1972 Volume 108 Issue 2 Pages 133-139
The incorporation of labeled lysolecithin into various rat organs was studied. Lysolecithin injected was rapidly taken up by various organs and it was found that the conversion into lecithin proceeded more rapidly in the liver and intestine than in other organs. The mode of formation of lecithin from lysolecithin in various organs was also studied in vivo. Using lysolecithin doubly labeled with the glycerol and fatty acid portions, it was shown that lysolecithin injected was preferentially converted to tetraenoic lecithin in all organs examined by Lands' pathway, while the saturated+monoenoic species of the lung and brain was formed with 14C/3H of approximately 2.0 by Marrinetti's pathway. These results suggest that the lysolecithin-lecithin cycle between liver and plasma may serve to retain polyunsaturated fatty acids, and the saturated lecithin in the lung known as a surfactant may only in some parts be derived from exogenous lysolecithin.