Serum enzymatic changes following infection of mice with Mycobacterium lepraemurium.

Mice injected interperitoneally with 1.5 X 10(8) Mycobacterium lepraemurium develop progressive visceral alterations that are reflected in the lactic dehydrogenase (LDH), glutamate-pyruvate transaminase (GPT), and glutamate-oxalacetate transaminase (GOT) levels. The rise in GPT and GOT levels starts earlier (about 30 days post-infection) than the rise in LDH activity (about 70 days), but the latter shows the most impressive increases. Differences between infected and control groups, however, reach statistical significance only at 75 days (LDH), 90 days (GOT), and 150 days (GPT) post-inoculation, still well before the appearance of obvious external signs of infection (about 240 days in our model). It is suggested that the ratio of enzyme levels in infected to enzyme levels in uninfected animals could be taken as a reliable index to follow the progress of the infection with M. lepraemurium.