TY - JOUR
T1 - Assessing recruitment of lung diffusing capacity in exercising guinea pigs with a rebreathing technique
AU - Yilmaz, Cuneyt
AU - Dane, D. Merrill
AU - Hsia, Connie C W
PY - 2008/7
Y1 - 2008/7
N2 - Noninvasive techniques for assessing cardiopulmonary function in small animals are limited. We previously developed a rebreathing technique for measuring lung volume, pulmonary blood flow, diffusing capacity for carbon monoxide (DLCO) and its components, membrane diffusing capacity (DMCO) and pulmonary capillary blood volume (Vc), and septal volume, in conscious nonsedated guinea pigs at rest. Now we have extended this technique to study guinea pigs during voluntary treadmill exercise with a sealed respiratory mask attached to a body vest and a test gas mixture containing 0.5% SF6 or Ne, 0.3% CO, and 0.8% C2H2 in 40% or 98% O2. From rest to exercise, O2 uptake increased from 12.7 to 25.5 ml·min-1·kg-1 while pulmonary blood flow increased from 123 to 239 ml/kg. The measured DLCO, DM CO, and Vc increased linearly with respect to pulmonary blood flow as expected from alveolar microvascular recruitment; body mass-specific relationships were consistent with those in healthy human subjects and dogs studied with a similar technique. The results show that 1) cardiopulmonary interactions from rest to exercise can be measured noninvasively in guinea pigs, 2) guinea pigs exhibit patterns of exercise response and alveolar microvascular recruitment similar to those of larger species, and 3) the rebreathing technique is widely applicable to human (∼70 kg), dog (20-30 kg), and guinea pig (1-1.5 kg). In theory, this technique can be extended to even smaller animals provided that species-specific technical hurdles can be overcome.
AB - Noninvasive techniques for assessing cardiopulmonary function in small animals are limited. We previously developed a rebreathing technique for measuring lung volume, pulmonary blood flow, diffusing capacity for carbon monoxide (DLCO) and its components, membrane diffusing capacity (DMCO) and pulmonary capillary blood volume (Vc), and septal volume, in conscious nonsedated guinea pigs at rest. Now we have extended this technique to study guinea pigs during voluntary treadmill exercise with a sealed respiratory mask attached to a body vest and a test gas mixture containing 0.5% SF6 or Ne, 0.3% CO, and 0.8% C2H2 in 40% or 98% O2. From rest to exercise, O2 uptake increased from 12.7 to 25.5 ml·min-1·kg-1 while pulmonary blood flow increased from 123 to 239 ml/kg. The measured DLCO, DM CO, and Vc increased linearly with respect to pulmonary blood flow as expected from alveolar microvascular recruitment; body mass-specific relationships were consistent with those in healthy human subjects and dogs studied with a similar technique. The results show that 1) cardiopulmonary interactions from rest to exercise can be measured noninvasively in guinea pigs, 2) guinea pigs exhibit patterns of exercise response and alveolar microvascular recruitment similar to those of larger species, and 3) the rebreathing technique is widely applicable to human (∼70 kg), dog (20-30 kg), and guinea pig (1-1.5 kg). In theory, this technique can be extended to even smaller animals provided that species-specific technical hurdles can be overcome.
KW - Cardiac output
KW - Exercise
KW - Lung volume
KW - Membrane diffusing capacity
KW - Pulmonary capillary blood volume
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U2 - 10.1152/japplphysiol.00155.2008
DO - 10.1152/japplphysiol.00155.2008
M3 - Article
C2 - 18483171
AN - SCOPUS:50649094737
SN - 8750-7587
VL - 105
SP - 316
EP - 321
JO - Journal of applied physiology
JF - Journal of applied physiology
IS - 1
ER -