Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5760255 | Journal of Theoretical Biology | 2017 | 27 Pages |
Abstract
Intestinal bioelectrical slow waves are a key regulator of intestinal motility. Peripheral pacemakers, ectopic initiations and sustained periods of re-entrant activities have all been experimentally observed to be important factors in setting the frequency of intestinal slow waves, but the tissue-level mechanisms underpinning these activities are unclear. This theoretical analysis aimed to define the initiation, maintenance, and termination criteria of two classes of intestinal re-entrant activities: anatomical re-entry and functional re-entry. Anatomical re-entry was modeled in a three-dimensional (3D) cylindrical model, and functional rotor was modeled in a 2D rectangle model. A single-pulse stimulus was used to invoke an anatomical re-entry and a prolonged refractory block was used to invoke the rotor. In both cases, the simulated re-entrant activities operated at frequencies above the baseline entrainment frequency. The anatomical re-entry simulation results demonstrated that a temporary functional refractory block would be required to initiate the re-entrant activity in a single direction around the cylindrical model. The rotor could be terminated by a single-pulse stimulus delivered around the core of the rotor. In conclusion, the simulation results provide the following new insights into the mechanisms of intestinal re-entry: (i) anatomical re-entry is only maintained within a specific range of velocities, outside of which the re-entrant activities become either an ectopic activity or simultaneous activations of the intestinal wall; (ii) a maintained rotor entrained slow waves faster in the antegrade direction than in the retrograde direction. Simulations are shown to be a valuable tool for achieving novel insights into the mechanisms of intestinal slow wave dysrhythmia.
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Authors
Du Peng, Gregory O'Grady, Cheng Leo K.,