| The main objective of this study is to implement and test a novel apparatus for simultaneously measuring cardiopulmonary parameters such as lung volume, diffusing capacity, cardiac output, alveolar tissue and capillary blood volume in fully awake small animals using a rebreathing technique. This technique is then applied to determine if high altitude residence enhances diffusive oxygen transport in guinea pigs thought to be pre-adapted to high altitude. Litter matched male weanling Hartley guinea pigs (Cavia porcellus) were raised at high (3800 m, n = 8) and low (150m, n = 10) altitudes for four months. In high altitude animals, resting hematocrit and cardiac output were significantly higher (p < 0.05). Lung diffusing capacity and membrane diffusing capacity were also significantly higher at a given cardiac output, consistent with enhanced lung growth following high altitude residence. These data also sow that guinea pigs are not pre-adapted to high altitude. |
