Evaluation of gastrointestinal transit after infection with different loads of Strongyloides venezuelensis in rats

Abstract

The aim was to correlate the gastrointestinal transit profile in rats, evaluated by a biomagnetic technique, in response to infection with different loads of Strongyloides venezuelensis. Eggs per gram, intestinal number of worms and fecundity, and also gastric emptying time, cecum arrival time, small intestinal transit time and stool weight were determined. Assessments occurred at 0 (control), 3, 6, 9, 12, 15, 18 and 21 days post infection (dpi) with three infective loads (400, 2000, and 10,000 L). Gastric emptying was faster (p=0.0001) and the intestinal transit was significantly slower (p=0.001) during the infection time course. Also, linear mixed-effects models showed significantly changes in small intestinal transit after three parasite load over time. Cecum arrival was not influenced by infection time course or parasite load. As indirect effect, stool weight decreased accompanied a strong oviposition peak at 9 dpi in 400 L and 2000 L. In several motor function instances, neuromuscular dysfunction persists after mucosal inflammation has decreased. Our approach could be very helpful to evaluate gastrointestinal motor abnormalities in vivo after parasite infection. Despite parasitological data progressively decreased after 15 dpi, small intestinal transit worse over time and according to burden.

Electroacupuncture in Rats Infected with Strongyloides venezuelensis: effects on gastrointestinal transit and parasitological measurements

“…It seems that at the peak of infection, EA exerted regulatory effects on gastric emptying and intestinal transit, bringing them to levels comparable with those observed in uninfected control animals. 26 On the other hand, EA did not impact parameters such as stool weight, water and food intake, or weight growth rate throughout the experiment.…”

“…Treatment at both acupuncture points increases the number of worms at 21 dpi and does not contribute to eradication of the infection, since the profile after EA is similar to that observed in untreated rats. 26 It is possible that Original paper acupuncture could modulate the adaptive immune response by altering the balance of Th1/Th2 T helper cells in disease states to maintain homeostasis. 42 The immune response to Strongyloides species is characterised by the production of Th2-type cytokines 21 and it has been suggested that sequential EA stimulation at ST36 suppresses the production of these cytokines.…”

“…23 Rats spontaneously eliminate adult worms 20-30 days following infection 24 25 ; however, previous studies using ACB have indicated that intestinal transit remains slow 21 days after infection despite a reduction in oviposition and worm numbers. 26 Indeed, accelerated GI transit has been considered to be part of the host response mechanism to expel parasites, a condition that could be induced by acupuncture. 1 27 In this study, our aim was to investigate the effects of EA at ST36 and CV12 on GI transit and parasitological measurements during S. venezuelensis infection in rats.…”

“…S. venezuelensis larvae were recovered and washed in phosphate-buffered saline (PBS) to be counted. The rats were individually inoculated via subcutaneous injection in the dorsal region with 2000 S. venezuelensis larvae (L3), as detailed by Anjos-Ramos et al 26…”