FATE OF 14C-LABELED HYDROXYETHYL STARCH IN ANIMALS

Hydroxyethyl starch (HES) with 14C in the hydroxyethyl radical, was injected into mice, rats, and dogs; beta-emission activity was subsequently measured in expired air, blood, urine, and tissues. Only trace amounts (0.03-0.05% of the total injected) were detected in the expired air of mice and rats over a 6-hour period, while in the same respirometer system, about 57% of the activity of d-glucose-1-14C was recovered in the expired air of mice similarly injected. Mean distribution of activity in the mice at the 6-hour period amounted to about 50% in blood, 25% in urine, 8% in muscle, and decreasing amounts in individual viscera; about 1.5% was recovered in feces. In dogs, about 80% was recovered in the urine at 12 hours and minimal but measurable amounts were present in the blood for 3-4 weeks. Molecular exclusion chromatography using a column of d-galactose polymer (Sagarose 6) showed that urine samples from one dog contained molecular weight fractions with lower values than the original labeled HES and with a smaller range of values (less polydispersity). A similar molecular weight change was observed when the labeled HES was incubated with saliva. © 1969.