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Dong J, Shang Y, Tian L, Tu J. Uniqueness of inspiratory airflow patterns in a realistic rat nasal cavity. Comput Biol Med 2021; 141:105129. [PMID: 34915333 DOI: 10.1016/j.compbiomed.2021.105129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 12/08/2021] [Accepted: 12/08/2021] [Indexed: 11/03/2022]
Abstract
In this study, we present a detailed flow analysis using an anatomically accurate rat nasal cavity model, in which the anatomy and physiology of the nasal airway was thoroughly examined. Special efforts were given to the swirling flow structures in the nasal vestibule (anterior section of the nose, lined by squamous epithelium), fractional flow patterns in the olfactory (posterior superior section of the rat nose, lined by olfactory epithelium), and a designated method to precisely quantify flow apportionment in the olfactory region was developed. Results revealed distinct inspiratory flow patterns in the anterior vestibule region, where the accelerated airflow undergoes two sharp turns as traveling through the tortuous airway, making a route in a shape of 8. Besides this, exceptionally large flow apportionment was observed at the interface of the olfactory recess, which can be as much as 15 times greater than that in the human nose. The thorough understanding of the airflow dynamics in the rat nasal cavity is necessary to avoid potential misinterpretation of rat-derived inhalation toxicity results. Research findings are expected to play a fundamental role in developing unbiased rat to human interspecies data extrapolation schemes.
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Affiliation(s)
- Jingliang Dong
- Mechanical & Automotive Engineering, School of Engineering, RMIT University, Bundoora, VIC, Australia.
| | - Yidan Shang
- Mechanical & Automotive Engineering, School of Engineering, RMIT University, Bundoora, VIC, Australia
| | - Lin Tian
- Mechanical & Automotive Engineering, School of Engineering, RMIT University, Bundoora, VIC, Australia
| | - Jiyuan Tu
- Mechanical & Automotive Engineering, School of Engineering, RMIT University, Bundoora, VIC, Australia.
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Robert-Hazotte A, Schoumacker R, Semon E, Briand L, Guichard E, Le Quéré JL, Faure P, Heydel JM. Ex vivo real-time monitoring of volatile metabolites resulting from nasal odorant metabolism. Sci Rep 2019; 9:2492. [PMID: 30792537 PMCID: PMC6385289 DOI: 10.1038/s41598-019-39404-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 01/22/2019] [Indexed: 12/02/2022] Open
Abstract
Odorant-metabolizing enzymes are critically involved in the clearance of odorant molecules from the environment of the nasal neuro-olfactory tissue to maintain the sensitivity of olfactory detection. Odorant metabolism may also generate metabolites in situ, the characterization and function of which in olfaction remain largely unknown. Here, we engineered and validated an ex vivo method to measure odorant metabolism in real-time. Glassware containing an explant of rat olfactory mucosa was continuously flushed with an odorant flow and was coupled to a proton transfer reaction-mass spectrometer for volatile compound analysis. Focusing on carboxylic esters and diketone odorants, we recorded the metabolic uptake of odorants by the mucosa, concomitantly with the release of volatile odorant metabolites in the headspace. These results significantly change the picture of real-time in situ odorant metabolism and represent a new step forward in the investigation of the function of odorant metabolites in the peripheral olfactory process. Our method allows the systematic identification of odorant metabolites using a validated animal model and permits the screening of olfactory endogenously produced chemosensory molecules.
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Affiliation(s)
- Aline Robert-Hazotte
- Centre des Sciences du Goût et de l'Alimentation, UMR 6265 CNRS/1324 INRA/Université de Bourgogne Franche-Comté, 9 boulevard Jeanne d'Arc, F-21000, Dijon, France
| | - Rachel Schoumacker
- Centre des Sciences du Goût et de l'Alimentation, UMR 6265 CNRS/1324 INRA/Université de Bourgogne Franche-Comté, 9 boulevard Jeanne d'Arc, F-21000, Dijon, France
| | - Etienne Semon
- Centre des Sciences du Goût et de l'Alimentation, UMR 6265 CNRS/1324 INRA/Université de Bourgogne Franche-Comté, 9 boulevard Jeanne d'Arc, F-21000, Dijon, France
| | - Loïc Briand
- Centre des Sciences du Goût et de l'Alimentation, UMR 6265 CNRS/1324 INRA/Université de Bourgogne Franche-Comté, 9 boulevard Jeanne d'Arc, F-21000, Dijon, France
| | - Elisabeth Guichard
- Centre des Sciences du Goût et de l'Alimentation, UMR 6265 CNRS/1324 INRA/Université de Bourgogne Franche-Comté, 9 boulevard Jeanne d'Arc, F-21000, Dijon, France
| | - Jean-Luc Le Quéré
- Centre des Sciences du Goût et de l'Alimentation, UMR 6265 CNRS/1324 INRA/Université de Bourgogne Franche-Comté, 9 boulevard Jeanne d'Arc, F-21000, Dijon, France
| | - Philippe Faure
- Centre des Sciences du Goût et de l'Alimentation, UMR 6265 CNRS/1324 INRA/Université de Bourgogne Franche-Comté, 9 boulevard Jeanne d'Arc, F-21000, Dijon, France
| | - Jean-Marie Heydel
- Centre des Sciences du Goût et de l'Alimentation, UMR 6265 CNRS/1324 INRA/Université de Bourgogne Franche-Comté, 9 boulevard Jeanne d'Arc, F-21000, Dijon, France.
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Dong J, Shang Y, Tian L, Inthavong K, Tu J. Detailed deposition analysis of inertial and diffusive particles in a rat nasal passage. Inhal Toxicol 2018; 30:29-39. [PMID: 29488421 DOI: 10.1080/08958378.2018.1439549] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Rats have been widely used as surrogates for evaluating the health effects of inhaled airborne particulate matter. To provide a thorough understanding of particle transport and deposition mechanisms in the rat nasal airway, this article presents a computational fluid dynamics (CFD) study of particle exposure in a realistic rat nasal passage under a resting flow condition. Particles covering a diameter range from 1 nm to 4 µm were passively released in front of the rat's breathing zone, and the Lagrangian particle tracking approach was used to calculate individual particle trajectories. Detailed particle deposition analysis shows the deposition of inertial particles >2 µm is high in the rat nasal vestibule and more than 70% of all inhaled inertial particles were trapped in this region. While for diffusive nanoparticles, the vestibule filtration effect is reduced, only less than 60% of inhaled nanoparticles were blocked by the anterior nasal structures. The particle exposure in the olfactory region only shows notable deposition for diffusive nanoparticles, which peaks at 9.4% for 5 nm particles. Despite the olfactory deposition remains at a low level, the ratio between the olfactory and the main passage is kept around 30-40% for 10-800 nm particles, which indicates a particle-size-independent distribution pattern in the main nasal passage and olfactory. This study provides a deep understanding of particles deposition features in a rat nasal passage, and the research findings can aid toxicologist in inter-species exposure-response extrapolation study.
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Affiliation(s)
- Jingliang Dong
- a Postdoctoral Station of Environmental Science and Engineering , School of Urban Construction and Environmental Engineering, Chongqing University , Chongqing , China.,b School of Engineering , RMIT University , Bundoora , Australia
| | - Yidan Shang
- b School of Engineering , RMIT University , Bundoora , Australia
| | - Lin Tian
- b School of Engineering , RMIT University , Bundoora , Australia
| | - Kiao Inthavong
- b School of Engineering , RMIT University , Bundoora , Australia
| | - Jiyuan Tu
- b School of Engineering , RMIT University , Bundoora , Australia.,c Key Laboratory of Ministry of Education for Advanced Reactor Engineering and Safety , Institute of Nuclear and New Energy Technology, Tsinghua University , Beijing , PR China
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Colby SM, Kabilan S, Jacob RE, Kuprat AP, Einstein DR, Corley RA. Comparison of realistic and idealized breathing patterns in computational models of airflow and vapor dosimetry in the rodent upper respiratory tract. Inhal Toxicol 2016; 28:192-202. [PMID: 26986954 DOI: 10.3109/08958378.2016.1150367] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
CONTEXT Computational fluid dynamics (CFD) simulations of airflows coupled with physiologically based pharmacokinetic (PBPK) modeling of respiratory tissue doses of airborne materials have traditionally used either steady-state inhalation or a sinusoidal approximation of the breathing cycle for airflow simulations despite their differences from normal breathing patterns. OBJECTIVE Evaluate the impact of realistic breathing patterns, including sniffing, on predicted nasal tissue concentrations of a reactive vapor that targets the nose in rats as a case study. MATERIALS AND METHODS Whole-body plethysmography measurements from a free-breathing rat were used to produce profiles of normal breathing, sniffing and combinations of both as flow inputs to CFD/PBPK simulations of acetaldehyde exposure. RESULTS For the normal measured ventilation profile, modest reductions in time- and tissue depth-dependent areas under the curve (AUC) acetaldehyde concentrations were predicted in the wet squamous, respiratory and transitional epithelium along the main airflow path, while corresponding increases were predicted in the olfactory epithelium, especially the most distal regions of the ethmoid turbinates, versus the idealized profile. The higher amplitude/frequency sniffing profile produced greater AUC increases over the idealized profile in the olfactory epithelium, especially in the posterior region. CONCLUSIONS The differences in tissue AUCs at known lesion-forming regions for acetaldehyde between normal and idealized profiles were minimal, suggesting that sinusoidal profiles may be used for this chemical and exposure concentration. However, depending upon the chemical, exposure system and concentration and the time spent sniffing, the use of realistic breathing profiles, including sniffing, could become an important modulator for local tissue dose predictions.
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Affiliation(s)
- Sean M Colby
- Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Senthil Kabilan
- Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Richard E Jacob
- Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Andrew P Kuprat
- Pacific Northwest National Laboratory, Richland, WA 99354, USA
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Shang Y, Dong J, Inthavong K, Tu J. Comparative numerical modeling of inhaled micron-sized particle deposition in human and rat nasal cavities. Inhal Toxicol 2015; 27:694-705. [PMID: 26406158 DOI: 10.3109/08958378.2015.1088600] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Micron-sized particle deposition in anatomically realistic models of a rat and human nasal cavity was numerically investigated. A steady laminar inhalation flow rate was applied and particles were released from the outside air. Particles showing equivalent total particle deposition fractions were classified into low, medium and high inertial particle. Typical particle sizes are 2.5, 9 and 20 μm for the human model and 1, 2 and 3 μm for the rat model, respectively. Using a surface-mapping technique the 3D nasal cavity surface was "unwrapped" into a 2D domain and the particle deposition locations were plotted for complete visual coverage of the domain surface. The total surface area comparison showed that the surface area of the human nasal model was about ten times the size of the rat model. In contrast, the regional surface area percentage analysis revealed the olfactory region of the rat model was significantly larger than all other regions making up ∼55.6% of the total surface area, while that of the human nasal model only occupying 10.5%. Flow pattern comparisons showed rapid airflow acceleration was found at the nasopharynx region and the nostril region for the human and rat model, respectively. For the human model, the main passage is the major deposition region for micro-particles. While for the rat model, it is the vestibule. Through comparing the regional deposition flux between human and rat models, this study can contribute towards better extrapolation approach of inhalation exposure data between inter-subject species.
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Affiliation(s)
- Yidan Shang
- a School of Aerospace, Mechanical & Manufacturing Engineering, and Platform Technologies Research Institute (PTRI), RMIT University , Bundoora , VIC , Australia
| | - Jingliang Dong
- a School of Aerospace, Mechanical & Manufacturing Engineering, and Platform Technologies Research Institute (PTRI), RMIT University , Bundoora , VIC , Australia
| | - Kiao Inthavong
- a School of Aerospace, Mechanical & Manufacturing Engineering, and Platform Technologies Research Institute (PTRI), RMIT University , Bundoora , VIC , Australia
| | - Jiyuan Tu
- a School of Aerospace, Mechanical & Manufacturing Engineering, and Platform Technologies Research Institute (PTRI), RMIT University , Bundoora , VIC , Australia
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Li A, Gire DH, Bozza T, Restrepo D. Precise detection of direct glomerular input duration by the olfactory bulb. J Neurosci 2014; 34:16058-64. [PMID: 25429146 PMCID: PMC4244471 DOI: 10.1523/jneurosci.3382-14.2014] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 10/07/2014] [Accepted: 10/15/2014] [Indexed: 12/17/2022] Open
Abstract
Sensory neuron input to the olfactory bulb (OB) was activated precisely for different durations with blue light in mice expressing channelrhodopsin-2 in olfactory sensory neurons. Behaviorally the mice discriminated differences of 10 ms in duration of direct glomerular activation. In addition, a subset of mitral/tufted cells in the OB of awake mice responded tonically therefore conveying information on stimulus duration. Our study provides evidence that duration of the input to glomeruli not synchronized to sniffing is detected. This potent cue may be used to obtain information on puffs in odor plumes.
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Affiliation(s)
- Anan Li
- Department of Cell and Developmental Biology, Neuroscience Program and Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, Wuhan Institute of Physics and Mathematics, The Chinese Academy of Sciences/State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan, China 430071
| | - David H Gire
- Department of Molecular and Cellular Biology, and Center for Brain Science, Harvard University, Cambridge, Massachusetts 02138, and
| | - Thomas Bozza
- Department of Neurobiology, Northwestern University, Evanston, Illinois 60208
| | - Diego Restrepo
- Department of Cell and Developmental Biology, Neuroscience Program and Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045,
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