论文部分内容阅读
Objective Chronic abdominal pain and cramping in patients with irritable bowel syndrome (IBS) remain a big challenge for clinicians.IBS is 2-3 times more prevalent in women than in men.However, the precise mechanism remains unknown.Therefore, we investigated whether adrenoceptor and estrogen signaling is involved in visceral hypersensitivity in a rat model of neonatal colonic inflammation (NCI).Methods Visceral hypersensitivity was induced by colonic injection of 0.5% acetic acid (AA) in 10-day-old female rats and ovariectomized (OVX) experiments were conducted at 7 weeks of age.Behavioral response to colorectal distension (CRD) was measured by visual observation of abdominal withdrawal reflex (AWR), Results NCI significantly increased the visceromoter response to CRD at 10, 20, 40, 60 and 80 mmHg.Systemic administration of nonselective β-adrenergic receptor antagonist (propranolol) prevented stress-induced visceral hypersensitivity in a dose-dependent manner.OVX significantly decreased AWR scores when compared with those of sham OVX rats with neonatal AA infusion.OVX produced no obvious effect on rats receiving normal saline injection when they were 10 days old.Conclusion NCI-induced visceral hypersensitivity in female rats is mediated by β-adrenergic receptor and estrogen.The present and future studies might provide insight into mechanisms underlying chronic visceral pain in female patients with functional gastrointestinal disorders such as IBS.