Alveolar phospholipids, hyperventilation and temperature of conservation of rat lungs

Hyperventilation has been found to increase the phospholipid content of broncho-alveolar lavage fluids. Had the temperature of conservation of the lungs an influence? Two groups of rats were allowed to ventilate normally (NV), and two groups (HV) were induced to hyperventilate for 1 h by addition of a dead space. After sacrifice, the isolated lungs were kept for 25 min at 37°C (NV37 and HV37), or 10°C(NV10 and HV10), and then washed at the same temperatures. The phospholipid content of lavage fluid was only found to be increased in the HV37 group (P < 0.05). Neither hyperventilation followed by conservation of lungs at 10°C nor normal ventilation followed by conservation of lungs at 37°C led to an increase in phospholipid content. It was the association of hyperventilation and conservation of lungs at 37°C that led to the increase. In vivo hyperventilation is thought to lead to an equal increase in secretion and reabsorption of alveolar phospholipids, and conservation of the lungs at 37°C was thought to lead to an imbalance between these two processes.