DEPLETION OF RADIOSENSITIVE LEUKOCYTES EXACERBATES THE HEART SYMPATHETIC DENERVATION AND PARASITISM IN EXPERIMENTAL CHAGAS-DISEASE IN RATS

The acute phase of the Trypanosoma cruzi infection induces damage of t he heart sympathetic nerve terminals in rats. The participation of the radiosensitive leukocytes in this process was assessed in young rats submitted to gamma irradiation 1 day before infection with T. cruzi, Y strain. Gamma irradiation increased the heart noradrenergic denervati on evaluated at day 12 of infection by histochemical and electron-micr oscopic methods. The presence of numerous macrophages with ultrastruct ural features of activation and a significant rise in the myocardial p arasitism suggest the involvement of radioresistant macrophages or par asite factors, or both, on the damage of the nerve terminals. (C) 1998 Elsevier Science B.V.