Dipeptidase Activity in Rat Carrageenin Granuloma

Dipeptidase activity was determined in rat carrageenin granuloma as a chronic inflammation model. The specific activity of dipeptidase in the granulation tissue was about 230 and 40 times higher than those in the exudate and in the serum, respectively. Most part of this activity was distributed in the soluble fraction. The dipeptidase partially purified was most active in the pH range 8.1 to 9.3 and preferentially hydrolyzed dipeptides, such as Gly-L-Leu, L-Val-L-Leu, L-Leu-L-Ala, L-Val-L-Phe and L-Leu-L-Len. This enzyme, however, did not split dipeptides containing C-or N-terminal L-proline, tripeptides, L-leucineamide, L-leucine-p-nitroanilide and hippuryl-L-Phe. After injection of carrageenin, the dipeptidase activity in the granulation tissue increased gradually and reached a maximum level on the 15th day.