Partitioning of airway responses to inhaled methacholine in the rat

Dimaria, G.; Wang, C. G.; Bates, Jason H. T.; Rd, Guttmann; Martin, James G.

doi:10.1152/jappl.1987.62.3.1317

Cited by 17 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mean value of sRaw-RWBP in C57 (0.51 cm/s) was about five times the value obtained for sRaw-FOT (0.095 cm/s), commensurate with the contribution from the upper airways. In support of this notion, the upper airways contributed to about four-fifths of total Raw in rats (13). The exact contribution of the upper airways to the baseline and postprovocation measurements of sRaw-RWBP were not disclosed by this study but require further study in conscious mice.…”

Section: Discussionsupporting

confidence: 57%

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

Lofgren

Mazan

Ingenito

et al. 2006

Journal of Applied Physiology

View full text Add to dashboard Cite

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.

show abstract

Section: Discussionsupporting

confidence: 57%

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

Lofgren

Mazan

Ingenito

et al. 2006

Journal of Applied Physiology

View full text Add to dashboard Cite

show abstract

“…The data obtained show that the upper airways (larynx, pharynx, nasal passages) comprise the major portion, approximately 90%, of total airway resistance. This is a greater proportion than the 45% found in guinea-pig by Amdur & Mead (1958), but is similar to the 80% shown in the rat by DiMaria et al (1987). Surprisingly, histamine consistently reduced the resistance of the upper airways while increasing that of the lower airways.…”

Section: Discussionsupporting

confidence: 73%

The effect of ozone on reactivity of upper and lower airways in guinea‐pigs

Holroyde¹,

Norris²

1988

British J Pharmacology

View full text Add to dashboard Cite

The effect of ozone inhalation on the responsiveness of upper and lower airways to histamine was examined in guinea‐pigs. The exposure of conscious guinea‐pigs to 3.5 p.p.m. ozone for 30 min rendered their lower airways 2–3 fold more sensitive to the bronchoconstrictor action of i.v. histamine, as assessed subsequently under anaesthesia. The development of lower airway hyperreactivity was not modified by bilateral cervical vagotomy or pretreatment with BW 755C, FPL 55712 or SC‐39070. Under the conditions used, ozone exposure produced a mild inflammatory response as monitored by bronchoalveolar lavage, characterized by epithelial damage and prostaglandin E2 generation, but no cellular infiltration or oedema. In contrast to the lower airways, upper airway resistance was reduced by i.v. histamine. This response was not affected by ozone exposure. Isolated tracheal preparations taken from ozone‐exposed guinea‐pigs were not significantly more sensitive to histamine than control tissues. The mechanism of hyperreactivity in this model is unknown but does not depend on leukotriene generation or a vagal reflex.

show abstract

“…Whereas penh and FDP have been applied to examination of bronchoconstricting aerosol dose response characteristics 58 and correlate well with more traditional measures of AR, 15,28,30,3 2 both may be influenced by CO 2 -induced elevation of ventilation in a manner that could be confused with an aerosol effect. Changes in ventilation, breathing pattern, and passive mechanics (Te and Tt) 59 and respiratory drive (Ti/Tt) 60 thought to be characteristic of AR can occur in the absence of bronchoconstriction, 8,26,61,62 and it is possible that the same is true of these nondimensional parameters.…”

Section: Discussionmentioning

confidence: 99%

Carbon Dioxide Accumulation during Small Animal, Whole Body Plethysmography: Effects on Ventilation, Indices of Airway Function, and Aerosol Deposition

Kimmel¹,

Whitehead

Reboulet³

et al. 2002

Journal of Aerosol Medicine

View full text Add to dashboard Cite

Barometric (whole body) plethysmography is used to examine changes in ventilation and breathing pattern in unrestrained animals during exposure to therapeutic or toxic aerosols. Whole body plethysmographs (WBP) may be operated with a bias flow in order to maintain an adequate supply of oxygen and remove expired CO(2). However, some aerosol generation and delivery methods may require operation of the WBP without bias flow, which would artificially deplete aerosol concentration. Under these conditions, expired CO(2) accumulates in the plethysmograph and stimulates ventilation, increasing total aerosol deposition, shifting regional deposition, and significantly altering some airway function indices. We characterized these effects in guinea pigs using a commercially available 4.5-L WBP, with and without a 1 L/min bias flow. CO(2)-induced changes in breathing frequency (f), tidal volume (Vt), minute ventilation (Ve), and indices of airway function -- including enhanced pause (penh), flow derived parameter (FDP), and respiratory duty cycle -- were measured. Without bias flow, CO(2) in the plethysmograph increased steadily to 5.4% after 30 min compared to a steady state 0.9% with bias flow. This resulted in a moderate suppression of f, and significant increases in Vt and Ve by factors of 1.5 and 1.4, respectively. Changes in regional deposition were stimulated for 300 mg/m(3) polydisperse aerosols with mass median aerodynamic diameters of 0.3, 1, 3, or 7 microm and geometric standard deviations of 1.7. Percent increase in aerosol deposition from CO(2) inhalation ranged from 24% to 90%, by mass, depending on aerosol size distribution and respiratory tract region. In addition, fractional deposition shifted toward the pulmonary region. Empirical indices of airway constriction, penh and FDP, also were increased significantly to 1.7 and 1.3 times their respective baseline values. The study quantifies the effect of inadvertent coexposure to CO(2) on ventilation, aerosol deposition, and airway function in WBP evaluation of aerosol effects in airway function.

show abstract

Partitioning of airway responses to inhaled methacholine in the rat

Cited by 17 publications

References 0 publications

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

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

The effect of ozone on reactivity of upper and lower airways in guinea‐pigs

Carbon Dioxide Accumulation during Small Animal, Whole Body Plethysmography: Effects on Ventilation, Indices of Airway Function, and Aerosol Deposition

Contact Info

Product

Resources

About