ABSTRACT: The phospholipid compositions of sheep liver, brain, kidney, spleen, heart, and adrenal gland and rat liver, as well as of subcellular organelles derived from some of these tissues, have been examined. Microsomes of all tissues are richest in phospholipid. Relatively little phospholipid was found in the cell sap of liver, brain, kidney and adrenal. Lecithin was the predominant phospholipid in all tissues and subcellular organelles examined. All tissues, with the exception of the liver contain substantial amounts of plasmalogen, which was mainly ethanolamine plasmalogen. In the heart, however, choline plasmalogen predominated. The mitochondria of all tissues contained relatively more ethanolamine phosphatide than was found in other subcellular sites. Most striking was the high concentration of polyglycerolphosphatide found only in the mitochondria. Despite this observation it is not quite certain that the mitochondria contain the entire cell complement of polyglycerolphosphatide. Evidence has been presented that purified nuclear preparations may contain significant amounts of this latter lipid. The relationship of this lipid to electron transport in mitochondria is discussed.
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism.