Systemic changes in hydrolytic enzyme activities in mice affected with murine leprosy.

In order to investigate the behavior of hydrolytic enzymes in chronic infections, the activities of 17 hydrolytic enzymes were tested in limb muscles, heart muscle, spleen, liver, and kidney of lepromatous mice infected with Mycobacterium lepraemurium (M. lepraemurium) and their controls. Typical increases in those enzymatic activities were seen in spleen and liver, where pathological changes were the most pronounced, especially at the 11th week after the inoculation of the bacilli. At the 16th week, the enzymatic changes became less remarkable probably because of the decreased viability of tissues in these organs. The enzymatic changes observed could not be explained as due to bacterial enzymes. These findings are compatible with the notion that the increases in hydrolytic enzyme activities are related to tissue damage caused by murine leprosy.