Apoptotic mechanisms are involved in the death of S trongyloides venezuelensis after triggering of nitric oxide

Summary Despite progress in understanding the role of nitric oxide ( NO ) in the pathogenesis of helminth infections, the role in strongyloidosis is unknown. Firstly, we studied the production of NO in mice infected with S trongyloides venezuelensis as well as in macrophage cultures stimulated with parasite antigens. Somatic larvae 3 ( L 3) and excretory–secretory female antigens stimulate specific NO production measured by G riess reaction and expression of inducible NO synthase by RT‐PCR and quantitative PCR . Moreover, mice infected with S . venezuelensis produce NO in migration stages. Secondly, we analysed the effect of NO production on L 3 and females of S . venezuelensis using NO donors such as diethylenetriamine and 3,3‐bis(aminoethyl)‐1‐hydroxy‐2‐oxo‐1‐triazene. Parasites died after NO donor treatment in a dose‐dependent manner. Finally, apoptotic mechanisms are involved in the death of S . venezuelensis larvae.