Phospholipids in the tissues of the eye: II. Composition and incorporation of 32P i Of phospholipids of normal rat and calf lens

Abstract

1. 1. Concentration and composition of phospholipids were determined in whole calf and rat lenses and in separate parts of calf lens. 2. 2. Epithelium and outer cortex had a higher phospholipid content and relatively more phosphatidyl choline and phosphatidyl inositol than the inner lens parts, while the latter parts contained more sphingomyelin, phosphatidyl serine and vinylether phospholipids. 3. 3. The uptake of 32P i into phospholipids was studied by incubations of calf and rat lenses in vitro and also by experiments with rat lenses in vivo. Incorporation of 32P into the phospholipids of lens epithelium was relatively high after incubation in vitro. Phospholipids of separately incubated lens nucleus showed very little activity. 4. 4. Phosphatidic acid and phosphatidyl inositol showed a high 32P turnover both in vivo and in vitro. 5. 5. Vinyl-ether phospholipids, phosphatidyl serine and sphingomyelin showed very little or no 32P incorporation. 6. 6. The distribution of 32P activity among the various phospholipids was quite different in incorporation experiments with rat lenses in vitro and in vivo.