慢性胰腺炎大鼠肠运动功能和肌间神经丛NOS阳性神经元的变化

Changes of intestinal motility and NOS immunoreactivity neurons in myenteric plexus in rats with chronic pancreatitis

目的观察大鼠慢性胰腺炎时肠运动功能和肌间神经丛NOS阳性神经元的变化,探讨慢性胰腺炎大鼠肠动力障碍的可能机制。方法 SD雄性大鼠20只随机分为假手术组(n=10)和慢性胰腺炎组(n=10),用质量浓度为30 g/L TNBS乙醇盐溶液逆行胰胆管灌注制作慢性胰腺炎模型;假手术组注射等体积生理盐水。造模成功后胃内灌服质量浓度为10 g/L台盼蓝溶液,测定小肠推进比。取胰腺组织进行HE染色,观察病理变化。取末段回肠制作肌间神经丛全层标本,应用双重免疫荧光染色法观察肌间神经丛神经元,计算NOS阳性神经元占总神经元的百分比。结果假手术组肌间神经丛NOS阳性神经元的比例为(29.40±2.03)%,慢性胰腺炎组肌间神经丛NOS阳性神经元的比例为(39.62±1.75)%,两组比较,差异有统计学意义(P<0.05)。慢性胰腺炎组大鼠小肠推进比显著降低[(49.70±3.74)%vs(31.14±3.23)%,P<0.05]。NOS阳性神经元比例与小肠推进比呈负相关(r=-0.853,P<0.05)。结论慢性胰腺炎大鼠存在肠动力障碍,同时回肠肌间神经丛NOS阳性神经元发生了重塑,慢性胰腺炎肠动力障碍可能与NOS抑制性神经元的表达上调相关。

Objective To investigate the changes of intestinal motilily and nitric oxide synthase（ NOS） immunoreactive neurons in myenteric plexus in rats with chronic pancreatitis,and to study the possible mechanism of intestinal motility disorder. Methods Twenty male Sprague Dawley rats were randomly divided into two groups： sham operated group（ n =10） and chronic pancreatitis group（ n =10）. Chronic pancreatitis model was induced by retrograde injection of 30 g/L trinitrobenenze sulfonic acid（ TNBS）-ethanol-NS into the bile-pancreatic duct. The rats in sham operated group were given the same volume of saline. Small intestine propulsion ratio was measured by administering 10 g/L trypan blue by gastric gavage. The pancreatic tissues were stained with HE and pathological changes were evaluated. Whole-mount samples of ileum myenteric plexus（ MP） were prepared and double immunofluorescence was applied to observe neurons in myenteric plexus. The percentages of NOS immunoreactive neurons（ NOS-IR） in total neurons were calculated.Results In the sham operated group,the percentage of NOS-IR neurons in ileum MP was（ 29. 40 ± 2. 03） %. In the chronic pancreatitis group,the percentage of NOS-IR neurons in ileum MP was（ 39. 62 ± 1. 75） %,the difference was statistically significant between two groups（ P〈0. 05）. In the chronic pancreatitis group,the small intestine propulsion ratio was decreased significantly from（ 49. 70 ± 3. 74） % to（ 31. 14 ± 3. 23） %. There was a negative correlation between the percentage of NOS-IR neurons and small intestine propulsion ratio（ r =-0. 853,P〈0. 05）. Conclusion Plasticity took palce in NOS neurons in ileum myenteric plexus of chronic pancreatitis rats with intestinal dysmotility. The intestinal dysmotility in chronic pancreatitis may be related to the increase of inhibitory NOS immunoreactive neurons in myenteric plexus.