Effect of inherent depression on chronic visceral hypersensitivity induced by colon acetate stimulation in neonatal rats / 北京大学学报(医学版)

ABSTRACT

Objective:To explore the effect of inherent depression on chronic visceral hypersensitivity. The differences of visceral sensitivity, colitis, and brain activation between Fawn-Hooded ( FH/Wjd) and Sprague-Dawley( SD) rats were identified after neonatal colon acetate stimulation.Methods:The specific pathogen free Fawn-Hooded (FH/Wjd) and Sprague-Dawley(SD) rats were used to establish irritable bowel syndrome (IBS) model.The visceral sensitivity was measured by colorectal distension (CRD). The expression of 5-hydroxytryptamine (5-HT), mast cell (MC), indoleamine 2,3-dioxygenase (IDO) in colon and IDO in specific cerebral regions were detected through immunohistochemistry.Results:Ab-dominal withdrawal reflex ( AWR) scores showed that visceral sensitivity of acetate-enema groups was sig-nificantly higher than that of saline-enema groups ( FH/Wjd2.44 ±0.04 vs.1.96 ±0.07, P Besides, the MC amounts of control and IBS group of FH/Wjd rats were significantly more than that of SD IBS group rats ( P<0 .01 ) .The IDO and 5-HT positive cells in colonic mucosa of IBS group of both SD and FH/Wjd rats were significantly more than those of their control groups, respectively(P <0.01). The IDO, 5-HT positive cells in colonic mucosa of both control and IBS group of FH/Wjd rats were significantly more than those of both control and IBS group of SD rats ( controlIDO,24.64 ±2.22 vs. 15.52 ±1.39;5-HT,21.32 ±1.26 vs.12.72 ±1.12.IBS IDO,44.92 ±2.31 vs.20.85 ±1.72;5-HT, 31.84 ±1.57 vs.19.65 ±1.09.P <0.01).The expression of IDO in prelimbic cortex (PrL) areas of FH/Wjd IBS rats was significantly higher than that of IBS group of SD rats (49.60 ±4.31 vs. 35.60 ±2.42, P <0.01) , and the expression of IDO in rostral anterior cingulate cortex ( rACC) areas of FH/Wjd IBS rats was significantly more than that of FH/Wjd control rats (45.44 ±1.16 vs.34.08 ± 2.76, P <0.01) .Conclusion:Inherent depressive FH/Wjd rats were more sensitive to neonatal colon acetate stimulation, presenting as visceral hypersensitivity which maybe associated with increased MC amounts and over-expression of 5-HT and IDO in colon, suggesting that depression disorder may aggra-vate functional disturbance of gastrointestinal tract by regulating the response to inflammatory stimulation.