Rat adrenal gland in experimental American trypanosomiasis: immunocytochemical study of tissue parasitism.

The rat adrenal gland is poorly parasitized during the experimental infection with Y strain of Trypanosoma cruzi. In both cortical and medullary regions, the parasitism peaked at day 10 and was characterized by the predominance of single amastigotes over nests containing 2 or more parasites. After day 10 of infection, the tissue parasitism dropped rapidly to become practically null at day 32 of infection. In cortical tissue, the amastigotes occurred mainly inside the endocrine cells. In the medulla, they found mainly in glial cells and non-identified stromal cells. In both cortex and medulla, inflammatory processes were found till day 20 of infection. Our data do not support the hypothesis that a corticoid rich environment would favor T. cruzi parasitism in adrenal medulla.