Acetylcholinesterase levels in skeletal muscle of mice infected with Trypanosoma cruzi

Acetylcholinesterase (AChE) activity was measured in skeletal muscle from susceptible (A/J) and resistant (C57BL/6) mice infected with the Brazil strain (myotropic) of Trypanosoma cruzi. There was a 60% decrease in activity in skeletal muscle obtained from A/J mice 20 days post-infection as compared to controls. There was no decrease in AChE activity in skeletal muscle obtained from infected C57BL/6 mice 20 and 150 days post-infection. Histologic examination of skeletal muscle from infected A/J mice revealed marked necrosis, pseudocysts, and minimal inflammation. Similar examinations in C57BL/6 mice revealed marked inflammation in the absence of necrosis and parasites. These data provide additional biochemical support that denervation hypersensitivity is an important concomitant of Chagas' disease and that it is already present during the acute stage. Additionally, it may support the notion that the presence of the parasite mediates these abnormalities.