Strongyloides venezuelensis infection augments arterial blood pressure in male wistar rats

Strongyloidiasis is an intestinal parasitosis that occurs in humans infected by Strongyloides stercoralis mostly. At its acute phase, symptoms like constipation, diarrhea and abdominal pain can be observed, but become asymptomatic for a long time, until an immunosuppression will start a hyperinfection and the dissemination of the disease, prevalent on the elderly population in tropical countries. Ivermectina treatment is the currently choice for this disease, due to its great efficacy and the results reported. It is expected that around one hundred million individuals have been infected around the world. Strongyloides venezuelensis is an intestinal helminth utilized on Strongyloidiasis investigations, in rodents. As the parasites reach the blood stream after subcutaneous infection, the larvae migrate to the lung by systemic circulation, but the effects of S. venezuelensis in the circulation remain widely unknown. Moreover, the role played by S. venezuelensis in the cardiovascular function has been understudied. Thus, the aim of this study is to determine whether acute infection with S. venezuelensis alters systemic blood pressure or not. Male wistar rats were infected subcutaneously with 2000 L3 larvae of S. venezuelensis and monitored during 21 days (Infected group), compared to a Healthy group, no infected. Oviposition, body and faeces weight, water and food intake were determined every 3 days. Moreover, systemic blood pressure was assessed by tail cuff plethysmography. At the end of experiments, the animals were euthanized and the number of worms, ventricles, lung and thymus and small intestine weight were registered. It was possible to observe that systolic blood pressure (126.86 ± 2.74 vs 155.08 ± 7.61 at 9°-day post infection – dpi - and 134.44 ± 5.22 vs 157.77 ± 9.55 at 21° dpi) and mean arterial pressure (71.72 ± 1.59 vs 80.51 ± 2.32 at 21° dpi) were markedly higher (P < 0.001) in infected group in comparison to the Healthy group. Those changes occurred after larvae passes through the circulation and demonstrated a late response to the presence of this parasite. These results suggest that host circulatory system reacts to this infection resulting in a significant increase in blood pressure.