THE APPEARANCE of fatty degeneration in the livers of depancreatized dogs is evidence of a metabolic defect presumably related to the metabolism and utilization of fats. The utilization of fats for energy begins with phosphorylation and transformation to phospholipids.1 Therefore, it seemed reasonable to ascertain the rate of phospholipid formation in depancreatized dogs maintained on insulin in order to clarify the nature of their metabolic defect.
The content of a recently injected isotope in a large organic complex, expressed as a function of time, constitutes a measure of the rate of synthesis of the large organic complex. In this paper a study of phospholipid formation is described in which the incorporation of radioactive phosphorus into the molecule is used as an indicator of the rate of formation of the phospholipid. Our findings suggest that in the absence of the pancreas in the dog phosphorylation of fat is unable to