Studies on asphyxia: lipids in the alveoli of rats in hypoxic state.

Biochemical characterization in alveolar lavage fluids of rats which had inhaled 5% oxygen, carbon dioxide and carbon monoxide was studied in comparison with control rats. The protein content, consisting mainly of serum albumin, markedly increased in the hypoxic states. The phospholipid content also increased one and a half to two times as much as in the control rats. The phospholipids which increased in the alveoli were mainly pulmonary surfactant phospholipids, i.e. phosphatidylcholine and phosphatidylglycerol. The phospholipid profiles did not appear to be affected by the leakage of plasma lipids. These findings indicate that pulmonary surfactant phospholipids accumulate in the alveoli of rats in the hypoxic states examined here.