Variations in the molecular species of lung phosphatidylglycerol.

Approximately 20% of the phosphatidylglycerol of the lung tissue of several animals was found to have both fatty acids saturated. Pulmonary washings from the lung of the rabbit and guinea pig had more saturated phosphatidylglycerol than the washed lung tissue. Lung-saturated phosphatidylglycerol was relatively low in the perinatal period, a time during which saturated phosphatidylcholine accumulated predominantly. This suggests that the metabolism of the saturated species of lung phosphatidylcholine and phosphatidylglycerol, which are considered to be the major pulmonary surfactants, may not be regulated in the same manner, at least in the perinatal lung.