scholarly journals Evaluation of a mechanical lung model to test small animal whole body plethysmography

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Swen Hülsmann ◽  
Amara Khan ◽  
Liya Hagos ◽  
Martin Hindermann ◽  
Torsten Nägel ◽  
...  
Keyword(s):  
Airway Resistance ◽  
Small Animal ◽  
Pressure Profile ◽  
Lung Model ◽  
Whole Body ◽  
Chamber Pressure ◽  
Body Plethysmography ◽  
Relative Contribution ◽  
Pressure Peak ◽  
Whole Body Plethysmography

AbstractWhole-body plethysmography (WBP) is an established method to determine physiological parameters and pathophysiological alteration of breathing in animals and animal models of a variety of diseases. Although frequently used, there is ongoing debate about what exactly is measured by whole-body-plethysmography and how reliable the data derived from this method are. Here, we designed an artificial lung model that enables a thorough evaluation of different predictions about and around whole-body plethysmography. Using our lung model, we confirmed that during WBP two components contribute to the pressure changes detected in the chamber: (1) the increase in the pressure due to heating and moistening of the air during inspiration, termed conditioning; (2) changes in the chamber pressure that depend on airway resistance. Both components overlap and contribute to the temporal pressure-profile measured in the chamber or across the wall of the chamber, respectively. Our data showed that a precise measurement of the breathing volume appears to be hindered by at least two factors: (1) the unknown relative contribution of each of these two components; (2) not only the air in the inspired volume is conditioned during inspiration, but also air within the residual volume and dead space that is recruited during inspiration. Moreover, our data suggest that the expiratory negative pressure peak that is used to determine the enhanced pause (Penh) parameter is not a measure for airway resistance as such but rather a consequence of the animal’s response to the airway resistance, using forced or active expiration to overcome the resistance by a higher thoracic pressure.

scholarly journals Whole-body plethysmography revisited

2021 ◽  
Author(s):  
Swen Hülsmann ◽  
Amara Khan ◽  
Liya Hagos ◽  
Martin Hindermann ◽  
Torsten Nägel ◽  
...  
Keyword(s):  
Airway Resistance ◽  
Pressure Profile ◽  
Lung Model ◽  
Whole Body ◽  
Chamber Pressure ◽  
Body Plethysmography ◽  
Relative Contribution ◽  
Pressure Peak ◽  
Temporal Pressure ◽  
Whole Body Plethysmography

AbstractWhole-body plethysmography (WBP) is an established method to determine physiological parameters and pathophysiological alteration of breathing in animals and animal models of a variety of diseases, reaching from pulmonary diseases to complex neurological syndromes. Although frequently used, there is ongoing debate about what exactly is measured by whole-body-plethysmography and how reliable the data derived from this method are? Here, we designed a simple device that can serve as an artificial lung model that enables a thorough evaluation of different predictions about and around whole-body plethysmography. Using our lung model, we confirmed that during WBP two components contribute to the pressure changes detected in the chamber: 1) the increase of the pressure due to heating and moistening of the air, termed as conditioning, during inspiration; 2) changes of chamber pressure that depend on airway resistance. Both components overlap and contribute to the temporal pressure-profile measured in the chamber or across the wall of the chamber. Our data showed that a precise measurement of the breathing volume appears to be hindered by at least two factors: 1) the unknown relative contribution of each of these components; 2) not only the air in the inspired volume is conditioned during inspiration, but also air within the residual volume and death space that is recruited during inspiration. Moreover, our data suggest that the expiratory negative pressure peak that is used to determine the so called “enhanced pause” (Penh) parameter is not a measure for airway resistance as such but rather a consequence of the animal’s response to the airway resistance, using active expiration to overcome the resistance by a higher thoracic pressure.

Restrained whole body plethysmography for measure of strain-specific and allergen-induced airway responsiveness in conscious mice

2006 ◽  
Vol 101 (5) ◽  
pp. 1495-1505 ◽  
Author(s):  
Jennifer L. S. Lofgren ◽  
Melissa R. Mazan ◽  
Edward P. Ingenito ◽  
Kara Lascola ◽  
Molly Seavey ◽  
...  
Keyword(s):  
Functional Residual Capacity ◽  
Airway Resistance ◽  
Allergen Challenge ◽  
Airway Disease ◽  
Airway Responsiveness ◽  
Whole Body ◽  
Forced Oscillation Technique ◽  
Body Plethysmography ◽  
Residual Capacity ◽  
Whole Body Plethysmography

The mouse is the most extensively studied animal species in respiratory research, yet the technologies available to assess airway function in conscious mice are not universally accepted. We hypothesized that whole body plethysmography employing noninvasive restraint (RWBP) could be used to quantify specific airway resistance (sRaw-RWBP) and airway responsiveness in conscious mice. Methacholine responses were compared using sRaw-RWBP vs. airway resistance by the forced oscillation technique (Raw-FOT) in groups of C57, A/J, and BALB/c mice. sRaw-RWBP was also compared with sRaw derived from double chamber plethysmography (sRaw-DCP) in BALB/c. Finally, airway responsiveness following allergen challenge in BALB/c was measured using RWBP. sRaw-RWBP in C57, A/J, and BALB/c mice was 0.51 ± 0.03, 0.68 ± 0.03, and 0.63 ± 0.05 cm/s, respectively. sRaw derived from Raw-FOT and functional residual capacity (Raw*functional residual capacity) was 0.095 cm/s, approximately one-fifth of sRaw-RWBP in C57 mice. The intra- and interanimal coefficients of variations were similar between sRaw-RWBP (6.8 and 20.1%) and Raw-FOT (3.4 and 20.1%, respectively). The order of airway responsiveness employing sRaw-RWBP was AJ > BALBc > C57 and for Raw-FOT was AJ > BALB/c = C57. There was no difference between the airway responsiveness assessed by RWBP vs. DCP; however, baseline sRaw-RWBP was significantly lower than sRaw-DCP. Allergen challenge caused a progressive decrease in the provocative concentration of methacholine that increased sRaw to 175% postsaline values based on sRaw-RWBP. In conclusion, the technique of RWBP was rapid, reproducible, and easy to perform. Airway responsiveness measured using RWBP, DCP, and FOT was equivalent. Allergen responses could be followed longitudinally, which may provide greater insight into the pathogenesis of chronic airway disease.

Ventilatory behavior after hypoxia in C57BL/6J and A/J mice

2001 ◽  
Vol 91 (5) ◽  
pp. 1962-1970 ◽  
Author(s):  
Fang Han ◽  
Shyam Subramanian ◽  
Thomas E. Dick ◽  
Ismail A. Dreshaj ◽  
Kingman P. Strohl
Keyword(s):  
Airway Resistance ◽  
Minute Ventilation ◽  
Genetic Effect ◽  
Strain Differences ◽  
Whole Body ◽  
Environmental Forcing ◽  
Ventilatory Responses ◽  
Term Potentiation ◽  
Genetic Mechanisms ◽  
Whole Body Plethysmography

Given the environmental forcing by extremes in hypoxia-reoxygenation, there might be no genetic effect on posthypoxic short-term potentiation of ventilation. Minute ventilation (V˙e), respiratory frequency (f), tidal volume (Vt), and the airway resistance during chemical loading were assessed in unanesthetized unrestrained C57BL/6J (B6) and A/J mice using whole body plethysmography. Static pressure-volume curves were also performed. In 12 males for each strain, after 5 min of 8% O2 exposure, B6 mice had a prominent decrease inV˙e on reoxygenation with either air (−11%) or 100% O2 (−20%), due to the decline of f. In contrast, A/J animals had no ventilatory undershoot or f decline. After 5 min of 3% CO2-10% O2 exposure, B6 exhibited significant decrease in V˙e (−28.4 vs. −38.7%, air vs. 100% O2) and f (−13.8 vs. −22.3%, air vs. 100% O2) during reoxygenation with both air and 100% O2; however, A/J mice showed significant increase inV˙e (+116%) and f (+62.2%) during air reoxygenation and significant increase in V˙e (+68.2%) during 100% O2 reoxygenation. There were no strain differences in dynamic airway resistance during gas challenges or in steady-state total respiratory compliance measured postmortem. Strain differences in ventilatory responses to reoxygenation indicate that genetic mechanisms strongly influence posthypoxic ventilatory behavior.

Whole-body plethysmography

2005 ◽  
pp. 15-43 ◽  
Author(s):  
M.D. Goldman ◽  
H.J. Smith ◽  
W.T. Ulmer
Keyword(s):  
Whole Body ◽  
Body Plethysmography ◽  
Whole Body Plethysmography

scholarly journals Measuring Breathing Patterns in Mice Using Whole-body Plethysmography

BIO-PROTOCOL ◽  
2020 ◽  
Vol 10 (17) ◽  
Author(s):  
Patricia Prada-Dacasa ◽  
Andrea Urpi ◽  
Laura Sánchez-Benito ◽  
Patrizia Bianchi ◽  
Albert Quintana
Keyword(s):  
Whole Body ◽  
Body Plethysmography ◽  
Breathing Patterns ◽  
Whole Body Plethysmography

Maturation of baseline breathing and of hypercapnic and hypoxic ventilatory responses in newborn mice

2001 ◽  
Vol 281 (5) ◽  
pp. R1746-R1753 ◽  
Author(s):  
Sylvain Renolleau ◽  
Stéphane Dauger ◽  
Fanny Autret ◽  
Guy Vardon ◽  
Claude Gaultier ◽  
...  
Keyword(s):  
Cesarean Section ◽  
Tidal Volume ◽  
Mammalian Species ◽  
Whole Body ◽  
Body Plethysmography ◽  
Genetic Studies ◽  
Newborn Mice ◽  
Ventilatory Responses ◽  
Neuronal Mechanisms ◽  
Whole Body Plethysmography

Breathing during the first postnatal hours has not been examined in mice, the preferred mammalian species for genetic studies. We used whole body plethysmography to measure ventilation (V˙e), breath duration (TTOT), and tidal volume (Vt) in mice delivered vaginally (VD) or by cesarean section (CS). In experiment 1, 101 VD and 100 CS pups aged 1, 6, 12, 24, or 48 h were exposed to 8% CO2 or 10% O2for 90 s. In experiment 2, 31 VD pups aged 1, 12, or 24 h were exposed to 10% O2 for 5 min. Baseline breathing maturation was delayed in CS pups, but V˙eresponses to hypercapnia and hypoxia were not significantly different between VD and CS pups [at postnatal age of 1 h (H1): 48 ± 44 and 18 ± 32%, respectively, in VD and CS pups combined]. TheV˙e increase induced by hypoxia was greater at H12 (46 ± 27%) because of TTOT response maturation. At all ages, hypoxic decline was ascribable mainly to a Vtdecrease, and posthypoxic decline was ascribable to a TTOTincrease with apneas, suggesting different underlying neuronal mechanisms.

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