The role of cathepsin B1 in the collagen breakdown of carrageenin granuloma in rats.

The crude cathepsin B1 isolated from granulation tissue was separated into two major peaks (P-2 and P-3 fractions) by chromatography on CM-cellulose. The changes in cathepsin B1 activity were studied at various phases of the development of granulation tissue. The cathepsin B1 activity of P-2 fraction, in contrast with that of P-3 fraction, increased with the passage of time after carrageenin injection and the cathepsin B1 activity of P-2 fraction was higher in the resorbing tissues than in non-resorbing tissues, suggesting that cathepsin B1 in P-2 fraction plays an important role in the resorption of granulation tissue, including collagen breakdown.