Abstract
In this study, we hypothesized that, in rats, adaptation to high altitude (2500 m) plus training at low altitude (610 m), “Living high and Training low”, improves pulmonary diffusing capacity at low altitude. However, whether the pulmonary circulation could be altered after “Living high and Training low” still remain unclear in rats. The purpose of this study was to examine the change of pulmonary resistance with the increases of a pulmonary perfusion rate. In the extraction perfused lung preparation. Rats were divided into for four groups: living at low altitude (LL), living and training at low altitude (LL+TL), living at high altitude (LH), living at high altitude and training at low altitude (LH+TL). The programs for living at high altitude involved raising rats under hypobaric hypoxia (equivalent to 2500 m), and the training program consisted of running on a treadmill at low altitude. All groups were raised at each altitude and trained to run at 15–34 m/min for 30–90 min/day, 5 days/week for 5 weeks. Right ventricular wall weight and base-line resistance of pulmonary circulation were significantly increased in the LH+TL groups than in the LL groups. However, pulmonary circulating resistance with increments of a pulmonary perfusion rate was inhibited in LL+TL groups when compared with other groups. From the above, it could be concluded that LH+TL depression pulmonary arterial pressure increment with exercise. In addition, if the pulmonary diffusing capacity was increased during endurance exercise, if was shown that vasodilation, capillary recruitment and arterializations may be increased by LH+TL.
