The Role of Mast Cell in Visceral Hypersensitivity of Irritable Bowel Syndrome

Objective To study the role of mast cell in visceral hypersensitivity of irritable bowel syndrome(IBS).Methods 36 SD male rats were divided into three groups: control group(intraperitoneal injection of distilled water),group A(intraperitoneal injection of chicken egg albumin) and group B(intraperitoneal injection of chicken egg albumin and mast cell stabilizer).Two weeks later,the abdominal withdrawal reflex(AWR) was used to evaluate visceral nociceptive transmission on the repeated colon distention.The ileoceal and colon tissues were evaluated by Haematoxylin-Eosin(HE).Toluidine blue staining was used for investigation of mast cells.Results The AWR scores of group A(2.50±0.52,3.91±0.28)and group B(2.33±0.49,3.33±0.49) at 3ml-or 5ml-distention level was significantly higher than control group(1.25±0.45,2.33±0.49)(P0.01,P0.01,respectively).The AWR scores of group A at 5ml was higher than that of group B(P0.05).There were no obviously different observations in ileocecal or colons tissues among three groups.However,the number of mast cell in ileocecal junction and colon in control group(2.83±0.38,1.58±0.51)was less than group A(6.66±0.65,4.17±0.72)(P0.01,P0.01,respectively) and group B(6.58±0.99,4.00±0.72)(P0.01,P0.01,respectively).Conclusion A model of IBS is successfully induced by intraperitoneal injection of chicken egg albumin.The present results suggest that mast cell in bowel play an important role in visceral hypersensitivity of IBS.