title: Impaired viscosity of gastric secretion and its mucin content as potential contributing factors to the development of chronic constipation.
abstract: BACKGROUND
  The alimentary tract mucosa continuously releases mucus-rich secretion. Mucin, the major component of mucus, determines its viscosity and provides lubrication for the luminal content of indigestible food particles.
  
  
  OBJECTIVE
  To measure mucin secretion rate and its viscosity in patients with chronic constipation (CC) and in asymptomatic volunteers.
  
  
  METHODS
  Nineteen patients with symptoms of CC and 19 controls were included in the study. Mucin secretion and viscosity were assessed in aspirated gastric juice in basal conditions and after stimulation with pentagastrin (1 h each). Mucin content was tested by PAS methodology. Viscosity was measured using cone/plate digital viscometer.
  
  
  RESULTS
  Mucin secretion rates in basal and stimulated conditions in controls were 65 and 42 % higher than in patients with CC (P < 0.05 and P < 0.001, respectively). Basal viscosity in controls was 48 % higher than in CC (P < 0.05) at the lowest and 55 % higher (P < 0.05) at the middle velocities. Viscosity in pentagastrin-stimulated conditions in controls was 71 % higher than in CC (P < 0.01) at the lowest and 35 % higher (P < 0.05) at the middle velocities.
  
  
  CONCLUSIONS
  (1) The significantly lower rate of soluble mucin secretion in patients with CC than in normal volunteers may reflect impairment in mucin-related lubrication. (2) Significantly lower viscosity of gastric secretion in patients with CC may result from the lower rate of mucin secretion and may also diminish lubrication within the alimentary tract. (3) This may potentially set the stage for the development of symptoms related to chronic constipation and open a new therapeutic avenue for this patient population.
authors.affiliation: Department of Internal Medicine, Molecular Medicine Research Laboratory, Texas Tech University Health Sciences Center, 4800 Alberta Av, El Paso, TX, 79905, USA, juan.castro@ttuhsc.edu.
authors.forename: Juan
authors.initials: J
authors.lastname: Castro-Combs
authors.forename: Cesar J
authors.initials: CJ
authors.lastname: Garcia
authors.forename: Marek
authors.initials: M
authors.lastname: Majewski
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Wallner
authors.forename: Jerzy
authors.initials: J
authors.lastname: Sarosiek
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002908:Chronic Disease; D003248:Constipation / Q000473:pathology*; D005752:Gastric Mucins / Q000737:chemistry* / Q000502:physiology; D005769:Gastrointestinal Motility / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D014783:Viscosity; D055815:Young Adult
chemical_list: D005752:Gastric Mucins