N-乙酰半胱氨酸对大鼠急性坏死性胰腺炎胰腺损伤的影响

N-acetyicysteine decreases the severity of pancreatic injury in rats with acute necrotizing pancreatitis

目的探讨急性坏死性胰腺炎（ANP）胰腺损伤与核因子-κB（NF-κB）活化、胰腺细胞凋亡的关系及N-乙酰半胱氨酸（NAC）对胰腺损伤的影响。方法33只wistar大鼠分为正常对照、盐水对照和胰腺炎组。以3．5％牛磺胆酸钠逆行注入胰胆管制作ANP模型，于造模前、后1h应用NAC，12h后取材，采用凝胶电泳迁移率实验测定胰腺组织NF-κB活性、改良TUNEL法检测细胞凋亡。同时观察血淀粉酶、脂肪酶、胰腺组织湿／干重比率及病理改变：结果盐水对照组NF-κB活性很低（2．00±0．33），胰腺炎组NF-κB明显活化（6．03±0．41），造模前使用NAC抑制NF-κB活性（3．28±0．42），降低淀粉酶及胰腺湿／干重比率，促进胰腺细胞凋亡（P〈0．05）。NF-κB活化与凋亡呈负相关（r=-0．96，P〈0．01），与胰腺损伤病理呈正相关（r=0．63，P〈0．01）；胰腺损伤病理分级与凋亡呈负相关（r=-0．98，P〈0．01）。结论NAC可能通过抑制胰腺NF-κB活化、促进胰腺细胞凋亡，减轻胰腺损伤。

Objective To investigate the correlation between pancreatic nuclear faetor-κB （NF-κB） activation, cell apoptosis and pancreatic injury. To determine effects of N-acetylcysteine （NAC） on pancreatic injury in rats with acute neerofizlng pancreatitis （ANP）. Methods Thirty-three Wistar rats were divided into five groups： normal group, normal saline （NS） group, ANP group, prophylactic and therapeutic groups with NAC randomly. ANP was produced by 3.5% sodium taurocholate retrograde injection. In the prophylactic group, rats received intravenous （i. v. ） injection of NAC （300 mg/kg） 1 hour before tauroeholate injection and in the therapeutic group, NAC i. v. injection was given 1 hour after sodium tauroeholate injection. Animals were sacrificed at 12 hours after induction of pancreatitls. Activation of NF-κB in pancreatic tissues was determined by electrophoretic mobility shift assay（EMSA）. Cell apoptosis was assessed by modified TUNEL method. The following parameters were also measured： plasma levels of amylase and lipase, pancreatic wet/dry weight ratio and bistologic grading. Results Taarocholate pancreatitis is characteristic of necrosis, haemmThage, and sexere leukocyte infiltration in the pancreas. Plasma amylase and lipase levels, pancreatic wet/dry weight ratio increased in rats of ANP. NF-κB banding activity was higher after pancreatitis induction （6.03±0. 41 ）. When NAC was given 1 hour before induction of pancreatitis, the activation （3.28 ± 0. 42） of NF-κB was prevented with significantly decreased severity of pancreatitis as assessed by amylase, pancreatic wet/dry weight ratio. The number of apoptotic cells in pancreatic tissue sections was greater in rats treated with NAC than in rats not treated with NAC. There was a negative correlation between NF-κB banding activity and apoptosis of pancreatic cells （ r = - 0. 96, P 〈 0. 01 ） and there was a positive correlation between NF-κB activation and histopathological score （ r = 0. 63, P 〈0. 01 ）. Histopathological score of pancreatic injury had negative correlation with apoptosis of pancreatic cells（r = -0. 98, P 〈 0.01 ）. Conclusion Early blocked NF-κB activation with NAC increases cell apoptosis in pancreatic tissue and decreases edema of pancreas and severity of pancreatitis in rats with ANP.