The Golgi complex of Trypanosoma cruzi epimastigote forms.

The distribution and morphology of the Golgi complex and endoplasmic reticulum of epimastigote forms of the protozoan Trypanosoma cruzi were analysed at the ultrastructural level, after post-fixation of the cells with osmium tetroxide/potassium iodide. Intense staining was found in these structures, as well as in the nuclear envelope, showing that these compartments present a reducing environment. Positive reaction also demonstrates that intense protein synthesis occurs in the parasites which were collected at the log phase of growth. A Cis Golgi network (CGN) and an endoplasmic reticulum cistern associated with it could be clearly demonstrated. Different Golgi complex patterns were seen, suggesting that this organelle has a dynamic structure. In most cells, only peripheral cisternae directed to the endoplasmic reticulum presented an electron-dense reaction product, possibly corresponding to the cis region of the Golgi complex. Some parasites were also incubated in the presence of brefeldin-A, a drug which disorganizes the Golgi complex of several eukaryotic cells. Our results showed that T. cruzi epimastigote forms are resistant to brefeldin-A treatment, suggesting that the targets of drug action are absent in these protozoa.