Relationship between “Spreading Factor” and Hyaluronidase.

SummaryEvidence is presented to show that hyaluronidase and “spreading factor” exhibit certain attributes in common. However, there is also considerable evidence that “spreading factor” does not owe its activity solely to the presence of hyaluronidase. It would seem probable that the phenomenon of “spreading” is a complex one and that several factors may be involved in its production. Further work is required to explain the mechanism of “spreading” in terms of known chemical and physico-chemical reactions.