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Melior Discovery gastrointestinal

IBS Model and Acetylcholine Writhing Assay

Irritable Bowel Syndrome (IBS) is a syndrome that is expressed as abdominal cramping, gastrointestinal pain and disturbances in GI transit.  These conditions are produced by colonic spasticity and irregular contractility.  The disturbances in GI transit can be modeled by examining expulsion of a colonically-inserted glass bead. The cramping and pain component of IBS can be modeled by injecting acetylcholine into the peritoneum of mice.  IP administered ACh promotes smooth muscle contractility and can be monitored, in animals, by quantifying the writhing response.  In this study, the acetylcholine writhing response was validated as a model of smooth muscle contractility and visceral pain.  This model was validating using Morphine as a reference anti-nociceptive compound.

                                                   IBS model ACh Writhing Morphine

IBS Model and ACh Writhing Assay.  CD1 mice were treated with vehicle or Morphine (9mg/kg) 30 minutes prior to testing.  The animals were injected with acetylcholine and placed in an observational chamber. The latency to writhe (A) and the number of writhes (B) were recorded over a period of 600 seconds.  Writhing was completely absent in mice administered Morphine.  Vehicle-treated animals had an average of 6.25 writhes and a latency of approximately 240 seconds to the first writhe. These data indicate that this model may be useful for identifying test agents that have therapeutic potential for treating abdominal discomfort. Data are mean ± SEM; ***p<0.001, ****p<0.0001compared to vehicle.

If you are interested in learning more about the IBS model and Acetylcholine Writhing Test, please contact models@meliordiscovery.com to start the conversation.