ubiquitous in the environment and is used for the production of polymers. It is metabolized in vivo to reactive epoxides, which might cause the tumors observed in IP exposed rodents. Detailed knowledge of the body and tissue burden of inhaled IP and its intermediate epoxides can be gained using a physiological toxicokinetic (PT) model. For this purpose, a PT-model was developed for IP in mouse, rat, and human. Experimentally determined partition coefficients were taken from the literature. Metabolic parameters were obtained from gas-uptake experiments. The measured data could be described by introducing hepatic and extrahepatic metabolism into the model. At exposure concentrations up to 50 ppm, the rate of metabolism at steady-state is 14 times faster in mice and about 8 times faster in rats than in humans (2.5 micromol/h/kg at 50 ppm IP in air). IP does accumulate only barely due to its fast metabolism and its low thermodynamic partition coefficient whole body:air. IP is produced endogenously. This production is negligible in rodents compared to that in humans (0.34 micromol/h/kg). About 90% of IP produced endogenously in humans is metabolized and 10% is exhaled unchanged. The blood concentration of IP in non-exposed humans is predicted to be 9.5 nmol/l. The area under the blood concentration-time curve (AUC) following exposure over 8 h to 10 ppm IP is about 4 times higher than the AUC resulting from the unavoidable endogenous IP over 24 h. A comparison of such AUCs can be used for establishing workplace exposure limits. For estimation of the absolute risk, knowledge of the body burden of the epoxide intermediates of IP is required. Unfortunately, such data are not yet available.
Collapse
Affiliation(s)
- G A Csanády
- Institute of Toxicology, GSF National Research Center for Environment and Health, Ingolstädter Landstrasse 1, D-85764 Neuherberg, Germany
| | | |
Collapse
|
31
|
Filser JG, Schmidbauer R, Rampf F, Baur CM, Pütz C, Csanády GA. Toxicokinetics of inhaled propylene in mouse, rat, and human. Toxicol Appl Pharmacol 2000; 169:40-51. [PMID: 11076695 DOI: 10.1006/taap.2000.9027] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A physiological toxicokinetic (PT) model was developed for inhaled propylene gas (PE) in mouse, rat, and human. Metabolism was simulated to occur in the liver (90%) and in the richly perfused tissue group (10%). The partition coefficients tissue:air were determined in vitro using tissues of mice, rats, and humans. Most of the tissues have partition coefficients of around 0.5. Only adipose tissue displays a 10 times higher value. The partition coefficient blood:air in human is 0.44, about half of that in rodents. PE can accumulate in the organism only barely. For male B6C3F1 mice and male Fischer 344/N rats, parameters of PE metabolism were obtained from gas uptake experiments. Maximum rates of metabolism (V(maxmo)) were 110 micromol/h/kg in mice and 50.4 micromol/h/kg in rats. V(maxmo)/2 was reached in mice at 270 ppm and in rats at 400 ppm of atmospheric PE. Pretreatment of the animals with sodium diethyldithiocarbamate resulted in an almost complete inhibition of PE metabolism in both species. Preliminary toxicokinetic data on PE metabolism in humans were obtained in one volunteer who was exposed up to 4.5 h to constant concentrations of 5 and 25 ppm PE. The PT model was used to calculate PE blood concentrations at steady state. At 25 ppm, the blood values were comparable across species, with 0.19, 0.32, and 0.34 micromol/L for mouse, rat, and human, respectively. However, the corresponding rates of PE metabolism differed dramatically, being 8.3, 2.1, and 0.29 micromol/h/kg in mouse, rat, and human. For a repeated human exposure to 25 ppm PE in air (8 h/day, 5 days/week), PE concentrations in venous blood were simulated. The prediction demonstrates that PE is eliminated so rapidly that it cannot accumulate in the organism. For low exposure concentrations, it became obvious that the rate of uptake into blood by inhalation is limited by the blood flow through the lung and the rate of metabolism is limited by the blood flow through the metabolizing organs.
Collapse
Affiliation(s)
- J G Filser
- GSF-Institute of Toxicology, Neuherberg, Germany
| | | | | | | | | | | |
Collapse
|
32
|
Csanády GA, Denk B, Pütz C, Kreuzer PE, Kessler W, Baur C, Gargas ML, Filser JG. A physiological toxicokinetic model for exogenous and endogenous ethylene and ethylene oxide in rat, mouse, and human: formation of 2-hydroxyethyl adducts with hemoglobin and DNA. Toxicol Appl Pharmacol 2000; 165:1-26. [PMID: 10814549 DOI: 10.1006/taap.2000.8918] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ethylene (ET) is a gaseous olefin of considerable industrial importance. It is also ubiquitous in the environment and is produced in plants, mammals, and humans. Uptake of exogenous ET occurs via inhalation. ET is biotransformed to ethylene oxide (EO), which is also an important volatile industrial chemical. This epoxide forms hydroxyethyl adducts with macromolecules such as hemoglobin and DNA and is mutagenic in vivo and in vitro and carcinogenic in experimental animals. It is metabolically eliminated by epoxide hydrolase and glutathione S-transferase and a small fraction is exhaled unchanged. To estimate the body burden of EO in rodents and human resulting from exposures to EO and ET, we developed a physiological toxicokinetic model. It describes uptake of ET and EO following inhalation and intraperitoneal administration, endogenous production of ET, enzyme-mediated oxidation of ET to EO, bioavailability of EO, EO metabolism, and formation of 2-hydroxyethyl adducts of hemoglobin and DNA. The model includes compartments representing arterial, venous, and pulmonary blood, liver, muscle, fat, and richly perfused tissues. Partition coefficients and metabolic parameters were derived from experimental data or published values. Model simulations were compared with a series of data collected in rodents or humans. The model describes well the uptake, elimination, and endogenous production of ET in all three species. Simulations of EO concentrations in blood and exhaled air of rodents and humans exposed to EO or ET were in good agreement with measured data. Using published rate constants for the formation of 2-hydroxyethyl adducts with hemoglobin and DNA, adduct levels were predicted and compared with values reported. In humans, predicted hemoglobin adducts resulting from exposure to EO or ET are in agreement with measured values. In rodents, simulated and measured DNA adduct levels agreed generally well, but hemoglobin adducts were underpredicted by a factor of 2 to 3. Obviously, there are inconsistencies between measured DNA and hemoglobin adduct levels.
Collapse
Affiliation(s)
- G A Csanády
- GSF, Neuherberg, Germany/Technische Universität München, Germany
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
Recent improvements in the ability to detect chemically modified bases in DNA have revealed that not only does the genetic material incur damage by foreign chemicals, but that it also sustains injury by reactive products of normal physiological processes. This review summarises current understanding of the DNA-damaging potential of various substances of endogenous origin, including oxidants, lipid peroxidation products, alkylating agents, estrogens, chlorinating agents, reactive nitrogen species, and certain intermediates of various metabolic pathways. The strengths and weaknesses of the existing database for DNA damage by each class of substance are discussed, as are future strategies for resolving the difficult question of whether endogenous chemicals are significant contributors to spontaneous mutagenesis and cancer development in vivo.
Collapse
Affiliation(s)
- P C Burcham
- Department of Clinical and Experimental Pharmacology, The University of Adelaide, Adelaide, SA 5005, Australia.
| |
Collapse
|