On The Structure And Function Of The Gastric Mucosa Of Rats With Obstructive Biliary External Drainage

Objective Patients with obstructive jaundice can complicate gastrointestinal bleeding to death after surgery. Preoperative biliary drainage can reduce postoperative complications and mortality. But the choice of the drainage way disputed. This test is through establishment of obstructive jaundice animal models, and compare the levels of tumor necrosis factor α (TNF-a)、nitric oxide (NO) in blood serum, and NO、inducible nitric oxide synthase (iNOS) in gastric mucosa to compare the quality of internal and external drainage, and explore the mechanism of gastric mucosa damage by OJ.Methods Experimental animal grouping:one hundred male adult Sprague-Dawley rats,12to14weeks, weighing270～320g, provided by the Experimental Animal Center of Yangzhou University School of Medicine. Rats were randomly assigned to five groups:obstructive jaundice for7days(OJ-7)、obstructive jaundice for14days(OJ-14)、internal bile drainage(ID)、 external bile drainage(ED) and sham operation(SH).The first operation:Establishing model of obstructive jaundice, All rats adaptive feeding one week. Fasted for8hours before surgery, free access to water. Limbs and head fixed on the operating table, abdominal skin ready, stringent skin disinfection, shop sterile single. Take the upper median abdominal incision into the abdomen, free the common bile duct. SH group close the abdomen afer free the common bile duct; Experimental group (include OJ-7group、OJ-14group、ID group、ED group) the common bile duct was punishable by4-0silk double at about1.0cm be away from duodenal major papilla, and close the abdomen. After rat restoration activities, let them ad libitum drinking water, feeded for one week.The second operation:The OJ-7group were sacrificed7days after surgery and collecting materials. The remaining four groups (include SH group、OJ-14group、ID group、ED group) had the second surgery Seven days after the first surgery, fasted for8hours before surgery, free access to water. Limbs and head fixed on the operating table, abdominal skin ready, stringent skin disinfection, shop sterile single. Take on the original abdominal incision into the abdomen, free the common bile duct. SH group close the abdomen afer free the common bile duct; OJ-14 group close the abdomen afer free the common bile duct; ID group internal drainage of the common bile duct bile by epidural catheter; ED group external drainage of the common bile duct bile by polyethylene drainage pipe from the back of the neck. After rat restoration activities, let them ad libitum drinking water, feeded for one week. All the rats were sacrificed7days after the second surgery and collecting materials.Collection of materials:Fasted for8hours before surgery, free access to water. Anesthetized by intraperitoneal injection with1%sodium pentobarbital(3.5mg/100g). Limbs and head fixed on the operating table, abdominal skin ready, stringent skin disinfection, shop sterile single. Take on the original abdominal incision into the abdomen, getting blood8ml from inferior vena cava, stand for1hour,3000r/min cryogenic centrifugal15min. The serum was stored in-70℃refrigerator, which will be used to detect TNF-a and NO. Removing the entire stomach, Breaking open along the greater curvature side,rinsing by ice brine. Taking glandular stomach part, each gastric tissue gain2to3block, size of about2×2mm stomach wall layer specimens. Quickly Fixed with10%neutral formalin, dehydration, dip wax, paraffin-embedded, now the gastric tissue paraffin blocks were done. Take down the remaining gastric adenocarcinoma mucosa, stored in-70℃refrigerator, which will be used to detect NO and iNOS.Results SH group:in blood serum TNF-α (11.93±2.15pg/ml) and NO (73.71±2.77umol/L), in gastric mucosa NO (4.30±0.20) and iNOS (4.27±0.16U/mgprot);OJ-7group:in blood serum TNF-α (53.46±2.99pg/ml) and NO (85.93±1.90umol/L), in gastric mucosa NO (5.64±0.24) and iNOS (5.80±0.24U/mgprot);OJ-14group:in blood serum TNF-α (77.03±1.45pg/ml) and NO(100.58±2.36umol/L), in gastric mucosa NO (6.73±0.20) and iNOS (6.52±0.28U/mgprot);ID group:in blood serum TNF-α (12.60±2.57pg/ml)�'�NO (75.46±3.08umol/L), in gastric mucosa NO (4.44±0.28)�'�iNOS (4.31±0.18U/mgprot);ED group:in blood serum TNF-α (71.45±3.03pg/ml) and NO (96.03±2.87umol/L), in gastric mucosa NO (6.49±0.29) and iNOS (6.45±0.24U/mgprot)。Pathology display:Mucous membrane in stomach of rats in OJ-7group、OJ-14group and ED group were damaged obviously, mucous membrane in stomach of rats in ID group、SH group do not have obvious damaged.Conclusions The Obstructive jaundice animal model were established(OJ-7group), the levels of tumor necrosis factor、nitric oxide in blood serum and nitric oxide、inducible nitric oxide synthase in gastric mucosa increased significantly. And significant higher than SH group. After internal drainage(ID group), the levels of tumor necrosis factor、nitric oxide in blood serum and nitric oxide、inducible nitric oxide synthase in gastric mucosa decreased significantly. And had no significant difference compared with the SH group. Obstruction continue(OJ-14group), the levels of tumor necrosis factor nitric oxide in blood serum and nitric oxide、inducible nitric oxide synthase in gastric mucosa continue to rise. And significant higher than OJ-7group. After external drainage (ED group), the levels of tumor necrosis factor、nitric oxide in blood serum and nitric oxide、inducible nitric oxide synthase in gastric mucosa continue to rise. And significant higher than OJ-7group.These results show that, the levels of tumor necrosis factor、nitric oxide in blood serum and nitric oxide、inducible nitric oxide synthase in gastric mucosa increased significantly under obstructive jaundice. The large number of TNF-a can lead to the systemic inflammatory response syndrome in rats. Also can activate the induced cells, such as the stomach cells, expressing iNOS. The persistence of iNOS causes the body to produce large amounts of NO which damage cells and tissues of the body.The pathological results also confirmed that, The ID group gastric mucosa had no significant damage, while ED group gastric mucosa were significantly impaired。In summary, after internal drainage(ID group), the levels of tumor necrosis factor、nitric oxide in blood serum and nitric oxide、inducible nitric oxide synthase in gastric mucosa decreased significantly. Protecting the gastric mucosa better than external drainage.