Effects of Posture on Pulmonary Diffusing Capacity and Regional Distribution of Pulmonary Blood Flow in Normal Male and Female High Altitude Dwellers at 3,650 m (12,200 ft)

Respiration ◽  
1978 ◽  
Vol 35 (3) ◽  
pp. 125-135 ◽  
Author(s):  
H. Spielvogel ◽  
E. Vargas ◽  
G. Antezana ◽  
L. Barragan ◽  
L. Cudkowicz
Keyword(s):  
Blood Flow ◽  
High Altitude ◽  
Pulmonary Blood Flow ◽  
Regional Distribution ◽  
Normal Male ◽  
Diffusing Capacity ◽  
Male And Female ◽  
Pulmonary Diffusing Capacity

Regional Distribution of Pulmonary Blood Flow in Normal High-Altitude Dwellers at 3,650 m (12,200 ft)

Respiration ◽  
1975 ◽  
Vol 32 (3) ◽  
pp. 189-209 ◽  
Author(s):  
J. Coudert ◽  
M. Paz-Zamora ◽  
L. Barragan ◽  
L. Briançon ◽  
H. Spielvogel ◽  
...  
Keyword(s):  
Blood Flow ◽  
High Altitude ◽  
Pulmonary Blood Flow ◽  
Regional Distribution

Unequal distribution of pulmonary diffusing capacity in the anesthetized dog

1961 ◽  
Vol 16 (3) ◽  
pp. 499-506 ◽  
Author(s):  
Johannes Piiper ◽  
Pierre Haab ◽  
Hermann Rahn
Keyword(s):  
Experimental Data ◽  
Blood Flow ◽  
Pulmonary Blood Flow ◽  
Diffusing Capacity ◽  
Distribution Factor ◽  
Q Value ◽  
Diffusion Limitation ◽  
Unequal Distribution ◽  
Pulmonary Diffusing Capacity ◽  
Anesthetized Dogs

In anesthetized dogs the alveolar-arterial O2 pressure difference (AaD) was measured at alveolar O2 pressures of 45, 75, 106, 146, and 255 mm Hg. The AaD values observed could not be explained by the conventional “shunt factor,” “diffusion-limitation factor,” or “distribution factor.” However, the experimental data could be explained on the basis of the concept of unequal distribution of pulmonary diffusing capacity, D, to perfusion, Q. A procedure for estimation of the pattern of distribution of D to Q from experimental data is described. The results were compatible with the assumption that the lung consisted of a minimum of three functional compartments characterized by different D/Q ratios. A small portion of the perfusion (1.5%) probably behaved like a true shunt (D/Q = 0); 13% of the pulmonary blood flow passed through a compartment that shared in 2% of the total diffusing capacity only, resulting in a relatively small D/Q ratio for this compartment. The presence of this compartment gave rise to the largest part of the AaD at air breathing. The calculated D/Q value for the remaining, major compartment was so high that a measurable AaD due to diffusion limitation in this compartment could occur only at alveolar O2 pressures lower than 60 mm Hg. The validity of the assumptions and the significance of the results are discussed. Submitted on May 23, 1960

Unequal distribution of pulmonary diffusing capacity and the alveolar-arterial PO2 differences: theory

1961 ◽  
Vol 16 (3) ◽  
pp. 493-498 ◽  
Author(s):  
Johannes Piiper
Keyword(s):  
Blood Flow ◽  
Pressure Difference ◽  
Pulmonary Blood Flow ◽  
Diffusing Capacity ◽  
Total Blood ◽  
Unequal Distribution ◽  
Equal Distribution ◽  
Pulmonary Diffusing Capacity ◽  
Total Blood Flow ◽  
Arterial Po2

The effects of unequal distribution of pulmonary diffusing capacity to the pulmonary blood flow on the alveolar-arterial O2 pressure difference have been studied theoretically. It is demonstrated that, if the diffusing capacity is not distributed proportionally to the blood flow in a lung, the alveolar-arterial O2 pressure difference will in most circumstances be greater than in a lung with the same total diffusing capacity and the same total blood flow, but with equal distribution of diffusing capacity to blood flow. Submitted on May 23, 1960

Alveolar diffusion-perfusion interactions during high-altitude residence in guinea pigs

2007 ◽  
Vol 102 (6) ◽  
pp. 2179-2185 ◽  
Author(s):  
Cuneyt Yilmaz ◽  
D. Merrill Dane ◽  
Connie C. W. Hsia
Keyword(s):  
Carbon Monoxide ◽  
Blood Flow ◽  
High Altitude ◽  
Lung Volume ◽  
Guinea Pigs ◽  
Pulmonary Blood Flow ◽  
Ultrastructural Changes ◽  
Diffusing Capacity ◽  
Adaptive Responses ◽  
Structural Adaptation

We previously reported in weanling guinea pigs raised at high altitude (HA; 3,800 m) an elevated lung diffusing capacity estimated by morphometry from alveolar-capillary surface area, harmonic mean blood-gas barrier thickness, and pulmonary capillary blood volume (Vc) compared with litter-matched control animals raised at an intermediate altitude (IA; 1,200 m) (Hsia CCW, Polo Carbayo JJ, Yan X, Bellotto DJ. Respir Physiol Neurobiol 147: 105–115, 2005). To determine if HA-induced alveolar ultrastructural changes are associated with improved alveolar function, we measured lung diffusing capacity for carbon monoxide (DlCO), membrane diffusing capacity for carbon monoxide (DmCO), Vc, pulmonary blood flow, and lung volume by a rebreathing technique in litter-matched male weanling Hartley guinea pigs raised at HA or IA for 4 or 12 mo. Separate control animals were also raised and studied at sea level (SL). Resting measurements were obtained in the conscious nonsedated state. In HA animals compared with corresponding IA or SL controls, lung volume and hematocrit were significantly higher while pulmonary blood flow was lower. At a given pulmonary blood flow, DlCO and DmCO were higher in HA-raised animals than in control animals without a significant change in Vc. We conclude that 1) HA residence enhanced physiological diffusing capacity corresponding to that previously estimated on the basis of structural adaptation, 2) adaptation in diffusing capacity and its components should be interpreted with respect to pulmonary blood flow, and 3) this noninvasive rebreathing technique could be used to follow adaptive responses in small animals.

Splenectomy impairs diffusive oxygen transport in the lung of dogs

2006 ◽  
Vol 101 (1) ◽  
pp. 289-297 ◽  
Author(s):  
D. Merrill Dane ◽  
Connie C. W. Hsia ◽  
Eugene Y. Wu ◽  
Richard T. Hogg ◽  
Deborah C. Hogg ◽  
...  
Keyword(s):  
Blood Flow ◽  
Blood Volume ◽  
Pulmonary Blood Flow ◽  
Compensatory Mechanism ◽  
Diffusing Capacity ◽  
Restrictive Lung Disease ◽  
Before And After ◽  
Capillary Blood Volume ◽  
Exercise Induced ◽  
Experimental Findings

The spleen acts as an erythrocyte reservoir in highly aerobic species such as the dog and horse. Sympathetic-mediated splenic contraction during exercise reversibly enhances convective O2 transport by increasing hematocrit, blood volume, and O2-carrying capacity. Based on theoretical interactions between erythrocytes and capillary membrane (Hsia CCW, Johnson RL Jr, and Shah D. J Appl Physiol 86: 1460–1467, 1999) and experimental findings in horses of a postsplenectomy reduction in peripheral O2-diffusing capacity (Wagner PD, Erickson BK, Kubo K, Hiraga A, Kai M, Yamaya Y, Richardson R, and Seaman J. Equine Vet J 18, Suppl: 82–89, 1995), we hypothesized that splenic contraction also augments diffusive O2 transport in the lung. Therefore, we have measured lung diffusing capacity (DlCO) and its components during exercise by a rebreathing technique in six adult foxhounds before and after splenectomy. Splenectomy eliminated exercise-induced polycythemia, associated with a 30% reduction in maximal O2 uptake. At any given pulmonary blood flow, DlCO was significantly lower after splenectomy owing to a lower membrane diffusing capacity, whereas pulmonary capillary blood volume changed variably; microvascular recruitment, indicated by the slope of the increase in DlCO with respect to pulmonary blood flow, was also reduced. We conclude that splenic contraction enhances both convective and diffusive O2 transport and provides another compensatory mechanism for maintaining alveolar O2 transport in the presence of restrictive lung disease or ambient hypoxia.

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