title: Enteroendocrine and neuronal mechanisms in pathophysiology of acute infectious diarrhea.
abstract: BACKGROUND
  While enterocyte secretion is the predominant mechanism considered responsible for secretory diarrhea in response to acute enteric infections, there are several lines of evidence that support alternative mechanisms controlling fluid and electrolyte secretion in diarrhea.
  
  
  OBJECTIVE
  To review enteroendocrine and neuronal mechanisms that participate in the development of acute infectious diarrhea.
  
  
  BACKGROUND
  Acute infectious diarrheas due to bacterial toxins (e.g., cholera, E. coli heat-stable enterotoxin, C. difficile) and rotavirus are all associated with secretion of transmitters from enteroendocrine cells (e.g., 5-HT) and activation of afferent neurons that stimulate submucosal secretomotor neurons. The latter secrete acetylcholine (which binds to muscarinic receptors on epithelial cells) and VIP. Involvement of nerves was demonstrated by inhibition of bacterial toxin-induced secretion by hexamethonium (nicotinic), tetrodotoxin (Na(+) channel blocker), and lidocaine (visceral/mucosal afferents). Nicotinic receptors are present on secretomotoneurons and these are activated by release of acetylcholine from enteric interneurons or extrinsic efferent fibers. Specific organisms also modify other mechanisms that may contribute to development of acute diarrhea. Thus, mucin secretion, activation of motor mechanisms, increased mucosal permeability and inhibition of bile acid absorption have been reported in specific types of acute infectious diarrhea.
  
  
  CONCLUSIONS
  New therapies targeting neural and transmitter mediation including 5-HT, VIP, NPY, as well as toxin receptors and channels activated during acute infectious diarrhea could usher in a novel approach to enhancing glucose-electrolyte solutions used in the treatment of acute diarrhea.
authors: Clinical Enteric Neuroscience Translational and Epidemiological Research, College of Medicine, Mayo Clinic, Charlton 8-110, 200 First St SW, Rochester, MN 55905, USA. camilleri.michael@mayo.edu
authors: Michael
authors: M
authors: Camilleri
authors: Sara
authors: S
authors: Nullens
authors: Tyler
authors: T
authors: Nelsen
mesh_terms: D000208:Acute Disease; D001427:Bacterial Toxins; D004403:Dysentery / Q000382:microbiology / Q000503:physiopathology*; D019858:Enteroendocrine Cells / Q000502:physiology*; D006801:Humans; D009475:Neurons, Afferent / Q000502:physiology*; D009478:Neuropeptide Y / Q000502:physiology; D012701:Serotonin / Q000502:physiology; D014660:Vasoactive Intestinal Peptide / Q000502:physiology
chemical_list: D001427:Bacterial Toxins; D009478:Neuropeptide Y; D012701:Serotonin; D014660:Vasoactive Intestinal Peptide