[Variation of phosphagens in sea urchin eggs before and after fertilization]

Improved methods of separation, identification and determination of phosphagens have been applied to the study of monosubstituted guanidines and phosphagenes in sea urchin eggs, before and after fertilization. We have been able not only to identify in these materials phosphoarginine, but also phosphocreatine and to detect an unknown phosphagen. After fertilization, free arginine and creatine decrease, within respect to unfertilized eggs, whereas phosphocreatine undergoes a large increase; phosphoarginine remains almost constant, and an unknown phosphagen appears. These observations allow to interprete the results of some authors, who, applyng less refined methods, found only an increase in phosphoarginine in the same materials.