THE FATE OF INTRAVENOUSLY INJECTED GELATIN IN HUMAN SUBJECTS 1

Abstract

By intraven. injn., 1000 ml. of 5% gelatin were administered to 42 hospital subjects; the avg mol. wts. were 58,000, 47,000 and 37,000, and all prepns. were liquid at room temp. The plasma gelatin concn. was highest at the end of the injn., averaging 0.78 g./lOO ml. for all 3 types. For the 1st 6 hrs., the plasma levels were significantly higher for the heavy gelatin, but at 24 hrs. all 3 types gave levels of about 0.3 g./lOO ml. At 48 and 72 hrs. the plasma still contained appreciable amts. of gelatin. Urinary gelatin varied considerably even with the same lots but a pattern was discernible; after 6 hrs. the heavy gelatin averaged 14.68 g., the light 22.72 g. By 72 hrs., 80% of all types of gelatin had been excreted, and still more was found on the 4th and 5th days. Probably no considerable quantity of gelatin had been catabolized. The avg. gelatin-creatinine clearance ratios were much higher for light gelatin than for heavy or intermediate. During 3 successive 2-hr. periods after the injn., the ratios fell, but much more steeply for light gelatin, and at 6 hrs. the ratios were all of the same order. Presumably the smaller gelatin molecules were rapidly excreted, leaving molecules of the same order of excretability for all 3 types. Plasma vol. detns. showed the well established hemodilution effect and demonstrated that at the end of the injn. about 55% of the gelatin was still in the blood stream, about 23% having been excreted and 22% filtered into the tissues.