Production of Hyaluronic Acid in Tissue Culture by Fibroblasts Growing from Intestinal,Stomach,Liver and Kidney Explants. ∗

Abstract

Summary

1. Tissue cultures of chick embryo liver, stomach, intestine and kidney, in which both epithelium and fibroblasts were growing for over 3 months produced hyaluronic acid, as shown by a positive mucin clot test and by the prevention of mucin clot formation by hyaluronidase. These findings are consistent with the demonstration of the spreading reaction in some of these organs and indicate that they belong to the group of hyaluronate-active spreading reactions. 2. In primary cultures production of hyaluronic acid may take place for very long periods of time, usually as long as the cultures do not deteriorate, while replica cultures, for instance strain L, sooner or later lose the ability to produce hyaluronic acid, despite their excellent appearance and good growth. 3. Although it has not yet been possible to separate factors promoting mucopolysaccharide production from factors promoting growth, it has been observed that cultures kept at room temperatures with considerably reduced growth, may sometimes continue to produce hyaluronic acid. 4. Hyaluronic acid of chick embryo extract is depolymerized in the first few days of incubation at 38°C (Table II), while hyaluronic acid produced in tissue culture is not depolymerized for months under the same conditions (Table IIa). A positive mucin clot test after a few days of incubation thus always indicates the presence of hyaluronic acid newly produced in vitro by fibroblasts. Chick embryo extract may therefore be used in any concentration in the culture medium in which production of hyaluronic acid in vitro will be tested by the mucin clot method.