Airway resistance due to alveolar gas compression measured by barometric plethysmography in mice.

We developed a method for measuring airway resistance (R(aw)) in mice that does not require a measurement of airway flow. An analysis of R(aw) induced by alveolar gas compression showed the following relationship for an animal breathing spontaneously in a closed box: R(aw) = A(bt)V(b)/[V(t) (V(e) + 0.5V(t))]. Here A(bt) is the area under the box pressure-time curve during inspiration or expiration, V(b) is box volume, V(t) is tidal volume, and V(e) is functional residual capacity (FRC). In anesthetized and conscious unrestrained mice, from experiments with both room temperature box air and body temperature humidified box air, the contributions of gas compression to the box pressure amplitude were 15 and 31% of those due to the temperature-humidity difference between box and alveolar gas. We corrected the measured A(bt) and V(t) for temperature-humidity and gas compression effects, respectively, using a sinusoidal analysis. In anesthetized mice, R(aw) averaged 4.3 cmH(2)O.ml(-1).s, fourfold greater than pulmonary resistance measured by conventional methods. In conscious mice with an assumed FRC equal to that measured in the anesthetized mice, the corrected R(aw) at room temperature averaged 1.9 cmH(2)O.ml(-1).s. In both conscious mice and anesthetized mice, exposure to aerosolized methacholine with room temperature box air significantly increased R(aw) by around eightfold. Here we assumed that in the conscious mice both V(t) and FRC remained constant. In both conscious and anesthetized mice, body temperature humidified box air reduced the methacholine-induced increase in R(aw) observed at room temperature. The method using the increase in A(bt) with bronchoconstriction provides a conservative estimate for the increase in R(aw) in conscious mice.

[1]  Per Aagaard,et al.  Muscle performance during maximal isometric and dynamic contractions is influenced by the stiffness of the tendinous structures. , 2005, Journal of applied physiology.

[2]  Christopher G. Wilson,et al.  Brain stem excitatory and inhibitory signaling pathways regulating bronchoconstrictive responses. , 2005, Journal of applied physiology.

[3]  G. E. Meadows,et al.  Cardiovascular response to arousal from sleep under controlled conditions of central and peripheral chemoreceptor stimulation in humans. , 2004, Journal of applied physiology.

[4]  W. Mitzner,et al.  Interpreting Penh in mice. , 2003, Journal of applied physiology.

[5]  J. Bates,et al.  A reevaluation of the validity of unrestrained plethysmography in mice. , 2002, Journal of applied physiology.

[6]  C. Greeff,et al.  Shock-induced α–ω transition in titanium , 2001 .

[7]  Z Hantos,et al.  Hyperoxia-induced changes in mouse lung mechanics: forced oscillations vs. barometric plethysmography. , 2001, Journal of applied physiology.

[8]  D. Bergren Chronic tobacco smoke exposure increases airway sensitivity to capsaicin in awake guinea pigs. , 2001, Journal of applied physiology.

[9]  Y. Lai,et al.  Respiratory mechanics and maximal expiratory flow in the anesthetized mouse. , 2000, Journal of applied physiology.

[10]  G. Cieslewicz,et al.  The late, but not early, asthmatic response is dependent on IL-5 and correlates with eosinophil infiltration. , 1999, The Journal of clinical investigation.

[11]  W. Mitzner,et al.  Noninvasive measurement of airway responsiveness in allergic mice using barometric plethysmography. , 1998, American journal of respiratory and critical care medicine.

[12]  D. Murphy,et al.  A novel method for chronic measurement of pleural pressure in conscious rats. , 1998, Journal of pharmacological and toxicological methods.

[13]  S. Gunst,et al.  Effect of tidal volume and frequency on airway responsiveness in mechanically ventilated rabbits. , 1997, Journal of applied physiology.

[14]  E. Gelfand,et al.  Noninvasive measurement of airway responsiveness in allergic mice using barometric plethysmography. , 1997, American journal of respiratory and critical care medicine.

[15]  M. Kumada,et al.  Determination of ventilatory volume in mice by whole body plethysmography. , 1997, The Japanese journal of physiology.

[16]  J. Bates,et al.  Temporal dynamics of acute isovolume bronchoconstriction in the rat. , 1997, Journal of applied physiology.

[17]  W. Mitzner,et al.  Respiratory system mechanics in mice measured by end-inflation occlusion. , 1995, Journal of applied physiology.

[18]  Y. Lai Maximal expiratory flow in the guinea pig. , 1988, Lung.

[19]  J. Mortola,et al.  Expiratory pattern of newborn mammals. , 1985, Journal of applied physiology.

[20]  J. Marini,et al.  Bronchodilatory effect of warm air inhalation during quiet breathing. , 1984, The Western journal of medicine.

[21]  J P Jacky,et al.  Barometric measurement of tidal volume: effects of pattern and nasal temperature. , 1980, Journal of applied physiology: respiratory, environmental and exercise physiology.

[22]  D. Leith,et al.  Dynamic mechanisms determine functional residual capacity in mice, Mus musculus. , 1979, Journal of applied physiology: respiratory, environmental and exercise physiology.

[23]  R. A. Epstein,et al.  A theoretical analysis of the barometric method for measurement of tidal volume. , 1978, Respiration physiology.

[24]  Physiologic basis and interpretation of common indices of respiratory mechanical function. , 1976, Environmental health perspectives.

[25]  B. Jonson,et al.  Measurement of alveolar pressure. , 1967, Journal of applied physiology.

[26]  A. Otis,et al.  MEASUREMENT OF AIRWAY RESISTANCE WITH A VOLUME DISPLACEMENT BODY PLETHYSMOGRAPH. , 1964, Journal of applied physiology.

[27]  J. Mead,et al.  Mechanics of respiration in unanesthetized guinea pigs. , 1958, The American journal of physiology.

[28]  J. H. Comroe,et al.  A new method for measuring airway resistance in man using a body plethysmograph: values in normal subjects and in patients with respiratory disease. , 1956, The Journal of clinical investigation.

[29]  W. O. Fenn,et al.  A barometric method for measuring ventilation in newborn infants. , 1955, Pediatrics.