Inhibition of visceral hypersensitivity in irritable bowel syndrome model rat by intrathecal administration of corticotrophin releasing factor / 中华行为医学与脑科学杂志

ABSTRACT

Objective To investigate whether intrathecal administration of corticotrophin releasing factor(CRF) has an efficacy on visceral hypersensitivity in irritable bowel syndrome model rat.Methods Thirty rats were randomly divided into three groups(n=10 ).After establishment of irritable bowel syndrome rat model were intrathecal injected with CRF or preemptive peritoneal injected with CP-154526,which is inhibitor of CRF-1 receptor,and the control group to give saline.After experiment all rat with the method of rectal balloon distention,the perception thresholds and the number of abdominal withdrawal reflexes (AWR) of different balloon volume were observed.Results The perception threshold of intrathecal administration of CRF group was(0.62±0.10)ml and higher than other two groups [(0.52±0.09)ml,(0.56±0.08)ml;F=3.25,P＜0.05].At the same time,the number of AWR to the lower balloon content (1.0 ml) was(9.10±1.97)in intrathecal administration of CRF group slightly lower than other two groups[(14.4±1.71),(15.6±2.32);F=29.4,P＜0.01],but no difference was found to the higher balloon content (1.5 ml and 2.0 ml).Besides,the areas and OD value of c-fos positive neurons in cornu posterius medullae spinalis in group with intrathecal administration of CRF were significantly lower than other two groups (P＜0.05).Conclusion Intrathecal administration of CRF can degrade the visceral hyperensitivity in irritable bowel syndrome model rat,and lower expression of c-fos in CNS is probably involved in the process.