Renal Clearances of Grass Polysaccharide: Observa- Tions

Dr. D. J. Bell, Biochemical Laboratory, Cambridge, drew our attention in 1948 to a fructosan polysaccharide (levan) prepared from Italian rye grass. It is readily soluble in cold water, yields levulose on acid hydrolysis and is not metabolized. At that time, the fructosan was believed to be a homogeneous substance with a molecular weight somewhat greater than that of inulin, so that the suggestion was made that it might replace inulin in the measurement of glomerular filtration rate. It has since (see below) been shown to be inhomogeneous. Thus, this report deals with the excretion characteristics of this dispersed polymer in normal unanesthetized dogs and in normal and abnormal human subjects.