Effects of intragastric ice water stimulation on bowel sensitivity and serum bioactive substances in rats / 解放军医学杂志

ABSTRACT

Objective To study the effects of intragastric ice water stimulation on bowel sensitivity, mast cells (MCs), the serum contents of serotonin (5-HT), leukotriene B 4 (LTB 4 ), histamine(HA)and bradykinin (BK) in rats, and explore the possible pathogenesis of cold drinks-induced irritable bowel syndrome (IBS). Methods 40 Wistar rats aged 4 weeks were randomly divided into two groups. Twenty rats of group A as experimental group were gavaged 0-4℃ ice water for 14 days, and the rats of group C as control group were not treated. On day 28, the group A and group C were again divided into two subgroups, respectively, i.e. A1, A2, C1, and C2. In the rats of subgroups A1 and C1, a balloon was introduced into the rectum of each animal, and number of abdominal withdrawal reflexes (AWR) was recorded after the balloon was distended for 3 minutes to assess bowel sensitivity. One hour after rectal distention, blood sample of each rat was collected from the heart for the measurement of the contents of 5-HT, LTB 4 , HA and BK in serum by enzyme linked immunoadsorbent assay (ELISA). Tissues harvested from the ileocecal junction and colon were sectioned and stained with haematoxylin-eosin (HE) for routine pathological examination, and with the improved toluidine blue method for the identification of MCs. Results The number of AWR to 1.0ml balloon distention in subgroup A 1 was significantly lower than that in subgroup C 1 (P0.05). Routine pathological examination did not show abnormality in both subgroups. In group A 1 , the numbers of MCs in the ileocecal junction and colon were significantly higher than those of group C 1 (P0.05). Conclusion The stimulation of the stomach with ice water results in lowering of bowel sensitivity, increase of MCs and elevation of serum contents of 5-HT, LTB 4 and HA, and the results might imply that cold stimulation of the stomach might play a role in the pathogenesis of IBS.