mechanisms of gastroparesis

Last reviewed 05/2021

Mechanisms of gastroparesis:

  • gastric motility results from:
    • the integration of tonic contractions of the fundus
    • phasic contractions of the antrum
    • inhibitory forces of pyloric and duodenal contraction
  • contractions require a complex interaction between gastric smooth muscle, the enteric nervous system and specialized pacemaker cells, the interstitial cells of Cajal
    • gastric accommodation enables adaptation of the proximal stomach to a liquid or solid volume load, i.e. a meal
    • antral contractions are required for grinding and transport of the meal towards the pyloric sphincter
    • pyloric relaxation enables the titration of the grinded meal (chyme) into the duodenum and requires coordination of propulsive contractions in the stomach and duodenum
      • rate of gastric emptying is influenced by the composition of the ingested meal
        • non-nutrient liquids are emptied almost immediately, whereas nutrient liquids and solids empty after a period of retention (lag phase) in a non-linear manner and linear manner respectively
          • fat rich meals show a more prolonged emptying pattern, resulting from duodenal feedback mechanisms, in particular, cholecystokinin
  • motor dysfunction of the stomach may result from autonomic neuropathy, enteric neuropathy, abnormalities of ICCs, fluctuations in blood glucose and psychosomatic factors
  • several mechanisms are involved in the process of gastric emptying
    • these actions are highly dependent on adequate neuronal and hormonal feedback mechanisms

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