Enteric nerves mediate the fluid secretory response due to Salmonella typhimurium R5 infection in the rat small intestine

Abstract

Eighteen hours after intragastric inoculation Salmonella typhimurium elicited a net fluid secretion in the jejunum and ileum of rats. The mechanisms behind the secretory response were analysed in vivo. Extrinsic denervation of the experimental intestinal segments had no effect. The nerve-blocking agents hexamethonium (i.v.) and lidocaine (serosally applied) blocked the secretion but atropine had no effect. It was demonstrated that the bacteria were invasive by culturing from the intestinal wall. The presence of inflammatory reactions was supported by the facts that i.v. indomethacin blocked the secretory response and that there was an increased capillary leakage of albumin-bound Evans Blue into the interstitium of the intestinal mucosa. There was also a secretory response upon inoculation of the jejunal and ileal segments by cell-free supernatants of broth where bacteria had been cultured for 24 h and thereafter lysed. This response was, however, blocked by i.v. atropine, which had no effect on the secretion elicited by living bacteria. We could show no presence of E. coli LT, ST or cholera toxin in the cell-free supernatant by means of ELISA-tests. We therefore conclude that (1) S. typhimurium R5 invaded the rat jejunal and ileal mucosa, thereby creating an inflammatory response which in turn activated a nerve reflex(es) within the ENS leading to a net fluid secretion; (2) the presence of prostaglandins was needed for activating the reflex(es); (3) the reflex(es) contained a nicotinergic transmission; (4) enterotoxin was of no importance for the secretory response in the model used.

Role of Cytokines in Experimental Colitis: Relation to Intestinal Permeability

“…These results provide insights into immune mechanisms of tissue dam age, and provide a useful framework for developing strat egies for therapeutic intervention. for EB measurement has previously been described in detail [23][24][25]. In the present study, we further confirmed this from the following observations.…”

Detection of apoptotic cells in intestines from horses with and without gastrointestinal tract disease

“…Because the myenteric plexus is important for functional motility and other gastrointestinal tract functions such as secretion, apoptosis of cells in the enteric nervous system may alter intestinal function. 42 Few apoptotic cells were observed in the serosa, although ischemia and reperfusion and intraluminal distension and decompression cause severe morphologic changes in the equine jejunal serosa. 7 Mesothelial and endothelial cells were apoptotic in the serosa but appeared to be few in number, compared with other layers.…”

NONRUMINANT NUTRITION SYMPOSIUM: Involvement of gut neural and endocrine systems in pathological disorders of the digestive tract1,2

“…Neurons within the secretomotor reflex pathways are stimulated by bacterial toxins, including cholera toxin (Cassuto et al, 1981;Gwynne et al, 2009) and heat-stable enterotoxin (Eklund et al, 1985;Hubel et al, 1991), and by infective agents, including Salmonella (Brunsson, 1987), cryptosporidium (Argenzio et al, 1996, and rotavirus (Lundgren et al, 2000). The neural circuitry for the pathological activation of secretomotor reflexes is illustrated in Figure 3.…”