Treatment with nitric oxide donors diminishes hyperinfection by Strongyloides venezuelensis in mice treated with dexamethasone.
The effects of using nitric oxide (NO) donors and inhibitors in experimental strongyloidiasis were showed using, both naïve and dexamethasone immunosuppressed BALB/c mice infected with Strongyloides venezuelensis. Aminoguanidine, an inhibitor of inducible NO synthase and LA419 a NO donor, were administered. Dexamethasone was used to induce immunosuppression. The study in BALB/c mice revealed increases in counts of fecal eggs, larvae in lungs and parasitic females following treatment with aminoguanidine, while mice treated with LA419 had limited egg output with low larval and adult recoveries. Mice immunosuppressed with dexamethasone developed hyperinfection with high long lasting fecal egg emission, high numbers of larvae in lungs and high numbers of parasitic females in the intestine even when the infection had already been cleared in non-immunosuppressed infected controls. Mice treated with dexamethasone and aminoguanidine had the highest egg output and the highest larva and parasitic female recovery showing a severe hyperinfection syndrome. In contrast, treatment with dexamenthasone and LA419 resulted in a controlled hyperinfection syndrome and these mice were able to eliminate the parasite. Therefore, NO modulation appears to be a determinant factor in severe strongyloidiasis and further studies should be conducted to confirm in other experimental models.
Parasite and Molecular Immunology Laboratory, Tropical Disease Research Centre, IBSAL-CIETUS, Universidad de Salamanca, Avda Licenciado Méndez Nieto s/n, 37007 Salamanca, Spain; Facultad de Ciencias Médicas-Universidad Central del Ecuador, Instituto Nacional de Investigaciones en Salud Pública INSPI,Quito, Ecuador.
Ana Lucía
AL
Ruano
Parasite and Molecular Immunology Laboratory, Tropical Disease Research Centre, IBSAL-CIETUS, Universidad de Salamanca, Avda Licenciado Méndez Nieto s/n, 37007 Salamanca, Spain. Electronic address: jlaban@usal.es.
Julio
J
López-Abán
Parasite and Molecular Immunology Laboratory, Tropical Disease Research Centre, IBSAL-CIETUS, Universidad de Salamanca, Avda Licenciado Méndez Nieto s/n, 37007 Salamanca, Spain.
Pedro
P
Fernández-Soto
Department of Parasitology, Federal University of Minas Geráis, Belo Horizonte, Brazil.
Alan Lane
AL
de Melo
Parasite and Molecular Immunology Laboratory, Tropical Disease Research Centre, IBSAL-CIETUS, Universidad de Salamanca, Avda Licenciado Méndez Nieto s/n, 37007 Salamanca, Spain.
Antonio
A
Muro
D000818:Animals; D003907:Dexamethasone / Q000494:pharmacology*; D005260:Female; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009569:Nitric Oxide / Q000502:physiology; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013322:Strongyloidiasis / Q000188:drug therapy*
D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D003907:Dexamethasone
Aminoguanidine; Dexamethasone; Hyperinfection syndrome; LA419; Nitric oxide; Strongyloides venezuelensis