The Metabolism of Aminoethylphosphoric Acid, Followed by Means of the Radio- Active Phosphorus Isotope* by Erwin Chargaff

Aminoethylphosphoric acid, NH&H&H~OPO(OH)~, was first isolated from bovine malignant tumors by Outhouse (1). Since benign tumors and a number of normal tissues did not yield this compound, it was thought to be specific for malignant tumor tissue. Recently, however, Colowick and Cori (2) reported the isolation of the acid from the small intestine of rabbits and pigs. The possible relationship of this compound to the metabolism of phosphatides, particularly to that of cephalin, is obvious. It may be significant that it appears to be present in largest amounts in tissues in which the phosphatide metabolism is extremely vigorous. The biological function of aminoethylphosphoric acid could be that of an intermediate in the synthesis of phosphat,ides by the organism, or that of a breakdown product, of the phosphatides. Very little is known about the mechanism by which phospholipids are formed in the body. A study of the utilization of aminoethylphosphoric acid appeared, therefore, of interest. For this purpose a preparation was employed which contained the radioactive phosphorus isotope P::. The present paper gives a report on the conversion of this compound into phosphatides in different organs. Some data on tumor-bearing animals are included.