Characterization of macrophages elicited by intraperitoneal injection of hyaluronate.

Hyaluronate of 120,000 molecular weight has been injected in the peritoneal cavity of mice to study its effect on migration of inflammatory cells in vivo. After one day a dose-dependent granulocyte migration is observed. Three days later the number of granulocytes is greatly reduced and macrophages form about half of the total cell population. Hyaluronate-elicited macrophages show a decreased 5'-nucleotidase and an increased acid phosphatase activity as compared to resident macrophages. The production of superoxide anion in response to the phorbol ester tetradecanoyl-phorbolacetate, and the phagocytic activity are also enhanced. Macrophages elicited by hyaluronate secrete growth factor(s) for non-lymphoid mesenchymal cells. It is concluded that hyaluronate in vivo stimulates the migration of inflammatory cells, thus causing the recruitment of a population of stimulating macrophages. These effects may explain previous reports on the acceleration of wound healing by hyaluronate.