DETRIMENTAL EFFECT OF NITRIC-OXIDE ON TRYPANOSOMA-CRUZI AND LEISHMANIA-MAJOR LIKE CELLS

The production of nitric oxide (NO) by activated macrophages has been reported to be a non-specific immune-effect mechanism against several parasites. In this work we investigate whether the NO has a detrimenta l effect on the intracellular parasites of the genus Leishmania and as well as Trypanosoma cruzi. This was assessed by co-cultivating infect ive Leishmania promastigotes and T. cruzi trypomastigotes and non-infe ctive T. cruzi epimastigotes forms of the parasites in the presence of the NO releasing molecule, S-nitroso-N-acetyl-DL-penicillamine (SNAP) . We demonstrate that the NO has the ability to inhibits the growth of all parasites in a concentration dependent manner. In addition, by an alysing purified protein and cell homogenates of L. major (promastigot es) and T. cruzi (epimastigotes and trypomastigotes) we demonstrated t hat the NO may regulate the glyceraldehyde-3-phosphate dehydrogenase ( GAPDH) activity of both parasites. (C) 1997 Elsevier Science B.V.