Positional distribution of fatty acids in rabbit lung phospholipids and triacylglycerols and effect of prolonged hyperoxy.

Investigations have been carried out for the determination of the effect of high oxygen concentration in inspired gas mixutre on the positional distribution of fatty acids in rabbit lung phospholipids and triacylglycerols. The following results were obtained: 1. In the phosphatidylcholine fraction, the high oxygen concentration caused a quantitative increase of palmitic acid (16 : 0) at the alpha-position, and of myristic (14 : 0), heptadecenic (17 : 1) and arachidonic (20 : 4) acids at the beta-position. 2. In t-e phosphatidylethanolamine fraction, the high oxygen concentration caused an increase of oleic acid (18 : 1) at the alpha-position, and of palmitoleic (16 : 1) and heptadecenic (17 : 1) acids at the beta-position. 3. In the triacylglycerol fraction such changes were not observed. In connection with these effects of oxygen, its possible influence on membrane structures in the lung has been discussed.