σ Receptors and Gastrointestinal Function

The properties reported in this chapter for σ ligands are in agreement with the localization of σ receptors that has been described in the gastrointestinal tract. The stimulating effects of σ ligands on mucosal alkaline secretion have been found to correlate with their protective effects on experimental duodenal ulcers. In the intestine, σ ligands have been shown to have potent antisecretory effects which are related to potent antidiarrheal efficacy in various animal models of diarrhea produced by toxins, including cholera toxin.