Exercise-related change in airway blood flow in humans: relationship to changes in cardiac output and ventilation.

School of Physiotherapy and Exercise Science, Griffith University, Gold Coast Campus, Qld 4222, Australia.
Respiratory Physiology & Neurobiology (Impact Factor: 2.05). 08/2008; 162(3):204-9. DOI: 10.1016/j.resp.2008.06.020
Source: PubMed

ABSTRACT This study examined the relationship between airway blood flow (Q(aw)), ventilation (V(E)) and cardiac output (Q(tot)) during exercise in healthy humans (n=12, mean age 34+/-11 yr). Q(aw) was estimated from the uptake of the soluble gas dimethyl ether while V(E) and Q(tot) were measured using open circuit spirometry. Measurements were made prior to and during exercise at 34+/-5 W (Load 1) and 68+/-10 W (Load 2) and following the cessation of exercise (recovery). Q(aw) increased in a stepwise fashion (P<0.05) from rest (52.8+/-19.5 microl min(-1) ml(-1)) to exercise at Load 1 (67.0+/-20.3 microl min(-1) ml(-1)) and Load 2 (84.0+/-22.9 microl min(-1) ml(-1)) before returning to pre-exercise levels in recovery (51.7+/-13.2 microl min(-1) ml(-1)). Q(aw) was positively correlated with both Q(tot) (r=0.58, P<0.01) and V(E) (r=0.50, P<0.01). These results demonstrate that the increase in Q(aw) is linked to an exercise related increase in both Q(tot) and V(E) and may be necessary to prevent excessive airway cooling and drying.

1 Bookmark
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The development and optimization of transient antennas for ground penetrating radar would be difficult without numerical simulations of their performance. To this end the FDTD algorithm should be considered as a useful and powerful tool for transient antenna analysis. As an example of such analysis we describe simulations of the dielectric wedge antenna. Good agreement between theoretical predictions and experimental results was observed. Some of the antenna characteristics (like the radial component of the electric field in the near zone, the radiated waveform and the antenna footprint in different grounds) cannot be measured easily, so the correct theoretical (numerical) model is essential for their determination. The numerical model of the antenna can also be used for optimization of the antenna. As an example of such optimization we present a design of the shield for the dielectrically embedded dipole antenna.
    Antenna Theory and Techniques, 2003. 4th International Conference on; 10/2003
  • [Show abstract] [Hide abstract]
    ABSTRACT: Endothelial dysfunction in the extrapulmonary circulation has been linked to cardiovascular disease. Recent investigations have revealed that in the airway circulation, cigarette smoking, chronic obstructive pulmonary disease (COPD), and asthma are also accompanied by endothelial dysfunction. Inhaled glucocorticosteroids can partially or fully restore normal endothelium-dependent vasodilation in these conditions, thereby identifying the airway endothelium as a novel therapeutic target in the treatment of airway disease. The role of the defective endothelium-dependent vasodilation in the pathophysiology in asthma and COPD is still subject to speculation. However, there appears to be an association between COPD and extrapulmonary vascular dysfunction, and the possibility exists that the use of inhaled glucocorticosteroids has a beneficial effect on cardiovascular disease in COPD as suggested by database studies showing that inhaled glucocorticosteroids reduce the incidence of nonfatal and fatal cardiovascular events in COPD.
    American Journal of Respiratory and Critical Care Medicine 12/2010; 182(11):1344-51. · 11.04 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to determine the relationship between body position, pulmonary function (PF) and bronchial blood flow (Q(aw)) in a group of heart failure (HF) and control subjects. Thirty-six subjects were studied: 24 stable, ambulatory HF patients (HF: LVEF=27±6%, age=65±9 yr) and 12 age- and sex-matched controls (CTRL: LVEF=60±7%, age=62±8 yr). Measures of Q˙(aw) (soluble gas method) and PF were collected upright and following 30min in the supine position. Q˙(aw) was similar between groups and remained unchanged with body position. Declines in forced vital capacity (FVC) and forced expiratory volume in 1s (FEV1) with the supine position were observed in both groups; declines in forced expiratory flow 25-75% (FEF(25-75)) and FEF 75% (FEF75) with the supine position were observed in the HF group only. Changes in Q˙(aw) were related to changes in PF only in the HF patient groups (ΔFVC, % predicted, r = -0.45, p<0.04, ΔFEV1 r = -0.61, p<0.01, ΔFEV1% predicted, r = -0.45, p<0.04). These data demonstrate that relationships between postural changes in Q˙(aw) and PF exist only in the HF population and that the bronchial circulation may contribute to postural PF decline in HF.
    Respiratory Physiology & Neurobiology 06/2011; 178(2):269-74. · 2.05 Impact Factor

Full-text (2 Sources)

Available from
May 21, 2014