Feasibility of using an isolated intestinal segment as an artificial organ for enzyme replacement therapy

Guinea pigs fed an ascorbic acid-deficient diet develop scurvy because of the absence of the enzyme L-gulonolactone oxidase. In theory if this enzyme is provided and its substrate L-gulonolactone is present at adequate concentrations ascorbic acid will be synthesized and the development of scurvy prevented. Using this model we tested whether a viable segment of intestine could be used to contain the administered enzyme and act as an artificial organ for the production of ascorbic acid. A surgical procedure was developed to prepare an externalized pouch of intestine with its circulation left intact. When enzyme is inserted in this intestinal bag it is not toxic and not antigenic in some animals, whereas, enzyme injected intraperitoneally is clearly antigenic. Synthesis of ascorbic acid by this artificial organ could not, however, be detected by elevation of plasma concentrations of the vitamin.